Residual Paralysis at the Time of Tracheal Extubation

Assessing pain in paralyzed critically ill patients receiving neuromuscular blocking agents: A monocenter prospective cohort

INTRODUCTION

Given the absence of established recommendations for pain assessment in pharmacologically paralyzed Intensive-Care-Units (ICU) patients under Neuro-Muscular-Blocking Agents (NMBA), this study assessed the validity of various parameters for evaluating pain in this specific population.

PATIENTS AND METHODS

Four electrophysiological parameters (instant-Analgesia-Nociception-Index (ANI), Bispectral index (BIS), Heart Rate (HR) and Mean Arterial Blood Pressure (ABP)) and one clinical parameter (Behavioural-Pain-Scale (BPS)) were recorded during tracheal-suctioning in all consecutive ICU patients who required a continuous infusion of cisatracurium, before and just after paralysis recovery measured by Train-of-Four ratio. The validity of the five pain-related parameters was assessed by comparing the values recorded during different situations (before/during/after the nociceptive procedure) (discriminant-validity, primary outcome), and the effect of paralysis was assessed by comparing values obtained during and after paralysis (reliability, secondary outcome).

RESULTS

Twenty patients were analyzed. ANI, BIS, and HR significantly changed during the nociceptive procedure in both paralysis and recovery, while BPS changed only post-recovery. ANI and HR were unaffected by paralysis, unlike BIS and BPS (mixed-effect model). ANI exhibited the highest discriminant-validity, with values (min 0/max 100) decreasing from 71 [48-89] at rest to 41 [25-72] during tracheal suctioning in paralyzed patients, and from 71 [53-85] at rest to 40 [31-52] in non-paralyzed patients.

CONCLUSIONS

ANI proves the most discriminant parameter for pain detection in both paralyzed and non-paralyzed sedated ICU patients. Its significant and clinically relevant decrease during tracheal suctioning remains unaltered by NMBA use. Pending further studies on analgesia protocols based on ANI, it could be used to assess pain during nociceptive procedures in ICU patients receiving NMBA.

Nanotherapeutics for Alleviating Anesthesia-Associated Complications

Current management of anesthesia-associated complications falls short in terms of both efficacy and safety. Nanomaterials with versatile properties and unique nano-bio interactions hold substantial promise as therapeutics for addressing these complications. This review conducts a thorough examination of the existing nanotherapeutics and highlights the strategies for developing prospective nanomedicines to mitigate anesthetics-related toxicity. Initially, general, regional, and local anesthesia along with the commonly used anesthetics and related prevalent side effects are introduced. Furthermore, employing nanotechnology to prevent and alleviate the complications of anesthetics is systematically demonstrated from three aspects, that is, developing 1) safe nano-formulization for anesthetics; 2) nano-antidotes to sequester overdosed anesthetics and alter their pharmacokinetics; 3) nanomedicines with pharmacodynamic activities to treat anesthetics toxicity. Finally, the prospects and challenges facing the clinical translation of nanotherapeutics for anesthesia-related complications are discussed. This work provides a comprehensive roadmap for developing effective nanotherapeutics to prevent and mitigate anesthesia-associated toxicity, which can potentially revolutionize the management of anesthesia complications.

Neuromuscular block: Monitoring, reversal, and residual blockade in small animals

Nondepolarizing neuromuscular blocking agents are used frequently during ophthalmic surgery of dogs and cats. Residual neuromuscular block (NMB)-impaired neuromuscular function at recovery from anesthesia-is a main concern when these agents are used in small animals. In humans, residual NMB reduces the ability to protect the airway (swallow and cough) and increases the incidence of hypoxia and upper airway collapse after recovery from anesthesia. In dogs, impaired neuromuscular function of the larynx can be detected even after common indicators of neuromuscular function suggest that recovery from NMB is complete. Objective monitoring of NMB is a simple, cost-effective strategy to minimize the risk of residual NMB. This review summarizes relevant aspects of monitoring and reversal of NMB, and strategies to minimize the risk of residual NMB in clinical practice of small animals.

Rate of residual neuromuscular block using single-dose rocuronium in general anesthesia for ENT surgery: a retrospective cohort study

INTRODUCTION

NMB facilitates intubating conditions in general anesthesia. However, it is associated with significant residual postoperative paralysis and morbidity.

OBJECTIVE

To investigate the rate of underdiagnosed residual NMB based on two TOFR criteria (< 0.91 and < 1.00).

METHODS

We performed a retrospective study adhering to STROBE guidelines. We included patients undergoing ENT surgery using single-dose neuromuscular block for balanced general anesthesia from June to December 2018. We collected demographic and anthropometric data, ASA score, NMBA dose, TOFR recordings at 5, 30 and 60 min and end of the surgery, anesthesia and surgery time, and administration of reversal agent. Statistical analysis included descriptive and dispersion measures statistics, curve and cross tables for residual NMB on different TOFR criteria with sub-analysis for AR, RR, and OR in patients over 65 years old.

RESULTS

We included 57 patients, mean age 41; 43 females and 14 males. Mean anesthetic and surgical time were 139.4 and 116.1 min, respectively. All the patients received rocuronium under a mean ponderal single-dose of 0.48 mg/kg. Residual NMB rates were 29.9 and 49.1% for a TOFR < 0.91 and < 1.00, respectively. Older adults had an OR of 6.08 for residual NMB.

CONCLUSIONS

The rate of residual NMB was 29.9 to 49.1%, depending on the criteria used (TOFR < 0.91 and < 1.00, respectively). Patients above 65 years old had an increased risk of residual NMB (6.08 OR) and clinical symptoms related to residual NMB (11.75 OR). We recommend future research aiming to provide a specific surveillance protocol for patients above 65 years old, including shorter-action NMB, early reversal, and prolonged surveillance using the TOFR criteria of < 1.00 to identify patients at risk of residual NMB readily.

2023 American Society of Anesthesiologists Practice Guidelines for Monitoring and Antagonism of Neuromuscular Blockade: A Report by the American Society of Anesthesiologists Task Force on Neuromuscular Blockade

These practice guidelines provide evidence-based recommendations on the management of neuromuscular monitoring and antagonism of neuromuscular blocking agents during and after general anesthesia. The guidance focuses primarily on the type and site of monitoring and the process of antagonizing neuromuscular blockade to reduce residual neuromuscular blockade.

Quantitative Neuromuscular Monitoring in Clinical Practice: A Professional Practice Change Initiative

BACKGROUND

Residual neuromuscular blockade can be avoided with quantitative neuromuscular monitoring. The authors embarked on a professional practice initiative to attain documented train-of-four ratios greater than or equal to 0.90 in all patients for improved patient outcomes through reducing residual paralysis.

METHODS

The authors utilized equipment trials, educational videos, quantitative monitors in all anesthetizing locations, and electronic clinical decision support with real-time alerts, and initiated an ongoing professional practice metric. This was a retrospective assessment (2016 to 2020) of train-of-four ratios greater than or equal to 0.9 that were documented before extubation. Anesthesia records were manually reviewed for neuromuscular blockade management details. Medical charts of surgical patients who received a neuromuscular blocking drug were electronically searched for patient characteristics and outcomes.

