Resistance towards nondepolarising muscle relaxants: prolonged onset time: A systematic review.

BACKGROUND: Nondepolarising muscle relaxants (NDMRs) provide optimal conditions for tracheal intubation and improve surgical conditions. Several clinical conditions, diseases and pharmacological interactions have been suggested to cause resistance towards NDMRs that may translate into difficult intubation or inadequate operating conditions during surgery. OBJECTIVE: The aim of this study was to evaluate the current evidence of patient groups with resistance towards NDMRs. A prolonged onset time was defined as a difference that exceeded 25% compared with controls. DESIGN: A systematic review of randomised controlled trials and cohort studies. DATA SOURCES: A comprehensive search was performed in 2016 in PubMed and EMBASE. ELIGIBILITY CRITERIA: Patients with conditions or diseases, or patients taking medication, which lead to resistance towards current NDMRs (rocuronium, vecuronium, cisatracurium, atracurium, mivacurium and pancuronium). Included outcomes were onset time defined as the time between administration of NDMR to maximal (90, 95 or 100%) depression of baseline twitch height of the first twitch in a train-of-four. RESULTS: Twenty-five studies were included. Strong evidence supports a prolonged onset time of rocuronium in patients with thermal injury and Duchenne muscular dystrophy. Moderate evidence supports a prolonged onset time of NDMRs during hypothermia and in patients with infection, oculopharyngeal muscular dystrophy, liver cirrhosis treated with ulinastatin, when remifentanil is administered prior to administration of an NDMR, in fasting patients being rehydrated intravenously prior to administration of NDMR, in children with end-stage renal failure and in patients with atrial or ventricular septal defects. CONCLUSION: A prolonged onset time should be suspected in patients with thermal injury and Duchenne's muscular dystrophy. Further, evidence supports a prolonged onset time in patients with infection, oculopharyngeal muscular dystrophy, congenital heart defects, kidney failure, liver cirrhosis treated with ulinastatin along with remifentanil or intravenous fluids administered prior to NDMR.

Deep neuromuscular blockade and surgical conditions during laparoscopic ventral hernia repair: A randomised, blinded study.

BACKGROUND: Laparoscopic ventral hernia repair is a common surgical procedure. However, muscle contractions and general muscle tension may impair the surgical view and cause difficulties suturing the hernial defect. Deep neuromuscular blockade (NMB) paralyses the abdominal wall muscles and may help to create better surgical conditions. OBJECTIVES: The current study investigated if deep compared with no NMB improved the surgical view during laparoscopic ventral hernia repair. DESIGN: Crossover study. SETTING: The study was carried out at Herlev and Gentofte Hospital, University of Copenhagen, Denmark and conducted from May 2015 until February 2017. PARTICIPANTS: A total of 34 patients were randomised in an investigator-initiated, assessor-blinded crossover design of deep vs. no NMB during laparoscopic ventral hernia repair. INCLUSION CRITERIA: Adults scheduled for elective laparoscopic ventral hernia repair. EXCLUSION CRITERIA: Known allergy to any study medication, known homozygous variants in the butyrylcholinesterase gene, severe renal disease, neuromuscular disease, lactating or pregnant women, any indication for rapid sequence induction. INTERVENTIONS: Deep NMB was established with rocuronium and reversed with sugammadex. Anaesthesia was conducted with propofol and remifentanil. MAIN OUTCOME MEASURES: The primary outcome was evaluation of surgical view assessed on a five-point rating scale. Other outcomes included the surgical conditions during laparoscopic suturing of the hernia defect. RESULTS: We found no difference in ratings for the surgical view when comparing deep with no NMB: mean -0.1 (95% confidence interval -0.4 to 0.2) (P = 0.521, paired t test). However, deep compared with no NMB improved the rating score for surgical conditions while suturing the hernia defect (P = 0.012, Mann-Whitney U test). No differences were found in either total length of surgery (P = 0.76) or hernia suturing time (P = 0.81). CONCLUSION: Deep compared with no NMB did not change the rating score of the surgical view immediately after introduction of trocars during laparoscopic ventral hernia repair, but the surgical condition were improved during suturing of the hernia. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02247466.

