title: Satire

text: Some critics of Mark Twain see "Huckleberry Finn" as racist and offensive, missing the point that its author clearly intended it to be satire (racism being in fact only one of a number of Mark Twain's known concerns attacked in "Huckleberry Finn"). This same misconception was suffered by the main character of the 1960s British television comedy satire "Till Death Us Do Part". The character of Alf Garnett (played by Warren Mitchell) was created to poke fun at the kind of narrow-minded, racist, little Englander that Garnett represented. Instead, his character became a sort of anti-hero to people who actually agreed with his views. (The same situation occurred with Archie Bunker in American TV show "All in the Family", a character derived directly from Garnett.)


title: Satire

text: The Australian satirical television comedy show "The Chaser's War on Everything" has suffered repeated attacks based on various perceived interpretations of the "target" of its attacks. The "Make a Realistic Wish Foundation" sketch (June 2009), which attacked in classical satiric fashion the heartlessness of people who are reluctant to donate to charities, was widely interpreted as an attack on the Make a Wish Foundation, or even the terminally ill children helped by that organisation. Prime Minister of the time Kevin Rudd stated that The Chaser team "should hang their heads in shame". He went on to say that "I didn't see that but it's been described to me. ...But having a go at kids with a terminal illness is really beyond the pale, absolutely beyond the pale." Television station management suspended the show for two weeks and reduced the third season to eight episodes.


title: Satire

text: The romantic prejudice against satire is the belief spread by the romantic movement that satire is something unworthy of serious attention; this prejudice has held considerable influence to this day. Such prejudice extends to humour and everything that arouses laughter, which are often underestimated as frivolous and unworthy of serious study. For instance, humor is generally neglected as a topic of anthropological research and teaching.


title: Satire

text: Because satire criticises in an ironic, essentially indirect way, it frequently escapes censorship in a way more direct criticism might not. Periodically, however, it runs into serious opposition, and people in power who perceive themselves as attacked attempt to censor it or prosecute its practitioners. In a classic example, Aristophanes was persecuted by the demagogue Cleon.


title: Satire

text: In 1599, the Archbishop of Canterbury John Whitgift and the Bishop of London Richard Bancroft, whose offices had the function of licensing books for publication in England, issued a decree banning verse satire. The decree, now known as the Bishops' Ban of 1599, ordered the burning of certain volumes of satire by John Marston, Thomas Middleton, Joseph Hall, and others; it also required histories and plays to be specially approved by a member of the Queen's Privy Council, and it prohibited the future printing of satire in verse.


title: Satire

text: The motives for the ban are obscure, particularly since some of the books banned had been licensed by the same authorities less than a year earlier. Various scholars have argued that the target was obscenity, libel, or sedition. It seems likely that lingering anxiety about the Martin Marprelate controversy, in which the bishops themselves had employed satirists, played a role; both Thomas Nashe and Gabriel Harvey, two of the key figures in that controversy, suffered a complete ban on all their works. In the event, though, the ban was little enforced, even by the licensing authority itself.


title: Satire

text: In 2005, the Jyllands-Posten Muhammad cartoons controversy caused global protests by offended Muslims and violent attacks with many fatalities in the Near East. It was not the first case of Muslim protests against criticism in the form of satire, but the Western world was surprised by the hostility of the reaction: Any country's flag in which a newspaper chose to publish the parodies was being burnt in a Near East country, then embassies were attacked, killing 139 people in mainly four countries; politicians throughout Europe agreed that satire was an aspect of the freedom of speech, and therefore to be a protected means of dialogue. Iran threatened to start an International Holocaust Cartoon Competition, which was immediately responded to by Jews with an Israeli Anti-Semitic Cartoons Contest.


title: Satire

text: In 2006 British comedian Sacha Baron Cohen released "Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan", a "mockumentary" that satirized everyone, from high society to frat boys. The film was criticized by many. Although Baron Cohen is Jewish, some complained that it was antisemitic, and the government of Kazakhstan boycotted the film. The film itself had been a reaction to a longer quarrel between the government and the comedian.


title: Satire

text: In 2008, popular South African cartoonist and satirist Jonathan Shapiro (who is published under the pen name Zapiro) came under fire for depicting then-president of the ANC Jacob Zuma in the act of undressing in preparation for the implied rape of 'Lady Justice' which is held down by Zuma loyalists. The cartoon was drawn in response to Zuma's efforts to duck corruption charges, and the controversy was heightened by the fact that Zuma was himself acquitted of rape in May 2006. In February 2009, the South African Broadcasting Corporation, viewed by some opposition parties as the mouthpiece of the governing ANC, shelved a satirical TV show created by Shapiro, and in May 2009 the broadcaster pulled a documentary about political satire (featuring Shapiro among others) for the second time, hours before scheduled broadcast.


title: Satire

text: On December 29, 2009, Samsung sued Mike Breen, and the "Korea Times" for $1 million, claiming criminal defamation over a satirical column published on Christmas Day, 2009.


title: Satire

text: On April 29, 2015, the UK Independence Party (UKIP) requested Kent Police investigate the BBC, claiming that comments made about Party leader Nigel Farage by a panelist on the comedy show "Have I Got News For You" might hinder his chances of success in the general election (which would take place a week later), and claimed the BBC breached the Representation of the People Act. Kent Police rebuffed the request to open an investigation, and the BBC released a statement, "Britain has a proud tradition of satire, and everyone knows that the contributors on "Have I Got News for You" regularly make jokes at the expense of politicians of all parties."


title: Sean Paul

text: Sean Paul Ryan Francis Henriques OD (born 9 January 1973) is a Jamaican rapper and singer who is regarded as one of dancehall's most prolific artists.


title: Sean Paul

text: Paul's singles "Get Busy" and "Temperature" topped the "Billboard" Hot 100 chart in the United States and most of his albums have been nominated for the Grammy's Best Reggae Album, with "Dutty Rock" winning the award. Paul has also been featured in many other singles including chart-toppers "Baby Boy" with Beyoncé, "What About Us" by The Saturdays, "Rockabye" by Clean Bandit, and "Cheap Thrills" by Sia.


title: Sean Paul

text: Sean Paul Ryan Francis Henriques was born in Kingston, Jamaica, on 9 January 1973. His mother Frances, a painter, is of English and Chinese Jamaican descent. His paternal great-grandfather's Sephardic Jewish family immigrated from Portugal to Jamaica in the 17th century, while his paternal grandmother was Afro-Jamaican.


title: Sean Paul

text: Paul was raised as a Catholic, though he also attended the Jewish private school Hillel Academy in Jamaica. Many members of his family are swimmers. His grandfather was on the first Sri Lankan men's national water polo team. His father also played water polo for the team in the 1960s, and competed in long-distance swimming, while Paul's mother was a butterfly swimmer. When Paul was 15, his father was arrested on charges of manslaughter and sentenced to 15 years in prison; he was released for good behaviour when Paul was 19.


title: Sean Paul

text: Paul played for the national water polo team from the age of 13 to 21, when he gave up the sport in order to launch his musical career. He attended Wolmer's Boys' School and the College of Arts, Science, and Technology, now known as the University of Technology, where he was trained in commerce with an aim of pursuing an occupation in swimming.


title: Sean Paul

text: Former manager and producer Jeremy Harding's brother told him about a singer at a small open mic event in Kingston who sounded a lot like dancehall DJ and toaster Super Cat. Harding eventually met the singer when Paul came by his studio to ask for some advice. During the meeting Paul recorded a vocal over Harding's rhythm track and in the process created the song "Baby Girl". Paul began hanging out at the studio every day, and the pair collaborated on several more tracks. When they recorded "Infiltrate" they decided they had something good enough to get on the radio. As Paul started to attract local attention, Harding began looking after his affairs. He later told HitQuarters that his support of Paul's fledgling career initially led him assuming the roles of "DJ, manager, road manager and security guard." Paul made a cameo appearance in the 1998 film "Belly" on stage performing. He made a successful collaboration with DMX and Mr. Vegas, "Top Shotter", to the soundtrack of the film. In 2000, Paul released his debut album, "Stage One" with VP Records.


title: Sean Paul

text: In 2002, Paul continued his work with manager and producer Jeremy Harding, and after a joint venture deal with his label VP Records and Atlantic Records, announced the release of his second album, "Dutty Rock". All of its hit singles would receive heavy airplay and rotation on MTV and BET. The first single "Gimme the Light" was an instant worldwide smash hit, reaching number 7 on the "Billboard" Hot 100. The second single "Get Busy" would end up topping the "Billboard" Hot 100, making it Paul's first number-one hit, it was also the first ever dancehall song to top the chart. "Dutty Rock" was a worldwide success, peaking in the top ten on the "Billboard" 200, was certified double-platinum by the RIAA and eventually selling over six million copies worldwide. "Dutty Rock" won the Reggae Album of the year at the 46th Annual Grammy Awards in 2004. "Get Busy" was also nominated for best Rap Song in that year. Simultaneously, Paul was featured on Beyoncé's U.S. number-one hit song "Baby Boy" and Blu Cantrell's "Breathe", although didn't perform well in the United States but was a massive hit in the Europe. Both helped to push his reputation further still in the United States. This album not only further popularized dancehall music in the 2000s, but also helped developed and popularized the genre of dancehall pop, a musical fusion between the rhythmic styles and melodies of dancehall and pop music.


title: Sean Paul

text: Paul's third album "The Trinity" was released on 27 September 2005. The album debuted at number 5 on the "Billboard" 200, breaking records with its first-week sales for a reggae/dancehall artist, eventually going Platinum in the United States and selling 4 million copies worldwide. The album produced five big hits, "We Be Burnin', "Ever Blazin', "Give It Up to Me", "Never Gonna Be the Same" and the U.S. chart-topping smash hit "Temperature", making it his second number-one hit on the "Billboard" Hot 100. The video of "Give It Up to Me" (featuring Keyshia Cole) was featured in the film "Step Up" in 2006. He was nominated for four awards at the 2006 "Billboard" Music Awards, including male artist of the year, rap artist of the year, hot 100 single of the year, and pop single of the year for "Temperature". He also won an American Music Award for "Give It Up to Me" beating Kanye West and Nick Lachey who were also nominated for the award. "Send It On" from "The Trinity" featured on the 2005 Vauxhall Corsa advert. Paul often contributes his songs to various "Riddim Driven" albums by VP Records. In March 2007, he returned to Jamaica to perform at the Cricket World Cup 2007 opening ceremony.