RESULTS

From pre- to postimplementation, more patients were assigned American Society of Anesthesiologists Physical Status III to V, fewer were inpatients, the rocuronium average dose was higher, and more patients had a prereversal train-of-four count less than 4. Manually reviewed anesthesia records (n = 2,807) had 2 of 172 (1%) cases with documentation of train-of-four ratios greater than or equal to 0.90 in November 2016, which was fewer than the cases in December 2020 (250 of 269 [93%]). Postimplementation (February 1, 2020, to December 31, 2020), sugammadex (650 of 935 [70%]), neostigmine (195 of 935 [21%]), and no reversal (90 of 935 [10%]) were used to attain train-of-four ratios greater than or equal to 0.90 in 856 of 935 (92%) of patients. In the electronically searched medical charts (n = 20,181), postimplementation inpatients had shorter postanesthesia care unit lengths of stay (7% difference; median [in min] [25th, 75th interquartile range], 73 [55, 102] to 68 [49, 95]; P < 0.001), pulmonary complications were less (43% difference; 94 of 4,138 [2.3%] to 23 of 1,817 [1.3%]; P = 0.010; -1.0% difference [95% CI, -1.7 to -0.3%]), and hospital length of stay was shorter (median [in days] [25th, 75th], 3 [2, 5] to 2 [1, 4]; P < 0.001).

CONCLUSIONS

In this professional practice initiative, documentation of train-of-four ratios greater than or equal to 0.90 occurred for 93% of patients in a busy clinical practice. Return-of-strength documentation is an intermediate outcome, and only one of many factors contributing to patient outcomes.

EDITOR’S PERSPECTIVE

Neuromuscular blockade with atracurium for ophthalmic surgery in horses-Effects on surgical and anesthetic characteristics and recovery quality

OBJECTIVE

To study the surgical, anesthetic and recovery qualities of horses receiving either a neuromuscular blocking agent (atracurium) or intravenous lidocaine (treatment groups A and L, respectively).

ANIMALS STUDIED

A total of thirty horses presented for ocular surgery were used in this study.

PROCEDURE

Horses were randomly assigned to receive either atracurium (group A) or a lidocaine constant rate infusion (group L). Surgical quality was graded on a scale from 1 (excellent)-5 (poor). While anesthetized, the heart rate, oxygen saturation and mean arterial blood pressure, and end-expiratory carbon dioxide and desflurane concentration were monitored and recorded every 5 minutes. Recovery was scored on a scale from 10 (best)-115 (worst).

RESULTS

Horses in treatment group A needed significantly less desflurane then horses in treatment group L (p = 0.04). Horses in treatment group A had a significantly better surgery score of 1 (1-2) (median and range) then horses in treatment group L (2.5; 1-5) (p = 0.02). The quality of recovery was significantly better in horses in treatment group A compared with treatment group L, and horses needed significantly less time to reach the standing position.

CONCLUSIONS

Atracurium and lidocaine CRI are safe methods of anesthesia for equine patients undergoing ocular surgery. Horses receiving atracurium needed less desflurane and had better surgery and recovery scores than horses receiving a lidocaine constant rate infusion.

Quantitative Neuromuscular Monitoring With Train-of-Four Ratio During Elective Surgery: A Prospective, Observational Study

OBJECTIVES

Postoperative residual neuromuscular block (PRNB) is a serious problem that can cause death after surgery. It was aimed to evaluate the adequacy of neuromuscular block (NMB) during endotracheal intubation and the adequacy of neuromuscular recovery during clinically extubation decision and follow-up with the train-of-four ratio (TOFR) using quantitative monitoring.

METHODS

This study has a prospective-observational single-blind study design. A total of 205 adult patients who underwent elective surgery, who had American Society of Anesthesiologists physical statuses I to III, and who were intubated with neuromuscular blocking agent under general anesthesia were included in the study. Train-of-four ratio measurements were provided single-blindly by another anesthesiologist outside the team. The TOFRs were measured at the time of intubation (TOFRind), before reversal agent administration (TOFRpre-rev) and after (TOFRpost-rev), at the time of extubation (TOFRext), and on admission to the postoperative care unit (TOFRPACU). If clinical signs of PRNB appeared, the recovery protocol was applied and then TOFRrec was measured. Postoperative respiratory complications were also evaluated for the first 24 hours after surgery.

RESULTS

Endotracheal intubation was performed in 41.5% of the patients (n = 85) without adequate NMB. In 48.8% (n = 100) of the patients, adequate recovery (TOFRext ˂0.9) was not available at the time of extubation. Adequate TOFRPACU rate was found to be significantly higher in those who did not receive additional neuromuscular blocking agent doses (P < 0.001). In the recovery protocol, low-dose sugammadex administered to patients with clinical signs of PRNB significantly increased the TOFRrec rate compared with neostigmine (P ˂ 0.001). The first 24 hours, postoperative respiratory complication rate was 5.4% (n = 11), and the most common hypoxemia was observed.

CONCLUSIONS

Approximately half of the patients are intubated without sufficient NMB and extubated without sufficient neuromuscular recovery. This suggests that routine use of quantitative neuromuscular monitoring is necessary for patient safety.

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.

Cautionary findings for motor evoked potential monitoring in intracranial aneurysm surgery after a single administration of rocuronium to facilitate tracheal intubation

Administration of rocuronium to facilitate intubation has traditionally been regarded as acceptable for intraoperative motor evoked potential (MEP) monitoring because of sufficiently rapid spontaneous neuromuscular blockade recovery. We hypothesized that residual neuromuscular blockade, in an amount that could hinder optimal neuromonitoring in patients undergoing intracranial aneurysm clipping, was still present at dural opening. We sought to identify how often this was occurring and to identify factors which may contribute to prolonged blockade. Records of 97 patients were retrospectively analyzed. Rocuronium was administered to facilitate intubation with no additional neuromuscular blockade given. Prolonged spontaneous recovery time to a train-of-four (TOF) ratio of 0.75 after rocuronium administration was defined as 120 min, which was approximately when dural opening and the setting of baseline MEPs were occurring. Logistic regression analysis was used to identify factors related to prolonged spontaneous recovery time. Prolonged spontaneous recovery time to a TOF ratio of 0.75 was observed in 44.3% of patients. Multivariable analysis showed that only the dosage of rocuronium based on ideal body weight had a positive correlation with prolonged spontaneous recovery time (P = 0.01). There was no significant association between dosage of rocuronium based on total body weight, age, sex, or body temperature and prolonged recovery time. This study demonstrates that the duration of relaxation for MEP monitoring purposes is well-beyond the routinely recognized clinical duration of rocuronium. Residual neuromuscular blockade could result in lower amplitude MEP signals and/or lead to higher required MEP stimulus intensities which can both compromise monitoring sensitivity.

