Reversal of mivacurium-induced neuromuscular blockade with a cholinesterase inhibitor: A systematic review.

BACKGROUND: Mivacurium is a short-acting non-depolarizing muscle relaxant, which is hydrolyzed by butyrylcholinesterase. The neuromuscular block (NMB) can be antagonized with cholinesterase inhibitors (CHEI), but the short duration of action of mivacurium questions the need. This systematic review evaluated if the use of CHEIs (neostigmine, pyridostigmine or edrophonium) facilitates reversal of mivacurium-induced NMB. METHOD: Randomized controlled trials and crossover-studies comparing spontaneous recovery with CHEI reversal in patients with mivacurium-induced NMB, assessed with quantitative neuromuscular monitoring, were included. Mean time from injection of the CHEI or allowing of spontaneous recovery to an endpoint representing full recovery was used as outcome. First response to train-of-four nerve stimulation (T1 ) described the level of NMB for administration of the CHEI. Moderate NMB refers to T1  ≥ 5% and deeper NMB refers to T1  < 5%. Systematic critical appraisal was performed using the Scottish Intercollegiate Guidelines Network guidelines. Overall quality assessment was done using the Grading of Recommendations Assessment, Development and Evaluation approach. RESULTS: Sixteen studies with data from 546 patients were included. Low quality of evidence was found that neostigmine and edrophonium administered at moderate NMB accelerated recovery with up to approximately 5.5-6.5 and 6.5-9.0 minutes, respectively. At deeper NMB only edrophonium accelerated recovery. The effect of neostigmine was not clarified at deeper mivacurium-induced NMB. No studies with reversal by pyridostigmine were identified. CONCLUSION: Low quality of evidence supports that neostigmine and edrophonium accelerate the recovery of mivacurium-induced NMB with 5-6.5 and 6-9.0 minutes respectively, when administered at moderate NMB. At deeper NMB only edrophonium accelerated the recovery.

Deep neuromuscular blockade and low insufflation pressure during laparoscopic hysterectomy.

INTRODUCTION: Establishment of sufficient muscle relaxation is essential in laparoscopic surgery. During laparoscopy, surgeons can experience abdominal contractions in their patients. Deep neuromuscular block (NMB) has the potential to prevent such episodes. In this study, we explored if deep NMB reduces the incidence of sudden abdominal contractions as compared with standard NMB. METHODS: This was a pre-planned secondary analysis of a randomized, controlled study. A total of 110 patients scheduled for laparoscopic hysterectomy were randomized to either deep NMB and 8 mmHg pneumoperitoneum (deep NMB group) or single-bolus NMB and 12 mmHg pneumoperitoneum (standard NMB group). NMB was established with rocuronium and reversed with sugammadex. Two gynaecologists registered episodes of sudden abdominal contractions, alarms from the insufflator due to increased intraabdominal pressure and incidences with tightness of the abdominal wall. RESULTS: No sudden abdominal contractions were detected in the deep NMB group as compared with 12 episodes in the standard NMB group (p < 0.001). The insufflator alarmed in no versus ten procedures (p = 0.001) in the deep and standard NMB group, respectively. The gynaecologists registered increasing abdominal tensions in no versus eight procedures (p = 0.006) in the deep and standard NMB group, respectively. CONCLUSION: Deep NMB in combination with 8 mmHg pneumoperitoneum prevented sudden abdominal contractions during laparoscopic hysterectomy. FUNDING: This work was funded in part by a research grant from the Investigator Initiated Studies Program of Merck Sharp & Dohme Corp, USA. The opinions expressed in this paper are those of the authors and do not necessarily represent those of Merck Sharp & Dohme Corp. TRIAL REGISTRATION: The study was assigned with EudraCT number 2012-003787-51 and registered with clinicaltrials.gov (NCT01722097).

Analysis of Resident Case Logs in an Anesthesiology Residency Program.

Our goal in this study was to examine Accreditation Council for Graduate Medical Education case logs for Stanford anesthesia residents graduating in 2013 (25 residents) and 2014 (26 residents). The resident with the fewest recorded patients in 2013 had 43% the number of patients compared with the resident with the most patients, and in 2014, this equaled 48%. There were residents who had 75% more than the class average number of cases for several of the 12 case types and 3 procedure types required by the Accreditation Council for Graduate Medical Education. Also, there were residents with fewer than half as many for some of the required cases or procedure types. Some of the variability may have been because of the hazards of self-reporting.

[When muscle relaxants have unexpected prolonged duration during anaesthesia]. / Uventet lang virkningsvarighed afmuskelrelaksantia kan forebygges

Muscle relaxation facilitates tracheal intubation and improves surgical conditions during anaesthesia. However, unexpected prolonged muscle relaxation may occur. This article describes important causes of prolonged muscle relaxation and gives suggestions for its prevention. Drug interactions, incomplete reversal, co-morbidity, inaccurate neuromuscular monitoring and critical illness may prolong the effect of muscle relaxants. The anaesthetist must titrate the muscle relaxants using objective neuromuscular monitoring and proper reversal of the blockade when needed.

Neuromuscular blockade for improvement of surgical conditions during laparotomy: protocol for a randomised study.