title: Sean Paul

text: Paul's fourth album "Imperial Blaze" was released on 18 August 2009. The lead single, "So Fine", which was produced by Stephen "Di Genius" McGregor, premiered on Paul's website on 26 April 2009.


title: Sean Paul

text: The album consists of 20 tracks including "So Fine", "Press it Up", "She Want Me", "Private Party" which are party tracks and also love songs such as "Hold My Hand" (feat Keri Hilson), "Lately", "Now That I've Got Your Love" among others. Producers on the album include Don Corleone, Jeremy Harding, and Paul's brother Jason 'Jigzagula' Henriques. All the songs of the album were added to Paul's Myspace page on the day of release of the album.


title: Sean Paul

text: The album spawned eight music videos: "Always On My Mind (with Da'Ville)", "Give It to You (with Eve)", "Watch Them Roll", "Back It Up" (with Leftside), "(I Wanna See You) Push It Baby" (with Pretty Ricky), "Hit 'Em" (with Fahrenheit and his brother Jason "Jigzagula" Henriques), "Come Over" with Estelle, and also the video of his first single, "So Fine".


title: Sean Paul

text: Paul appeared in Shaggy's video, "Save a Life", which also includes appearances from Elephant Man and Da'Ville, among others. In an effort to raise money for a children's hospital, Shaggy, Paul and others had a benefit concert. All proceeds went towards getting new equipment and technology 'For Aid to the Bustamante Hospital for Children'. During the premiere for MNET's "Big Brother Africa: All-Stars" on 18 July 2010, he performed his songs "Temperature", "Hold My Hand", and "So Fine".


title: Sean Paul

text: Paul's fifth album "Tomahawk Technique" was released on 24 January 2012. The first single "Got 2 Luv U" features vocals from American singer Alexis Jordan. The song was written by Paul, Ryan Tedder and Stargate and produced by Stargate.


title: Sean Paul

text: "She Doesn't Mind" is the second single from the album. It was written by Paul, Shellback and Benny Blanco and was produced by Shellback and Benny Blanco. It was released on 29 September 2011 on NRJ and Skyrock (French radios), and to iTunes on 31 October. Like its proceeder, "Got 2 Luv U", it topped the charts in Switzerland, but it debuted at that spot. Paul appeared on the "Never Mind the Buzzcocks" episode which aired on 21 November 2011.


title: Sean Paul

text: "Tomahawk Technique" was released on 18 September 2012 in the U.S. The album was nominated for the best reggae album in the 55th Grammy awards.


title: Sean Paul

text: In 2011, Paul released his first riddim called "Blaze Fia Riddim" under Dutty Rock Productions his own label.


title: Sean Paul

text: In 2012, Paul was asked to team up with electronic artist Congorock and production/DJ duo Stereo Massive to feature vocals on their song "Bless Di Nation".


title: Sean Paul

text: During 2013, Paul worked on his sixth studio album "Full Frequency", which was released on 18 February 2014. The first single on the album, "Other Side of Love", was released to iTunes on 10 June 2013. The second single, "Entertainment", which features 2 Chainz and Juicy J, was released on 25 June 2013. Paul released the official remix to "Entertainment" on 3 September 2013 with an additional feature from Nicki Minaj. "Turn It Up" was released as a single in the UK on 20 October 2013. It was to be released in Germany on 22 November 2013. "Want Dem All" was released as a single in the U.S. on 5 November 2013. The album features guest appearances from Damian Marley, Iggy Azalea, Brick & Lace, Konshens, Nicki Minaj, 2 Chainz and Juicy J. Also in 2013, Paul was featured on the single "What About Us" by British girl group The Saturdays. The single went straight to the top of the Official UK Charts with over 100,000 sales in its first week, becoming the fastest selling single of the year at the time of release.


title: Sean Paul

text: In January 2014, Paul was the main international artist at Fiestas Palmares 2014 in Costa Rica. Also in 2014, Paul was featured on the official English-language version of long-running Latin American chart topper "Bailando" by Enrique Iglesias featuring Gente de Zona and Descemer Bueno. The video for the English version was shot concurrently with the video for the Spanish version in Santo Domingo, Dominican Republic. The English version reached top 10 status in the United States and topping the charts of several other countries.


title: Sean Paul

text: Paul appeared on the "Apocalypse Soon" EP by electronic group Major Lazer, on the track "Come On to Me", which was released as the second single from the album, after "Aerosol Can", a collaboration with Pharrell Williams. He also collaborated with Nigerian recording artist Timaya on a remix of his song "Bum Bum". An accompanying video directed by Shutah Films was released online on 11 April. On 6 July 2015, Paul released the music video for his song "Take It Low" on the album "Full Frequency"


title: Sean Paul

text: Paul had already became an independent artist after parting ways with Atlantic Records in September 2014. Under new management of Jules Dougall of Dougall Group & Steve "Urchin" Wilson, Paul enjoyed a commercial resurgence in his career throughout 2016 after being featured on Australian-singer Sia's remix version of her song "Cheap Thrills", it topped the Billboard Hot 100, making it Paul's first number-one hit on the chart since 2006. The song was also a global success, reaching number one in more than 15 other countries. It reportedly ended up becoming the most Shazamed song of 2016.


title: Sean Paul

text: In October 2016, Clean Bandit released the song "Rockabye", which features Paul and English singer Anne-Marie. It peaked at number 9 on the Billboard Hot 100 and spent nine consecutive weeks at number one of the UK Singles Chart, and gained the coveted Christmas number one. The song would go on to become a massive global hit in 2017, reaching number one in 18 other countries.


title: Sean Paul

text: In November 2016, Paul cited Toots and the Maytals as inspiration when it comes to his own personal career longevity by saying, "I've seen some great people in my industry, you know, people like Toots... Toots and the Maytals. Toots he's a great reggae artist and he's still doing it... He's up there in years and he's doing it. Those kind of artists inspire me. I know I'm just going to keep on doing music as long as I can."


title: Sean Paul

text: On 18 November 2016, he released a new single "No Lie" featuring Dua Lipa, which served as the lead single from his EP "Mad Love The Prequel" (which would be released in 2018, making it his first project release with Island Records). The song would eventually become a global phenomenon over the following six years after its release, it became a top-ten hit in 10 different countries and would end up becoming his most streamed song across streaming platforms, the music video (directed by Tim Nackashi) also surpassed 1 billion views on YouTube in April 2022, making it his most popular music video.


title: Sean Paul

text: One of the few other singles off the EP, "Mad Love" a collaboration with David Guetta which features singer Becky G would also make a global impact on the charts, peaking within the top 50 in multiple continents.


title: Sean Paul

text: In March 2019, Paul collaborated with Colombian singer J Balvin on a bilingual song called "Contra La Pared", the song peaked within the top 15 of the "Billboard" Hot Latin Songs chart, making it his seventh entry on the chart. It was also a major hit in Spain, peaking in the top 10 on the nation's chart and was a top 30 hit in both Colombia and Argentina.


title: Sean Paul

text: Paul had suggested that Jamaican musicians making use of "hardcore patois", a mixture of English with several languages spoken in Jamaica, create a language barrier that prevents them from becoming successful in the United States and the United Kingdom.


title: Sean Paul

text: It was announced that he would receive the Order of Distinction, Officer class (OD) from the Jamaican government on 21 October 2019, "for contribution to the global popularity and promotion of reggae music".


title: Sean Paul

text: In August 2019, Paul was nominated alongside Drake, DJ Snake, and Snow for the 'Favorite Crossover Artist' category of the 2019 Latin American Music Awards


title: Sean Paul

text: In March 2021, Paul released his seventh studio album called "Live n Livin" under his own label Dutty Rock Productions.


title: Sean Paul

text: Paul, collaborated with fellow Jamaican artists Spice and Shaggy for a dancehall single called "Go Down Deh". They performed the song live on Good Morning America, Jimmy Kimmel Live! and The Wendy Williams Show. The song was massively well-received worldwide on the internet, and was named the "Dancehall track of the year" for 2021 by NPR.


title: Sean Paul

text: In 2011, Paul established his own record label, Dutty Rock Productions along with his production team. In 2017, Paul signed Jamaican artist Chi Ching Ching to the label, making it the label's first signing. In 2022, in promotion of his eighth studio album "Scorcha", he released his own brand of Jamaican patties called the "Scorcha Patty" along with its hot sauce in partnership with a United Kingdom-based Jamaican restaurant called Port Royal, which was made available for a limited time.


title: Sean Paul

text: In 2016, Paul donated $1 million JMD towards Bustamante Hospital for Children. During the COVID-19 pandemic, Paul founded the "Sean Paul Foundation" in 2020, aiding less fortunate communities in Jamaica with donations of groceries to poor families and distribution of tablet computers to primary schools for students.


title: Sean Paul

text: Paul has spoken out about climate change. In 2015, he attended the United Nations Climate Change conference, expressing concerns over pollution and has said that athletes in Jamaica are having to "run in smog". He has advocated for waste reduction, solar power and the use of electric cars. He collaborated with Paul McCartney, Natasha Bedingfield, Bon Jovi, Colbie Caillat and various other artists on a single called "Love Song to the Earth" to spread awareness about climate change. In 2018, Paul was named an ambassador for climate change in the Caribbean. In 2022, Paul stated in his efforts to help combat climate change; "I have made the move to make my whole house solar powered. From the water to all the lights, And it runs my studio as well".


title: Sean Paul

text: In 2012, Paul married his long-term girlfriend, Jamaican TV host Jodi Stewart. In August 2016, it was announced that the couple was expecting their first child. On 26 February 2017, Paul announced the birth of his son, Levi Blaze. Their second child, Remi, was born on 20 August 2019.