Epidemiology and outcomes of residual neuromuscular blockade: A systematic review of observational studies

OBJECTIVES

Complete reversal of neuromuscular blockade (NMB) is important for patient safety and prognosis following surgical procedures involving NMB agents (NMBAs). Published evidence on the epidemiology and consequences of residual neuromuscular blockade (rNMB; incomplete neuromuscular recovery) in real-world clinical settings is lacking with advances in NMB management. Therefore, we aimed to examine the burden of rNMB and its associated clinical, economic and humanistic outcomes using a systematic review framework.

REVIEW METHODS

Electronic and conference database searches were performed to include observational studies examining rNMB or related outcomes in adults undergoing surgery and receiving NMBAs with or without NMBA antagonists.

RESULTS

Of 1438 screened abstracts, 58 studies with 25,277 total patients were included. Inconsistent definitions of rNMB were reported across studies with 44 (76%) and 29 (50%) studies utilizing quantitative and qualitative measures to detect rNMB, respectively. The most common definition of rNMB was train-of-four ratio (TOFR) <0.9 (29 studies) and TOFR <0.7 (16 studies) measured at post-anesthesia care unit (PACU) entry. For TOFR <0.9 at PACU entry, rNMB incidence ranged from 0% to 90.5% (median 30%) overall; 0% to 16.0% in the sugammadex (SUG) group; 3.5% to 90.5% in the neostigmine (NEO) group; and 15% to 89% in the spontaneous recovery (SR) group. Twenty-one studies reported clinical outcomes (reintubation, mild hypoxemia, or a respiratory event) or resource utilization outcomes (hospital/PACU length of stay [LOS]) by presence/absence of rNMB. Patients with rNMB had higher rates of acute respiratory events compared to those without rNMB.

CONCLUSIONS

Real-world observational studies show a significant burden of rNMB and associated health sequelae, though rNMB measures were not reported consistently across studies. Appropriate quantitative measurement is needed to accurately identify rNMB, and interventions are needed to reduce its burden and associated adverse outcomes.

Neuromuscular blockade management in the critically Ill patient

Neuromuscular blocking agents (NMBAs) can be an effective modality to address challenges that arise daily in the intensive care unit (ICU). These medications are often used to optimize mechanical ventilation, facilitate endotracheal intubation, stop overt shivering during therapeutic hypothermia following cardiac arrest, and may have a role in the management of life-threatening conditions such as elevated intracranial pressure and status asthmaticus (when deep sedation fails or is not tolerated). However, current NMBA use has decreased during the last decade due to concerns of potential adverse effects such as venous thrombosis, patient awareness during paralysis, development of critical illness myopathy, autonomic interactions, and even residual paralysis following cessation of NMBA use.

It is therefore essential for clinicians to be familiar with evidence-based practices regarding appropriate NMBA use in order to select appropriate indications for their use and avoid complications. We believe that selecting the right NMBA, administering concomitant sedation and analgesic therapy, and using appropriate monitoring techniques mitigate these risks for critically ill patients. Therefore, we review the indications of NMBA use in the critical care setting and discuss the most appropriate use of NMBAs in the intensive care setting based on their structure, mechanism of action, side effects, and recognized clinical indications. Lastly, we highlight the available pharmacologic antagonists, strategies for sedation, newer neuromuscular monitoring techniques, and potential complications related to the use of NMBAs in the ICU setting.

A randomized-controlled trial of sugammadex versus neostigmine: impact on early postoperative strength

BACKGROUND

Residual neuromuscular blockade after surgery is associated with airway obstruction, hypoxia, and respiratory complications. Compared with neostigmine, sugammadex reverses neuromuscular blockade to a train-of-four ratio > 0.9 more rapidly. It is unknown, however, whether the superior reversal profile of sugammadex improves clinically relevant measures of strength in the early postoperative period.

METHODS

Patients undergoing general, gynecological, or urologic surgery were randomized to receive either neostigmine (70 µg·kg^-1, maximum 5 mg) or sugammadex (2 or 4 mg·kg^-1) to reverse neuromuscular blockade. The primary outcome was the ability to breathe deeply measured by incentive spirometry at 30, 60, and 120 min after reversal.

RESULTS

We randomized 62 patients to either a neostigmine (n = 31) or sugammadex (n = 31) group. The incentive spirometry volume recovery trajectory was not different between the two groups (P = 0.35). Median spirometry volumes at baseline, 30, 60, and 120 min postoperatively were 2650 vs 2500 mL, 1775 vs 1750 mL, 1375 vs 2000 mL, and 1800 vs 1950 mL for the sugammadex and neostigmine groups, respectively. Postoperative incentive spirometry decrease from baseline was not different between the two groups. Hand grip strength, the ability to sit unaided, train-of-four ratio on postanesthesia care unit (PACU) admission, time to extubation, time to PACU discharge readiness, and Quality of Recovery-15 scores were also not different between the groups.

CONCLUSIONS

Measures of postoperative strength, such as incentive spirometry, hand group strength, and the ability to sit up in the early postoperative period were not different in patients who received neostigmine or sugammadex for the reversal of neuromuscular blockade.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT02909439); registered: 21 September, 2016.

Comparison of sugammadex and pyridostigmine bromide for reversal of rocuronium-induced neuromuscular blockade in short-term pediatric surgery: A prospective randomized study

BACKGROUND

Sugammadex reverses rocuronium-induced neuromuscular blockade quickly and effectively. This study compared efficacy of sugammadex and pyridostigmine for reversal of rocuronium-induced light block or minimal block in children scheduled for elective entropion surgery.

METHODS

A prospective randomized study was conducted on 60 pediatric patients aged 1 to 11 years and scheduled for entropion surgery under sevoflurane anesthesia. Neuromuscular blockade was achieved by administration of 0.6 mg/kg rocuronium and assessed using train-of-four (TOF) ulnar nerve stimulation. Patients were randomly assigned to 2 groups receiving sugammadex 2 mg/kg or pyridostigmine 0.2 mg/kg plus glycopyrrolate 0.01 mg/kg. Primary outcomes were time from reversal agents administration to TOF ratio 0.9 and time from reversal agent administration to TOF ratio 1.0. Time from TOF ratio 0.9 to extubation, time from TOF ratio 1.0 to extubation, and postoperative adverse events were also recorded.

RESULTS

There were no substantial differences in demographic variables. Time from reversal agents administration to TOF ratio 0.9 and time from reversal agents to TOF ratio 1.0 were significantly faster in sugammadex group: 1.30 ± 0.84 versus 3.53 ± 2.73 minutes (P < .001) and 2.75 ± 1.00 versus 5.73 ± 2.83 minutes (P < .001). Extubation time was shorter in sugammadex group. Incidence of skin rash, nausea, vomiting, and postoperative residual neuromuscular blockade (airway obstruction) was not statistically different between groups. Incidence of patients agitation in recovery room was lower in sugammadex group.