INTRODUCTION: During laparotomy, surgeons frequently experience difficult surgical conditions if the patient's abdominal wall or diaphragm is tense. This issue is particularly pertinent while closing the fascia and placing the intestines into the abdominal cavity. Establishment of a deep neuromuscular blockade (NMB), defined as a post-tetanic-count (PTC) of 0-1, paralyses the abdominal wall muscles and the diaphragm. We hypothesised that deep NMB (PTC 0-1) would improve surgical conditions during upper laparotomy as compared to standard NMB with bolus administration. METHODS: This is an investigator-initiated, assessor- and patient-blinded, randomised study. A total of 128 patients scheduled for elective upper laparotomy will be included and randomised to either continuous deep NMB or standard NMB defined as bolus administrations. Surgical conditions are evaluated using a five-point rating scale every 30 min. Primary outcome is the average score for a patient's surgical condition. Secondary outcomes are, among others, surgical rating score during fascial closure, wound dehiscence, wound infection requiring surgical drainage and incisional hernia at the six-month follow-up. CONCLUSIONS: This randomised, double-blinded study investigates potential effects of deep NMB on surgical conditions and patient outcomes during elective laparotomy. FUNDING: The study is funded in part by a research grant from the Investigator Initiated Studies Program of Merck Sharp & Dohme Corp. TRIAL REGISTRATION: NCT02140593.

[Challenges when improving surgical conditions by use of neuromuscular blockade]. / Udfordringer ved brug af muskelrelaksantia til forbedring af kirurgiske forhold.

Neuromuscular blockade (NMB) may pose a clinical dilemma between surgeons' requirements of muscle relaxation and the risk of residual blockade. This review has aimed at describing the challenges when using NMB for optimizing surgical conditions and reasons for inadequate relaxation despite use of NMB. Interdisciplinary collaboration, proper neuromuscular monitoring, knowledge on differences in pharmacodynamics and pharmacokinetics of NMB are essential factors when optimizing surgical conditions by use of NMB.

Influence of intense neuromuscular blockade on surgical conditions during laparotomy: a pig model.

PURPOSE: Intense neuromuscular block may improve surgical conditions in ileus laparotomies; however, it is difficult to evaluate. The aim of this study was to investigate if neuromuscular block improved surgical conditions in pigs with artificial ileus laparotomy. METHODS: Six pigs were endotracheally intubated, mechanically ventilated, anesthetized with propofol and fentanyl, and randomized into two groups in a cross-over assessor-blinded design. Neuromuscular block was established with rocuronium. Artificial laparotomy for ileus was performed. We investigated the influence of intense neuromuscular block on surgical conditions with a subjective rating scale, force needed to close the fascia, incidences of abdominal contractions while suctioning the lungs, width of the wound diastase and operating time as outcome parameters. RESULTS: In all six pigs no abdominal contractions occurred while suctioning the lungs at intense neuromuscular block. Without neuromuscular block we detected abdominal contractions seen as hiccups and bucking. In all six pigs during intense neuromuscular block we found no visible electromyographic (EMG) activity in the abdominal muscles while suctioning the lungs. Without neuromuscular block suctioning the lungs elicited brief periods of abdominal EMG activity. No difference was found in the force needed to close the fascia when comparing no neuromuscular block with intense neuromuscular block. Furthermore, no significant differences were found in the width of the diastase, operating time and subjective ratings using a four-point rating scale when comparing no neuromuscular block with intense neuromuscular block. However, these outcomes were related to the order of the suturing round. CONCLUSION: Intense neuromuscular block prevented abdominal muscle contractions but did not influence the force needed to close the fascia.

Acupuncture treatment for pain: systematic review of randomised clinical trials with acupuncture, placebo acupuncture, and no acupuncture groups.

OBJECTIVES: To study the analgesic effect of acupuncture and placebo acupuncture and to explore whether the type of the placebo acupuncture is associated with the estimated effect of acupuncture. DESIGN: Systematic review and meta-analysis of three armed randomised clinical trials. DATA SOURCES: Cochrane Library, Medline, Embase, Biological Abstracts, and PsycLIT. Data extraction and analysis Standardised mean differences from each trial were used to estimate the effect of acupuncture and placebo acupuncture. The different types of placebo acupuncture were ranked from 1 to 5 according to assessment of the possibility of a physiological effect, and this ranking was meta-regressed with the effect of acupuncture. DATA SYNTHESIS: Thirteen trials (3025 patients) involving a variety of pain conditions were eligible. The allocation of patients was adequately concealed in eight trials. The clinicians managing the acupuncture and placebo acupuncture treatments were not blinded in any of the trials. One clearly outlying trial (70 patients) was excluded. A small difference was found between acupuncture and placebo acupuncture: standardised mean difference -0.17 (95% confidence interval -0.26 to -0.08), corresponding to 4 mm (2 mm to 6 mm) on a 100 mm visual analogue scale. No statistically significant heterogeneity was present (P=0.10, I(2)=36%). A moderate difference was found between placebo acupuncture and no acupuncture: standardised mean difference -0.42 (-0.60 to -0.23). However, considerable heterogeneity (P<0.001, I(2)=66%) was also found, as large trials reported both small and large effects of placebo. No association was detected between the type of placebo acupuncture and the effect of acupuncture (P=0.60). CONCLUSIONS: A small analgesic effect of acupuncture was found, which seems to lack clinical relevance and cannot be clearly distinguished from bias. Whether needling at acupuncture points, or at any site, reduces pain independently of the psychological impact of the treatment ritual is unclear.