Chronic lumbar zygapophysial joint pain is a common cause of chronic low back pain. Percutaneous radiofrequency ablation (RFA) is one of the effective management options; however, the results from the traditional RFA need to be improved in certain cases. The aim of this study is to investigate the effect of percutaneous radiofrequency ablation under endoscopic guidance (ERFA) for chronic low back pain secondary to facet joint arthritis.This is a prospective study enrolled 60 patients. The cases were randomized into two groups: 30 patients in the control group underwent traditional percutaneous radiofrequency ablation, others underwent ERFA. The lumbar visual analog scale (VAS), MacNab score, and postoperative complications were used to evaluate the outcomes. All outcome assessments were performed at postoperative 1 day, 1 month, 3 months, 6 months, and 12 months.P > 0.05). VAS scores, except the postoperative first day, in all other postoperative time points were significantly lower than preoperative values each in both groups (P < 0.05). There was no significant difference between the two groups in VAS at 1 day, 1 month, and 3 months after surgery (P > 0.05). However, the EFRA demonstrated significant benefits at the time points of 3 months and 6 months (P > 0.05). The MacNab scores of 1-year follow-up in the ERFA group were higher than that in the control group (P < 0.05). The incidence of complications in the ERFA group was significantly less than that in the control group (P < 0.05).There was no difference between the two groups in preoperative VAS (ERFA may achieve more accurate and definite denervation on the nerves, which leads to longer lasting pain relief. The lumbar zygapophysial joint is a synovial joint between two adjacent vertebrae. The joint capsule and surrounding tissues are densely covered with nerve terminal which mainly originate from the lumbar dorsal medial branch .Chronic lumbar zygapophysial joint pain refers to low back pain with a course longer than 3 months accompanied by radiating pain down to the buttocks and legs . Medial Percutaneous radiofrequency nerve ablation is an effective management with the problem of neural anatomic variation and regeneration . This stInclusion criteria are as follows: 1) chronic low back pain with a course longer than 3 months; (2) failed 2 months of conservative treatment including physical therapy and NSAIDs; (3) no change of lower limb sensation, movement and nervous reflex, no disorder of defecation or urination; (4) imaging feature: hyperplasia of the zygapophysial joints, osteophytes of the articular process, narrowing of the joint space (less than 2~4 mm), osteoarthritis, asymmetry, and intra-articular vacuum phenomenon; (5) more than 80% pain relief after controlled differential MBB with 0.5 ml 2% lidocaine and 1% bupivacaine at transitional part of superior articular process and transverse process in a week, respectively. The use of long-acting local anesthetic drugs to obtain longer pain relief time than short-acting local anesthetic drugs means true-positive response  tuberculosis, infections, tumors, and fractures, etc.; (2) spinal canal compromise, lumbar disc herniation, and spinal stenosis; (3) hematological diseases, diabetes, and gastrointestinal ulcers; and (4) age < 18 years or pregnant women.P > 0.05). There was no significant difference in age, duration of back pain, and body mass index .Participants: A total of 60 patients with chronic lumbar zygapophysial joint pain who fulfilled inclusion criteria were randomized into the ERFA group and control group according to the principle of randomized control and informed consent. Radiofrequency ablation was performed on 30 patients in the control group while endoscopic radiofrequency rhizotomy was performed for the 30 patients in the ERFA group. The demographic characteristics such as age, gender, body mass index, history of lumbar surgery, and low back pain in both groups are shown in Table This prospective randomized trial was performed and approved by medical ethical committees, written informed consent was obtained from all patients.Operation was performed under local anesthesia. Patients were placed in the prone position with a soft pillow under the abdomen to maintain lumbar kyphosis and the abdomen unstressed. After confirming the segment , C-arm was adjusted until the clear transition site of the facet joints and transverse processes are observed. Following local anesthetic injection of the puncture site on the skin, the tip of the radiofrequency needle reached the base of the transverse process, where the rigid bony was encountered. Adjust needle tip cranially sliding over the bony tissue and parallel to the medial branch. After the probe is in place, the guide needles were inserted through the radiofrequency needle, following stepwise dilation and placement of working channel. Under the endoscope, dorsal medial branch was dissected and ablated with a radio frequency cutting head. The radiofrequency denervation is performed on the severed nerve end using high frequency to avoid nerve regeneration. The soft tissue was fully ablated to expose the bone surface of dorsal transverse process and the superior articular process. A skin incision was sutured by absorbable suture material after the endoscope and working cannula were removed. Other targets were operated referring to this method. On the second postoperative day, normal life and work can be resumed Figs.  and 3.FThe radiofrequency ablation of medial branches of the dorsal rami was performed under local anesthesia. The patient was placed in a prone position; responsible segment and the upper segment of the lumbar spinal nerve medial branch were selected. A 22-G, 10-cm-long radiofrequency needle with the 0.5-cm bare end was punctured into the transitional part of the facet joint and transverse process under C-arm fluoroscopy. After location, sensory testing and motor testing were performed. The sensory test was performed with frequency at 50 Hz. The sensory test was successful if the chief complaint pain area had slight pain, warmth, bulging sensation, or string numbness, without severe pain of lower extremities. If motor test with low-frequency stimulation at 2 Hz did not induce muscle twitching in lower extremities, the tip position was considered accurate and ablation was feasible. The ablation parameters were set to 80 °C, lasting 60 s once, and 90 °C, 80 s one more time.The lumbar visual analog scale (VAS) scores were recorded previous to treatment, posterior to second MBB, 1 day, and 1, 3, 6, and 12 months posterior to treatment. MacNab scores at the 12 months after treatment were recorded.T test was used to compare the VAS scores at each time point after surgery. The comparison of MacNab score and follow-up complications among groups was done with chi-square test. Differences were considered statistically significant when P < 0.05.All analyses were performed using SPSS 21.0 . One-way ANOVA analysis was used to compare preoperative and postoperative VAS scores. P < 0.05). Cases underwent ERFA returned to daily life after 3–7-day wound care and observation. There were multiple anatomic variations of medial dorsal rami observed. There was no significant difference in pre MBB VAS scores (P > 0.05). Because of the pain in the wound, the VAS score of back pain at the first day after surgery was higher than that before surgery in both two groups (P < 0.05). Post MBB and postoperative VAS scores were significantly lower than pre MBB ones at 1 month, 3 months,6 months, and 12 months (P < 0.05); there was no significant difference in VAS scores between the ERFA group and the control group at 1 day, 1 month, and 3 months (P > 0.05). In the ERFA group, the low back pain showed a lower score at postoperative 6 and 12 months (P < 0.05). There was no significant difference in VAS scores at all time points after surgery except postoperative 1 day in the ERFA group (P > 0.05), VAS scores of the control group decreased firstly and then increased with time after radiofrequency treatment (Table P < 0.05) (Table P < 0.05) (Table The average duration of ERFA and radiofrequency ablation was 55 min 35–75 min) and 33 min (15–51 min), respectively. The duration of ERFA is longer than that of radiofrequency ablation (5–75 min 5) Table .Table 2Chronic low back pain is one of the common diseases in orthopedic outpatient clinics, and low back pain secondary to facet joint arthritis accounts for about 30% circa. 15 to 45%) of patients with chronic low back pain  to 45% o. When thControlled MBB is the only mean diagnostic method for the diagnosis of lumbar zygapophysial joint pain. The false-positive rate of single uncontrolled MBB is between 22 and 32% . ControlPercutaneous radiofrequency ablation of spinal nerves is effective; however, the long-term efficacy is unsatisfactory due to the variation of dorsal medial branch and the recurrence caused by nerve regeneration .Indications for EFRA include (1) chronic lumbar zygapophysial joint pain with a definite diagnosis of controlled MBB and patient has a pronounced surgical aspiration and (2) failure or short-time recurrence after 6-week standard conservative treatment and percutaneous radiofrequency ablation. In the current study, the therapeutic effect of ERFA is superior to percutaneous radiofrequency ablation. The reasons may include direct vision of the variability of the nerve under endoscopy , with diCompared with radiofrequency ablation, ERFA also has corresponding disadvantages, such as longer duration of procedure, lengthened recovery time, and increased cost. Besides, insertion of the working channel may cause potential cosmetic scarring. But given the advantages of the procedure, these disadvantages are also acceptable.In summary, radiofrequency needle guiding ERFA has advantages of more accurate positioning, more thorough denervation, fewer complications, lower risk, and better long-term efficacy up to 5 years post-procedure. The surgery may be used in selected patients. However, this study involves a small sample size and short follow-up time. The long-term efficacy needs further follow-up studies.