CONCLUSION

Sugammadex provided more rapid reversal of rocuronium-induced neuromuscular blockade in pediatric patients undergoing surgery lasting 30 to 60 minutes than did pyridostigmine plus glycopyrrolate, with no differences in incidence of adverse events between groups.

Guidelines on muscle relaxants and reversal in anaesthesia

OBJECTIVES

To provide an update to the 1999 French guidelines on "Muscle relaxants and reversal in anaesthesia", a consensus committee of sixteen experts was convened. A formal policy of declaration and monitoring of conflicts of interest (COI) was developed at the outset of the process and enforced throughout. The entire guidelines process was conducted independently of any industrial funding (i.e. pharmaceutical, medical devices). The authors were required to follow the rules of the Grading of Recommendations, Assessment, Development and Evaluation (GRADE®) system to assess the quality of the evidence on which the recommendations were based. The potential drawbacks of making strong recommendations based on low-quality evidence were stressed. Few of the recommendations remained ungraded.

METHODS

The panel focused on eight questions: (1) In the absence of difficult mask ventilation criteria, is it necessary to check the possibility of ventilation via a facemask before muscle relaxant injection? Is it necessary to use muscle relaxants to facilitate facemask ventilation? (2) Is the use of muscle relaxants necessary to facilitate tracheal intubation? (3) Is the use of muscle relaxants necessary to facilitate the insertion of a supraglottic device and management of related complications? (4) Is it necessary to monitor neuromuscular blockade for airway management? (5) Is the use of muscle relaxants necessary to facilitate interventional procedures, and if so, which procedures? (6) Is intraoperative monitoring of neuromuscular blockade necessary? (7) What are the strategies for preventing and treating residual neuromuscular blockade? (8) What are the indications and precautions for use of both muscle relaxants and reversal agents in special populations (e.g. electroconvulsive therapy, obese patients, children, neuromuscular diseases, renal/hepatic failure, elderly patients)? All questions were formulated using the Population, Intervention, Comparison and Outcome (PICO) model for clinical questions and evidence profiles were generated. The results of the literature analysis and the recommendations were then assessed using the GRADE® system.

RESULTS

The summaries prepared by the SFAR Guideline panel resulted in thirty-one recommendations on muscle relaxants and reversal agents in anaesthesia. Of these recommendations, eleven have a high level of evidence (GRADE 1±) while twenty have a low level of evidence (GRADE 2±). No recommendations could be provided using the GRADE® system for five of the questions, and for two of these questions expert opinions were given. After two rounds of discussion and an amendment, a strong agreement was reached for all the recommendations.

CONCLUSION

Substantial agreement exists among experts regarding many strong recommendations for the improvement of practice concerning the use of muscle relaxants and reversal agents during anaesthesia. In particular, the French Society of Anaesthesia and Intensive Care (SFAR) recommends the use of a device to monitor neuromuscular blockade throughout anaesthesia.

Usefulness of intra-operative neuromuscular blockade monitoring and reversal agents for postoperative residual neuromuscular blockade: a retrospective observational study

BACKGROUND

Complete avoidance of residual neuromuscular blockade (RNMB) during the postoperative period has not yet been achieved in current anesthesia practice. Evidently, compliance with NMB monitoring is persistently low, and the risk of RNMB during the perioperative period remains underestimated. To our knowledge, no publications have reported the incidence of RNMB in a university hospital where access to quantitative NMB monitoring and sugammadex is unlimited and where NMB management is not protocolised. The primary aim of this study was to estimate the incidence of RNMB in patients managed with or without sugammadex or neostigmine as antagonists and quantitative NMB monitoring in the operating room. The secondary aim was to explore the associations between RNMB and potentially related variables.

METHODS

This retrospective observational cohort study was conducted at a tertiary referral university hospital in Buenos Aires, Argentina. Records created between June 2015 and December 2015 were reviewed. In total, 240 consecutive patients who had undergone elective surgical procedures requiring NMB were included. All patients were monitored via acceleromyography at the adductor pollicis muscle within 5 min of arrival in the postanaesthesia care unit (PACU). Scheduled recovery in the intensive care unit was the only exclusion criterion.

RESULTS

RNMB was present in 1.6% patients who received intra-operative quantitative NMB monitoring and 32% patients whose NMB was not monitored (P <  0.01). Multivariable analysis revealed that the use of intra-operative quantitative NMB monitoring and sugammadex were associated with a lower incidence of RNMB, with calculated odds ratios of 0.04 (95% confidence interval [CI]: 0.005 to 0.401) and 0.18 (95% CI: 0.046 to 0.727), respectively.

CONCLUSIONS

The results of the present study suggest that intra-operative quantitative NMB monitoring and use of sugammadex are associated with a decreased incidence of RNMB in the PACU, reinforcing the contention that the optimal strategy for RNMB avoidance is the use of quantitative NMB monitoring and eventual use of reversal agents, if needed, prior to emergence from anaesthesia.

Optimised reversal without train-of-four monitoring versus reversal using quantitative train-of-four monitoring: An equivalence study

Background and Aims:

Less residual paralysis in recovery room was demonstrated when train-of-four (TOF) monitoring was applied. The aim of this study was to know whether optimisation of neostigmine reversal without TOF monitoring was equivalent to reversal using TOF monitoring.

Methods:

Seventy two patients, aged 18–60 years, undergoing elective surgery under general anaesthesia (sevoflurane and rocuronium) with intubation were randomised into two interventions: an optimised neostigmine reversal strategy without TOF monitoring (group A, n = 36) and a neostigmine reversal strategy using quantitative TOF monitoring (group B, n = 36). Per-protocol analysis was performed to compare incidence of residual paralysis in the recovery room between the two groups.

Results:

Six residual paralyses occurred in group A in the recovery room, whereas one case occurred in group B. The equivalence test showed that the 95% confidence interval of this study was outside the range of equivalence margin (15%). The absolute difference was 13.9%: standard error (SE) =0.068 (P = 0.107; 95% confidence interval (CI): 1%, 27.2%). No subjects had TOF ratio <0.70 in the recovery room. The TOF ratio in the recovery room did not differ between the two groups (mean difference: −2.58; P = 0.05; 95% CI: −5.20, 0.29). One respiratory adverse event occurred in this study.

Conclusion:

An optimised reversal strategy without TOF monitoring is not equivalent to a reversal strategy based on quantitative TOF monitoring. TOF monitoring should be used whenever applicable, although neostigmine is optimised.

Differences of Recovery from Rocuronium-induced Deep Paralysis in Response to Small Doses of Sugammadex between Elderly and Nonelderly Patients

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Complete recovery from rocuronium-induced muscle paralysis with sugammadex is reported to be delayed in elderly patients. The authors tested a hypothesis that recovery from deep neuromuscular block with low-dose sugammadex is slower (primary hypothesis) and incidence of recurarization is higher (secondary hypothesis) in elderly patients than in nonelderly patients.

