Recent advances in neuromuscular block during anesthesia

Residual Neuromuscular Block Remains a Safety Concern for Perioperative Healthcare Professionals: A Comprehensive Review

Residual neuromuscular block (RNMB) remains a significant safety concern for patients throughout the perioperative period and is still widely under-recognized by perioperative healthcare professionals. Current literature suggests an association between RNMB and an increased risk of postoperative pulmonary complications, a prolonged length of stay in the post anesthesia care unit (PACU), and decreased patient satisfaction. The 2023 American Society of Anesthesiologists Practice Guidelines for Monitoring and Antagonism of Neuromuscular Blockade provide guidance for the use of quantitative neuromuscular monitoring coupled with neuromuscular reversal to recognize and reduce the incidence of RNMB. Using sugammadex for the reversal of neuromuscular block as well as quantitative neuromuscular monitoring to quantify the degree of neuromuscular block may significantly reduce the risk of RNMB among patients undergoing general anesthesia. Studies are forthcoming to investigate how using neuromuscular blocking agent reversal with quantitative monitoring of the neuromuscular block may further improve perioperative patient safety.

The impact of moderate versus deep neuromuscular blockade on the recovery characteristics following laparoscopic sleeve gastrectomy: A randomized double blind clinical trial

Background

Anesthesia with deep neuromuscular block for laparoscopic surgery may result in less postoperative pain with lower intra-abdominal pressure. However, the results in the existing literature are controversial. This study aimed to evaluate the effect of deep versus moderate neuromuscular block (NMB) on the postoperative recovery characteristics after laparoscopic sleeve gastrectomy (LSG) for weight loss surgery.

Methods

This is parallel-group, randomized clinical trial. The study was conducted at a tertiary care center. Patients undergoing LSG were included. Patients were randomly assigned to either deep (post-tetanic count 1-2) or moderate (train-of-four 1-2) NMB group. The primary outcomes were numeric rating scale scores of the postoperative pain at rest and postoperative shoulder pain. The secondary outcomes were the length of hospital stay (LOS) and postoperative complications. The statistics were performed using StatsDirect statistical software (Version 2.7.9).

Results

Two groups were identified: Group D (deep NMB), 29 patients, and Group M (moderate NMB), 28 patients. The BMI mean values for groups D and M were 44 and 45 kg/m2 respectively (P > 0.05). The mean durations of surgery for were 46.7 min and 44.1 min for groups M and D, respectively (P > 0.05). The mean train-of-four (TOF) counts were 0.3 and 0 for groups M and D, respectively (P < 0.05). The mean times from giving reversal agent to tracheal extubation (minutes) were 6.5 and 6.58 min for groups M and D, respectively (P > 0.05). In the recovery room, the means of pain scores were 3 and 4 for groups M and D, respectively (P > 0.05). Upon admission to the surgical ward, the median values of the pain score were non-significant (P > 0.05) (95% CI: 0.4-0.7). The opioid consumption in the recovery room was non-significant between both groups (P > 0.05) (95% CI: 0.3-0.6). Postoperative shoulder pain was non-significant between both groups (P > 0.05) (95% CI: 0.4-0.7). The median values of surgeon opinion of both groups were non-significant (P > 0.05). Regarding the LOS, the mean values of groups D and M were 1.20 and 1.21 days, respectively (P > 0.05).

Conclusions

There was no significant difference between moderate and deep NMB techniques in terms of duration of the surgical procedure, postoperative pain, shoulder pain, and length of hospital stay. Further studies on a larger sample size are required to investigate the long-term recovery characteristics of patients with obesity undergoing LSG.

Sugammadex versus neostigmine for neuromuscular blockade reversal in outpatient surgeries: A randomized controlled trial to evaluate efficacy and associated healthcare cost in an academic center

Introduction

Neuromuscular blockade is an essential component of the general anesthesia as it allows for a better airway management and optimal surgical conditions. Despite significant reductions in extubation and OR readiness-for-discharge times have been associated with the use of sugammadex, the cost-effectiveness of this drug remains controversial. We aimed to compare the time to reach a train-of-four (TOF) response of ≥0.9 and operating room readiness for discharge in patients who received sugammadex for moderate neuromuscular blockade reversal when compared to neostigmine during outpatient surgeries under general anesthesia. Potential reduction in time for OR discharge readiness as a result of sugammadex use may compensate for the existing cost-gap between sugammadex and neostigmine.

