There are a number of methods through which hypothermia is induced. These include: cooling catheters, cooling blankets, and application of ice applied around the body among others. As of 2013 it is unclear if one method is any better than the others. While cool intravenous fluid may be given to start the process, further methods are required to keep the person cold. Core body<unk>  must be measured (either via the esophagus, rectum, bladder in those who are producing urine, or within the pulmonary artery) to guide cooling. A<unk>  below should be avoided, as adverse events increase significantly. The person should be kept at the goal<unk>  plus or minus half a degree Celsius for 24 hours. Rewarming should be done slowly with suggested speeds of per hour.<unk>  should be started as soon as possible. The goal<unk>  should be reached before 8 hours.<unk>  remains partially effective even when initiated as long as 6 hours after collapse. Prior to the induction of<unk> , pharmacological agents to control shivering must be administered. When body<unk>  drops below a certain threshold—typically around —people may begin to shiver. It appears that regardless of the technique used to induce hypothermia, people begin to shiver when<unk>  drops below this threshold. Drugs commonly used to prevent and treat shivering in<unk>  include acetaminophen, buspirone, opioids including pethidine (meperidine), dexmedetomidine, fentanyl, and/or propofol. If shivering is unable to be controlled with these drugs, patients are often placed under general anesthesia and/or are given paralytic medication like vecuronium. People should be rewarmed slowly and steadily in order to avoid harmful spikes in intracranial pressure. Cooling catheters Cooling catheters are inserted into a femoral vein. Cooled saline solution is circulated through either a metal coated tube or a balloon in the catheter. The saline cools the person's whole body by lowering the<unk>  of a person's blood. Catheters reduce<unk>  at rates ranging from per hour. Through the use of the control unit, catheters can bring body<unk>  to within of the target level. Furthermore, catheters can raise<unk>  at a steady rate, which helps to avoid harmful rises in intracranial pressure. A number of studies have demonstrated that<unk>  via catheter is safe and effective. Adverse events associated with this invasive technique include bleeding, infection, vascular puncture, and deep vein thrombosis (DVT). Infection caused by cooling catheters is particularly harmful, as resuscitated people are highly vulnerable to the complications associated with infections. Bleeding represents a significant danger, due to a decreased clotting threshold caused by hypothermia. The risk of deep vein thrombosis may be the most pressing medical complication. Deep vein thrombosis can be characterized as a medical event whereby a blood clot forms in a deep vein, usually the femoral vein. This condition may become potentially fatal if the clot travels to the lungs and causes a pulmonary embolism. Another potential problem with cooling catheters is the potential to block access to the femoral vein, which is a site normally used for a variety of other medical procedures, including angiography of the venous system and the right side of the heart. However, most cooling catheters are triple lumen catheters, and the majority of people post-arrest will require central venous access. Unlike non-invasive methods which can be administered by nurses, the insertion of cooling catheters must be performed by a physician fully trained and familiar with the procedure. The time delay between identifying a person who might benefit from the procedure and the arrival of an interventional radiologist or other physician to perform the insertion may minimize some of the benefit of invasive methods' more rapid cooling. Transnasal evaporative cooling Transnasal evaporative cooling is a method of inducing the hypothermia process and provides a means of continuous cooling of a person throughout the early stages of<unk>  and during movement throughout the hospital environment. This technique uses two cannulae, inserted into a persons nasal cavity, to deliver a spray of coolant mist that evaporates directly underneath the brain and base of the skull. As blood passes through the cooling area, it reduces the<unk>  throughout the rest of the body. The method is compact enough to be used at the point of cardiac arrest, during ambulance transport, or within the hospital proper. It is intended to reduce rapidly the person's<unk>  to below while targeting the brain as the first area of cooling. Research into the device has shown cooling rates of per hour in the brain (measured through infrared tympanic measurement) and per hour for core body<unk>  reduction. Water blankets With these technologies, cold water circulates through a blanket, or torso wraparound vest and leg wraps. To lower<unk>  with optimal speed, 70% of a person's surface area should be covered with water blankets. The treatment represents the most well studied means of controlling body<unk> . Water blankets lower a person's<unk>  exclusively by cooling a person's skin and accordingly require no invasive procedures. Water blankets possess several undesirable qualities. They are susceptible to leaking, which may represent an electrical hazard since they are operated in close proximity to electrically powered medical equipment. The Food and Drug Administration also has reported several cases of external cooling blankets causing significant burns to the skin of person. Other problems with external cooling include overshoot of<unk>  (20% of people will have overshoot), slower induction time versus internal cooling, increased compensatory response, decreased patient access, and discontinuation of cooling for invasive procedures such as the cardiac catheterization. If therapy with water blankets is given along with two litres of cold intravenous saline, people can be cooled to in 65 minutes. Most machines now come with core<unk>  probes. When inserted into the rectum, the core body<unk>  is monitored and feedback to the machine allows changes in the water blanket to achieve the desired set<unk> . In the past some of the models of cooling machines have produced an overshoot in the target<unk>  and cooled people to levels below , resulting in increased adverse events. They have also rewarmed patients at too fast a rate, leading to spikes in intracranial pressure. Some of the new models have more software that attempt to prevent this overshoot by utilizing warmer water when the target<unk>  is close and preventing any overshoot. Some of the new machines now also have 3 rates of cooling and warming; a rewarming rate with one of these machines allows a patient to be rewarmed at a very slow rate of just an hour in the "automatic mode," allowing rewarming from to over 24 hours. Cool caps There are a number of non-invasive head cooling caps and helmets designed to target cooling at the brain. A hypothermia cap is typically made of a synthetic material such as neoprene, silicone, or polyurethane and filled with a cooling agent such as ice or gel which is either cooled to a very cold<unk> , , before application or continuously cooled by an auxiliary control unit. Their most notable uses are in preventing or reducing alopecia in chemotherapy, and for preventing cerebral palsy in babies born with hypoxic ischemic encephalopathy. In the continuously cooled iteration, coolant is cooled with the aid of a compressor and pumped through the cooling cap. Circulation is regulated by means of valves and<unk>  sensors in the cap. If the<unk>  deviates or if other errors are detected, an alarm system is activated. The frozen iteration involves continuous application of caps filled with Crylon gel cooled to to the scalp before, during and after intravenous chemotherapy. As the caps warm on the head, multiple cooled caps must be kept on hand and applied every 20 to 30 minutes.
Targeted temperature management
Basic airway management
Extracorporeal carbon dioxide removal
Surgical airway management
Active cooling
Advanced airway management
Neurally adjusted ventilatory assist
Intracranial pressure monitoring