Methods

In anesthetized elderly (n = 20; 76.9 ± 5.0 yr of age) and nonelderly patients (n = 20; 53.7 ± 12.8 yr of age) under deep paralysis with rocuronium, change of train-of-four ratio per minute (primary outcome variable) was measured with an acceleromyograph neuromuscular monitor during spontaneous recovery from rocuronium-induced muscle paralysis (0.6 mg/kg) and after infusion of low-dose sugammadex (50 µg · kg-1 · min-1). Recurarization was defined as the negative change of train-of-four ratio.

Results

Spontaneous train-of-four ratio recovery rate was significantly slower in the elderly group (median [25th percentile, 75th percentile]: 1.89 [1.22, 2.90] %/min) than in the nonelderly group (3.45 [1.96, 4.25] %/min, P = 0.024). Train-of-four ratio change rate in response to low-dose sugammadex was significantly slower in elderly (0.55 [–0.29, 1.54] %/min) than in the nonelderly group (1.68 [0.73, 3.13] %/min, P = 0.024). Incidence of recurarization was significantly higher in the elderly group than in the nonelderly group (35% vs. 5%, P = 0.044). Multiple linear regression analyses indicate that slower spontaneous train-of-four ratio recovery rate and impaired renal function are two major contributing factors that decrease train-of-four ratio change rate in response to low-dose sugammadex.

Conclusions

Elderly patients are at greater risk for recurarization and residual muscle paralysis when low-dose sugammadex is administered.

Quantitative Relationships between Pulmonary Function and Residual Neuromuscular Blockade

Background

Neuromuscular blockade is a risk factor for postoperative respiratory weakness during the immediate postoperative period. The quantitative relationships between postoperative pulmonary-function impairment and residual neuromuscular blockade are unknown.

Methods

113 patients who underwent elective laparoscopic cholecystectomy were enrolled in this study. They all had a pulmonary-function test (PFT) during the preoperative evaluation. Predictive values based on demographic data were also recorded. The train-of-four ratio (TOFR) was recorded at the same time as the PFT and at every 5 minutes in the qualified 98 patients in the postanesthesia care unit (PACU). We analyzed the degree of PFT recovery when the TOFR had recovered to different degrees.

Results

There was a significant difference (P < 0.05) between the preoperative baseline value and the postoperative forced vital capacity at each TOFR point, except at a TOFR value of 1.1. There was also a significant difference (P < 0.05) between the preoperative baseline value and the postoperative peak expiratory flow at each TOFR point.

Conclusions

Postoperative residual neuromuscular blockade was common (75.51%) after tracheal extubation, and pulmonary function could not recover to an acceptable level (85% of baseline value), even if TOFR had recovered to 0.90.

Trial Registration

Chinese Clinical Trial Register is ChiCTR-OOC-15005838.

A randomized control trial comparing train of four ratio > 0.9 to clinical assessment of return of neuromuscular function before endotracheal extubation on critical respiratory events in adult patients undergoing elective surgery at a tertiary hospital in Nairobi

BACKGROUND

There is increasing evidence that the incidence of postoperative residual paresis after using neuromuscular blockers ranges from 24 to 50% in post anaesthesia care unit (PACU) and is associated with postoperative complications such as critical respiratory events as evidenced by hypoxia, hypoventilation and upper airway obstruction. Quantitative neuromuscular monitoring (such as the assessment of Train of four (TOF) ratio) and reversal of neuromuscular blockers has been shown to reduce postoperative residual paresis. There are very few outcome studies on effect of residual paresis in PACU. There is a paucity of published randomized controlled trials investigating whether using a TOF ratio ≥0.9 before endotracheal extubation compared to clinical assessment of return of neuromuscular function reduces the incidence of critical respiratory events in PACU.

OBJECTIVE

To determine whether using TOF ratio ≥ 0.9 compared to clinical assessment of return of neuromuscular function before endotracheal extubation reduces the incidence of critical respiratory events in PACU.

METHODS

Onehundred sixty eight adult patients in ASA physical status I and II requiring general anaesthesia for elective surgery with cisatracurium as the muscle relaxant were randomized into 2 groups of 84 each. Group 1 were patients who required a TOF ratio of ≥0.9 before extubation. Group 2 patients were extubated based on clinical assessment of return of adequate neuromuscular function by the anaesthetist as is the standard of practice at the Aga Khan University hospital Nairobi. General anaesthesia was standardized in both groups. Both the investigators and patients were blinded during the study.Once the patient was transferred to PACU, oxygen saturation (SP02), respiratory rate and any signs of upper airway obstruction as demonstrated by stridor, laryngospasms or requirement of any airway manipulation was recorded for the first 30 minutes. Duration of anaesthesia and surgery was also recorded. Patient demographics were recorded and analyzed.

RESULTS

There was no statistical difference between the 2 groups in terms of patient demographics, duration of surgery and anaesthesia and duration since last muscle relaxant was given. In terms of hypoxia on arrival in PACU, the incidence of mild hypoxia (SPO2 90-93%) was 11% in clinical assessment groupversus 5% in TOF group P-value 0.149 while severe hypoxia (SPO2 <90%) was 19% versus 10% P-value 0.078. During the first 30 minutes in PACU, the incidence of mild hypoxia (SPO2 90-93%) was statistically significant between the 2 groups (12% in clinical assessment group versus 1% in TOF group, P-value 0.005) while severe hypoxia (SPO2 <90%) was 7% versus 5%, P-value 0.373. The incidence of upper airway obstruction was statistically significant between the two groups (45% in clinical assessment group versus 14% in TOF group P-value<0.0001 for patients requiring airway maneuver, 21% versus 2% P-value <0.0001 for those who required tactile stimulation and 31% versus 12% were snoring, P-value 0.003. Logistic regression analysis revealed TOF group was less likely associated with mild hypoxia (OR 0.09 95% CI 0.01-0.71 P-value 0.023), tactile stimulation (OR 0.09 95% CI 0.02-0.40 P-value 0.002), airway maneuver (OR 0.20 95% CI 0.10-0.43 P-value <0.001) and snoring (OR 0.30 95% CI 0.13-0.68 P-value 0.04).

CONCLUSION

Among this population, there is a lower incidence of critical respiratory events in PACU with the use of neuromuscular monitoring using TOF ratio ≥0.9 to assess neuromuscular function before endotracheal extubation compared with the use of clinical assessment methods.

Postoperative complications with neuromuscular blocking drugs and/or reversal agents in obstructive sleep apnea patients: a systematic review

BACKGROUND

Neuromuscular blocking drugs (NMBD) are administered intra-operatively to facilitate intubation and to achieve muscle relaxation for surgical procedures. Incomplete reversal of NMBD can lead to adverse events in the postoperative period. Patients with obstructive sleep apnea (OSA) may be at higher risk of complications related to the use of NMBD. The objectives of this systematic review were to determine whether: 1) OSA patients are at higher risk of postoperative complications from the use of NMBD than non-OSA patients, and 2) the choice of NMBD reversal agent affects the risk of postoperative complications in OSA patients.