Methods

We conducted a single-center, randomized, double arm, open-label, prospective clinical trial involving adult patients undergoing outpatient surgeries under general anesthesia. Eligible subjects were randomized (1:1 ratio) into two groups to receive either sugammadex (Groups S), or neostigmine/glycopyrrolate (Group N) at the time of neuromuscular blockade reversal. The primary outcome was the time to reverse moderate rocuronium-induced neuromuscular blockade (TOF ratio ≥0.9) in both groups. In addition, post-anesthesia care unit (PACU)/hospital length of stay (LOS) and perioperative costs were compared among groups as secondary outcomes.

Results

Thirty-seven subjects were included in our statistical analysis (Group S= 18 subjects and Group N= 19 subjects). The median time to reach a TOF ratio ≥0.9 was significantly reduced in Group S when compared to Group N (180 versus 540 seconds; p = 0.0052). PACU and hospital LOS were comparable among groups. Postoperative nausea and vomiting was the main adverse effect reported in Group S (22.2% versus 5.3% in Group N; p = 0.18), while urinary retention (10.5%) and shortness of breath (5.3%) were only experienced by some patients in Group N. Moreover, no statistical differences were found between groups regarding OR/anesthesia, PACU, and total admission costs.

Discussion

Sugammadex use was associated with a significantly faster moderate neuromuscular blockade reversal. We found no evidence of increased perioperative costs associated with the use of sugammadex in patients undergoing outpatient surgeries in our academic institution.

Clinical trial registration

[https://clinicaltrials.gov/] identifier number [NCT03579589].

Provider variability in the intraoperative use of neuromuscular blocking agents: a retrospective multicentre cohort study

OBJECTIVE

To assess variability in the intraoperative use of non-depolarising neuromuscular blocking agents (NMBAs) across individual anaesthesia providers, surgeons and hospitals.

DESIGN

Retrospective observational cohort study.

SETTING

Two major tertiary referral centres, Boston, Massachusetts, USA.

PARTICIPANTS

265 537 adult participants undergoing non-cardiac surgery between October 2005 and September 2017.

MAIN OUTCOME MEASURES

We analysed the variances in NMBA use across 958 anaesthesia and 623 surgical providers, across anaesthesia provider types (anaesthesia residents, certified registered nurse anaesthetists, attendings) and across hospitals using multivariable-adjusted mixed effects logistic regression. Intraclass correlations (ICC) were calculated to further quantify the variability in NMBA use that was unexplained by other covariates. Procedure-specific subgroup analyses were performed.

RESULTS

NMBAs were used in 183 242 (69%) surgical cases. Variances in NMBA use were significantly higher among individual surgeons than among anaesthesia providers (variance 1.32 (95% CI 1.06 to 1.60) vs 0.24 (95% CI 0.19 to 0.28), p<0.001). Procedure-specific subgroup analysis of hernia repairs, spine surgeries and mastectomies confirmed our findings: the total variance in NMBA use that was unexplained by the covariate model was higher for surgeons versus anaesthesia providers (ICC 37.0% vs 13.0%, 69.7% vs 25.5%, 69.8% vs 19.5%, respectively; p<0.001). Variances in NMBA use were also partially explained by the anaesthesia provider's hospital network (Massachusetts General Hospital: variance 0.35 (95% CI 0.27 to 0.43) vs Beth Israel Deaconess Medical Center: 0.15 (95% CI 0.12 to 0.19); p<0.001). Across provider types, surgeons showed the highest variance, and anaesthesia residents showed the lowest variance in NMBA use.

CONCLUSIONS

There is wide variability across individual surgeons and anaesthesia providers and institutions in the use of NMBAs, which could not sufficiently be explained by a large number of patient-related and procedure-related characteristics, but may instead be driven by preference. Surgeons may have a stronger influence on a key aspect of anaesthesia management than anticipated.