title: Polymerase chain reaction

text: The polymerase chain reaction (PCR) is a method widely used to rapidly make millions to billions of copies (complete or partial) of a specific DNA sample, allowing scientists to take a very small sample of DNA and amplify it (or a part of it) to a large enough amount to study in detail. PCR was invented in 1983 by the American biochemist Kary Mullis at Cetus Corporation; Mullis and biochemist Michael Smith, who had developed other essential ways of manipulating DNA, were jointly awarded the Nobel Prize in Chemistry in 1993.


title: Polymerase chain reaction

text: PCR is fundamental to many of the procedures used in genetic testing and research, including analysis of ancient samples of DNA and identification of infectious agents. Using PCR, copies of very small amounts of DNA sequences are exponentially amplified in a series of cycles of temperature changes. PCR is now a common and often indispensable technique used in medical laboratory research for a broad variety of applications including biomedical research and criminal forensics.


title: Polymerase chain reaction

text: The majority of PCR methods rely on thermal cycling. Thermal cycling exposes reactants to repeated cycles of heating and cooling to permit different temperature-dependent reactions—specifically, DNA melting and enzyme-driven DNA replication. PCR employs two main reagents—primers (which are short single strand DNA fragments known as oligonucleotides that are a complementary sequence to the target DNA region) and a DNA polymerase. In the first step of PCR, the two strands of the DNA double helix are physically separated at a high temperature in a process called nucleic acid denaturation. In the second step, the temperature is lowered and the primers bind to the complementary sequences of DNA. The two DNA strands then become templates for DNA polymerase to enzymatically assemble a new DNA strand from free nucleotides, the building blocks of DNA. As PCR progresses, the DNA generated is itself used as a template for replication, setting in motion a chain reaction in which the original DNA template is exponentially amplified.


title: Polymerase chain reaction

text: Almost all PCR applications employ a heat-stable DNA polymerase, such as "Taq" polymerase, an enzyme originally isolated from the thermophilic bacterium "Thermus aquaticus". If the polymerase used was heat-susceptible, it would denature under the high temperatures of the denaturation step. Before the use of "Taq" polymerase, DNA polymerase had to be manually added every cycle, which was a tedious and costly process.


title: Polymerase chain reaction

text: Applications of the technique include DNA cloning for sequencing, gene cloning and manipulation, gene mutagenesis; construction of DNA-based phylogenies, or functional analysis of genes; diagnosis and monitoring of genetic disorders; amplification of ancient DNA; analysis of genetic fingerprints for DNA profiling (for example, in forensic science and parentage testing); and detection of pathogens in nucleic acid tests for the diagnosis of infectious diseases.


title: Polymerase chain reaction

text: PCR amplifies a specific region of a DNA strand (the DNA target). Most PCR methods amplify DNA fragments of between 0.1 and 10 kilo base pairs (kbp) in length, although some techniques allow for amplification of fragments up to 40 kbp. The amount of amplified product is determined by the available substrates in the reaction, which becomes limiting as the reaction progresses.


title: Polymerase chain reaction

text: The reaction is commonly carried out in a volume of 10–200 μL in small reaction tubes (0.2–0.5 mL volumes) in a thermal cycler. The thermal cycler heats and cools the reaction tubes to achieve the temperatures required at each step of the reaction (see below). Many modern thermal cyclers make use of the Peltier effect, which permits both heating and cooling of the block holding the PCR tubes simply by reversing the electric current. Thin-walled reaction tubes permit favorable thermal conductivity to allow for rapid thermal equilibrium. Most thermal cyclers have heated lids to prevent condensation at the top of the reaction tube. Older thermal cyclers lacking a heated lid require a layer of oil on top of the reaction mixture or a ball of wax inside the tube.


title: Polymerase chain reaction

text: Typically, PCR consists of a series of 20–40 repeated temperature changes, called thermal cycles, with each cycle commonly consisting of two or three discrete temperature steps (see figure below). The cycling is often preceded by a single temperature step at a very high temperature (>), and followed by one hold at the end for final product extension or brief storage. The temperatures used and the length of time they are applied in each cycle depend on a variety of parameters, including the enzyme used for DNA synthesis, the concentration of bivalent ions and dNTPs in the reaction, and the melting temperature ("T") of the primers. The individual steps common to most PCR methods are as follows:


title: Polymerase chain reaction

text: To check whether the PCR successfully generated the anticipated DNA target region (also sometimes referred to as the amplimer or amplicon), agarose gel electrophoresis may be employed for size separation of the PCR products. The size of the PCR products is determined by comparison with a DNA ladder, a molecular weight marker which contains DNA fragments of known sizes, which runs on the gel alongside the PCR products.


title: Polymerase chain reaction

text: As with other chemical reactions, the reaction rate and efficiency of PCR are affected by limiting factors. Thus, the entire PCR process can further be divided into three stages based on reaction progress:


title: Polymerase chain reaction

text: In practice, PCR can fail for various reasons, such as sensitivity or contamination. Contamination with extraneous DNA can lead to spurious products and is addressed with lab protocols and procedures that separate pre-PCR mixtures from potential DNA contaminants. For instance, if DNA from a crime scene is analyzed, a single DNA molecule from lab personnel could be amplified and misguide the investigation. Hence the PCR-setup areas is separated from the analysis or purification of other PCR products, disposable plasticware used, and the work surface between reaction setups needs to be thoroughly cleaned.


title: Polymerase chain reaction

text: Specificity can be adjusted by experimental conditions so that no spurious products are generated. Primer-design techniques are important in improving PCR product yield and in avoiding the formation of unspecific products. The usage of alternate buffer components or polymerase enzymes can help with amplification of long or otherwise problematic regions of DNA. For instance, Q5 polymerase is said to be ~280 times less error-prone than Taq polymerase. Both the running parameters (e.g. temperature and duration of cycles), or the addition of reagents, such as formamide, may increase the specificity and yield of PCR. Computer simulations of theoretical PCR results (Electronic PCR) may be performed to assist in primer design.


title: Polymerase chain reaction

text: PCR allows isolation of DNA fragments from genomic DNA by selective amplification of a specific region of DNA. This use of PCR augments many ways, such as generating hybridization probes for Southern or northern hybridization and DNA cloning, which require larger amounts of DNA, representing a specific DNA region. PCR supplies these techniques with high amounts of pure DNA, enabling analysis of DNA samples even from very small amounts of starting material.


title: Polymerase chain reaction

text: Other applications of PCR include DNA sequencing to determine unknown PCR-amplified sequences in which one of the amplification primers may be used in Sanger sequencing, isolation of a DNA sequence to expedite recombinant DNA technologies involving the insertion of a DNA sequence into a plasmid, phage, or cosmid (depending on size) or the genetic material of another organism. Bacterial colonies "(such as E. coli)" can be rapidly screened by PCR for correct DNA vector constructs. PCR may also be used for genetic fingerprinting; a forensic technique used to identify a person or organism by comparing experimental DNAs through different PCR-based methods.


title: Polymerase chain reaction

text: Some PCR fingerprint methods have high discriminative power and can be used to identify genetic relationships between individuals, such as parent-child or between siblings, and are used in paternity testing (Fig. 4). This technique may also be used to determine evolutionary relationships among organisms when certain molecular clocks are used (i.e. the 16S rRNA and recA genes of microorganisms).


title: Polymerase chain reaction

text: Because PCR amplifies the regions of DNA that it targets, PCR can be used to analyze extremely small amounts of sample. This is often critical for forensic analysis, when only a trace amount of DNA is available as evidence. PCR may also be used in the analysis of ancient DNA that is tens of thousands of years old. These PCR-based techniques have been successfully used on animals, such as a forty-thousand-year-old mammoth, and also on human DNA, in applications ranging from the analysis of Egyptian mummies to the identification of a Russian tsar and the body of English king Richard III.


title: Polymerase chain reaction

text: Quantitative PCR or Real Time PCR (qPCR, not to be confused with RT-PCR) methods allow the estimation of the amount of a given sequence present in a sample—a technique often applied to quantitatively determine levels of gene expression. Quantitative PCR is an established tool for DNA quantification that measures the accumulation of DNA product after each round of PCR amplification.


title: Polymerase chain reaction

text: qPCR allows the quantification and detection of a specific DNA sequence in real time since it measures concentration while the synthesis process is taking place. There are two methods for simultaneous detection and quantification. The first method consists of using fluorescent dyes that are retained nonspecifically in between the double strands. The second method involves probes that code for specific sequences and are fluorescently labeled. Detection of DNA using these methods can only be seen after the hybridization of probes with its complementary DNA (cDNA) takes place. An interesting technique combination is real-time PCR and reverse transcription. This sophisticated technique, called RT-qPCR, allows for the quantification of a small quantity of RNA. Through this combined technique, mRNA is converted to cDNA, which is further quantified using qPCR. This technique lowers the possibility of error at the end point of PCR, increasing chances for detection of genes associated with genetic diseases such as cancer. Laboratories use RT-qPCR for the purpose of sensitively measuring gene regulation. The mathematical foundations for the reliable quantification of the PCR and RT-qPCR facilitate the implementation of accurate fitting procedures of experimental data in research, medical, diagnostic and infectious disease applications.


title: Polymerase chain reaction

text: Prospective parents can be tested for being genetic carriers, or their children might be tested for actually being affected by a disease. DNA samples for prenatal testing can be obtained by amniocentesis, chorionic villus sampling, or even by the analysis of rare fetal cells circulating in the mother's bloodstream. PCR analysis is also essential to preimplantation genetic diagnosis, where individual cells of a developing embryo are tested for mutations.


title: Polymerase chain reaction

text: PCR allows for rapid and highly specific diagnosis of infectious diseases, including those caused by bacteria or viruses. PCR also permits identification of non-cultivatable or slow-growing microorganisms such as mycobacteria, anaerobic bacteria, or viruses from tissue culture assays and animal models. The basis for PCR diagnostic applications in microbiology is the detection of infectious agents and the discrimination of non-pathogenic from pathogenic strains by virtue of specific genes.