High-resolution impedance manometry (HRiM) is the test of choice to diagnose esophageal motility disorders and is particularly useful for identifying achalasia subtypes, which often guide therapy. HRiM is typically performed without sedation in the office setting. However, a substantial number of patients fail this approach. We report our single-center experience on endoscopy-assisted HRiM under monitored anesthesia care (MAC) in adults to demonstrate the feasibility and effectiveness of this approach. Patients who had failed prior HRiM attempts received propofol under MAC. Patients then underwent an upper endoscopy, followed immediately by passage of a Diversateck HRiM motility catheter through the nares and under direct visualization into the stomach, often using the tip of the endoscope to guide the catheter. We then awakened the patients and asked them to perform 10 saline swallows. We successfully completed HRiM studies in 14 consecutive patients. Six patients had achalasia; two had esophagogastric junction outflow obstruction; two had absent contractility; one had distal esophageal spasm; one had ineffective esophageal motility; and one had a normal study. The majority of these patients were treated successfully with targeted interventions, including per oral endoscopic myotomy, gastrostomy, botox injection, medical therapy, and dietary modifications. Esophageal manometry has become the gold-standard test to diagnose esophageal motility disorders and is also useful in the evaluation of gastroesophageal reflux disease (GERD), noncardiac chest pain, or systemic conditions that may lead to esophageal dysmotility. High-resolution impedance manometry (HRiM) with topography plotting incorporates impedance and manometry sensors, providing information on esophageal peristaltic patterns and pressures. Identification of specific esophageal motility disorders, especially subtypes of achalasia, is important, since this often guides therapeutic options . The proPrevious reports trialed using through-the-scope manometric assessment revealed a good correlation between LES pressures obtained by standard manometry. However, these reports were limited by reduced peristaltic wave amplitudes due to the use of dry swallows . AnotherWe report our single-center experience on endoscopy- and monitored anesthesia care- (MAC-) assisted high-resolution esophageal impedance manometry in adult patients to demonstrate the feasibility and effectiveness of this technique.We evaluated patients who had failed prior attempts at manometry in the office setting for this study. All MAC- and EGD-assisted HRiM studies were performed within one week of prior failed attempts of unsedated HRiM tests. Subjects arrived at the endoscopy suite after fasting for a minimum of 6 hours. Topical anesthesia was provided with Cetacaine  spray to the throat and 5 mL of viscous lidocaine 2% solution to the nares. Patients were then sedated using propofol at the anesthetist's discretion in a monitored anesthesia care (MAC) setting. First, while, in the supine position, patients underwent a standard upper endoscopy using an Olympus GIF H180 or H190 gastroscope; an Olympus GIF XP190 scope was required in some cases. A Diversateck HRiM motility catheter was then passed through the right or left nostril into the esophagus and proximal stomach, under direct visualization and guidance with an endoscope. The tip of the catheter was centered directly above the esophagogastric junction (EGJ) prior to entering the stomach. One patient required insertion of a nasopharyngeal trumpeted airway to allow passage of the manometry catheter through the nares due to a history of prior craniofacial surgery. Once the manometry probe was in the correct position, the endoscope was withdrawn. To avoid damaging the motility catheter, endoscopic tools such as biopsy forceps or snares were not used. In some cases, simple endoscopic maneuvers such as opening the EGJ with the neonatal endoscope or gently nudging the tip of the catheter with an endoscope to redirect the motility probe were required to successfully place the motility catheter into the stomach. There was no visible damage to the motility catheter. After allowing sufficient time to awaken , patients were given 10 consecutive 5-mL boluses of normal saline, followed by 5 mL of a viscous solution  as needed, while being in supine position for a total of 10 to 20 swallows. Esophageal muscle functions were recorded using the Diversatek ZVU software. The motility catheter was removed at the end of the procedure. On average, the EGD-assisted HRiM study took about 30 minutes versus 15 to 20 minutes for conventional HRiM test.As shown in Patient 1 was a 32-year-old woman with a history of achalasia with a Heller myotomy at age of eight years. She developed recurrent dysphagia that had been either refractory or with only temporary response, to multiple pneumatic dilations at other institutions. She was unable to tolerate unsedated manometry. The manometry catheter was successfully placed at the time of sedated endoscopy with findings of patent esophagogastric junction (EGJ)/LES, severe ineffective motility and distal esophageal spasm, and a normal IRP consistent with her history of previously treated type III achalasia.Patient 2 was a 51-year-old woman with prior laparoscopic hiatal hernia repair and Toupet fundoplication with solid and liquid dysphagia and nausea who was being considered for surgical revision. Due to a history of craniofacial fractures and postsurgical anatomy and refusal to undergo unsedated manometry, she required direct visual guidance with an EGD scope for proper passage and positioning of the catheter; her manometry was normal.Patient 3 was a 62-year-old woman with a prior Nissen fundoplication for GERD followed by repair of type III paraesophageal hernia with Belsey-Mark IV fundoplication two years later who developed dysphagia and regurgitation. She was unable to tolerate unsedated manometry due to severe gagging. Subsequently, the motility catheter was successfully advanced into the proximal stomach with MAC-assisted endoscopic guidance and showed findings of severe ineffective esophageal motility.Patient 4 was a 71-year-old woman with reflux symptoms and pulmonary fibrosis undergoing evaluation for lung transplantation. Unsedated manometry was attempted but unsuccessful due to inability to traverse the EGJ with the motility catheter. Under endoscopic guidance, the catheter was visualized abutting the distal esophagus just above the EGJ and was successfully guided into the proximal stomach with the assistance of a neonatal endoscope (Olympus GIF XP190). Her motility findings were consistent with type II achalasia. After discussing risks and benefits with the transplant team, patient deferred Heller myotomy and transplant listing.Patient 5 was a 52-year-old woman with a six-month history of progressively worsening solid and liquid dysphagia associated with a >50 lbs weight loss. Patient discomfort and inability to traverse the EGJ precluded her from completing unsedated manometry. Via endoscopy-assisted manometry, a diagnosis of type II achalasia was made and the patient proceeded to POEM with improvement in Eckardt score from 10 (preop) to 3 (postop).Patient 6 was an 18-year-old man with progressive dysphagia and an associated 65-lb weight loss who was unable to tolerate insertion of the manometry probe due to severe gagging and discomfort. He underwent MAC-assisted probe placement; direct visualization was needed due to a dilated esophagus and tight gastroesophageal junction. He was diagnosed with type II achalasia and proceeded to POEM with improvement in Eckardt score from 9 to 0.Patient 7 was an 85-year-old man with solid and liquid dysphagia and an inability to traverse the gastroesophageal junction during prior attempts at manometry. He had undergone prior endoscopies with balloon dilation of the mid esophagus with minimal relief. Barium esophagram revealed a corkscrew appearance. He underwent endoscopy-assisted manometry that showed distal esophageal spasm; he was referred for Botox injection 5 cm above the EGJ with significant symptomatic improvement.Patient 8 was a 63-year-old man with a history of a bilateral lung transplant due to silicosis with episodes of recurrent aspiration and a barium esophagram concerning for a gastroesophageal junction stricture. Due to this known abnormality, direct visualization following standard upper endoscopy exam was used to help advance the manometry probe past a tight lower esophageal sphincter. A diagnosis of EGJ outflow obstruction was made; due to fragile pulmonary status following frequent aspiration events, a percutaneous endoscopic gastrostomy tube was placed following this diagnosis.Patient 9 was a 65-year-old man with a history of dysphagia who failed awake manometry due to inability to pass the probe through his nares with looping in the posterior oropharynx. He had a history of prior craniofacial surgery. After MAC sedation, attempt to insert the motility catheter via either nostril failed. A trumpeted nasal airway was used to allow passage of the probe through his nares and into the esophagus. Due to difficulty traversing the EGJ, an Olympus GIF XP190 scope was used to help guide the probe into proximal stomach. Manometry revealed EGJ outflow obstruction and he was treated successfully with a calcium channel blocker.Patient 10 was a 66-year-old man with two years of worsening dysphagia and 40-lb weight loss referred from another institution after an EGD showed a dilated esophagus and inability to traverse the EGJ with the endoscope, suggestive of achalasia. He underwent repeat EGD at our institution, noting a tight EGJ/LES that was traversed with moderate pressure. Under direct visualization, the manometry catheter was placed into the distal esophagus but was unable to be advanced further due to patient's oxygen desaturation that resolved after propofol infusion was discontinued. Manometry revealed aperistalsis with panesophageal pressurization that, in conjunction with the EGD results and barium esophagram showing tapering of the distal esophagus, was strongly suggestive of type II achalasia. The patient was referred for and underwent successful POEM.Patient 11 was a 58-year-old man with a history of bilateral lung transplant due to cryptogenic organizing pneumonia referred for recurrent aspiration pneumonia and abnormal esophagram with poor antegrade peristalsis and distal intraesophageal reflux. After failing unsedated probe placement, he underwent EGD with endoscopic placement of the motility catheter into the proximal stomach. Manometry revealed ineffective esophageal motility.Patient 12 was a 24-year-old woman with a history of Type I achalasia who had undergone Heller myotomy seven years earlier and complained of progressively worsening dysphagia. Unsedated manometry was unsuccessful, as the probe was not able to enter the esophagus. During sedated probe placement with direct visualization, the probe was not able to enter esophagus via the right pyriform sinus. The probe was repositioned to the left pyriform sinus and able to be advanced into proximal stomach. EGD showed evidence of prior myotomy and patent EGJ/LES. Postsurgical type I achalasia was diagnosed based on manometry findings and dietary modifications were recommended.Patient 13 was a 61-year-old man with a two-year history of solid and liquid dysphagia. An esophagram revealed smooth narrowing of the gastroesophageal junction with incomplete relaxation, a bird's beak appearance, and esophageal dysmotility suggestive of achalasia. Unsedated manometry was attempted and revealed absent peristalsis. However, the probe had looped in the distal esophagus and did not traverse the EGJ. Due to the uncertainty in diagnosis, the patient underwent endoscopy-guided placement of the motility catheter into the proximal stomach under MAC. EGD showed patent EGJ/LES. Manometry confirmed absent contractility and dietary modifications were recommended.Patient 14 was a 75-year-old woman with a history of atypical chest pain and dysphagia who did not tolerate unsedated manometry due to gagging. She underwent successful placement of the manometry catheter into the proximal stomach with EGD guidance under MAC. EGD showed patent EGJ/LES. Manometry findings were consistent with absent contractility and she was currently treated with Bethanechol.We report our experience with MAC/endoscopy-assisted HRiM and clinical outcomes in 14 patients in whom unsedated manometry had previously failed or was contraindicated. The approach was used in a subset of our patients in whom manometric data was required prior to referral for possible invasive procedures or in whom there was diagnostic uncertainty. Notably, all procedures were successful without any peri- or postprocedural complications.This technique effectively overcame anatomical issues related to esophageal tortuosity, distal esophageal dilation, tight LES, deviated septum, or prior craniofacial surgery, respectively. Additionally, patient-related issues such as excessive coughing or gagging and inability to complete the study due to excessive discomfort were managed. Lastly, direct visualization was able to resolve uncertainty in cases with questionable prior manometric findings related to uncertain probe placement. Examples of nasopharyngeal/laryngeal and esophageal/EGJ issues of manometry probe placement are shown in Figures In our experience, the use of endoscopy-assisted HRiM allowed for the successful diagnosis of dysphagia and subsequent treatment with a procedural intervention in a substantial portion of our cohort , as well as medical therapy in three patients (21.4%), or dietary modifications in four (28.6%). In addition, in four patients (28.6%), the manometry findings supported the decision to defer further interventional procedures, including two patients with previously treated achalasia found to have a normal IRP, and two patients with prior hiatal hernia repair under consideration for surgical revision. Lastly, in one pre-lung transplant patient (Patient #4), a new diagnosis of achalasia assisted the patient in deciding not to pursue lung transplantation after a risk-benefit discussion with the transplant team.Limitations of this study include the small sample size, retrospective review of the cases, and lack of a controlled comparative group. However, our study does show the potential benefit of pursuing objective HRiM data and a definitive diagnosis in patients who fail initial attempts at unsedated manometry. Due to the additional expense and small increase in risk of complication due to the endoscopic procedure and required sedation, we only selected a subset of our patients in whom there was a particularly high suspicion of a major motility disorder in which a procedural intervention might be beneficial. Also, we selected patients in whom the decision to recommend a surgical procedure was, in large part, dependent on the manometry findings. Furthermore, obtaining a definitive manometric diagnosis for spastic esophageal disorders as the cause of dysphagia becomes increasingly important as POEM emerged as an attractive treatment option , 9.Another potential limitation of this technique is that the effect of anesthesia on esophageal motility is uncertain. Topical anesthetics do not influence the pharyngeal phase of swallowing, once the swallowing reflex is triggered . PropofoIn conclusion, endoscopy- and MAC-assisted HRiM can ensure completion of esophageal motility studies in patients otherwise unable to achieve definitive manometric diagnoses. In selected patients with suspected major motility disorders such as achalasia, EGJOO, or spastic esophageal motility disorders, our approach can help guide therapy and result in successful treatment outcomes.