METHODS

A literature search of multiple databases was conducted up to April 2017. The inclusion criteria were: (1) adult surgical patients (≥18 years old) with OSA diagnosed by polysomnography, or history, or suspected by screening questionnaire; (2) patients who were given NMBD and/or NMBD reversal agents intraoperatively; (3) reports on postoperative adverse events, particularly respiratory events were available; (4) published studies were in English; and (5) RCTs or observational cohort studies. The quality of evidence was determined by the Oxford Center for Evidence Based Medicine levels of evidence.

RESULTS

Out of 4123 studies, five studies (2 RCTs and 3 observational studies) including 1126 patients were deemed eligible. These studies were heterogeneous precluding a meta-analysis of the results. Two of three studies (1 RCT, 2 observational studies) reported that OSA patients given NMBD may be at higher risk of developing postoperative pulmonary complications (PPCs) like hypoxemia, residual neuromuscular blockade or respiratory failure compared to non-OSA patients. Two studies (1 RCT, 1 observational study) reported that OSA patients who were reversed with sugammadex vs. neostigmine had less PPCs and chest radiographic changes, but the quality of the included studies was Oxford level of evidence: low to moderate.

CONCLUSIONS

OSA patients who receive intraoperative NMBD may be at higher risk for postoperative hypoxemia, respiratory failure and residual neuromuscular blockade compared to non-OSA patients. There is some, albeit very limited evidence that NMBD reversal with sugammadex may be associated with less PPCs than neostigmine in patients with OSA. More high-quality studies are needed.

Neuromuscular blockers and reversal agents and their impact on anesthesia practice

Neuromuscular blockers have long been an intricate part of the anesthesia regimen. The scientific progress in pharmacology and physiology has strengthened their clinical relevance, has helped to delineate with precision their medical role, and has enhanced the safety and effectiveness of their use. New frontiers in research will define further the role of these agents in modern anesthesia practice and guide their expanding and discrete clinical applications.

Recovery characteristics of patients receiving either sugammadex or neostigmine and glycopyrrolate for reversal of neuromuscular block: a randomised controlled trial

Sugammadex more rapidly and reliably reverses rocuronium-induced neuromuscular block compared with neostigmine, but it is not known if subsequent patient outcomes, including nausea, vomiting and other aspects of recovery are modified. In this study, we compared the recovery characteristics of sugammadex and neostigmine/glycopyrrolate following reversal of neuromuscular block. This was a single-centre, randomised, blinded, parallel-group clinical trial in women undergoing elective day-surgical laparoscopic gynaecological surgery, with a standardised general anaesthesia regimen that included rocuronium. Neuromuscular block was reversed with either sugammadex 2 mg.kg^-1 or neostigmine 40 μg.kg^-1 and glycopyrrolate 400 μg. The primary outcome was the incidence of nausea and vomiting during the first six postoperative hours. Secondary outcomes included other measures of postoperative recovery such as patient symptoms and recovery scores. Three-hundred and four women were analysed by intention-to-treat (sugammadex n = 151, neostigmine n = 153), which included four major protocol violations. There was no significant difference between sugammadex and neostigmine groups in the incidence of early nausea and vomiting (49.0% vs. 51.0%, respectively; OR 0.92, 95%CI 0.59-1.45; p = 0.731). Double vision (11.5% vs. 20.0%; p = 0.044) and dry mouth (71.6% vs. 85.5%; p = 0.003) were less common after sugammadex. Sedation scores at 2 h were also lower after sugammadex (median (IQR [range]) 0 (0-3 [0-10]) vs. 2 (0-4.[0-10]); p = 0.021). Twenty-four-hour recovery scores were not significantly different between groups. Reversal with sugammadex in this patient population did not reduce postoperative nausea or vomiting compared with neostigmine/glycopyrrolate.

Recovery and prediction of postoperative muscle power - is it still a problem?

BACKGROUND

In the postoperative period, immediate recovery of muscular power is essential for patient safety, but this can be affected by anaesthetic drugs, opioids and neuromuscular blocking agents (NMBA). In this cohort study, we evaluated anaesthetic and patient-related factors contributing to reduced postoperative muscle power and pulse oximetric saturation.

METHODS

We prospectively observed 615 patients scheduled for minor surgery. Premedication, general anaesthesia and respiratory settings were standardized according to standard operating procedures (SOP). If NMBAs were administered, neuromuscular monitoring was applied to establish a Train of four (TOF)-Ratio of >0.9 before extubation. After achieving a modified fast track score > 10 at 4 time points up to 2 h postoperatively, we measured pulse oximetric saturation and also static and dynamic muscle power, using a high precision digital force gauge. Loss of muscle power in relation to the individual preoperative baseline value was analysed in relation to patient and anaesthesia-related factors using the T-test, simple and multiple stepwise regression analysis.

RESULTS

Despite having achieved a TOF ratio of >0.9 a decrease in postoperative muscle power was detectable in most patients and correlated with reduced postoperative pulse oximetric saturation. Independent contributing factors were use of neuromuscular blocking agents (p < 0.001), female gender (p = 0.001), TIVA (p = 0.018) and duration of anaesthesia >120 min (p = 0.019).

CONCLUSION

Significant loss of muscle power and reduced pulse oximetric saturation are often present despite a TOF-Ratio > 0.9. Gender differences are also significant. A modified fast track score > 10 failed to predict recovery of muscle power in most patients.

TRIAL REGISTRATION

German Clinical Trial Register DRKS-ID DRKS00006032 ; Registered: 2014/04/03.

The efficacy and safety of sugammadex for reversing postoperative residual neuromuscular blockade in pediatric patients: A systematic review

The aim of this study is to evaluate the efficacy and safety of sugammadex for reversing neuromuscular blockade in pediatric patients. MEDLINE and other three Databases were searched. Randomized clinical trials were included if they compared sugammadex with neostigmine or placebo in pediatric patients undergoing surgery involving the use of rocuronium or vecuronium. The primary outcome was the time interval from administration of reversal agents to train-of-four ratio (TOFr, T4/T1) > 0.9. Incidences of any drug-related adverse events were secondary outcomes. Trial inclusion, data extraction, and risk of bias assessment were performed independently. Mean difference and relative risk were used as summary statistics with random effects models. Statistical heterogeneity was assessed by the I2 statistic. Funnel plot was used to detect publication bias. Ten studies with 580 participants were included. Although considerable heterogeneity (I2 = 98.5%) was detected in primary outcome, the results suggested that, compared with placebo or neostigmine, sugammadex can reverse rocuronium-induced neuromuscular blockade more rapidly with lower incidence of bradycardia. No significant differences were found in the incidences of other adverse events. Compared with neostigmine or placebo, sugammadex may reverse rocuronium-induced neuromuscular blockade in pediatric patients rapidly and safely.

A discrete event simulation model of clinical and operating room efficiency outcomes of sugammadex versus neostigmine for neuromuscular block reversal in Canada

Background

The objective of this analysis is to explore potential impact on operating room (OR) efficiency and incidence of residual neuromuscular blockade (RNMB) with use of sugammadex (Bridion™, Merck & Co., Inc., Kenilworth, NJ USA) versus neostigmine for neuromuscular block reversal in Canada.