title: Polymerase chain reaction

text: Characterization and detection of infectious disease organisms have been revolutionized by PCR in the following ways:


title: Polymerase chain reaction

text: The development of PCR-based genetic (or DNA) fingerprinting protocols has seen widespread application in forensics:


title: Polymerase chain reaction

text: PCR has a number of advantages. It is fairly simple to understand and to use, and produces results rapidly. The technique is highly sensitive with the potential to produce millions to billions of copies of a specific product for sequencing, cloning, and analysis. qRT-PCR shares the same advantages as the PCR, with an added advantage of quantification of the synthesized product. Therefore, it has its uses to analyze alterations of gene expression levels in tumors, microbes, or other disease states.


title: Polymerase chain reaction

text: PCR is a very powerful and practical research tool. The sequencing of unknown etiologies of many diseases are being figured out by the PCR. The technique can help identify the sequence of previously unknown viruses related to those already known and thus give us a better understanding of the disease itself. If the procedure can be further simplified and sensitive non-radiometric detection systems can be developed, the PCR will assume a prominent place in the clinical laboratory for years to come.


title: Polymerase chain reaction

text: One major limitation of PCR is that prior information about the target sequence is necessary in order to generate the primers that will allow its selective amplification. This means that, typically, PCR users must know the precise sequence(s) upstream of the target region on each of the two single-stranded templates in order to ensure that the DNA polymerase properly binds to the primer-template hybrids and subsequently generates the entire target region during DNA synthesis.


title: Polymerase chain reaction

text: Like all enzymes, DNA polymerases are also prone to error, which in turn causes mutations in the PCR fragments that are generated.


title: Polymerase chain reaction

text: Another limitation of PCR is that even the smallest amount of contaminating DNA can be amplified, resulting in misleading or ambiguous results. To minimize the chance of contamination, investigators should reserve separate rooms for reagent preparation, the PCR, and analysis of product. Reagents should be dispensed into single-use aliquots. Pipettors with disposable plungers and extra-long pipette tips should be routinely used. It is moreover recommended to ensure that the lab set-up follows a unidirectional workflow. No materials or reagents used in the PCR and analysis rooms should ever be taken into the PCR preparation room without thorough decontamination.


title: Polymerase chain reaction

text: Environmental samples that contain humic acids may inhibit PCR amplification and lead to inaccurate results.


title: Polymerase chain reaction

text: The heat-resistant enzymes that are a key component in polymerase chain reaction were discovered in the 1960s as a product of a microbial life form that lived in the superheated waters of Yellowstone's Mushroom Spring.


title: Polymerase chain reaction

text: A 1971 paper in the "Journal of Molecular Biology" by Kjell Kleppe and co-workers in the laboratory of H. Gobind Khorana first described a method of using an enzymatic assay to replicate a short DNA template with primers "in vitro". However, this early manifestation of the basic PCR principle did not receive much attention at the time and the invention of the polymerase chain reaction in 1983 is generally credited to Kary Mullis.


title: Polymerase chain reaction

text: When Mullis developed the PCR in 1983, he was working in Emeryville, California for Cetus Corporation, one of the first biotechnology companies, where he was responsible for synthesizing short chains of DNA. Mullis has written that he conceived the idea for PCR while cruising along the Pacific Coast Highway one night in his car. He was playing in his mind with a new way of analyzing changes (mutations) in DNA when he realized that he had instead invented a method of amplifying any DNA region through repeated cycles of duplication driven by DNA polymerase. In "Scientific American", Mullis summarized the procedure: "Beginning with a single molecule of the genetic material DNA, the PCR can generate 100 billion similar molecules in an afternoon. The reaction is easy to execute. It requires no more than a test tube, a few simple reagents, and a source of heat." DNA fingerprinting was first used for paternity testing in 1988.


title: Polymerase chain reaction

text: Mullis has credited his use of LSD as integral to his development of PCR: "Would I have invented PCR if I hadn't taken LSD? I seriously doubt it. I could sit on a DNA molecule and watch the polymers go by. I learnt that partly on psychedelic drugs."


title: Polymerase chain reaction

text: Mullis and biochemist Michael Smith, who had developed other essential ways of manipulating DNA, were jointly awarded the Nobel Prize in Chemistry in 1993, seven years after Mullis and his colleagues at Cetus first put his proposal to practice. Mullis's 1985 paper with R. K. Saiki and H. A. Erlich, "Enzymatic Amplification of β-globin Genomic Sequences and Restriction Site Analysis for Diagnosis of Sickle Cell Anemia"—the polymerase chain reaction invention (PCR)—was honored by a Citation for Chemical Breakthrough Award from the Division of History of Chemistry of the American Chemical Society in 2017.


title: Polymerase chain reaction

text: At the core of the PCR method is the use of a suitable DNA polymerase able to withstand the high temperatures of > required for separation of the two DNA strands in the DNA double helix after each replication cycle. The DNA polymerases initially employed for in vitro experiments presaging PCR were unable to withstand these high temperatures. So the early procedures for DNA replication were very inefficient and time-consuming, and required large amounts of DNA polymerase and continuous handling throughout the process.


title: Polymerase chain reaction

text: The discovery in 1976 of "Taq" polymerase—a DNA polymerase purified from the thermophilic bacterium, "Thermus aquaticus", which naturally lives in hot () environments such as hot springs—paved the way for dramatic improvements of the PCR method. The DNA polymerase isolated from "T. aquaticus" is stable at high temperatures remaining active even after DNA denaturation, thus obviating the need to add new DNA polymerase after each cycle. This allowed an automated thermocycler-based process for DNA amplification.


title: Polymerase chain reaction

text: The PCR technique was patented by Kary Mullis and assigned to Cetus Corporation, where Mullis worked when he invented the technique in 1983. The "Taq" polymerase enzyme was also covered by patents. There have been several high-profile lawsuits related to the technique, including an unsuccessful lawsuit brought by DuPont. The Swiss pharmaceutical company Hoffmann-La Roche purchased the rights to the patents in 1992. The last of the commercial PCR patents expired in 2017.


title: Polymerase chain reaction

text: A related patent battle over the "Taq" polymerase enzyme is still ongoing in several jurisdictions around the world between Roche and Promega. The legal arguments have extended beyond the lives of the original PCR and "Taq" polymerase patents, which expired on 28 March 2005.


title: Political science

text: Political science is the scientific study of politics. It is a social science dealing with systems of governance and power, and the analysis of political activities, political thought, political behavior, and associated constitutions and laws.


title: Political science

text: Modern political science can generally be divided into the three subdisciplines of comparative politics, international relations, and political theory. Other notable subdisciplines are public policy and administration, domestic politics and government, political economy, and political methodology. Furthermore, political science is related to, and draws upon, the fields of economics, law, sociology, history, philosophy, human geography, political anthropology, and psychology.


title: Political science

text: Political science is methodologically diverse and appropriates many methods originating in psychology, social research, and political philosophy. Approaches include positivism, interpretivism, rational choice theory, behaviouralism, structuralism, post-structuralism, realism, institutionalism, and pluralism. Political science, as one of the social sciences, uses methods and techniques that relate to the kinds of inquires sought: primary sources, such as historical documents and official records, secondary sources, such as scholarly journal articles, survey research, statistical analysis, case studies, experimental research, and model building.


title: Political science

text: As a social political science, contemporary political science started to take shape in the latter half of the 19th century and began to separate itself from political philosophy and history. Into the late 19th century, it was still uncommon that political science was considered a distinct field from history. The term "political science" was nothing always distinguished from political philosophy, and the modern discipline has a clear set of antecedents including also moral philosophy, political economy, political theology, history, and other fields concerned with normative determinations of what ought to be and with deducing the characteristics and functions of the ideal state.


title: Political science

text: The advent of political science as a university discipline was marked by the creation of university departments and chairs with the title of political science arising in the late 19th century. The designation "political scientist" is commonly used to denote someone with a doctorate or master's degree in the field. Integrating political studies of the past into a unified discipline is ongoing, and the history of political science has provided a rich field for the growth of both normative and positive political science, with each part of the discipline sharing some historical predecessors. The American Political Science Association and the "American Political Science Review" were founded in 1903 and 1906, respectively, in an effort to distinguish the study of politics from economics and other social phenomena. APSA membership rose from 204 in 1904 to 1,462 in 1915. APSA members played a key role in setting up political science departments that were distinct from history, philosophy, law, sociology, and economics.


title: Political science

text: The journal "Political Science Quarterly" was established in 1886 by the Academy of Political Science. In the inaugural issue of "Political Science Quarterly", Munroe Smith defined political science as "the science of the state. Taken in this sense, it includes the organization and functions of the state, and the relation of states one to another."


title: Political science

text: As part of a UNESCO initiative to promote political science in the late 1940s, the International Political Science Association was founded in 1949, as well as national associations in France in 1949, Britain in 1950, and West Germany in 1951.


title: Political science

text: In the 1950s and the 1960s, a behavioral revolution stressing the systematic and rigorously scientific study of individual and group behavior swept the discipline. A focus on studying political behavior, rather than institutions or interpretation of legal texts, characterized early behavioral political science, including work by Robert Dahl, Philip Converse, and in the collaboration between sociologist Paul Lazarsfeld and public opinion scholar Bernard Berelson.


title: Political science

text: The late 1960s and early 1970s witnessed a takeoff in the use of deductive, game-theoretic formal modelling techniques aimed at generating a more analytical corpus of knowledge in the discipline. This period saw a surge of research that borrowed theory and methods from economics to study political institutions, such as the United States Congress, as well as political behavior, such as voting. William H. Riker and his colleagues and students at the University of Rochester were the main proponents of this shift.


title: Political science

text: Despite considerable research progress in the discipline based on all the kinds of scholarship discussed above, it has been observed that progress toward systematic theory has been modest and uneven.


title: Political science

text: In 2000, the Perestroika Movement in political science was introduced as a reaction against what supporters of the movement called the mathematicization of political science. Those who identified with the movement argued for a plurality of methodologies and approaches in political science and for more relevance of the discipline to those outside of it.