Although pain treatment is an important objective in prehospital emergency medicine the incidence of oligoanalgesia is still high in prehospital patients. Given that prehospital emergency medicine in Germany is open for physicians of any speciality, the prehospital pain treatment may differ depending on the primary medical education. Aim of this study was to explore the difference in pain treatment between surgeons and anaesthesiologists in a physician staffed emergency medical service.Retrospective single centre cohort analysis in a physician staffed ground based emergency medical service from January 2014 until December 2016. A total of 8882 consecutive emergency missions were screened. Primary outcome measure was the difference in application frequency of prehospital analgesics by anaesthesiologist or surgeon. Univariate and multivariate logistic regression analysis was used for statistical analysis including subgroup analysis for trauma and acute coronary syndrome.p < 0.001, OR 0.68 [0.56–0.82]). Fentanyl was the most common administered analgesic in the trauma subgroup, but significantly less common used by surgeons . In acute coronary syndrome cases there was no significant difference in morphine administration between anaesthesiologists and surgeons .A total of 8238 patients were included in the analysis. There was a significant difference in the application frequency of analgesics between surgeons and anaesthesiologists especially for opioids  contains supplementary material, which is available to authorized users. Stabilization of vital functions and treatment of pain is essential in prehospital emergency medicine. Importantly, pain is the main indication for alerting the prehospital emergency medical service (EMS) in Germany . MoreoveIn Germany, the EMS is staffed with paramedics and supported by physicians working in any patient caring discipline, who have completed a postgraduate training and examination in prehospital medicine. If the rescue centre decides, based on severity, a physician is needed, or the paramedic on scene calls for reinforcement, the physician is dispatched. Administration of analgesics is allowed to physicians only by federal law and forbidden for paramedics and nurses.To work in prehospital care, physicians require a minimum clinical experience of 24 months in any patient caring department, including at least six months in anaesthesiology, intensive care medicine or an emergency department. In addition, treatment of 50 prehospital emergency patients under supervision of a responsible prehospital physician, and a preparation course of 80 h in prehospital emergency medicine is necessary . PhysiciAim of this study, therefore, is the exploration of differences in pain treatment between surgeons and anaesthesiologists in a physician staffed EMS service with a focus on the two most frequent subgroups with severe pain and opioid administration: chest pain and trauma , 11.After Ethics Committee approval , data were obtained from all prehospital emergency physician standardized forms of one dispatch location (fire department 10) in Munich, Germany between January 1st, 2014, to December 31st, 2016. The ethical committee waived the requirement for informed consent. This ground based EMS is a special equipped BMW X3  staffed with a paramedic from the Munich fire department who also serves as driver and a physician working at a university hospital  mainly of the specialities anaesthesiology or surgery. The BMW X3 is equipped with different analgesics according to Bavarian standards: acetaminophen, butylscopolamine, metamizole, acetylsalicylic acid, ketamine and the opioids fentanyl and morphine.Data was collected from standardized EMS forms  cases were defined with documentation of a suspected diagnosis of instable angina pectoris, ACS, non-ST segment elevation myocardial infarction (NSTEMI) and ST elevation myocardial infarction (STEMI).Primary outcome measures were selection of prehospital analgesics and administration frequency by anaesthesiologist or surgeon. Prehospital analgesics selection and frequency was chosen as a measurement for the difference in prehospital pain treatment between members of these two medical specialities.We further assessed documentation quality, that means documentation frequency of GCS, NRS, patient sex, age, heart rate and NACA severity score.Statistical analysis was done in the anonymized dataset. Results are expressed as median [Interquartile Range (IQR)] or frequencies with counts and percentages as appropriate. For statistical calculation we used logistic regression for binary outcomes and t-test or Mann-Whitney test as appropriate. For data points with adequate documentation frequency (> 90%) univariate analysis was performed. If significant, the variable was included in the multivariate analysis. Analyses were performed with IBM SPSS Premium Statistics for Windows v24.0 . All statistical tests were based on a 0.05 significance level and presented with 95% confidence intervals (CI). A subanalysis was performed for trauma and ACS cases.A total of 8882 protocols during January 1st 2014 and December 31st 2016 were evaluated and consequently 644 excluded due to false alerts, treatment by one specialist of internal medicine or missing documentation of the treating physician . Consequently, 8238 cases were included in the analysis, performed by anaesthesiologists and surgeons. Patient characteristics are presented in Table Most consistently documented was age (99%), sex (99%) and initial GCS , butylscopolamine (p = 0.88), acetaminophen (p = 0.25) and metamizole , the disease category (p < 0.001), the physician’s qualification (p = 0.004) and the physician’s sex (p < 0.001). In the subgroup of fentanyl administration, the difference remained significant  evidence- and consensus-based guideline on the treatment of patients with severe and multiple injuries published , includeFor ACS, however, distinct guidelines are available: According to the 2015 European Society of Cardiology (ESC) guidelines for NSTEMI patients, morphine administration is reasonable for patients with persisting severe chest pain if the ischaemic symptoms do not relieve by nitrates and beta-blockers . This miPain treatment and sedation is an inherent part of speciality trainings in anaesthesiology as well as in surgery . While ap < 0.001, see Additional file While surgeons and anaesthesiologists built a team in operating theatre and use their different abilities synergistically, they are alone in the emergency field, that leads to different views depending on their speciality. Mechanical skills like splinting and positioning of fractures might be a common attempt of pain treatment by surgeons, maybe more common compared to anaesthesiologists. This could explain the difference in the use of fentanyl was highly significant  Sattler et al.  suggesteIn our comparison, the physicians’ speciality influenced the frequency of pain treatment with opioids significantly. A study about prehospital care differences between male and female trauma patients in Stockholm showed, that nearly one third of these patients received analgesics . In thisFrequency of pain assessment in our trauma cases Additional file 2:Standardized Bavarian EMS form for physicians DIVI version 5.0. (PDF 626 kb)Additional file 3:Standardized Bavarian EMS form for physicians DIVI version 5.1. (PDF 940 kb)Additional file 4:Table Univariate analysis of pain medication use. Presented as no. (%), ACS, acute coronary syndrome; Opioids  and non-opioid pain medication ; n/a, not applicable. (PDF 44 kb)Additional file 5:p < 0.05 in univariate analysis; n/a, not applicable; −, not significant in univariate analysis; ORadj, adjusted Odds-Ratio in multivariate analysis; CI, Confidence Interval; yrs., years; GCS, Glasgow Coma Scale; ACS, acute coronary syndrome. (PDF 39 kb)Table Multivariate analysis of Fentanyl use. Factors included in the multivariate analysis if Additional file 6:p < 0.05 in univariate analysis; n/a, not applicable; −, not significant in univariate analysis, ORadj adjusted Odds-Ratio in multivariate analysis, CI Confidence Interval, yrs. years, GCS Glasgow Coma Scale, ACS acute coronary syndrome. (PDF 38 kb)Table Multivariate analysis of Morphine use. Factors included in the multivariate analysis if


Purpose: The aims of this prospective study were to determine the prevalence of pain 6 months after arthroscopic subacromial decompression (ASD) and/or acromioclavicular joint resection (AC resection), to reveal causes of the pain, and to identify risk factors for persistent pain.Methods: Preoperatively, patients were tested for their endogenous capacity to modulate pain and completed questionnaires concerning psychological vulnerability. Patients with pain 6 months after surgery were examined by an experienced orthopaedic surgeon to reveal any shoulder pathology responsible for the pain.Results: Data from 101 patients were available for analysis 6 months after surgery. Thirty-six patients had persistent pain: 32 underwent examination by the surgeon who identified shoulder pathology in ten patients, but not in the remaining 22 in whom ongoing insurance case, unemployment, and a general tendency to worry were risk factors for persistent pain.Conclusion: The prevalence of persistent pain 6 months after ASD and/or AC resection was 35.6% (95% CI 26.1–45.8%) and the proportion of patients with shoulder pathology was 9.9%. An association between ongoing insurance case, unemployment, general tendency to worry (t-STAI), and unexplained persistent pain 6 months after surgery was found. Shoulder pain is one of the most common musculoskeletal complaints and leads to an increasing rate of outpatient arthroscopic shoulder surgery such as arthroscopic subacromial decompression (ASD) and acromioclavicular joint resection (AC resection) . High suTherefore, these high failure rates stress the importance of identifying preoperative risk factors for a poor outcome and persistent pain. Several preoperative risk factors for persistent pain have previously been identified in other types of surgery, including a decreased capacity of endogenous pain modulation  and psycClinicalTrials.gov (NCT02924519).A prospective observational study with a 6-month follow-up was conducted. Based on the preoperative diagnosis and after obtaining signed informed consent, 150 patients scheduled for outpatient arthroscopic shoulder surgery (ASD and/or AC resection) were enrolled at the Day Surgery Unit at Horsens Regional Hospital. Primary exclusion criteria included age <18 years of age, shoulder surgery within the last year, Raynaud’s phenomenon, psychiatric illness, or inability to communicate in our language. Secondary exclusion criteria included more extensive surgery than planned, e.g., intraoperative rotator cuff repair, biceps tenodesis or labral repair, since a longer recovery period would be expected for these patients. The study was approved by the Data Protection Agency (1-16-02-213-14), the Committees in Health Research