Economic impact of improving patient safety using Sugammadex for routine reversal of neuromuscular blockade in Spain

Background

Neuromuscular blocking (NMB) agents are often administered to facilitate tracheal intubation and prevent patient movement during surgical procedures requiring the use of general anesthetics. Incomplete reversal of NMB, can lead to residual NMB, which can increase the risk of post-operative pulmonary complications. Sugammadex is indicated to reverse neuromuscular blockade induced by rocuronium or vecuronium in adults. The aim of this study is to estimate the clinical and economic impact of introducing sugammadex to routine reversal of neuromuscular blockade (NMB) with rocuronium in Spain.

Methods

A decision analytic model was constructed reflecting a set of procedures using rocuronium that resulted in moderate or deep NMB at the end of the procedure. Two scenarios were considered for 537,931 procedures using NMB agents in Spain in 2015: a scenario without sugammadex versus a scenario with sugammadex. Comparators included neostigmine (plus glycopyrrolate) and no reversal agent. The total costs for the healthcare system were estimated from the net of costs of reversal agents and overall cost offsets via reduction in postoperative pneumonias and atelectasis for which incidence rates were based on a Spanish real-world evidence (RWE) study. The model time horizon was assumed to be one year. Costs were expressed in 2019 euros (€) and estimated from the perspective of a healthcare system. One-way sensitivity analysis was carried out by varying each parameter included in the model within a range of +/− 50%.

Results

The estimated budget impact of the introduction of sugammadex to the routine reversal of neuromuscular blockade in Spanish hospitals was a net saving of €57.1 million annually. An increase in drug acquisition costs was offset by savings in post-operative pulmonary events, including 4806 post-operative pneumonias and 13,996 cases of atelectasis. The total cost of complications avoided was €70.4 million. All parameters included in the model were tested in sensitivity analysis and were favorable to the scenario with sugammadex.

Conclusions

This economic analysis shows that sugammadex can potentially lead to cost savings for the reversal of rocuronium-induced moderate or profound NMB compared to no reversal and reversal with neostigmine in the Spanish health care setting. The economic model was based on data obtained from Spain and from assumptions from clinical practice and may not be valid for other countries.

Methocarbamol blocks muscular Nav 1.4 channels and decreases isometric force of mouse muscles

BACKGROUND

The muscle relaxant methocarbamol is widely used for the treatment of muscle spasms and pain syndromes. To elucidate molecular mechanisms of its action, we studied its influence on neuromuscular transmission, on isometric muscle force, and on voltage-gated Na+ channels.

METHODS

Neuromuscular transmission was investigated in murine diaphragm-phrenic nerve preparations and muscle force studied on mouse soleus muscles. Nav 1.4 channels and Nav 1.7 channels were functionally expressed in eukaryotic cell lines.

RESULTS

Methocarbamol, at 2 mM, decreased the decay of endplate currents, slowed the decay of endplate potentials and reduced tetanic force of soleus muscles. The drug reversibly inhibited current flow through muscular Nav 1.4 channels, while neuronal Nav 1.7 channels were unaffected.

CONCLUSIONS

The study provides evidence for peripheral actions of methocarbamol on skeletal muscle. Muscular Na+ channels are a molecular target of methocarbamol. Since Nav 1.7 currents were unaffected, methocarbamol is unlikely to exert its analgesic effect by directly blocking Nav 1.7 channels.

Reducing the dose of neuromuscular blocking agents with adjuncts: a systematic review and meta-analysis

BACKGROUND

Acute global shortages of neuromuscular blocking agents (NMBA) threaten to impact adversely on perioperative and critical care. The use of pharmacological adjuncts may reduce NMBA dose. However, the magnitude of any putative effects remains unclear.