title: Political science

text: Some evolutionary psychology theories argue that humans have evolved a highly developed set of psychological mechanisms for dealing with politics. However, these mechanisms evolved for dealing with the small group politics that characterized the ancestral environment and not the much larger political structures in today's world. This is argued to explain many important features and systematic cognitive biases of current politics.


title: Political science

text: Political science is a social study concerning the allocation and transfer of power in decision making, the roles and systems of governance including governments and international organizations, political behaviour, and public policies. It measures the success of governance and specific policies by examining many factors, including stability, justice, material wealth, peace, and public health. Some political scientists seek to advance positive theses (which attempt to describe how things are, as opposed to how they should be) by analysing politics; others advance normative theses, such as by making specific policy recommendations. The study of politics and policies can be closely connected—for example, in comparative analyses of which types of political institutions tend to produce certain types of policies. Political science provides analysis and predictions about political and governmental issues. Political scientists examine the processes, systems and political dynamics of countries and regions of the world, often to raise public awareness or to influence specific governments.


title: Political science

text: Political scientists may provide the frameworks from which journalists, special interest groups, politicians, and the electorate analyze issues. According to Chaturvedy,


title: Political science

text: Political scientists may study political phenomena within one specific country; for example, they may study just the politics of the United States or just the politics of China.


title: Political science

text: Political scientists look at a variety of data, including constitutions, elections, public opinion, and public policy, foreign policy, legislatures, and judiciaries. Political scientists will often focus on the politics of their own country; for example, a political scientist from Indonesia may become an expert in the politics of Indonesia.


title: Political science

text: The theory of political transitions, and the methods of analyzing and anticipating crises, form an important part of political science. Several general indicators of crises and methods were proposed for anticipating critical transitions. Among them, one statistical indicator of crisis, a simultaneous increase of variance and correlations in large groups, was proposed for crisis anticipation and may be successfully used in various areas. Its applicability for early diagnosis of political crises was demonstrated by the analysis of the prolonged stress period preceding the 2014 Ukrainian economic and political crisis. There was a simultaneous increase in the total correlation between the 19 major public fears in the Ukrainian society (by about 64%) and in their statistical dispersion (by 29%) during the pre-crisis years. A feature shared by certain major revolutions is that they were not predicted. The theory of apparent inevitability of crises and revolutions was also developed.


title: Political science

text: The study of major crises, both political crises and external crises that can affect politics, is not limited to attempts to predict regime transitions or major changes in political institutions. Political scientists also study how governments handle unexpected disasters, and how voters in democracies react to their governments' preparations for and responses to crises.


title: Political science

text: Program evaluation is a systematic method for collecting, analyzing, and using information to answer questions about projects, policies, and programs, particularly about their effectiveness and efficiency. In both the public and private sectors, stakeholders often want to know whether the programs they are funding, implementing, voting for, receiving, or objecting to are producing the intended effect. While program evaluation first focuses on this definition, important considerations often include how much the program costs per participant, how the program could be improved, whether the program is worthwhile, whether there are better alternatives, whether there are unintended outcomes, and whether the program goals are appropriate and useful.


title: Political science

text: Policy analysis is a technique used in public administration to enable civil servants, activists, and others to examine and evaluate the available options to implement the goals of laws and elected officials.


title: Political science

text: Some political science departments also classify methodology as well as scholarship on the domestic politics of a particular country as distinct fields. In the United States, American politics is often treated as a separate subfield. In contrast to this traditional classification, some academic departments organize scholarship into thematic categories, including political philosophy, political behaviour (including public opinion, collective action, and identity), and political institutions (including legislatures and international organizations). Political science conferences and journals often emphasize scholarship in more specific categories. The American Political Science Association, for example, has 42 organized sections that address various methods and topics of political inquiry.


title: Political science

text: Political science is methodologically diverse; political scientists approach the study of politics from a host of different ontological orientations and with a variety of different tools. Because political science is essentially a study of human behaviour, in all aspects of politics, observations in controlled environments are often challenging to reproduce or duplicate, though experimental methods are increasingly common (see experimental political science). Citing this difficulty, former American Political Science Association President Lawrence Lowell once said "We are limited by the impossibility of experiment. Politics is an observational, not an experimental science." Because of this, political scientists have historically observed political elites, institutions, and individual or group behaviour in order to identify patterns, draw generalizations, and build theories of politics.


title: Political science

text: Like all social sciences, political science faces the difficulty of observing human actors that can only be partially observed and who have the capacity for making conscious choices, unlike other subjects such as non-human organisms in biology or inanimate objects as in physics. Despite the complexities, contemporary political science has progressed by adopting a variety of methods and theoretical approaches to understanding politics, and methodological pluralism is a defining feature of contemporary political science.


title: Political science

text: Empirical political science methods include the use of field experiments, surveys and survey experiments, case studies, process tracing, historical and institutional analysis, ethnography, participant observation, and interview research.


title: Political science

text: Political scientists also use and develop theoretical tools like game theory and agent-based models to study a host of political systems and situations.


title: Political science

text: Political theorists approach theories of political phenomena with a similar diversity of positions and tools, including feminist political theory, historical analysis associated with the Cambridge school, and Straussian approaches.


title: Political science

text: Political science may overlap with topics of study that are the traditional focuses of other social sciences—for example, when sociological norms or psychological biases are connected to political phenomena. In these cases, political science may either inherit their methods of study or develop a contrasting approach. For example, Lisa Wedeen has argued that political science's approach to the idea of culture, originating with Gabriel Almond and Sidney Verba and exemplified by authors like Samuel P. Huntington, could benefit from aligning more closely with the study of culture in anthropology. In turn, methodologies that are developed within political science may influence how researchers in other fields, like public health, conceive of and approach political processes and policies.


title: Political science

text: Political science, possibly like the social sciences as a whole, can be described "as a discipline which lives on the fault line between the 'two cultures' in the academy, the sciences and the humanities." Thus, in most American colleges, especially liberal arts colleges it would be located within the school or college of arts and sciences, if no separate college of arts and sciences exist or if the college or university prefers that it be in a separate constituent college or academic department, political science may be a separate department housed as part of a division or school of humanities or liberal arts while at some universities, especially research universities and in particular those that have a strong cooperation between research, undergraduate, and graduate faculty with a stronger more applied emphasis in public administration, political science would be taught by the university's public policy school. Whereas classical political philosophy is primarily defined by a concern for Hellenic and Enlightenment thought, political scientists are also marked by a great concern for "modernity" and the contemporary nation state, along with the study of classical thought, and as such share more terminology with sociologists (e.g., structure and agency).


title: Political science

text: Most United States colleges and universities offer BA programs in political science. MA or MAT and PhD or EdD programs are common at larger universities. The term "political science" is more popular in North America than elsewhere; other institutions, especially those outside the United States, see political science as part of a broader discipline of "political studies," "politics," or "government." While "political science" implies the use of the scientific method, "political studies" implies a broader approach, although the naming of degree courses does not necessarily reflect their content. Separate programs (often professional degrees) in international relations, public policy, and public administration, are not uncommon at both the undergraduate and postgraduate levels, although most but not all undergraduate level education in these sub-fields are generally found in academic concentration within a political science academic major. Master's-level programs in public administration are professional degrees covering public policy along with other applied subjects; they are often seen as more linked to politics than any other discipline, which may be reflected by being housed in that department.


title: Political science

text: The national honor society for college and university students of government and politics in the United States is Pi Sigma Alpha.


title: Political science

text: The most common piece of writing in political sciences are research papers, which investigate an original research question.


title: Cardiac arrest

text: Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possibly defibrillation are needed until further treatment can be provided. Cardiac arrest results in a rapid loss of consciousness, and breathing may be abnormal or absent.


title: Cardiac arrest

text: While cardiac arrest may be caused by heart attack or heart failure, these are not the same, and in 15 to 25% of cases, there is a non-cardiac cause. Some individuals may experience chest pain, shortness of breath, nausea, an elevated heart rate, and a light-headed feeling immediately before entering cardiac arrest.


title: Cardiac arrest

text: The most common cause of cardiac arrest is an underlying heart problem like coronary artery disease that decreases the amount of oxygenated blood supplying the heart muscle. This, in turn, damages the structure of the muscle, which can alter its function. These changes can, over time, cause ventricular fibrillation (V-fib), which most commonly precedes cardiac arrest. Less common causes include major blood loss, lack of oxygen, very low potassium, electrical injury, heart failure, inherited heart arrhythmias, and intense physical exercise. Cardiac arrest is diagnosed by the inability to find a pulse.


title: Cardiac arrest

text: CPR and defibrillation can reverse a cardiac arrest, leading to return of spontaneous circulation (ROSC), but without such intervention, it will prove fatal. In some cases, cardiac arrest is an anticipated outcome of serious illnesses where death is expected. Treatment for cardiac arrest includes immediate CPR and, if a shockable rhythm is present, defibrillation. Two protocols have been established for CPR: basic life support (BLS) and advanced cardiac life support (ACLS). Among those whose pulses are reestablished, targeted temperature management may improve outcomes. In addition, the care team may initiate measures to protect the patient from brain injury and preserve brain function. In post-resuscitation care, an implantable cardiac defibrillator may be considered to reduce the chance of death from recurrence.


title: Cardiac arrest

text: In the United States, approximately 535,000 cases occur annually (about 13 per 10,000 people). Of these, 326,000 (61%) experience cardiac arrest outside of a hospital setting, while 209,000 (39%) occur within a hospital. Cardiac arrest becomes more common with age and affects males more often than females.


title: Cardiac arrest

text: The percentage of people who survive out-of-hospital cardiac arrest (OHCA) with treatment by emergency medical services is about 8%. However, fictional media in the U.S. has often portrayed the immediate survival rate of cardiac arrest to be unreasonably high. This may contribute to misinformed expectations of resuscitative efforts from the general public, with many studies showing the expected survival rate of resuscitative efforts after cardiac arrest exceeding 40–50%. These portrayals may also contribute to a patient's or medical decision maker's desire to pursue aggressive measures. However, it has been shown that many of the critically ill are less likely to choose resuscitation when given accurate information about its limitations.