Ethics (1-10-72-103-14), and registered at Oral postoperative analgesic treatment was started before discharge from the post-anaesthesia care unit at the Day Surgery Unit and consisted of acetaminophen 1 g orally every 6 h up to 4 g daily, ibuprofen 400 mg orally three times daily. If ibuprofen was contraindicated, it was replaced by tramadol 50 mg orally four times daily. As rescue medication, patients were instructed in taking morphine 10 mg orally with a maximum of 60 mg per day. If morphine was contraindicated, it was replaced by 5 mg oxynorm with a maximum of 30 mg per day.Postoperatively, patients were provided with written instructions about postoperative exercises including passive exercises and active exercises for the rotator cuff. Patients were told to follow the exercise programme to the best of their ability: use the arm freely and perform the exercises until pain threshold. The postoperative rehabilitation exercises in the first 3 months were self-monitored and patients were offered an examination with the physiotherapist 3 months after surgery.We chose to define pain as being persistent postoperative pain if the following criteria were met: (1) pain 6 months after surgery, (2) average pain intensity within the last 2 weeks ≥ 3 on a numerical rating scale , and (3) confirmed impact of pain on the patient’s daily living (no/yes).Patients, who fulfilled the criteria for persistent pain, were offered a thorough clinical examination by an experienced shoulder surgeon supplemented by diagnostic imaging, if relevant. The pain was classified as “unexplained persistent pain” if no shoulder pathology was responsible for the pain.Preoperatively, on the day of surgery, a conditioned pain modulation test was performed to examine the endogenous pain modulation capacity of the patient. An efficient endogenous pain modulation capacity is important in order to cope with e.g., postoperative pain. The test is known as a “pain inhibits pain” paradigm and is typically assessed by recordings of pain elicited by a painful (test) stimulus before and during the application of another (conditioning) painful stimulus  . Thus, aIn this study, pressure pain was used as test stimulus  and cold water immersion as conditioning stimulus (using a box containing ice water at 2 °C). In brief, pain elicited by 1.5 × pressure pain threshold was assessed before and during submersion of the contralateral hand into cold water. The pressure algometer was applied at two sites; one on the central part of supraspinatus muscle of the affected shoulder and one 10 cm proximal to patella on the central part of quadriceps muscle on the contralateral side. The test was performed by one of the authors, or in a few cases by a trained project nurse. The duration of the test was approximately 15 min with a maximum of 2 min in the cold water.All patients completed six paper questionnaires before surgery. One questionnaire was developed by the authors for the purpose of this study and contained questions about shoulder pain [intensity was recorded on a Numeric Rating Scale ], pain elsewhere (no/yes), and baseline characteristics .The remaining five questionnaires were all validated in Danish and included two patient-reported outcome measures, i.e., the Western Ontario Rotator Cuff Index (WORC)  and the Six months after surgery, patients received a postal questionnaire regarding shoulder pain. Patients with persistent pain 6 months after surgery were offered a thorough musculoskeletal examination. Prior to the examination, patients underwent anterior-posterior, outlet view, and AC joint X-ray examination of the affected shoulder. This was done to exclude major pathology such as insufficient bone resection of the acromial spur or AC joint, glenohumeral osteoarthritis, calcifications or other degenerative changes. Next, the affected shoulder was examined to reveal potential sources of pain , and the elbow and neck were examined with focus on potential sources of referred pain. Patients were referred to diagnostic imaging including MRI, CT and local block test if considered relevant by the surgeon: intraarticular block test (if a frozen shoulder was suspected), and subacromial block test .Data were entered into Excel and exported to Stata software version 15.0 , in which statistical analyses were performed.p-values were two-tailed and those below 0.05 were considered significant.A sample size of 140 patients was required to detect an expected prevalence of unexplained persistent pain of 10% . We chose to enrol 150 patients to allow for drop-outs. Results were presented as either mean ± standard deviation (parametric data) or as frequencies or medians with interquartile range (IQR) (non-parametric) as appropriate. All Risk factors for unexplained pain were identified using multivariable logistic regression models. All independent risk factors were assessed in univariable logistic models to estimate odds ratio (OR) with a significance level <5% including the following variables: age, gender, BMI, level of education, ongoing insurance case, employment, pain elsewhere, type of surgery, pain intensity in the shoulder, the conditioned pain modulation test response, WORC score, SANE score, the PCS, HADS and STAI.A total of 240 patients were assessed for eligibility from October 2014 to June 2016. One-hundred-and-fifty patients agreed to participate and were enrolled in the study, 31 patients had to be excluded after surgery due to more extensive surgery than planned. In all, 119 participants were eligible and consenting. Forty-three patients underwent ASD, 20 patients underwent AC resection, and 56 patients underwent ASD with AC resection. All surgical procedures were performed by the same four experienced surgeons with specialty training in shoulder surgery. Eighteen patients did not respond to the 6-month questionnaire, leaving data from 101 patients available for analysis . Baselinn = 4), frozen shoulder (n = 1), calcifying tendinitis (n = 1), cervical intervertebral disc protrusion (n = 1), AC joint arthritis (n = 1), os acromiale (n = 1), and multidirectional shoulder instability (n = 1). The distribution of the ten patients with an explained reason for the pain was as follows: ASD (n = 4), AC resection (n = 3), and ASD with AC resection (n = 3). The ten patients with shoulder pathology and the four patients who declined having an examination were excluded from further analysis, leaving 22 patients  with unexplained persistent pain. The 22 patients with unexplained persistent pain had undergone ASD (n = 8), AC resection (n = 7), and ASD with AC resection (n = 7).Three months after surgery 73 out of 101 patients (72.3%) accepted the examination with the physiotherapist and 6 months after surgery 36 out of 101 patients  had persistent pain; 65 patients (64.4%) had no pain . The 36 n = 19; 29.2% vs. n = 4; 18.2%; p = 0.26 (shoulder) and n = 4; 6.2% vs. n = 3; 13.6%; p = 0.36 (thigh), respectively.The conditioned pain modulation was tested in 95 out of 101 patients. The number of patients with an inefficient endogenous pain inhibition was similar in patients with no persistent pain and unexplained persistent pain; Out of several potential preoperative risk factors including age, gender, BMI, level of education, ongoing insurance case, employment, pain elsewhere, pain intensity in the shoulder, WORC score, SANE score, the PCS, HADS, STAI, and the conditioned pain modulation test response, the univariable analysis  showed aIn this study, we found that 35.6% (95% CI 26.4–45.8%) of patients still report pain 6 months after surgery. Thus, our findings are in accordance with the results from a retrospective study including 108 patients in which as many as 31 patients (29%) had >3 on a visual analogue scale score 6 months after ASD surgery . Other sAt follow-up examination, we identified shoulder pathology responsible for the pain in ten patients (9.9%). The examination revealed many causes of persistent pain, which remind us of more careful preoperative diagnostics and the necessity of follow-up after surgery, targeted those with persistent pain, to uncover remaining pathology. The clinical examination is a strength of our study compared to the studies relying on follow-up by patient reports alone. To optimize the use of healthcare resources this could be done by screening patients using a questionnaire survey 6 months after surgery.Only a few other studies have examined patients after ASD and/or AC resection. In an ASD study including 114 patients, 25% reported that the outcome was unsatisfactory 19 months (12–40 months) after surgery and they were offered a follow-up examination in which the authors were able to identify a medical reason for the failure in 19 patients (16.7%) . HoweverWe evaluated several potential independent risk factors of unexplained persistent postoperative pain including a preoperative decreased capacity of endogenous pain modulation and psychological vulnerability. We were unable to demonstrate that patients with unexplained persistent pain had a less inefficient endogenous pain modulation capacity than patients without persistent pain , 25. ThiWe found an association between ongoing insurance case, unemployment, and general tendency to worry (t-STAI) with unexplained persistent pain 6 months after surgery. Previous studies have shown that patients with workers’ compensation have lower shoulder-specific measures  and general health measures before and after surgery and have worse outcomes , 27, 28.We expected to find an association between psychological vulnerability parameters  and unexplained persistent pain, however, except for the association between unexplained persistent pain and high t-STAI score, present results found no associations between unexplained persistent pain and psychological vulnerability parameters. These findings are in contrast with a retrospective ASD study where an association between persistent pain and depression was found . A prospThe study has a few shortcomings. Firstly, the sample size was not reached after 6 months; this reduced power in the regression, but the estimate of prevalence still had a reasonable confidence interval. Secondly, a longer follow-up period would have provided additional information, since studies have suggested that patients undergoing orthopaedic surgery, in particular shoulder surgery, have longer convalescence compared to patients undergoing e.g., abdominal and gynaecological surgical procedures . HoweverIn conclusion, the prevalence of persistent pain 6 months after ASD and/or AC resection was 35.6% (95% CI 26.1–45.8%) and the proportion of patients with shoulder pathology was 9.9%.Furthermore, an association between ongoing insurance case, unemployment, general tendency to worry (t-STAI), and unexplained persistent pain 6 months after surgery was found. However, the present study was unable to demonstrate that patients with unexplained persistent pain had a more inefficient endogenous pain modulation capacity than patients without persistent pain.