Methods

A discrete event simulation (DES) model was developed to compare ORs using either neostigmine or sugammadex for NMB reversal over one month. Selected inputs included OR procedure and turnover times, hospital policies for paid staff overtime and procedural cancellations due to OR time over-run, and reductions in RNMB and associated complications with sugammadex use. Trials show sugammadex’s impact on OR time and RNMB varies by whether full neuromuscular recovery (train-of-four ratio ≥0.9) is verified prior to extubation in the OR. Scenarios were therefore evaluated reflecting varied assumptions for neuromuscular reversal practices.

Results

With use of moderate neuromuscular block, when full neuromuscular recovery is verified prior to extubation (93 procedures performed with sugammadex, 91 with neostigmine), use of sugammadex versus neostigmine avoided 2.4 procedural cancellations due to OR time over-run and 33.5 h of paid staff overtime, while saving an average of 62 min per OR day. No difference was observed between comparators for these endpoints in the scenario when full neuromuscular recovery was not verified prior to extubation, however, per procedure risk of RNMB at extubation was reduced from 60% to 4% (reflecting 51 cases prevented), with associated reductions in risks of hypoxemia (12 cases avoided) and upper airway obstruction (23 cases avoided).

Sugammadex impact in reversing deep neuromuscular block was evaluated in an exploratory analysis. When it was hypothetically assumed that 30 min of OR time were saved per procedure, the number of paid hours of staff over-time dropped from 84.1 to 32.0, with a 93% reduction in the per patient risk of residual blockade.

Conclusions

In clinical practice within Canada, for the majority of patients currently managed with moderate neuromuscular block, the principal impact of substituting sugammadex for neostigmine is likely to be a reduction in the risk of residual blockade and associated complications. For patients maintained at a deep level of block to the end of the procedure, sugammadex is likely to both enhance OR efficiency and reduce residual block complications.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-016-0281-3) contains supplementary material, which is available to authorized users.

Qualitative Neuromuscular Monitoring: How to Optimize the Use of a Peripheral Nerve Stimulator to Reduce the Risk of Residual Neuromuscular Blockade

This review provides recommendations for anesthesia providers who may not yet have quantitative monitoring and sugammadex available and thus are providing care within the limitations of a conventional peripheral nerve stimulator (PNS) and neostigmine. In order to achieve best results, the provider needs to understand the limitations of the PNS. The PNS should be applied properly and early. All overdosing of neuromuscular blocking drugs should be avoided and the intraoperative neuromuscular blockade should be maintained only as deep as necessary. The adductor pollicis is the gold standard site and must be used for the pre-reversal assessment, also when the ulnar nerve and thumb were not accessible intraoperatively. Spontaneous recovery should be maximized and neostigmine should be administered after a TOF count of 4 has been confirmed at the adductor pollicis. Extubation should not occur within 10 min after administration of an appropriate dose of neostigmine.

Incidence of postoperative residual neuromuscular blockade after general anesthesia: a prospective, multicenter, anesthetist-blind, observational study

OBJECTIVE

Evidences demonstrate that postoperative residual neuromuscular blockade (rNMB) is a primary and frequent anesthetic risk factor for postoperative complications. This study was designed to mitigate the paucity of data regarding the occurrence and degree of rNMB in a real-life setting.

METHODS

This prospective, multicenter, anesthetist-blind, observational study enrolled 1571 Chinese adults undergoing elective open or laparoscopic abdominal surgery lasting ≤4 hours from 32 hospitals across China. The patients received anesthesia in accordance with routine practice at the study site. Neuromuscular blockade (NMB) was monitored using acceleromyography, with rNMB defined as a train-of-four (TOF) ratio <0.9.

RESULTS

The patients' mean age was 46 years and 71% were female. The procedures included laparoscopic (67%), open abdominal (31%), and laparoscopic to open abdominal (2%). NMB was reversed with neostigmine in 78% of patients. The overall incidence of rNMB at extubation was 57.8%, and the proportions of participant with TOF ratios <0.6, 0.6-0.7, 0.7-0.8, 0.8-0.9 were 22.9%, 6.9%, 11.1% and 16.9%, respectively, immediately prior to endotracheal extubation. Age <45 years (OR = 0.630, 95% CI = 0.496-0.801, p = 0.002), use of one neuromuscular blocking agent (NMBA) (OR = 0.387, 95% CI = 0.243-0.618, p < 0.0001), time from neostigmine administration to endotracheal extubation ≥10 min (OR = 0.513, 95% CI = 0.400-0.658, p < 0.0001) and time from last NMBA administration to endotracheal extubation ≥60 min (OR = 0.902, 95% CI = 0.801-0.989, p = 0411) were correlated with non-rNMB at the time of extubation.

CONCLUSIONS

This observational study demonstrated that the overall incidence of rNMB at the time of endotracheal extubation was high in Chinese patients undergoing abdominal procedures, which necessitates appropriate management in current real-life practice.

CLINICAL TRIAL REGISTRY NUMBER

NCT01871064.

The RECITE Study: A Canadian Prospective, Multicenter Study of the Incidence and Severity of Residual Neuromuscular Blockade

BACKGROUND

Postoperative residual neuromuscular blockade (NMB), defined as a train-of-four (TOF) ratio of <0.9, is an established risk factor for critical postoperative respiratory events and increased morbidity. At present, little is known about the occurrence of residual NMB in Canada. The RECITE (Residual Curarization and its Incidence at Tracheal Extubation) study was a prospective observational study at 8 hospitals in Canada investigating the incidence and severity of residual NMB.

METHODS

Adult patients undergoing open or laparoscopic abdominal surgery expected to last <4 hours, ASA physical status I-III, and scheduled for general anesthesia with at least 1 dose of a nondepolarizing neuromuscular blocking agent for endotracheal intubation or maintenance of neuromuscular relaxation were enrolled in the study. Neuromuscular function was assessed using acceleromyography with the TOF-Watch SX. All reported TOF ratios were normalized to the baseline values. The attending anesthesiologist and all other observers were blinded to the TOF ratio (T4/T1) results. The primary and secondary objectives were to determine the incidence and severity of residual NMB (TOF ratio <0.9) just before tracheal extubation and at arrival at the postanesthesia care unit (PACU).

RESULTS

Three hundred and two participants were enrolled. Data were available for 241 patients at tracheal extubation and for 207 patients at PACU arrival. Rocuronium was the NMB agent used in 99% of cases. Neostigmine was used for reversal of NMB in 73.9% and 72.0% of patients with TE and PACU data, respectively. The incidence of residual NMB was 63.5% (95% confidence interval, 57.4%-69.6%) at tracheal extubation and 56.5% (95% confidence interval, 49.8%-63.3%) at arrival at the PACU. In an exploratory analysis, no statistically significant differences were observed in the incidence of residual NMB according to gender, age, body mass index, ASA physical status, type of surgery, or comorbidities (all P > 0.13).