METHODS

We conducted a systematic review and meta-analysis of RCTs. We searched Medline, Embase, Web of Science, and Cochrane Database (1970-2020) for RCTs comparing use of pharmacological adjuncts for NMBAs. We excluded RCTs not reporting perioperative NMBA dose. The primary outcome was total NMBA dose used to achieve a clinically acceptable depth of neuromuscular block. We assessed the quality of evidence using the GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) criteria. Data are presented as the standardised mean difference (SMD); I² indicates percentage of variance attributable to heterogeneity.

RESULTS

From 3082 records, the full texts of 159 trials were retrieved. Thirty-one perioperative RCTs met the inclusion criteria for meta-analysis (n=1962). No studies were conducted in critically ill patients. Reduction in NMBA dose was associated with use of magnesium (SMD: -1.10 [-1.44 to -0.76], P<0.001; I²=85%; GRADE=moderate), dexmedetomidine (SMD: -0.89 [-1.55 to -0.22]; P=0.009; I²=87%; GRADE=low), and clonidine (SMD: -0.67 [-1.13 to -0.22]; P=0.004; I²=0%; GRADE=low) but not lidocaine (SMD: -0.46 [-1.01 to -0.09]; P=0.10; I²=68%; GRADE=moderate). Meta-analyses for nicardipine, diltiazem, and dexamethasone were not possible owing to the low numbers of studies. We estimated that 30-50 mg kg^-1 magnesium preoperatively (8-15 mg kg h^-1 intraoperatively) reduces rocuronium dose by 25.5% (inter-quartile range, 14.7-31).

CONCLUSIONS

Magnesium, dexmedetomidine, and clonidine may confer a clinically relevant sparing effect on the required dose of neuromuscular block ing drugs in the perioperative setting.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42020183969.

Neuromuscular block monitoring by smartphone application (i-TOF© system): an observational pilot study

Neuromuscular block monitoring is recommended by international guidelines to improve myorelaxation during surgery and reduce the risk of postoperative residual curarization. We conducted a pilot study to verify the efficacy of i-TOF, a wireless neuromuscular monitoring device connectable to a smartphone, comparing it with TOF WATCH SX. We enrolled 53 patients who underwent general anesthesia. For each patient, we recorded by both devices, in different time intervals, train-of-four (TOF) count/ratio after induction to general anesthesia (TI0-TI3) and during recovery (TR0-TR3). Moreover, post-tetanic count (PTC) was evaluated during deep neuromuscular block (TP0-TP2). We noticed no significant differences between the devices in recorded mean values of TOF ratio, TOF count, and PTC analyzed at time intervals for every phase of general anesthesia, although the i-TOF tends to an underestimation compared to TOF WATCH SX. For each patient, data sessions were successfully recorded by a smartphone. This aspect could be relevant for clinicians in order to have a stored proof of good clinical practice to be added on anesthesiologist records. By our results, i-TOF demonstrates a comparable efficacy to TOF WATCH SX, suggesting that it could be a proven alternative to standard devices for neuromuscular block monitoring. Further studies are needed to confirm our findings.

The effect of low- versus normal-pressure pneumoperitoneum during laparoscopic colorectal surgery on the early quality of recovery with perioperative care according to the enhanced recovery principles (RECOVER): study protocol for a randomized controlled study

BACKGROUND

There is increasing evidence for the use of lower insufflation pressures during laparoscopic surgery. Deep neuromuscular blockade allows for a safe reduction in intra-abdominal pressure without compromising the quality of the surgical field. While there is considerable evidence to support superior surgical conditions during deep neuromuscular blockade, there is only a limited amount of studies investigating patient outcomes. Moreover, results are not always consistent between studies and vary between different types of laparoscopic surgery. This study will investigate the effect of low-pressure pneumoperitoneum facilitated by deep NMB on quality of recovery after laparoscopic colorectal surgery.

METHODS

The RECOVER study is a multicenter double-blinded randomized controlled trial consisting of 204 patients who will be randomized in a 1:1 fashion to group A, low-pressure pneumoperitoneum (8 mmHg) facilitated by deep neuromuscular blockade (post tetanic count of 1-2), or group B, normal-pressure pneumoperitoneum (12 mmHg) with moderate neuromuscular blockade (train-of-four response of 1-2). The primary outcome is quality of recovery on postoperative day 1, quantified by the Quality of Recovery-40 questionnaire.