Postoperative shoulder pain after laparoscopic hysterectomy with deep neuromuscular blockade and low-pressure pneumoperitoneum: A randomised controlled trial.

BACKGROUND: Postoperative shoulder pain remains a significant problem after laparoscopy. Pneumoperitoneum with insufflation of carbon dioxide (CO2) is thought to be the most important cause. Reduction of pneumoperitoneum pressure may, however, compromise surgical visualisation. Recent studies indicate that the use of deep neuromuscular blockade (NMB) improves surgical conditions during a low-pressure pneumoperitoneum (8 mmHg). OBJECTIVE: The aim of this study was to investigate whether low-pressure pneumoperitoneum (8 mmHg) and deep NMB (posttetanic count 0 to 1) compared with standard-pressure pneumoperitoneum (12 mmHg) and moderate NMB (single bolus of rocuronium 0.3 mg kg with spontaneous recovery) would reduce the incidence of shoulder pain and improve recovery after laparoscopic hysterectomy. DESIGN: A randomised, controlled, double-blinded study. SETTING: Private hospital in Denmark. PARTICIPANTS: Ninety-nine patients. INTERVENTIONS: Randomisation to either deep NMB and 8 mmHg pneumoperitoneum (Group 8-Deep) or moderate NMB and 12 mmHg pneumoperitoneum (Group 12-Mod). Pain was assessed on a visual analogue scale (VAS) for 14 postoperative days. MAIN OUTCOME MEASURES: The primary endpoint was the incidence of shoulder pain during 14 postoperative days. Secondary endpoints included area under curve VAS scores for shoulder, abdominal, incisional and overall pain during 4 and 14 postoperative days; opioid consumption; incidence of nausea and vomiting; antiemetic consumption; time to recovery of activities of daily living; length of hospital stay; and duration of surgery. RESULTS: Shoulder pain occurred in 14 of 49 patients (28.6%) in Group 8-Deep compared with 30 of 50 (60%) patients in Group 12-Mod. Absolute risk reduction was 0.31 (95% confidence interval 0.12 to 0.48; P = 0.002). There were no differences in any secondary endpoints including area under the curve for VAS scores. CONCLUSION: Deep NMB and low-pressure pneumoperitoneum (8 mmHg) reduced the incidence of shoulder pain after laparoscopic hysterectomy in comparison to moderate NMB and standard-pressure pneumoperitoneum (12 mmHg). TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT01722097.

Monitoring of intense neuromuscular blockade in a pig model.

Intense neuromuscular blockade (NMB) measured by post tetanic count (PTC) was monitored, reversed and verified in this pig model. In a cross-over assessor blinded design six pigs were randomized to either no NMB followed by intense NMB, or intense NMB followed by no NMB. Neuromuscular measurements were performed with acceleromyography [train-of-four (TOF) Watch SX]. In all pigs, the response to TOF nerve stimulation was stable and intense NMB (PTC 0-1) was established with rocuronium 3 mg/kg. For reversal, the pigs received sugammadex 20-35 mg/kg and returned to TOF-ratio above 0.90 within 2.15 min after injection. We established a pig model for monitoring intense NMB with surface stimulation electrodes and acceleromyography. We verified total relaxation of the diaphragm and the abdominal muscles at the PTC 0-1 by suction test and with surface electromyography. This pig model is suitable for studies with experimental abdominal surgery with monitoring of intense NMB, and where relaxation of the diaphragm and the abdominal muscles are required.

Comparing Anesthesiology Residency Training Structure and Requirements in Seven Different Countries on Three Continents.