To compare global surgical pain under nerve block and mandibular infiltration anesthesia techniques, and to evaluate pain during drilling and the distance to the mandibular canal in posterior mandible implant surgeries.A prospective, randomized, controlled, double-blind, clinical trial was conducted to compare nerve block (Group A) to mandibular infiltration (Group B) techniques for dental implant placement. Global surgical pain , pain during drilling or implant placement (MPQ = McGill pain questionnaire) and distance to the mandibular canal (Image J) were statically analyzed. Age, gender, anxiety levels, tooth to be replaced, implant size, adjacent teeth and duration of surgery were also analyzed.p<0.05). In Group A, 99% of the surgeries were performed painlessly during drilling and implant placement, but in Group B, 11.6% of implant placements (17 implants) felt pain during these surgical steps. Mean distance to mandibular canal  in those 17 implants placed under mandibular infiltration was clinically and statistically similar to the mean distance  of 130 implants placed painless (p=0.10). Pain during drilling under mandibular infiltration was significantly associated with the duration of surgery (p<0.05) and to both adjacent teeth being present (p<0.05).172 patients were included and 283 dental implants were analyzed. VAS values were significantly higher in Group B (Although both techniques are safe and effective for placing implants in the posterior mandible, nerve block provides a more profound analgesia than mandibular infiltration. When placing implants under mandibular infiltration, as getting closer to the canal does not increase the feeling of pain, it is not recommended to use the presence of pain as a preventive resource to avoid inferior alveolar nerve injuries. Key words:Dental implant, mandibular infiltration anesthesia, nerve block, pain, nerve injury. Peripheral sensory nerves are essential in enabling people to interact with the environment because they provide sensations of touch, pressure, temperature change and pain . SpeakinInferior alveolar nerve (IAN) and lingual nerve (LN) injuries could occur in surgeries such as wisdom teeth extractions, orthognathic procedures and dental implant placements. They could also occur during the application of routine nerve block anesthesia or during endodontic treatment -7. PatieThe mandibular infiltration anesthesia technique has been proposed as an alternative to the IAN block for placing dental implants in the posterior mandible ,10. SomeIn contrast, another study observed that in edentulous mandibles the IAN is found as a single trunk in only 3.6% of the cases, being much more likely to present a different kind of plexus . It may The aims of this RCT were:-To compare global surgical pain in dental implant surgeries performed under nerve block and mandibular infiltration.-To evaluate the association between pain during drilling or implant placement and distance to the MC in dental implant surgeries performed under nerve block and mandibular infiltration.* Study Population This was a prospective, randomized, double-blind (patient and operator), parallel group comparison clinical trial, conducted at the Department of Oral Surgery I of the School of Dentistry of the University of Buenos Aires (Argentina), from January 2013 to December 2016, on patients requiring implant-prosthetic rehabilitation in the posterior mandible.Anesthesia techniques for surgeries were previously randomized using random numbers function in software  and kept inside envelopes numbered according to the order in which patients presented for surgery. The patients and evaluators were blinded to the group assignments. Group A patients received implants under nerve block technique, and Group B patients received implants under mandibular infiltration technique.This research was performed following the recommendations of the Consort Statement for reporting RCTs and the ethical principles of the Helsinki Declaration regarding research on humans. Accordingly, all patients provided written informed consent prior to surgery in order to take part in the trial. The study design was approved by the Ethical Committee of the University of Buenos Aires (Research Ethics Committee No. 53-2013). This study did not receive industrial funding.* Selection Criteria Inclusion criteria for this study were.- Age > 18 years.- Dental implant placement for inferior first and second molars, and inferior first and second premolars.- Single or multiple dental implant surgeries.- Healed alveolar ridges.- Signature of informed consent form.Exclusion criteria were: - Immediate dental implant placement.- Dental implant placements including any bone grafting procedures.- Medical conditions contraindicating implant surgery.- Patient unable to receive any standard medications.- Administration within 48 hs. of any analgesic or sedation drug.- Patients able to identify the anesthesia technique administrated (e.g. dentists).Implant surgeries were excluded from analysis if:- There were two consecutive failed anesthesia applications, - Surgery lasted more than 90 minutes.* Surgical Procedure All patients were specifically informed that the main objective was to provide painless surgery, and that if they felt pain, immediate anesthesia reinforcement would be provided. Clinical examination, evaluation of local and systemic factors, panoramic radiograph and CT scan were used to plan surgery. Patients received 500mg amoxicillin  or 500mg azithromycin  1 hour before surgery . AnestheIAN block (Group A) was performed using the conventional Halstead approach with a 27-G long needle by touching the bone and retrieving the needle for the IAN and another withdrawal for the LN providing 1.8ml of anesthetic solution . After bMandibular infiltration technique (Group B) was done using a 27-G long needle to place 1.8ml in the buccal vestibule and another 0.9ml in the lingual vestibule, and finally 0.3ml under the lingual periosteum to help to raise the flap . For eacIf anesthesia was not achieved after two approaches, the patient received intervention but was excluded from analysis. After anesthesia was confirmed, the operator entered the room and began the surgery. All surgical interventions consisted of raising a muco-periosteal flap, drilling with copious cooling at 800 - 1200 rpm, manual and instrumental implant placement , and primary closure of the wound . When su* Data CompilationAll information was recorded on the day of the surgery. No drop-out was recorded. A previously established standard protocol was used to compile the following data for all patients: age, sex, teeth to be replaced, implant length and diameter, adjacent mesial and distal teeth (present or absence), duration of surgery.The following data and clinical parameters were registered.• Previous anxiety scale: before surgery, the Modified Dental Anxiety Scale (MDAS) was provided. It consists of 5 questions about anxiety level regarding normal dental treatment situations (score 5 to 25) .• Global surgical pain : All patients were asked to report global surgical pain experienced throughout surgery on the visual analogue scale (VAS), which consists of a 10 cm line to evaluate the amount of pain, ranging from 0 (no pain whatsoever) to 10 (worst pain imaginable) .• Pain during drilling or implant placement: if patient referred pain during these surgical steps, the Mc Gill Pain Questionnaire – Spanish Version (MPQ-SV) was completed . If the • Distance from the bottom of the implant to the internal roof of the MC was evaluated on intraoral radiographs performed using paralleling technique immediately after the surgery concluded. Radiographs were scanned, digitized in JPG format with 300-dpi resolution, and stored in a personal computer. The distance was measured using Image J 1.42 software  . Measure* Statistical Analysis Descriptive statistics of numerical variables included arithmetic mean, median, standard deviation (SD), minimum and maximum (range). Between-group comparisons were done by Wilcoxon rank-sum test. Correlation among MDAS and VAS was explored using the Spearman correlation coefficient. Non-parametric tests were performed because the data did not follow normal distribution as suggested by the Shapiro-Wilk test. Association between categorical variables was examined using Pearson Chi-square or Fisher exact test when there were expected frequencies under 5. The statistical analysis was performed with the software package Infostat version 2015. The level of significance was set at 0.05.* Patient populationOne hundred and seventy two consecutive patients were included in this study . Mean age was 50 (SD 11) years. No patient withdrawal was recorded. Two patients in group A (IAN block group) received intervention but were excluded from analysis – one because complete anesthesia of IAN and LN was not achieved after two nerve blocks, and another because surgery lasted 105 minutes. One hundred and thirty-six (136) implants were placed in Group A (Nerve Block) and 147 in Group B (Mandibular Infiltration) Fig. .Sixty-six percent of the implants were 10mm long, and only 1.4% was longer than 12mm . No impl* Clinical DataGLOBAL SURGICAL PAIN (VAS)p<0,05). The means were 0.4 (SD 0.8) (range = 0.0 to 4.0) and 0.7 (SD 1.1) (range = 0.0 to 5.0), respectively  values were significantly lower in the group receiving nerve block (Group A) than in the group receiving mandibular infiltration (Group B) (ectively .p=0.39), or in group A (p=0.10) or group B (p=0.72).The correlation between VAS values and anxiety levels (MDAS) was not statistically significant in the entire population (p=0.09) or group B (p=0.22).Comparison of VAS values between operators skills (residents and professors) showed no statistically significant difference for group A (p=0.67) or gender (p=0.24), or tooth to be replaced (p=0.63), in the whole population.No correlation was found between VAS values and age (PAIN DURING DRILLING OR IMPLANT PLACEMENT (MPQ-SV)Group A (Nerve Block)In group A, only one implant placement referred pain during drilling or implant placement. In this patient, the implant was placed at 4mm from the MC, MDAS was 21, duration of surgery was 65 min, MPQ-SV score was 10, and VAS was 4. All other 135 implants were placed in absence of pain during drilling and implant placement. Mean distance to MC was 3.00 (range: 0.0 to 8.5) .Group B (Mandibular Infiltration)p=0.10) (p<0.05).In group B, 17 implant patients referred pain during drilling or implant placement, while 130 implants were placed in absence of pain during these steps. In the cases that referred pain, mean MPQ-SV was 11 (SD 4) and mean distance to MC was 3.8 (range: 0.0 to 7.0). Mean distance to MC in the group without pain was 3.0 (range: 0.0 to 9.0). No significant difference was observed between the two groups (p=0.10) . Comparip = 0.39) between pain during drilling or implant placement and the tooth to be replaced under mandibular infiltration.No significant association was found (p<0.05). Pain was more frequent when both adjacent teeth were present (30%), than when only one tooth or no tooth was present .Statistical association was found between the number of adjacent teeth and pain during drilling or implant placement under mandibular infiltration (p<0.05). This finding enabled a logistic model to be developed ). Out of 17 pain situations, 10 occurred only during drilling, 5 occurred only during implant placement, and 2 occurred during both steps. MPQ-SV mean (ranges) were 10 (6 to 16), 11 (6 to 16) and 18.5 (18 to 19), respectively.p=0.76).The overall tendency of fewer cases of painful than painless surgeries during drilling or implant placement continued after a cutoff of the sample at the traditionally proposed safety zone (2mm) during the mandibular infiltration technique. Only 3 out of 33 surgeries in which implants were placed closer than 2mm to the MC referred pain during these steps. No significant association was found between distance to MC (<2mm or ≥2mm) and presence of pain  in the nerve block group and 0.7 (SD 1.1) in the mandibular infiltration group. These results are similar to the mean VAS values reported in other studies of posterior mandible implant surgeries: 1.03 (SD 0.83) , 1 SD 2 and 0.42As has been reported in other studies on dental implants, previous anxiety level , gender p=0.10). Also, when working closer than 2mm to the MC , there were fewer painful than painless surgeries, with only 3 (9%) out of 33 implant placements feeling pain.The possibility of feeling pain during drilling or implant placement steps under nerve block is practically zero, and the possibility of it happening under mandibular infiltration is approximately one in ten implants placed. Pain experienced was variously reported as acute, short-termed, ceasing when stimulus ceased, low intensity, weak and bearable; and easily resolved by applying more anesthesia (MPQ-SV = 11 SD 4). Comparison of pain experiences under mandibular infiltration during these surgical steps (n=17) to painless surgeries (n=130) shows no statistical association with distance from the MC. Mean distance in the pain group was 3.8 (SD 2.2), and mean distance in the painless group was 3.00 (SD 1.8) (The reasons for pain during drilling under mandibular infiltration technique may be the distribution of the IAN in edentulous mandibles, the presence of both adjacent teeth, and the duration of the surgery.In a cadaveric study on edentulous mandibles, IAN arrangement was found as a plexus inside the mandible in 96.3% of the sample, and as a single trunk in only 3.7% . When teTeeth adjacent to dental implant surgeries may contribute to presence of pain during these steps under mandibular infiltration. In this study, pain was significantly higher when both adjacent teeth were present than in surgeries performed next to only one or no adjacent tooth. This may be due to the mechanical stimulation of nerve endings of the periodontal ligament, which has not been reported previously.Longer surgeries have been found to be significantly associated with intra-surgical pain in dental extractions . In the In this clinical trial, posterior mandibular bone was stimulated without working near the MC under mandibular infiltration anesthesia, as has been suggested by other authors ,14,15,30As global pain VAS values for mandibular infiltration technique were statistically higher than those for nerve block, and pain during drilling or implant placement under infiltration was significantly associated to longer surgical times, it is recommended to apply the nerve block technique when surgery is expected to be prolonged.Pain should not be considered as a warning symptom to prevent nerve injuries in posterior mandible implant surgeries; since the proximity to the mandibular canal does not increase pain levels under mandibular infiltration technique.