CONCLUSIONS

Residual paralysis is common at tracheal extubation and PACU arrival, despite qualitative neuromuscular monitoring and the use of neostigmine. More effective detection and management of NMB is needed to reduce the risks associated with residual NMB.

Dose-dependent Association between Intermediate-acting Neuromuscular-blocking Agents and Postoperative Respiratory Complications

Background:

Duration of action increases with repeated administration of neuromuscular-blocking agents, and intraoperative use of high doses of neuromuscular-blocking agent may affect respiratory safety.

Methods:

In a hospital-based registry study on 48,499 patients who received intermediate-acting neuromuscular-blocking agents, the authors tested the primary hypothesis that neuromuscular-blocking agents are dose dependently associated with the risk of postoperative respiratory complications. In the secondary analysis, the authors evaluated the association between neostigmine dose given for reversal of neuromuscular-blocking agents and respiratory complications. Post hoc, the authors evaluated the effects of appropriate neostigmine reversal (neostigmine ≤60 μg/kg after recovery of train-of-four count of 2) on respiratory complications. The authors controlled for patient-, anesthesia-, and surgical complexity–related risk factors.

Results:

High doses of neuromuscular-blocking agents were associated with an increased risk of postoperative respiratory complications (n = 644) compared with low doses (n = 205) (odds ratio [OR], 1.28; 95% CI, 1.04 to 1.57). Neostigmine was associated with a dose-dependent increase in the risk of postoperative respiratory complications (OR, 1.51; 95% CI, 1.25 to 1.83). Post hoc analysis revealed that appropriate neostigmine reversal eliminated the dose-dependent association between neuromuscular-blocking agents and respiratory complications (for neuromuscular-blocking agent effects with appropriate reversal: OR, 0.98; 95% CI, 0.63 to 1.52).

Conclusions:

The use of neuromuscular-blocking agents was dose dependently associated with increased risk of postoperative respiratory complications. Neostigmine reversal was also associated with a dose-dependent increase in the risk of respiratory complications. However, the exploratory data analysis suggests that the proper use of neostigmine guided by neuromuscular transmission monitoring results can help eliminate postoperative respiratory complications associated with the use of neuromuscular-blocking agents.

Survey of postoperative residual curarization, acute respiratory events and approach of anesthesiologists

BACKGROUND AND OBJECTIVES

residual paralysis following the use of neuromuscular blocking drugs (NMBDs) without neuromuscular monitoring remains a clinical problem, even when NMBDs are used. This study surveys postoperative residual curarization and critical respiratory events in the recovery room, as well as the clinical approach to PORC of anesthesiologists in our institution.

METHODS

This observational study included 415 patients who received general anesthesia with intermediate-acting NMBDs. Anesthesia was maintained by non-participating anesthesiologists who were blinded to the study. Neuromuscular monitoring was performed upon arrival in the recovery room. A CRE was defined as requiring airway support, peripheral oxygen saturation <90% and 90-93% despite receiving 3 L/min nasal O2, respiratory rate > 20 breaths/min, accessory muscle usage, difficulty with swallowing or speaking, and requiring reintubation. The clinical approach of our anesthesiologists toward reversal agents was examined using an 8-question mini-survey shortly after the study.

RESULTS

The incidence of PORC was 43% (n = 179) for TOFR < 0.9, and 15% (n = 61) for TOFR < 0.7. The incidence of TOFR < 0.9 was significantly higher in women, in those with ASA physical status 3, and with anesthesia of short duration (p < 0.05). In addition, 66% (n = 272) of the 415 patients arriving at the recovery room had received neostigmine. A TOFR < 0.9 was found in 46% (n = 126) of the patients receiving neostigmine.

CONCLUSIONS

When routine objective neuromuscular monitoring is not available, PORC remains a clinical problem despite the use of NMBDs. The timing and optimal antagonism of the neuromuscular blockade, and routine objective neuromuscular monitoring is recommended to enhance patient safety.

Residual neuromuscular blockade and postoperative critical respiratory events: literature review

AIMS AND OBJECTIVES

To investigate and synthesise published literature on the associations between residual neuromuscular blockade and critical respiratory events of postoperative adult patients in the postanaesthesia care unit.

BACKGROUND

Residual neuromuscular blockade continues to be common among patients transferred to the postanaesthesia care unit after general anaesthesia, while negative effects of residual neuromuscular blockade on respiratory function have been demonstrated in laboratory volunteers.

DESIGN

Literature review.

METHODS

Using key terms, a search was conducted in Cumulative Index for Nursing and Allied Health Literature, PubMed, Web of Science, Cochrane Database and EMBASE (January 1990-May 2013) for clinical trials or observational studies on the associations between residual neuromuscular blockade and critical respiratory events, published in English-language journals.

RESULTS

Nine articles met the inclusion criteria. Residual neuromuscular blockade definition threshold differed between studies. Among critical respiratory events, only hypoxaemia was investigated in all included studies. Residual neuromuscular blockade was significantly associated with increased incidence of hypoxaemia during postanaesthesia care unit stay in most studies, while associations with the rest of the critical respiratory events were inconclusive.

CONCLUSIONS

Although limited, existing research has provided evidence that patients with residual neuromuscular blockade are at high risk of early postoperative hypoxaemia. Further studies are needed to investigate independent associations between residual neuromuscular blockade and critical respiratory events, along with causality of these associations. The clinical importance of residual neuromuscular blockade for groups at high risk of critical respiratory events should also be investigated.

RELEVANCE TO CLINICAL PRACTICE

Healthcare professionals have to be aware of the increased risk of hypoxaemia in patients with residual neuromuscular blockade. Efforts to decrease residual neuromuscular blockade incidence, combined with identification and appropriate evaluation of patients with residual neuromuscular blockade during postanaesthesia care unit stay, are recommended.

Rocuronium reversed by sugammadex versus mivacurium during high-risk eye surgery: An institutional anaesthetic practice evaluation

Objective

This institutional anaesthetic practice evaluation compared patient safety with respect to residual neuromuscular blockade (NMB) at the time of tracheal extubation in patients undergoing high-risk eye surgery.

Methods

Two muscle relaxation regimens were compared: rocuronium administered via intravenous (i.v.) bolus dosing combined with reversal through sugammadex at end of surgery (group R/S; 17 patients); mivacurium administered via continuous i.v. infusion without antagonization (group M; 22 patients). Train-of-four (TOF) monitoring determined the depth of NMB.

Results

The TOF ratio at the time of tracheal extubation was greater in group R/S (median 1.03) than in group M (median 0.62). Time from end of surgery to tracheal extubation was not significantly different. The surgeons were 100% satisfied with the working conditions provided under both relaxation regimens.

Conclusions

Residual postoperative curarization at the time of extubation was frequently observed in group M, whereas there was complete recovery in group R/S. Reversal of NMB by sugammadex provides an additional safety dimension to patient care and should thus be considered especially for those at risk of airway complications or aspiration, in addition to frail patients.