DISCUSSION

Few studies have investigated the effect of lower insufflation pressures facilitated by deep neuromuscular blockade on patient outcomes after laparoscopic colorectal procedures. This study will identify whether low pressure pneumoperitoneum and deep neuromuscular blockade will enhance recovery after colorectal laparoscopic surgery and, moreover, if this could be a valuable addition to the Enhanced Recovery After Surgery guidelines.

TRIAL REGISTRATION

EudraCT 2018-001485-42. Registered on April 9, 2018. Clinicaltrials.govNCT03608436. Registered on July 30, 2018.

Does deep neuromuscular blockade during laparoscopy procedures change patient, surgical, and healthcare resource outcomes? A systematic review and meta-analysis of randomized controlled trials

Background

Deep neuromuscular blockade may facilitate the use of reduced insufflation pressure without compromising the surgical field of vision. The current evidence, which suggests improved surgical conditions compared with other levels of block during laparoscopic surgery, features significant heterogeneity. We examined surgical patient- and healthcare resource use-related outcomes of deep neuromuscular blockade compared with moderate neuromuscular blockade in adults undergoing laparoscopic surgery.

Methods

We conducted a systematic literature review according to the quality standards recommended by the Cochrane Handbook for Systematic Reviews. Randomized controlled trials comparing outcomes of deep neuromuscular blockade and moderate neuromuscular blockade among adults undergoing laparoscopic surgeries were included. A random-effects model was used to conduct pair-wise meta-analyses.

Results

The systematic literature review included 15 studies—only 13 were analyzable in the meta-analysis and none were judged to be at high risk of bias. Compared with moderate neuromuscular blockade, deep neuromuscular blockade was associated with improved surgical field of vision and higher vision quality scores. Also, deep neuromuscular blockade was associated with a reduction in the post-operative pain scores in the post-anesthesia care unit compared with moderate neuromuscular blockade, and there was no need for an increase in intra-abdominal pressure during the surgical procedures. There were minor savings on resource utilization, but no differences were seen in recovery in the post-anesthesia care unit or overall length of hospital stay with deep neuromuscular blockade.

Conclusions

Deep neuromuscular blockade may aid the patient and physician surgical experience by improving certain patient outcomes, such as post-operative pain and improved surgical ratings, compared with moderate neuromuscular blockade. Heterogeneity in the pooled estimates suggests the need for better designed randomized controlled trials.

Incidence of residual neuromuscular blockade and use of neuromuscular blocking agents with or without antagonists: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

Neuromuscular blocking agents (NMBAs) have revolutionized the field of anesthesiology as they facilitate airway management and ensure optimal surgical conditions. Despite their beneficial and ubiquitous use during surgery, delayed or partial recovery from NMBAs, referred to as residual neuromuscular block (rNMB), is a common clinical problem. While it is well accepted that the antagonist sugammadex, compared to neostigmine, can more rapidly reverse rocuronium-induced NMB regardless of depth of block, the occurrence of rNMB for routinely used combinations of NMBAs with sugammadex or neostigmine has not yet been quantified or evaluated systematically.

REVIEW METHODS

We conducted a systematic literature review and meta-analysis of randomized controlled trials (RCTs) to quantify and compare the incidence of rNMB [defined as train-of-four ratio (TOFR) <0.9] in patients with moderate and deep neuromuscular block. Methods recommended by Cochrane Collaboration and PRISMA group were followed.

RESULTS

A total of 35 RCTs were identified, of which 20 contributed to the meta-analysis. For moderate block, rNMB incidence at 2 min after sugammadex administration was 19.2% (95% CI 0.0-57.8; 122 patients) and declined to 2.8% (95% CI 0.0-16.7; 93 patients) at 6 min post administration. For timepoints 10 to 60 min after administration, rNMB incidence ranged between 0.05% to 2.8%. In contrast, rNMB incidence at 2 min after neostigmine administration was 100% (95% CI 89.9-100; 182 patients) and was 82% (95% CI 71.4-91.2; 93 patients) at 6 min post administration. For timepoints 10 to 60 min after administration, rNMB incidence ranged between 14 and 32%. For deep block, rNMB incidence following sugammadex was essentially reduced to 1% at 15 min after administration. Residual NMB incidence following neostigmine remained at or above 95% for the first 60 min after administration.