TEA  is considered a basic method of analgesia used in thoracic surgeries. PVB  is an alternative method. The thesis compares effectiveness of both methods in postoperative analgesia with particular focus on assessment of the postoperative pain management quality.The study involved 2 groups of patients, each consisting of 30 patients undergoing posterolateral thoracotomy. The study group involved patients anesthetized applying PVB method, while the control group involved patients anesthetized with TEA. Hemodynamic and respiratory parameters as well as severity of pain assessed using NRS  during the first 3 days after the surgery, number of days of hospitalization, and the need to use additional pain relievers were taken into account in both groups. Evaluation of postoperative pain management quality was performed applying Clinical Quality Indicators in Postoperative Pain Management.p = 0.019).No statistical significance was demonstrated between the groups in respect of hemodynamic and respiratory parameters values, the need to use additional pain relievers and the number of days of hospitalization. There was no statistically significant difference between the groups in respect of general assessment of pain management quality, except for the assessment of the lowest level of pain within the last 24 h of measurement. This result in TEA group was statistically significantly lower than the one in PVB group (In the assessment of postoperative pain management quality both analyzed methods are statistically significantly different only in the category of “lowest level of pain within the last 24 hours of measurement”, to the benefit of TEA group. No statistically significant difference has been observed between the two study groups with respect to the remaining parameters.KB-0012/71/15. Date of registration 22 June 2015. Thoracotomy is a type of a surgery that involves one of the most perceptible pains during the postoperative period . Pain afDue to the fact that during posterolateral thoracotomy numerous layers of the chest wall are being cut and dissected, and the dissection takes place within the lung itself and its components , there are many sources and mechanisms of the post-thoracotomy pain. This not only results from nociceptive mechanisms, but also involves neuropathic component resulting from minor or larger damage to intercostal nerves or other nerves during the surgery. Pulling of visceral or vagus nerves as well as the presence of drain in the pleural cavity after the operative procedure also cause the sensation of pain . MethodsThoracic epidural analgesia (TEA) is commonly used. The use of the thoracic epidural analgesia in the case of thoracic surgical procedures reduces the stress response to a surgical injury; it favorably affects systemic homeostasis in respect of hormonal response, functions of the immune, coagulation and alimentary system. Epidural analgesia may be accompanied by adverse reactions such as hypotonia, urine retention, respiratory muscles weakness. Other possible complications include epidural abscess, hematoma in the epidural area. In extreme cases, it may result in paraplegia due to damage to the spinal cord, what is observed extremely rarely (below 0.02%) , 3, 5. TThere are quite numerous contraindications to TEA, such as clotting disturbances caused by intake of anticoagulant medications . If a patient is treated with Low Molecular Weight Heparin, epidural block may be performed after 12 hours of heparin administration. According to some authors, TEA is ineffective in more than 12% of patients, in particular in the case of difficult anatomic conditions .Paravertebral block (PVB) within the chest area is considered an alternative method to TEA, among others, in the case of contraindications to TEA. PVB enables analgesia of the chest only on the side being operated, and the analgesia involves only the area of surgical wound and additionally few segments above and few below the wound, depending on the volume of the regional analgesic agent injected , 10.To reach higher precision, ultrasonography control or nerves stimulation are more often used while applying the paravertebral block , 11. TheOther methods of regional analgesia, such as intercostal block or intrapleural administration of pain relievers are also applied .Although PVB was belived as effective on pain relief as TEA, there are limited evidence on postoperative analgesia for posterolateral thoracotomy. In this study, we goaled to compare the effectiveness between TEA and PVB by measuring numeric pain rating scale (NRS) and clinical quality index (CQI) during the first 3 postoperative days.Comparison of the effectiveness of PVB and TEA in treatment of postoperative pain in patients undergoing posterolateral thoracotomy.Assessment of postoperative pain management quality based on Clinical Quality Indicators in Postoperative Pain Management in patients who underwent posterolateral thoracotomy and were treated with PVB or TEA.Primary purposes of the study involved:Informed consent to participate in the study was obtained from each patient. Patients were provided with detailed description of benefits, side effects and complications related to both types of analgesia. Ethics Committee of the Pomeranian Medical University in Szczecin approved the study conduct (KB-0012/71/15).All surgeries were performed applying 10-12 cm long thoracotomy without the use of VATS at one Department of Thoracic Surgery, as consecutive cases. Operations in both groups had similar scope - from tumor resection through segmentectomy, lobectomy through pneumonectomy.The study involved two groups of patients, each consisting of 30 patients of both sexes, above 18 years of age. Patients were randomized to particular groups (simple randomization). Patients from both groups had no contraindications to application of any of the postoperative analgesia methods.Group 1 involves patients who had PVB, while group 2 involves patients who were treated with TEAPVB was performed in the case of patients premedicated with 7.5 mg oral midazolam. It was performed in sitting position, according to slightly modified technique provided for by Cousin and Bridenbaugh . EpiduraThe second group involved patients who, prior to the posterolateral thoracotomy, were given epidural analgesia performed in the sitting position applying the “hanging drop” technique at the level of Th5/Th6 in the medial body line. Upon identification of the epidural area, an epidural catheter was inserted through Tuohy needle about 4 to 5 cm into the epidural space. Thereafter, test dose of 2 ml of 1% lidocaine was injected to exclude spinal anesthesia. Then from 6 to 8 ml of 0.5% bupivacaini with 0.05 mg of fentanyl was injected. Analgesia induction (in the case of both groups of patients) involved intravenous injection of propofol at the dose of 2 mg per kilogram of the body weight, fentanyl 0.1 mg, cisatracurium at the dose of 0.15 mg per kilogram of the body weight. Patients were intubated with two-channel tube. Analgesia was maintained with respiratory mixture of sevoflurane, nitrous oxide and oxygen in commonly used concentrations. Upon completion of the procedure, patients were additionally given 6-8 ml of 0.5 % bupivacaini to epidural catheter. After being transferred to the Department of Thoracic Surgery the patients were given continuous infusion of 0.125% bupivacaini in the volume of 0.1 ml per kilogram of the body weight (6-8 ml per hour) and fentanyl at the dose of 2 micrograms per ml for 72 hours.All patients were administered nasal oxygen with the flow of 3 liters per minute, for 24 hours. Patients were provided with continuous monitoring of vital signs: saturation (SpO2), systolic and diastolic blood pressure, pulse, number of breaths, consciousness.Patients from each of the groups underwent posterolateral thoracotomy and resection of pulmonary parenchyma mainly due to lung tumor, but also due to the presence of emphysematous bulla, diagnosed based on the typical diagnostic methods, the same for both groups.Patients qualified to the study were randomized to particular groups (simple randomization).Exclusion criteria included: failure to obtain the patient’s consent, clotting disturbances making it impossible to perform regional analgesia, infection in the area of planned catheter insertion, significant spinal column deformation, difficulties with proper pain severity assessment and T4-infiltrating tumors with continuous pain.The study was performed in each of the groups according to the same schedule. Measurements had been performed for first three days after the procedure.Each group had evaluations of SpO2 every 4 hours, arterial blood pressure and pulse every 4 hours, assessment of pain (NRS) every 4 hours, anesthetized area every 4 hours, the use of additional pain relievers, Clinical Quality Indicators in Postoperative Pain Management.Values regarding current pain in NRS scale (0-10 pints), the highest level of pain within the last 24 hours (0-10 pints), the lowest level of pain within the last 24 hours (0-10 pints) were marked on the linear scale in the same intervals in the scale of 0-10 points. Satisfaction with the manner of postoperative pain management was assessed using the scale of 1-10 points.Clinical Quality Indicators in Postoperative Pain Management scale was used to assess satisfaction with postoperative pain relieving treatment and quality of the postoperative pain management.Clinical Quality Indicators in Postoperative Pain Management scale allows to assess satisfaction with postoperative pain relieving treatment and quality of the postoperative pain management, however Visual Analog Scale (VAS) and Numeric Pain Rating Scale (NRS) are the simplest and most often used to assess pain. Clinical Quality Indicators in Postoperative Pain Management, a scale developed by Swedish author, Eva Idvall, enables assessment of many various aspects of postoperative pain management quality . This scAnesthetized area, i.e. extent of the sensory blockade, was determined based on the number of anesthetized spinal segments according to the anatomic scheme.Collected data was subject to statistical analysis performed with the use of SPSS package .T-test for dependent groups and Mann-Whitney U test were used in statistical analysis. Statistical calculations were performed applying the statistical significance of 0.05.p = 0.74 and p = 0.58, respectively.The studied groups have not demonstrated statistically significant difference in terms of age and sex - In the first group indication for surgery constituted: in the case of 14 patients – primary lung cancer, in the case of 4 patients – metastatic tumors, in the case of 3 patients – pleural mesothelioma, while in the case of 9 persons non-neoplastic diseases, such as recurrent spontaneous pneumothorax, benign tumors, pulmonary tuberculosis. In the second group primary lung cancer constituted indication for thoracotomy in the case of 11 persons, metastatic tumors in 4 patients, mediastinal tumors in 2 patients, while non-neoplastic diseases in 13 persons.In the first group 11 lobectomies, 2 bilobectomies, 1 pneumonectomy, 2 segmentectomies, 7 tumor resections and 6 other surgeries  were performed.In the second group 7 lobectomies, 6 segmentectomies, 11 tumor resections and 6 other surgeries, such as decortication, explorative thoracotomy were performed. Range of mesothelioma operations were similar to the decortications or pleurectomy for non-neoplastic diseases.Results of hemodynamic parameters measurements in the study group