title: Cardiac arrest

text: In the event that cardiopulmonary resuscitation is successful, complete recovery is not guaranteed as many survivors experience an array of disabilities, including partial paralysis; seizures; difficulty with walking, speaking, or memory; limited consciousness; or persistent vegetative state and brain death.


title: Cardiac arrest

text: Cardiac arrest is not preceded by any warning symptoms in approximately 50 percent of people. For individuals who do experience symptoms, the symptoms are usually nonspecific to the cardiac arrest. This can present in the form of new or worsening:


title: Cardiac arrest

text: When cardiac arrest is suspected due to signs of unconsciousness or abnormal breathing, a bystander should attempt to feel a pulse for 10 seconds; if no pulse is felt, it should be assumed the victim is in cardiac arrest. As a result of loss of cerebral perfusion (blood flow to the brain), the person will rapidly lose consciousness and can stop breathing. Near-death experiences are reported by 10 to 20 percent of people who survived cardiac arrest, which demonstrates a certain level of cognitive processes that are still active during resuscitation.


title: Cardiac arrest

text: The risk factors for sudden cardiac arrest (SCA) are similar to those of coronary artery disease and include age, cigarette smoking, high blood pressure, high cholesterol, lack of physical exercise, obesity, diabetes, and family history and Cardiomyopathy of cardiac disease. A prior episode of sudden cardiac arrest also increases the likelihood of future episodes. A statistical analysis of many of these risk factors determined that approximately 50% of all cardiac arrests occur in 10% of the population perceived to be at greatest risk due to aggregate harm of multiple risk factors, demonstrating that cumulative risk of multiple comorbidities exceeds the sum of each risk individually.


title: Cardiac arrest

text: Previous adverse cardiac events, non-sustained ventricular tachycardia (NSVT), syncope, and left ventricular hypertrophy (LVT) have been shown to predict sudden cardiac death in children. Current cigarette smokers with coronary artery disease were found to have a two to threefold increase in the risk of sudden death between ages 30 and 59. Furthermore, it was found that former smokers' risk was closer to that of those who had never smoked.


title: Cardiac arrest

text: Functional changes in the heart such as reduced ejection fraction or cardiac arrhythmia have been shown to increase the risk of cardiac arrest and act independently from the aforementioned risk factors. Conditions that produce these functional changes can be acquired following previous cardiac injury or inherited through familial history of arrhythmogenic disorders.


title: Cardiac arrest

text: Sudden cardiac arrest (SCA), or sudden cardiac death (SCD), occurs when the heart abruptly begins to beat in an abnormal or irregular rhythm (arrhythmia). Without organized electrical activity in the heart muscle, there is no consistent contraction of the ventricles, which results in the heart's inability to generate an adequate cardiac output (forward pumping of blood from the heart to the rest of the body). There are many different types of arrhythmias, but the ones most frequently recorded in sudden cardiac arrest are ventricular tachycardia and ventricular fibrillation. Less common causes of dysrhythmias in cardiac arrest include pulseless electrical activity (PEA), bradyarrhythmias, or asystole. Such rhythms are seen when there is prolonged cardiac arrest, progression of ventricular fibrillation, or efforts like defibrillation executed to resuscitate the person. The rhythm changes also appear to correlate with the underlying cause of cardiac injury when present (ischemic vs. nonischemic causes).


title: Cardiac arrest

text: Coronary artery disease (CAD), also known as ischemic heart disease, is responsible for 62 to 70 percent of all sudden cardiac deaths. CAD is a much less frequent cause of sudden cardiac death in people under the age of 40. Cases have shown that the most common finding at postmortem examination of sudden cardiac death is chronic high-grade stenosis of at least one segment of a major coronary artery, an artery that supplies the heart muscle with its blood supply. This stenosis is often the result of narrowing and hardening of the arteries following deposition of cholesterol plaques and inflammation over several years. This accumulation and remodeling of the coronary vessels along with other systemic blood vessels characterizes the progression of Atherosclerotic Cardiovascular Disease. When a stable plaque ruptures, it can block the flow of blood and oxygen through small arteries resulting in ischemic injury as a result. The injury to tissue following ischemia can lead to structural and functional changes preventing the heart from continuing normal conduction cycles and altering heart rate.


title: Cardiac arrest

text: Abnormalities of the coronary arteries not related to atherosclerosis include congenital coronary artery anomalies (most commonly anomalous origin of the left coronary artery from the pulmonary artery), inflammation known as coronary arteritis, embolism, vasospasm, and mechanical abnormalities related to connective tissue diseases or trauma. These conditions account for 10-15% of cardiac arrest and sudden cardiac death.


title: Cardiac arrest

text: Structural heart diseases unrelated to coronary artery disease account for 10% of all sudden cardiac deaths. Examples of these include: cardiomyopathies (hypertrophic, dilated, or arrhythmogenic), cardiac rhythm disturbances, myocarditis, hypertensive heart disease, and congestive heart failure.


title: Cardiac arrest

text: Left ventricular hypertrophy is thought to be a leading cause of sudden cardiac deaths in the adult population. This is most commonly the result of longstanding high blood pressure, or hypertension, which has caused a maladaptive change to the wall of the heart's main pumping chamber, the left ventricle. Increased blood pressure means the heart must pump harder to adequately circulate blood throughout the body. If the heart does this for a prolonged period of time due to uncontrolled hypertension, the left ventricle can experience hypertrophy (grow larger) in a way that decreases the heart's effectiveness. Left ventricular hypertrophy can be demonstrated on an echocardiogram and electrocardiogram (EKG).


title: Cardiac arrest

text: A 1999 review of sudden cardiac deaths in the United States found that structural heart diseases accounted for over 30% of sudden cardiac arrests for those under 30 years. A study of military recruits ages 18-35 found that this accounted for over 40% of sudden cardiac deaths.


title: Cardiac arrest

text: Structural abnormalities of the cardiac conduction system (notably the Atrioventricular Node and His-Purkinje system) may predispose an individual to arrhythmias with a risk of progressing to sudden cardiac arrest, albeit this risk remains low. Many of these conduction blocks can be treated with internal cardiac defibrillators for those determined to be at high risk due to severity of fibrosis or severe electrophysiologic disturbances.


title: Cardiac arrest

text: Arrhythmias not due to structural heart disease account for 5 to 10% of sudden cardiac arrests. These are frequently caused by genetic disorders that lead to abnormal heart rhythms. The genetic mutations often affect specialized proteins known as ion channels that conduct electrically charged particles across the cell membrane, and this group of conditions is therefore often referred to as channelopathies. Examples of these inherited arrhythmia syndromes include Long QT syndrome (LQTS), Brugada Syndrome, Catecholaminergic polymorphic ventricular tachycardia, and Short QT syndrome. Many are also associated with environmental or neurogenic triggers such as response to loud sounds that can initiate lethal arrhythmias. Other conditions that promote arrhythmias but are not caused by genetic mutations include Wolff-Parkinson-White syndrome.


title: Cardiac arrest

text: Long QT syndrome, a condition often mentioned in young people's deaths, occurs in one of every 5000 to 7000 newborns and is estimated to be responsible for 3000 deaths annually compared to the approximately 300,000 cardiac arrests seen by emergency services. These conditions are a fraction of the overall deaths related to cardiac arrest but represent conditions that may be detected prior to arrest and may be treatable. The symptomatic expression of Long-QT syndrome is quite broad and more often presents with syncope rather than cardiac arrest. However, the risk of cardiac arrest is still present, and individuals with a family history of sudden cardiac arrests should be screened for LQTS and other treatable causes of lethal arrhythmia. Higher levels of risk for cardiac arrest are associated with female sex, more significant QT prolongation, history of unexplained syncope (fainting spells), or premature sudden cardiac death. Additionally, individuals with LQTS should avoid certain medications that carry the risk of increasing the severity of this conduction abnormality, such as certain anti-arrhythmic, anti-depressant, and quinolone or macrolide antibiotics.


title: Cardiac arrest

text: Non-cardiac causes account for 15 to 25% of cardiac arrests. The most common non-cardiac causes are trauma, major bleeding (gastrointestinal bleeding, aortic rupture, or intracranial hemorrhage), hypovolemic shock, overdose, drowning, and pulmonary embolism. Cardiac arrest can also be caused by poisoning like the stings of certain jellyfish or through electrocution like lightning.


title: Cardiac arrest

text: Other non-cardiac causes of cardiac arrest may result from temporary disturbances in the body's homeostasis. This may be the result of changes in electrolyte ratios, oxygen saturation, or alterations of other ions influencing the body's pH.


title: Cardiac arrest

text: "Hs and Ts" is a mnemonic used to remember the treatable or reversible causes of cardiac arrest. Note: This mnemonic includes causes of cardiac and non-cardiac origin, but all are reversible with appropriate and time-sensitive treatment.


title: Cardiac arrest

text: In children, the most common cause of cardiopulmonary arrest is shock or respiratory failure that has not been treated. Heart arrhythmia is not the most common cause in children. When there is a cardiac arrhythmia, it is most often asystole or bradycardia, in contrast to ventricular fibrillation or tachycardia as seen in adults. Other causes can include drugs such as cocaine and methamphetamine or overdose of medications such as antidepressants in a child who was previously healthy but is now presenting with a dysrhythmia that has progressed to cardiac arrest. Common causes of sudden unexplained cardiac arrest in children include hypertrophic cardiomyopathy, coronary artery abnormalities, and arrhythmias.


title: Cardiac arrest

text: The definitive electrical mechanisms of cardiac arrest, which may arise from any of the functional, structural, or physiologic abnormalities mentioned above, are characterized by tachyarrhythmic or bradyarrhythmic events that do not result in systole. The tachyarrhythmias can be further classified as Ventricular fibrillation (V-fib) and pulseless or sustained Ventricular tachycardia (V-tach), both of which are rapid and erratic arrhythmias that alter the circulatory pathway such that adequate blood flow cannot be sustained and is inadequate to meet the body's needs.