Little has been published comparing the graduate medical education training structure and requirements across multiple countries. The goal of this study was to summarize and compare the characteristics of anesthesiology training programs in the USA, UK, Canada, Japan, Brazil, Denmark, and Switzerland as a way to better understand efforts to train anesthesiologists in different countries. Two physicians trained in each of the seven countries (convenience sample) were interviewed using a semi-structured approach. The interview was facilitated by use of a predetermined questionnaire that included, for example, the duration of post-medical school training and national requirements for certain rotations, a number of cases, faculty supervision, national in-training written exams, and duty hour limits. These data were augmented by review of each country's publicly available residency training documents as available on the internet. Post-medical school anesthesia residency duration varied: three years (Brazil), four years (USA), five years (Canada and Switzerland), six years (Japan and Denmark) to nine years (UK), as did the number of explicitly required clinical rotations of a defined duration: zero (Denmark), one (Switzerland and UK), four (Brazil), six (Canada), and 12 (USA). Minimum case requirements exist in the USA, Japan, and Brazil, but not in the other countries. National written exams taken during training exist for all countries studied except Japan and Denmark. The countries studied increasingly aim to have competency-based education with milestone assessments. Training duty hour limits also varied including for example 37 hours/week averaged over a one month with limitations on night duties (Denmark), a weekly average of 48 hours taken over a 17 week period (UK), 50 hours/week maximum (Switzerland), 60 hours/week maximum (Brazil), and 80 hours/week averaged over four weeks (USA). Some countries have highly structured training programs with multiple national requirements with training principally carried out at a home institution. Other countries have a more decentralized and unregulated approach with fewer (if any) specific case or rotation requirements, where the trainee creates his/her own customized training to meet broad objectives and goals. The countries studied have different national training requirements, unique duty hour rules and are at varying stages in transitioning to an outcome based model of residency.

Does Faculty Follow the Recommended Structure for a New Classroom-based, Daily Formal Teaching Session for Anesthesia Residents?

BACKGROUND:  A newly implemented 15-minute classroom-based, formal teaching session for anesthesia residents is given three times daily by the same faculty. The faculty member was provided a suggested template for the presentation. The template structure was developed by a group of residents and faculty to include best teaching practices. The goal of the current study was to measure how frequently the faculty teaching these sessions followed the template. METHODS: From February 20, 2015 to February 6, 2016, a research assistant trained in education mapped a total of 48 teaching sessions to determine how frequently the teaching sessions included each of the elements in the recommended template structure. The assistant was chosen from outside the anesthesia department so as to minimize biases. RESULTS: It was found that 98% of the sessions used the teaching template's suggestion of using computer slides (e.g., a Powerpoint presentation). We observed that 75% of the sessions provided specific recommendations about patient care, 65% had reinforcement of learning points, 56% had a test or a quiz, 49% provided references and directions for further reading, 44% provided take-home messages, and 31% used a clinical case vignette presentation to introduce the keyword. The most common visuals were the use of a picture (38%) and a chart or a graph (35%). We also saw that 65% of the sessions had active involvement of residents. With respect to time and slide limitations mentioned in the template, we saw that 35% of the sessions finished within the recommended time limit of 15 mins and 21% had the recommended 10 or fewer slides.  Conclusion: Compliance by the faculty to the recommended structure was variable. Despite this, the sessions have been well received and have become a permanent part of the residency curriculum more than two years after their implementation.

Neuromuscular blockade during laparoscopic ventral herniotomy: protocol for a randomised controlled trial.

INTRODUCTION: Laparoscopic herniotomy is the preferred technique for some ventral hernias. Several factors may influence the surgical conditions, one being the depth of neuromuscular blockade (NMB) applied. We hypothesised that deep neuromuscular blockade defined as a post-tetanic count below eight would provide a better surgical workspace. METHODS: This was an investigator-initiated, assessor- and patient-blinded randomised cross-over study. A total of 34 patients with planned laparoscopic umbilical, incisional and linea alba herniotomy were studied. Patients would be randomised to receive deep NMB followed by no NMB, or no NMB followed by deep NMB. Our primary outcome was improvement of the surgical workspace (rated on a five-point scale) estimated as the difference between the workspace during deep NMB and the workspace without NMB. Secondary outcomes included, among others, surgeon's rating of surgical conditions during suturing, duration of surgery and duration of the suturing of the hernia. CONCLUSION: This randomised cross-over study investigated a potential effect on the surgical workspace in laparoscopic ventral herniotomy using deep NMB compared with no NMB. The study may provide knowledge relevant to other laparoscopic techniques. FUNDING: The study is funded by a research grant from the Investigator Initiated Studies Program of Merck Sharp & Dohme Corp. TRIAL REGISTRATION: NCT02247466.