presents Table Tables Table There were additional pain relievers  with basic analgesia method (PVB or TEA), while in the case of some patients combination of these drugs was used Table .Table 7UMorphine and other pain relievers, such as paracetamol or ketoprofen were used more often in PVB group, while metamizole was more often used in TEA group; however, there was no statistical difference in terms of the use of additional pain relievers between the groups.p = 0.32). Leaking of regional analgesia medications outside the epidural catheter, catheter coming out from the paravertebral area, fever, retention of secretion in the respiratory tract, respiratory failure have been observed in PVB group. In the TEA group complications included, among others, retention of secretion in the respiratory tract, paroxysmal atrial fibrillation.Complications were observed in 11 persons (18.3%). In 4 persons (13.3%) from the PVB group, and in 7 persons (23.3%) from the TEA group. The difference between the groups was not statistically significant .On the first day NRS value for both groups altogether was 4.13 with standard deviation of 1.28; on the second day 3.08 with standard deviation of 1.08, and on the third day 2.46 with standard deviation of 1.15. For both groups altogether, NRS values on the first day compared to the values obtained on the second day and values obtained on the first day compared to the values obtained on the third day, as well as values obtained on the second day compared to the values obtained on the third day were statistically significantly lower .No statistically significant differences in assessment of particular statements in both groups have been observed, except for the assessment of the lowest level pain within the last 24 h , where saturation in PVB group was significantly higher in the follow-up period exceeding 48 hours than in the case of TEA group [Additional pain relievers were used in both study groups. Morphine, metamizole and other pain relievers, mainly acetaminofen or ketoprofen, were used in the same administration.p = 0.26) [In the case of PVB group morphine was twice as likely often and medicines from other groups were slightly less often used compared to TEA group, while metamizole was more often used in TEA group compared to PVB group. No statistically significant differences have been observed between the groups in terms of the need to use additional pain relievers; however, patients from PVB group needed them a bit more often. Authors from India have similar observations - their study showed no statistically significant difference in terms of use of Morphine  between PVB and TEA groups . In the  = 0.26) . In the  = 0.26) .In our own studies complications were more often observed in TEA group than in PVB group. In PVB group complications were observed in 4 persons, i.e. in 13.3% of the group, while in TEA group complications were observed in 7 persons, i.e. in 23.3%; however the difference in respect of frequency of complications between the study groups was not statistically significant. Complications in PVB group were more often related to catheter and included, among others, leaking of drug outside the catheter or catheter coming out, rather than general complications .In TEA group there were no complications such as hematoma or epidural empyema or damage to nerves. Partial spinal anesthesia with symptoms of paraplegia involving all body segments from Th4 downwards was observed in one patient from TEA group. Symptoms of spinal anesthesia resolved within four hours. Many authors, among others Davies et al. or Baidya et al., emphasize that PVB has in general less complications than TEA, what involves less complications such as decrease in arterial blood pressure, hypoxia, nausea and vomiting or postoperative respiratory failure or pneumonia , 10. JapIn the conducted studies we have observed comparable severity of pain in both groups. In the studies conducted by Szebla and Machała, who also used NRS to compare pain in PVB and TEA groups, NRS values in both groups were similar and the result was below 3 . Tsuboshp = 0.02). While, in the meta-analysis of Ding et al. there were no statistically significant differences in VAS values between PVB and TEA groups at 4-8 hours after the surgery (p = 0.19), 24 hours after the surgery (0.77) and 48 hours after the surgery (p = 0.19) [Majority of authors assessing postoperative pain uses VAS. In the study conducted by Richardson et al., for example, VAS value was statistically significantly lower in PVB group than in TEA group  = 0.19) , 9. , 9.p = In the study conducted by Japanese authors, there were no differences between PVB and TEA groups in terms of pain ailments assessed using VRS  .In the conducted studies it was assessed if the type of regional postoperative analgesia in chest surgeries affects the number of days of the patient’s stay at the hospital. Statistically significant difference in the number of days of hospitalization between PVB and TEA groups has not been observed.p = 0.008) of 1 day (6 days vs. 7 days) - time of hospitalization of patients treated with PVB was 1 day shorter and based on this observation they suggested that PVB can become an element of the so called fast track management in chest surgeries. However, this requires further research and improvement of PVB technique [However, Elsayed et al. observed statistically significant difference between the time of hospitalization of patients who were treated with PVB compared to TEA patients (echnique .p = 0.019). In the case of other criteria, PVB and TEA groups were not statistically significantly different. In the study conducted by Okajima et al., no statistically significant difference in respect of the general patient’s satisfaction with treatment  was observed between PVB and TEA group (p = 0.26) [Assessment of patients’ satisfaction with pain management was performed based on the Clinical Quality Indicators in Postoperative Pain Management scale, translated into Polish and adopted to local conditions , 14. Amo = 0.26) .PVB and TEA are not significantly different in terms of postoperative pain management and the need to use additional pain relievers.In the assessment of postoperative pain management quality, both analyzed methods are statistically significantly different in favor of TEA only in the category of “the lowest level of pain within the last 24 hours” of the Quality of Indicators in Postoperative Pain Management scale.No significant differences have been observed in respect of occurrence of complications between the two compared methods.TEA seems to be better in managing pain after thoracotomy on the basis of our results, however both methods are comparable.


The aim of this study was to compare the anesthetic efficacy of two volumes of articaine in conventional inferior alveolar nerve block (IANB) of mandibular molars with irreversible pulpitis, and in cases of anesthetic failure, its complementation with periodontal ligament injection (PDL).Ninety patients with irreversible pulpitis in mandibular molars received conventional IANB with 1.8 mL or 3.6 mL of 4% articaine with 1:100,000 epinephrine. In cases of IANB failure, the same volumes were administered in the PDL. Presence of pulpal anesthesia and absence/presence of pain during pulpectomy were evaluated by electric pulp stimulation and verbal analogue scale, respectively. Relative risks (RR) with corresponding 95% confidence intervals (95% CI) were calculated for each outcome.27% and 42% of the patients achieved pulpal anesthesia following IANB with 1.8 mL and 3.6 mL, respectively . Analgesia during pulpectomy was present in 64% and 73% of the patients, respectively, for 1.8 mL and 3.6 mL . In cases of IANB failure, 75% and 42% of the patients that received 1.8 mL and 3.6 mL of PDL injection, respectively, achieved pulpal anesthesia . During a new attempt at the pulpectomy procedure, analgesia was present in 69% and 75% of the patients, respectively, for 1.8 mL and 3.6 mL .Increasing the volume from 1.8 mL to 3.6 mL of the 4% articaine with 1:100,000 epinephrine in the IANB and in the PDL, did not significantly increase the success rate of pulpal anesthesia and clinical analgesia during the pulpectomy procedure. Therefore, both volumes presented a similar efficacy, though neither resulted in effective pain control during irreversible pulpitis treatment.NCT02422823.ClinicalTrials.gov  The conventional inferior alveolar nerve block (IANB) is the most commonly used technique for pulpal anesthesia in endodontic mandibular molar procedures –4. HowevSome authors have suggested that the use of 2 anesthetic cartridges in the IANB (3.6 mL) with 2% lidocaine with different concentrations of epinephrine in asymptomatic teeth , as wellRecently a systematic review concluded that increasing the volume of anesthetic agent from 1.8 to 3.6 mL significantly increased the success rate of IANB in mandibular molars with irreversible pulpitis . HoweverThe primary objective of this clinical trial was to compare the anesthetic efficacy of 1 cartridge (1.8 mL) and 2 cartridges (3.6 mL) of articaine 4% with epinephrine 1:100,000 in conventional IANB in patients with irreversible pulpitis in mandibular molars with spontaneous pain. The secondary objective was to compare the anesthetic efficacy of these different volumes in the periodontal ligament injection (PDL) as a complement in cases where the conventional IANB failed.https://osf.io/u2zx8/?view_only=6dcdcf8cf4fb46eb84c68811c2eadc22).The study was approved by the University of São Paulo’s Dental School’s Committee for Ethics in Human Research (protocol # 626.279/2014).  Files anThis is a randomized (1:1) controlled parallel single blind clinical trial. To ensure transparence and quality, the CONSORT  recommendations were followed .The sample size calculation was based on an 80% chance of detecting, with significance at the 5% level, a difference in success rate of 25% (65% control and 90% test). Ninety patients were recruited from April 2015 to June 2016, from the University of São Paulo’s Dental School’s Emergency Center. Recruitment was based on a diagnosis of irreversible pulpitis in the first or second mandibular molar participated with moderate to severe spontaneous pain, a positive response to the electric pulp test and a prolonged response to the thermal test with Endo-Frost . Only healthy patients, according to the health history questionnaire, ranging in age from 18 to 50 years old, who had at least 1 adjacent tooth and a healthy contralateral canine tooth, and were without deep cavities, extensive restorations, advanced periodontal disease (insertion loss > 5 mm), and/or no history of trauma or sensitivity were included. Patients who used drug products that could interact with the local anesthetic were excluded from the study. No changes were made to the methods or trial outcomes after trial commencement.The patients were randomized into 2 groups of 45 patients and received, at random (1:1), 1.8 mL or 3.6 mL of articaine hydrochloride 4% with epinephrine 1:100,000  in the IANB .We considered the 3.6 mL group the control group because at the University of São Paulo’s Dental School’s Emergency Center it is common to administer 2 cartridges in irreversible pulpitis. To ensure that the anesthetic volume was randomly chosen, we placed 45 brown envelopes in a box with 2 anesthetic tubes and 45 envelopes with 4 anesthetic cartridges. At the beginning of the anesthesia procedure, the operator (IPT) took, at random, a sealed brown envelope from the box. The