title: Cardiac arrest

text: The mechanism responsible for the majority of sudden cardiac deaths is ventricular fibrillation. Ventricular fibrillation is a tachyarrhythmia characterized by turbulent electrical activity in the ventricular myocardium leading to a heart rate too disorganized and rapid to produce any meaningful cardiac output, thus resulting in insufficient perfusion of the brain and essential organs. In ventricular tachycardia, the heart also beats faster than normal, which may prevent the heart chambers from properly filling with blood. Some of the electrophysiologic mechanisms underpinning ventricular fibrillations include ectopic automaticity, re-entry, and triggered activity. Structural changes in the diseased heart as a result of inherited factors (mutations in ion-channel coding genes, for example) cannot explain the suddenness of sudden cardiac death.


title: Cardiac arrest

text: Both ventricular fibrillation and ventricular tachycardia can result in the heart ineffectively pumping blood to the body. Ventricular tachycardia is characterized by an altered QRS complex and a heart rate greater than 100 beats per minute. When V-tach is sustained (lasts for at least 30 seconds), inadequate blood flow to heart tissue can lead to cardiac arrest.


title: Cardiac arrest

text: Bradyarrhythmias occur following dissociation of spontaneous electrical conduction and the mechanical function of the heart resulting in pulseless electrical activity (PEA) or through complete absence of electrical activity of the heart resulting in asystole. Similar to the result of tachyarrhythmias, these conditions lead to an inability to sustain adequate blood flow as well, though in the case of bradyarrhythmias, the underlying cause is an absence of mechanical activity rather than rapid beats leading to disorganization.


title: Cardiac arrest

text: Cardiac arrest is synonymous with clinical death. Historical information and a physical exam can diagnose cardiac arrest and provide information regarding the potential cause and prognosis. The provider taking the person's clinical history should aim to determine if the episode was observed by anyone else, what time the episode took place, what the person was doing (in particular if there was any trauma), and if there were involvement of drugs. The physical examination portion of diagnosing cardiac arrest focuses on the absence of a pulse. In many cases, lack of a carotid pulse is the gold standard for diagnosing cardiac arrest. Lack of a pulse in the periphery (radial/pedal) may also result from other conditions (e.g. shock) or simply an error on the part of the rescuer. Studies have shown that rescuers may often make a mistake when checking the carotid pulse in an emergency, whether they are healthcare professionals or lay persons.


title: Cardiac arrest

text: Point-of-care ultrasound (POCUS) is a tool that can be used to examine the movement of the heart and its force of contraction at the patient's bedside. POCUS can accurately diagnose cardiac arrest in hospital settings, overcoming some of the shortcomings of diagnosis through checking the central pulse (carotid arteries or subclavian arteries), as well as detecting movement and contractions of the heart.


title: Cardiac arrest

text: Using POCUS, clinicians can have limited, two-dimensional views of different parts of the heart during arrest. These images can help clinicians determine whether electrical activity within the heart is pulseless or pseudo-pulseless, as well as help them diagnose the potentially reversible causes of an arrest. Published guidelines from the American Society of Echocardiography, American College of Emergency Physicians, European Resuscitation Council, and the American Heart Association, as well as the 2018 preoperative Advanced Cardiac Life Support guidelines, have recognized the potential benefits of using POCUS in diagnosing and managing cardiac arrest.


title: Cardiac arrest

text: Owing to the inaccuracy of this method of diagnosis, some bodies like the European Resuscitation Council (ERC) have de-emphasized its importance. Instead, the current guidelines prompt individuals to begin CPR on any unconscious person with absent or abnormal breathing. The Resuscitation Council in the United Kingdom stands in line with the ERC's recommendations and those of the American Heart Association. They have suggested that the technique to check carotid pulses should be used only by healthcare professionals with specific training and expertise, and even then that it should be viewed in conjunction with other indicators like agonal respiration.


title: Cardiac arrest

text: Various other methods for detecting circulation and therefore diagnosing cardiac arrest have been proposed. Guidelines following the 2000 International Liaison Committee on Resuscitation (ILCOR) recommendations were for rescuers to look for "signs of circulation" but not specifically the pulse. These signs included coughing, gasping, color, twitching, and movement. However, in face of evidence that these guidelines were ineffective, the current recommendation of ILCOR is that cardiac arrest should be diagnosed in all casualties who are unconscious and not breathing normally, a similar protocol to that which the European Resuscitation Council has adopted. In a non-acute setting where the patient is expired, diagnosis of cardiac arrest can be done via molecular autopsy or postmortem molecular testing, which uses a set of molecular techniques to find the ion channels that are cardiac defective. This could help elucidate the cause of death in the patient.


title: Cardiac arrest

text: Other physical signs or symptoms can help determine the potential cause of the cardiac arrest. Below is a chart of the clinical findings and signs/symptoms a person may have and potential causes associated with them.


title: Cardiac arrest

text: Clinicians classify cardiac arrest into "shockable" versus "non-shockable", as determined by the EKG rhythm. This refers to whether a particular class of cardiac dysrhythmia is treatable using defibrillation. The two "shockable" rhythms are ventricular fibrillation and pulseless ventricular tachycardia, while the two "non-shockable" rhythms are asystole and pulseless electrical activity.


title: Cardiac arrest

text: With the lack of positive outcomes following cardiac arrest, efforts have been spent finding effective strategies to prevent cardiac arrest. With the prime causes of cardiac arrest being ischemic heart disease, efforts to promote a healthy diet, exercise, and smoking cessation are important. For people at risk of heart disease, measures such as blood pressure control, cholesterol lowering, and other medico-therapeutic interventions are used. Of note, however, a Cochrane review published in 2016 found moderate-quality evidence to show that blood pressure-lowering drugs do not reduce the risk of sudden cardiac death. Exercise is an effective preventative measure for cardiac arrest in the general population but may be risky for those with pre-existing conditions. The risk of a transient catastrophic cardiac event increases in individuals with heart disease during and immediately after exercise. However, both the lifetime and acute risk of cardiac arrest are decreased in individuals with heart disease that perform regular exercise, which suggests the benefits of exercise outweigh the risks.


title: Cardiac arrest

text: According to a study published in the Journal of the American Heart Association in 2021, diet may be a modifiable risk factor that leads to a lower incidence of sudden cardiac death. The study found that those who fell under the category of having "Southern diets" representing those of "added fats, fried food, eggs, organ and processed meats, and sugar‐sweetened beverages" had a positive association with an increased risk of cardiac arrest, while those deemed following the "Mediterranean diets" had an inverse relationship regarding the risk of cardiac arrest. The American Heart Association also has diet recommendations aimed at preventing cardiovascular disease.


title: Cardiac arrest

text: Additionally, marine-derived omega-3 polyunsaturated fatty acids (PUFAs) have been promoted for preventing sudden cardiac death due to their postulated ability to lower triglyceride levels, prevent arrhythmias, decrease platelet aggregation, and lower blood pressure. However, according to a systematic review published in 2012, omega-3 PUFA supplementation is not associated with a lower risk of sudden cardiac death.


title: Cardiac arrest

text: In medical parlance, cardiac arrest is referred to as a "code" or a "crash". This typically refers to "code blue" on the hospital emergency codes. A dramatic drop in vital sign measurements is referred to as "coding" or "crashing", though coding is usually used when it results in cardiac arrest, while crashing might not. Treatment for cardiac arrest is sometimes referred to as "calling a code".


title: Cardiac arrest

text: Patients in general wards often deteriorate for several hours or even days before a cardiac arrest occurs. This has been attributed to a lack of knowledge and skill amongst ward-based staff, in particular, a failure to measure the respiratory rate, which is often the major predictor of a deterioration and can often change up to 48 hours prior to a cardiac arrest. In response, many hospitals now have increased training for ward-based staff. A number of "early warning" systems also exist that aim to quantify the person's risk of deterioration based on their vital signs and thus provide a guide to staff. In addition, specialist staff are being used more effectively to augment the work already being done at the ward level. These include:


title: Cardiac arrest

text: An implantable cardioverter defibrillator (ICD) is a battery-powered device that monitors electrical activity in the heart, and when an arrhythmia is detected, can deliver an electrical shock to terminate the abnormal rhythm. ICDs are used to prevent sudden cardiac death (SCD) in those who have survived a prior episode of sudden cardiac arrest (SCA) due to ventricular fibrillation or ventricular tachycardia (secondary prevention). ICDs are also used prophylactically to prevent sudden cardiac death in certain high-risk patient populations (primary prevention).


title: Cardiac arrest

text: Numerous studies have been conducted on the use of ICDs for the secondary prevention of SCD. These studies have shown improved survival with ICDs compared to the use of anti-arrhythmic drugs. ICD therapy is associated with a 50% relative risk reduction in death caused by an arrhythmia and a 25% relative risk reduction in all-cause mortality.


title: Cardiac arrest

text: Primary prevention of SCD with ICD therapy for high-risk patient populations has similarly shown improved survival rates in several large studies. The high-risk patient populations in these studies were defined as those with severe ischemic cardiomyopathy (determined by a reduced left ventricular ejection fraction (LVEF)). The LVEF criteria used in these trials ranged from less than or equal to 30% in MADIT-II to less than or equal to 40% in MUSTT.


title: Cardiac arrest

text: Sudden cardiac arrest may be treated via attempts at resuscitation. This is usually carried out based on basic life support, advanced cardiac life support (ACLS), pediatric advanced life support (PALS), or neonatal resuscitation program (NRP) guidelines.