CONCLUSIONS

Overall, based on evidence from 20 RCTs, our results suggest that the combination of rocuronium or vecuronium plus sugammadex is more effective and more rapid in reversing NMB compared with combinations of rocuronium, vecuronium, cisatracurium, or pancuronium plus neostigmine.

The impact of intra-abdominal pressure on perioperative outcomes in laparoscopic cholecystectomy: a systematic review and network meta-analysis of randomized controlled trials

Background

Laparoscopic cholecystectomy involves using intra-abdominal pressure (IAP) to facilitate adequate surgical conditions. However, there is no consensus on optimal IAP levels to improve surgical outcomes. Therefore, we conducted a systematic literature review (SLR) to examine outcomes of low, standard, and high IAP among adults undergoing laparoscopic cholecystectomy.

Methods

An electronic database search was performed to identify randomized controlled trials (RCTs) that compared outcomes of low, standard, and high IAP among adults undergoing laparoscopic cholecystectomy. A Bayesian network meta-analysis (NMA) was used to conduct pairwise meta-analyses and indirect treatment comparisons of the levels of IAP assessed across trials.

Results

The SLR and NMA included 22 studies. Compared with standard IAP, on a scale of 0 (no pain at all) to 10 (worst imaginable pain), low IAP was associated with significantly lower overall pain scores at 24 h (mean difference [MD]: − 0.70; 95% credible interval [CrI]: − 1.26, − 0.13) and reduced risk of shoulder pain 24 h (odds ratio [OR] 0.24; 95% CrI 0.12, 0.48) and 72 h post-surgery (OR 0.22; 95% CrI 0.07, 0.65). Hospital stay was shorter with low IAP (MD: − 0.14 days; 95% CrI − 0.30, − 0.01). High IAP was not associated with a significant difference for these outcomes when compared with standard or low IAP. No significant differences were found between the IAP levels regarding need for conversion to open surgery; post-operative acute bleeding, pain at 72 h, nausea, and vomiting; and duration of surgery.

Conclusions

Our study of published trials indicates that using low, as opposed to standard, IAP during laparoscopic cholecystectomy may reduce patients’ post-operative pain, including shoulder pain, and length of hospital stay. Heterogeneity in the pooled estimates and high risk of bias of the included trials suggest the need for high-quality, adequately powered RCTs to confirm these findings.

Electronic supplementary material

The online version of this article (10.1007/s00464-020-07527-2) contains supplementary material, which is available to authorized users.

Neurophysiological Assessment of Prolonged Recovery From Neuromuscular Blockade in the Neonatal Intensive Care Unit

Objective: To evaluate recovery from neuromuscular blockade in infants using Train-of-Four nerve stimulation. Study Design: Ulnar nerve stimulation was used to evoke thumb twitch and reported as Train-of-Four ratio. Thumb twitch was also recorded visually in real-time. Primary outcome was time to near recovery of muscle function (Train-of-Four ratio >70%). Secondary analyses were time to greater degrees of recovery (Train-of-Four ratio >80, 90%), sensitivity of accelerometry vs. visual thumb-twitch and clinical variates to assess safety. Results: Patients were enrolled following rocuronium-boluses (n = 10) and vecuronium-infusions (n = 9). Median recovery time to Train-of-Four ratio >70% was 14 h following rocuronium-bolus dosing and 34 h following cessation of continuous vecuronium infusion. Median stimulus threshold for accelerometry was 27.5 mA and visual observation was 20 mA. There were no safety concerns. Conclusion(s): Neuromuscular monitoring using Train-of-Four nerve stimulation is feasible in infants. Some infants exhibited prolonged recovery from neuromuscular-blockade. These pilot data may facilitate future standardized pediatric protocols on neuromuscular monitoring for safer dosing.