electrical tests (SAS) and the pulpectomy procedure (IAB) were performed by different professionals, thus ensuring that they were not aware of the volume used and guaranteeing that the study was random and single blinded. Before anesthetic injection, the tooth with irreversible pulpitis, the adjacent tooth, and the contralateral canine had their pulp vitality tested twice with the electrical stimulator . The contralateral canine was used as a parameter for analysis of the correct functioning of the equipment and to see if the patient was responding adequately. Two consecutive negative responses at maximal electrical stimulation (80uA) of the electrical pulp stimulator were the criteria that determined the success of pulpal anesthesia 10 minutes after IANB and immediately after the complementary periodontal ligament injection. Pulpal anesthesia, pulpectomy, and electrical tests were performed by three different professionals, throughout the study, each of them dedicated to a specific phase. For the conventional IANB injection, we used a side-loading carpule syringe and blood aspirator attached to a ring  as well as 27G disposable needles . For the 3.6 mL group (2 cartridges), the second anesthesia was initiated immediately after the second step of the first anesthesia. Technique are detailed in supplemental material (protocol.io). Ten minutes after the IANB, the subjective signal of lip anesthesia was evaluated, by questioning the patient if his/her lip was numb. Immediately after questioning, a new electrical pulp vitality test was performed, and then preparation to access the cavity commenced. During the clinical procedure the patient was instructed to report any type of discomfort or pain, using a verbal analog scale where 0 = no pain; 1 = weak pain, mild and bearable; 2 = moderate and unbearable pain; 3 = severe, intense, and unbearable pain. The extent of access achieved when the patient felt pain was recorded as within the dentin, entering the pulp chamber, or during the pulpectomy procedure. Anesthesia was defined as successful when the professional could complete the pulpectomy without the patient reporting pain (pain scores 0 and 1). Pain scores of 2 and 3 were classified as failure of the IANB. This evaluation is the primary outcome measure. In these cases, we opted for PDL for anesthetic supplement.2 test. Age distributions were analyzed using the Mann-Whitney test. The likelihood ratio test was applied to compare pain site distribution in the two groups after failure of the IANB as well as the responses obtained with the electrical stimulator (negative or positive) and the pain scale  after the injection in the periodontal ligament. Relative risks (RR) with the corresponding 95% confidence intervals (95% CI) were calculated for each outcome. For all tests performed, the difference was assumed significant when P≤0.05.In determining the failure of the IANB, we created a subgroup in which the PDL was necessary. Technique are detailed in supplemental material (protocol.io). This evaluation is a secondary outcome measure. The injections were administered by the same professional who had previously performed the IANB (IPT). Soon after completion of the anesthetic supplement, new electrical pulp vitality tests were performed. Subsequently, a new attempt at a pulpectomy was performed, in which the verbal analog scale was again used. Anesthesia success was defined as finishing the pulpectomy procedure without the patient reporting pain; in the case of a pain report, it was considered to be an anesthetic failure. At which point it was necessary to supplement with an intrapulpal injection. After 24 hours all patients were contacted by telephone by the urgent care center to register any adverse effects, related to paresthesia and postoperative pain. The distribution of sex, tooth type, and responses obtained with the electrical stimulator (negative or positive) and the pain scale after the IANB  of the 2 groups (1.8 mL e 3.6 mL) were compared using the χAll demographic data was presented in All patients reported the subjective signal of lip anesthesia after 10 minutes of IANB. Immediately before the start of the pulpectomy procedure and after the application of the IANB, 12 patients from the 1.8 mL group (27%) and 19 patients from the 3.6 mL group (42%) achieved pulpal anesthesia . The use of 1.8 mL volume of anesthesia did not significantly increase the risk of achieving pulpal anesthesia During the pulpectomy procedure, after the IANB, 29 patients from the 1.8 mL group (64%) and 33 from the 3.6 mL group (73%) didn’t report pain. The use of 1.8 mL volume of anesthesia was not significantly associated with analgesia during pulpectomy Regarding the site of pain reported after the IANB, for the group receiving 1.8 mL pain was concentrated in the pulp chamber in 10 patients (62%), followed by pain in the dentin in 5 patients (31%), and pain in the root canal in 1 patient (6%) . SimilarAfter PDL, 12 patients from the 1.8 mL group (75%) and 5 from the 3.6 mL group (42%) achieved pulpal anesthesia. The use of 1.8 mL volume of anesthesia increased the risk of achieving pulpal anesthesia, but this difference was not significant .During the new attempt at the pulpectomy procedure, 11 patients from the 1.8 mL group (69%) and 9 patients from the 3.6 mL group (75%) didn’t report pain, but these differences were not statistically significant . All these results are presented in graphics in Suplemental material  Tables.The site of pain reported after the PDL in the 1.8 mL group was concentrated in the pulp chamber for 4 patients (80%) and the other patient reported pain in the dentin (20%). In the 3.6 mL group, we had an equal distribution among the 3 sites, and 1 patient experienced pain at each site (33% each), these differences were not statistically significant (P = 0.2456) and are shown in There were no important adverse events or unintended effects in either group of this study.After 10 minutes of conventional IANB, profound lip anesthesia was verified in all patients (100%) for the 2 doses of articaine studied. However, pulpal anesthesia was not achieved in all patients at the 2 doses used. Therefore, lip anesthesia, often used as a clinical indicator of block success, is not a guaranteed signal of pulpal anesthesia; also, the onset of lip numbness might not indicate the onset of pulpal anesthesia , 26, 29.The maximal power use of the electric pulp stimulator (80μA) as criteria for pulpal anesthesia was based on previous studies , 31. TheOur study showed that neither of the two anesthetic volumes of articaine were sufficient to guarantee complete clinical analgesia during the pulpectomy procedure after the IANB. The results found in our study are in line with two studies that analyzed the anesthetic volume of 2% lidocaine in the IANB of patients with irreversible pulpitis . In one et al. (2012) who evaluated the anesthetic volumes (1.8 mL and 3.6 mL) of lidocaine 2% with 1:200,000 epinephrine, and the study by Abazarpoor et al. (2015) which evaluated 4% articaine with 1:100,000 epinephrine. In the study by Abazarpoor et al. (2015) the authors found a statistically significant difference between the volumes of 1.8 mL and 3.6 mL, of 27.5% and 77.5%, respectively, for the success of pulpal anesthesia after the IANB with 4% articaine with epinephrine 1:100,000. It should be noted, however, that their study recruited patients with irreversible pulpitis, who did not present spontaneous pain, only prolonged response to the thermal test. This makes it difficult to compare to our study, because we recruited patients with irreversible pulpitis who reported spontaneous pain, and therefore probably presented a more exacerbated degree of inflammation.Only two studies have found better results with increasing anesthetic volume in the IANB in patients with irreversible pulpitis and therefore are not in line with our results: Aggarwal It is very difficult to measure pain intensity. There is extensive literature regarding pain scales dating from the 1950s. Verbal Rating Scale (VRS), Visual Analogue Scale (VAS) or Numerical Rating Scale (NRS) are widely recommended for the assessment of pain intensity. However, VRS was preferred by the less educated patients ,36. Theyet al. (2004) the pain site was predominantly in the dentin, 57% of articaine patients and 51% of lidocaine patients, followed by pain in the pulp chamber, 32% for articaine and 41% for lidocaine, and in the root canal, 11% for the articaine group and 7% for lidocaine group. The fact that pain occurred predominantly in the dentin led Claffey et al. (2004) to emphasize that clinicians would probably have difficulty administering supplemental techniques, such as intrapulpal anesthesia, in cases of failure of the IANB, requiring other techniques such as intraosseous and intraligamentary. However, in our study, after the IANB, a large number of the patients  referred to pain only when the pulp chamber was accessed  the site at which the majority of patients reported pain during the endodontic procedure was in the pulp chamber, similar to our study. However, the difference between both volumes was significant, in the 1.8 mL group, 23 patients (57.5%) had pain in the pulp chamber while in the 3.6 mL group only 7 patients (17.5%) had pain, which differed from our study. In our study, there were no statistically significant differences between volumes and pain sites  and in the supplemental anesthetic technique in the periodontal ligament (PDL) did not significantly increase the success rate of pulpal anesthesia and clinical analgesia during the pulpectomy procedure. However, it must be pointed out that the p-value was very close to 5% and therefore could be considered marginally significant. Future investigation related to the volume of the anesthetic solution of 4% articaine with 1:100,000 epinephrine, in the IANB and in the periodontal ligament injection, are still needed.It is important to note that, in our study, a lower dose of the anesthetic solution was as effective as double the dose. Thus, clinicians should wait a few minutes before injecting the second cartridge allowing the local anesthetic time to propagate properly. Another option for a second injection may be a supplemental buccal infiltration injection of 4% articaine with 1: 100,000 epinephrine, according to the literature –17. ThisBoth volumes of 4% articaine with 1: 100,000 epinephrine (1.8 mL and 3.6 mL), in the IANB and in the PDL, presented similar efficacy, though neither were entirely efficient in controlling pain during treatment for irreversible pulpitis.We have concluded that an increase in anesthetic volume from 1.8 mL to 3.6 mL of articaine 4% with epinephrine 1:100 000 in the inferior alveolar nerve block (IANB) and in the supplemental anesthetic technique in the periodontal ligament (PDL) does not significantly increase the success rate for pulpal anesthesia and clinical analgesia during the pulpectomy procedure. Therefore both volumes presented a similar efficacy, though neither resulted in effective pain control for irreversible pulpitis treatment.S1 Checklist(PDF)Click here for additional data file.S1 File(DOC)Click here for additional data file.S2 File(PDF)Click here for additional data file.S3 File(PDF)Click here for additional data file.S1 Table(TIF)Click here for additional data file.S2 Table(TIF)Click here for additional data file.S3 Table(TIF)Click here for additional data file.S4 Table(TIF)Click here for additional data file.S1 Protocol(PDF)Click here for additional data file.