title: Cardiac arrest

text: Early cardiopulmonary resuscitation (CPR) is essential to surviving cardiac arrest with good neurological function. It is recommended that it be started as soon as possible with minimal interruptions once begun. The components of CPR that make the greatest difference in survival are chest compressions and defibrillating shockable rhythms. After defibrillation, chest compressions should be continued for two minutes before another rhythm check. This is based on a compression rate of 100-120 compressions per minute, a compression depth of 5–6 centimeters into the chest, full chest recoil, and a ventilation rate of 10 breath ventilations per minute. Correctly performed bystander CPR has been shown to increase survival; however, it is performed in less than 30% of out-of-hospital cardiac arrests (OHCAs) . If high-quality CPR has not resulted in return of spontaneous circulation (ROSC) and the person's heart rhythm is in asystole, discontinuing CPR and pronouncing the person's death is generally reasonable after 20 minutes. Exceptions to this include certain cases with hypothermia or drowning victims. Some of these cases should have longer and more sustained CPR until they are nearly normothermic. Longer durations of CPR may be reasonable in those who have cardiac arrest while in hospital. Bystander CPR by the lay public before the arrival of EMS also improves outcomes.


title: Cardiac arrest

text: Either a bag valve mask or an advanced airway may be used to help with breathing particularly since vomiting and regurgitation are common, especially in OHCA. If this occurs, then modification to existing oropharyngeal suction may be required, such as the use of Suction Assisted Laryngoscopy Airway Decontamination. High levels of oxygen are generally given during CPR. Tracheal intubation has not been found to improve survival rates or neurological outcomes in cardiac arrest and in the prehospital environment, may worsen it. Endotracheal tubes and supraglottic airways appear equally useful. When done by EMS, 30 compressions followed by two breaths appear better than continuous chest compressions and breaths being given while compressions are ongoing.


title: Cardiac arrest

text: For bystanders, CPR that involves only chest compressions results in better outcomes as compared to standard CPR for those who have gone into cardiac arrest due to heart issues. Mouth-to-mouth as a means of providing respirations to the patient has been phased out due to the risk of contracting infectious diseases from the patient. Mechanical chest compressions (as performed by a machine) are no better than chest compressions performed by hand. It is unclear if a few minutes of CPR before defibrillation results in different outcomes than immediate defibrillation. If cardiac arrest occurs after 20 weeks of pregnancy, the uterus should be pulled or pushed to the left during CPR. If a pulse has not returned by four minutes, an emergency Cesarean section is recommended.


title: Cardiac arrest

text: Defibrillation is indicated if an electric-shockable heart rhythm is present. The two shockable rhythms are ventricular fibrillation and pulseless ventricular tachycardia. In children, 2 to 4 J/Kg is recommended.


title: Cardiac arrest

text: In out-of-hospital arrests, the defibrillation is made by an automated external defibrillator (AED), a portable machine that can be used by any user: it provides voice instructions that guide the process, automatically checks the victim's condition, and applies the appropriate electric shocks. Some defibrillators even provide feedback on the quality of CPR compressions, encouraging the lay rescuer to press the person's chest hard enough to circulate blood.


title: Cardiac arrest

text: In addition, there is increasing use of public access defibrillation. This involves placing AEDs in public places and training staff in these areas on how to use them. This allows defibrillation to occur prior to the arrival of emergency services, which has been shown to increase chances of survival. It has been shown that those who have arrests in remote locations have worse outcomes following cardiac arrest.


title: Cardiac arrest

text: , medications other than epinephrine (adrenaline), while included in guidelines, have not been shown to improve survival to hospital discharge following OHCAs. This includes the use of atropine, lidocaine, and amiodarone. Epinephrine in adults, as of 2019, appears to improve survival but does not appear to improve neurologically normal survival. It is generally recommended every three to five minutes. Epinephrine acts on the alpha-1 receptor, which in turn increases the blood flow that supplies the heart. This would assist with providing more oxygen to the heart. Based on 2019 guidelines, 1 mg of epinephrine may be administered to patients every 3–5 minutes, but doses higher than 1 mg of epinephrine are not recommended for routine use in cardiac arrest. If the patient has a non-shockable rhythm, epinephrine should be administered as soon as possible. For a shockable rhythm, epinephrine should only be administered after an initial defibrillation attempt. Vasopressin overall does not improve or worsen outcomes compared to epinephrine. The combination of epinephrine, vasopressin, and methylprednisolone appears to improve outcomes. Some of the lack of long-term benefits may be related to delays in epinephrine use. While evidence does not support its use in children, guidelines state its use is reasonable. Lidocaine and amiodarone are also deemed reasonable in children with cardiac arrest who have a shockable rhythm. The general use of sodium bicarbonate or calcium is not recommended. The use of calcium in children has been associated with poor neurological function as well as decreased survival. Correct dosing of medications in children is dependent on weight. To minimize time spent calculating medication doses, the use of a Broselow tape is recommended.


title: Cardiac arrest

text: The 2010 guidelines from the American Heart Association no longer contain the recommendation for using atropine in pulseless electrical activity and asystole for lack of evidence supporting its use. Neither lidocaine nor amiodarone, in those who continue in ventricular tachycardia or ventricular fibrillation despite defibrillation, improves survival to hospital discharge, despite both equally improving survival to hospital admission.


title: Cardiac arrest

text: Thrombolytics may cause harm but may be of benefit in those with a confirmed pulmonary embolism as the cause of arrest. Evidence for use of naloxone in those with cardiac arrest due to opioids is unclear, but it may still be used. In those with cardiac arrest due to local anesthetic, lipid emulsion may be used.


title: Cardiac arrest

text: Current international guidelines suggest cooling adults after cardiac arrest using targeted temperature management (TTM), which was previously known as therapeutic hypothermia. People are typically cooled for a 24-hour period, with a target temperature of . There are several methods used to lower the body temperature, such as applying ice packs or cold-water circulating pads directly to the body or infusing cold saline. This is followed by gradual rewarming over the next 12 to 24 hrs.


title: Cardiac arrest

text: The effectiveness of TTM after OHCA is an area of ongoing study. Pre-hospital TTM after OHCA has been shown to increase the risk of adverse outcomes. The rates of re-arrest may be higher in people who were treated with pre-hospital TTM; however, more research is needed on the effectiveness and risks of TTM. TTM in post-arrest care has not been found to improve mortality or neurological outcomes. Moreover, TTM may have adverse neurological effects in people who survive post-cardiac arrest"."


title: Cardiac arrest

text: Some people choose to avoid aggressive measures at the end of life. A do not resuscitate order (DNR) in the form of an advance health care directive makes it clear that in the event of cardiac arrest, the person does not wish to receive cardiopulmonary resuscitation. Other directives may be made to stipulate the desire for intubation in the event of respiratory failure or, if comfort measures are all that are desired, by stipulating that healthcare providers should "allow natural death".


title: Cardiac arrest

text: Several organizations promote the idea of a chain of survival. The chain consists of the following "links":


title: Cardiac arrest

text: If one or more links in the chain are missing or delayed, then the chances of survival drop significantly.


title: Cardiac arrest

text: These protocols are often initiated by a code blue, which usually denotes impending or acute onset of cardiac arrest or respiratory failure.


title: Cardiac arrest

text: Resuscitation with extracorporeal membrane oxygenation devices has been attempted with better results for in-hospital cardiac arrest (29% survival) than OHCA (4% survival) in populations selected to benefit most. Cardiac catheterization in those who have survived an OHCA appears to improve outcomes, although high-quality evidence is lacking. It is recommended to be done as soon as possible in those who have had a cardiac arrest with ST elevation due to underlying heart problems.


title: Cardiac arrest

text: The precordial thump may be considered in those with witnessed, monitored, unstable ventricular tachycardia (including pulseless VT) if a defibrillator is not immediately ready for use, but it should not delay CPR and shock delivery or be used in those with unwitnessed OHCA.


title: Cardiac arrest

text: The overall rate of survival among those who have cardiac arrest outside the hospital is 10%. Among those who have an OHCA, 70% occur at home, and their survival rate is 6%. For those who have an in-hospital cardiac arrest (IHCA), the survival rate one year from at least the occurrence of cardiac arrest is estimated to be 13%. One-year survival is estimated to be higher in people with cardiac admission diagnoses (39%) when compared to those with non-cardiac admission diagnoses (11%). Children rates of survival are 3 to 16% in North America. For IHCA, survival to discharge is around 22%. Those who survive to ROSC and hospital admission frequently present with Post-Cardiac Arrest Syndrome, which usually presents with neurological injury that can range from mild memory problems to coma.


title: Cardiac arrest

text: Hypoxic ischemic brain injury is the most detrimental outcome for people suffering a cardiac arrest. Poor neurological outcomes following cardiac arrest are much more prevalent in countries that do not use withdrawal of life support (≈50%) as compared to those that do (less than 10%). Most improvements in cognition occur during the first three months following cardiac arrest, with some individuals reporting improvement up to one year post-cardiac arrest. 50 – 70% of cardiac arrest survivors report fatigue as a symptom, making fatigue the most prevalent patient-reported symptom.


title: Cardiac arrest

text: Prognosis is typically assessed 72 hours or more after cardiac arrest. Rates of survival are better in those who had someone witness their collapse, received bystander CPR, and/or had either V-fib or V-tach when assessed. Survival among those with V-fib or V-tach is 15 to 23%. Women are more likely to survive cardiac arrest and leave the hospital than men.


title: Cardiac arrest

text: A 1997 review found rates of survival to discharge of 14%, although different studies varied from 0 to 28%. In those over the age of 70 who have a cardiac arrest while in hospital, survival to hospital discharge is less than 20%. How well these individuals manage after leaving the hospital is not clear.


title: Cardiac arrest

text: The global rate of people who were able to recover from OHCA after receiving CPR has been found to be approximately 30%, and the rate of survival to discharge from the hospital has been estimated at 9%. Survival to discharge from the hospital is more likely among people whose cardiac arrest was witnessed by a bystander or emergency medical services, who received bystander CPR, and who live in Europe and North America. Relatively lower survival to hospital discharge rates have been observed in Asian countries.


title: Cardiac arrest

text: The risk of cardiac arrest varies with geographical region, age, and gender. The lifetime risk is three times greater in men (12.3%) than women (4.2%) based on analysis of the Framingham Heart Study. However, this gender difference disappeared beyond 85 years of age. Around half of these individuals are younger than 65 years of age.