Clinical limitations of acetylcholinesterase antagonists

Emergency use of sugammadex after failure of standard reversal drugs and postoperative pulmonary complications: A retrospective cohort study

Background and Aims

The use of sugammadex instead of neostigmine for the reversal of neuromuscular blockade may decrease postoperative pulmonary complications. It is unclear if this finding is applicable to situations where sugammadex is administered after the administration of neostigmine. The objective of this study was to compare the incidence of a composite outcome measure of major postoperative pulmonary complications in patients who received sugammadex as a rescue agent after neostigmine versus those who received sugammadex alone for reversal of neuromuscular blockade.

Material and Methods

This retrospective cohort study analyzed the medical records of adult patients who underwent elective inpatient noncardiac surgery under general anesthesia and received sugammadex for reversal of neuromuscular blockade, at a tertiary care academic hospital between August 2016 and November 2018.

Results

A total of 1,672 patients were included, of whom 1,452 underwent reversal with sugammadex alone and 220 received sugammadex following reversal with neostigmine/glycopyrrolate. The composite primary outcome was diagnosed in 60 (3.6%) patients. Comparing these two groups, and after adjusting for confounding factors, patients who received sugammadex after reversal with neostigmine had more postoperative pulmonary complications than those reversed with sugammadex alone (6.8% vs. 3.1%, odds ratio, 2.29; 95% confidence interval [CI], 1.25 to 4.18; P = 0.006).

Conclusion

The use of sugammadex following reversal with neostigmine was associated with a higher incidence of postoperative pulmonary complications as compared to the use of sugammadex alone. The implications of using sugammadex after the failure of standard reversal drugs should be investigated in prospective studies.

Superiority of sugammadex in preventing postoperative pulmonary complications

BACKGROUND

Postoperative pulmonary complications often lead to increasing mortality and financial burden. Residual paralysis plays a critical role in postoperative pulmonary complications. This meta-analysis was performed to determine whether sugammadex overmatch neostigmine in reducing postoperative pulmonary complications.

METHODS

PubMed, Embase, Web of Science, Medline through Ovid, Cochrane Library, Wan fang, China National Knowledge Infrastructure, and Chinese BioMedical Literature Databases were searched from their inception to 24 June 2021. Random effects models were used for all analyses. Cochrane risk of bias tool was used to assess the quality of RCTs, while Newcastle Ottawa Quality Assessment Scale was used to assess for the quality of cohort studies.

RESULTS

Seventeen studies were included in the meta-analysis. Pooled data from cohort studies showed reversing neuromuscular blocking with sugammadex had less risk of compound postoperative pulmonary complications [relative risk (RR): 0.73; 95% confidence interval (CI): 0.60-0.89; P = 0.002; I2 = 81%], pneumonia (RR: 0.64; 95% CI: 0.48-0.86; I2 = 42%) and respiratory failure (RR: 0.48, 95% CI: 0.41-0.56, I2 = 0%). However, pooled data from RCTs did not show any difference between the two groups in pneumonia (RR: 0.58; 95% CI: 0.24-1.40; I2 = 0%) and respiratory failure. The difference was not found between sugammadex and neostigmine about atelectasis in pooled data from either RCTs (RR: 0.85; 95% CI: 0.69-1.05; I2 = 0%) or cohort studies (RR: 1.01; 95% CI: 0.87 to 1.18; I2 = 0%).

CONCLUSION

The evidence of superiority of sugammadex was limited by the confounding factors in cohort studies and small scale of RCTs. Whether sugammadex precedes neostigmine in preventing pulmonary complications after surgery is still unknown. Well-designed RCTs with large scale are needed.

REGISTRATION

PROSPERO CRD 42020191575.

Effects of hydrocortisone-presensitized sugammadex on recovery from neuromuscular blockade induced by rocuronium: a rodent in vivo study

Background

Sugammadex is a specific antagonist of aminosteroidal neuromuscular blocking agents with 1:1 binding to guest molecules. Sugammadex can also bind to other drugs having a steroid component in its chemical structure. In this in vivo experiment, we investigated the differences in the recovery of rocuronium-induced neuromuscular blockade using sugammadex pre-exposed with two different concentrations of hydrocortisone.

Methods

The sciatic nerves and tibialis anterior muscles of 30 adult Sprague–Dawley rats were prepared for the experiment. The sciatic nerves were stimulated using a train-of-four (TOF) pattern with indirect supramaximal stimulation at 20 s intervals. After 15 min of stabilization, a 250 μg loading dose and 125 μg booster doses of rocuronium were serially administered until > 95% depression of the first twitch tension of TOF stimulation (T1) was confirmed. The study drugs were prepared by mixing sugamadex with the same volume of three different stock solutions (0.9% normal saline, 10 mg/ml hydrocortisone, and 100 mg/ml hydrocortisone). The recovery of rats from neuromuscular blockade was monitored by assessing T1 and the TOF ratio (TOFR) simultaneously until T1 was recovered to > 95% and TOFR to > 0.9.

Results

In the group injected with sugammadex premixed with a high concentration of hydrocortisone, statistically significant intergroup differences were observed in the recovery progression of T1 and TOFR (P < 0.050).

Conclusions

When sugammadex was pre-exposed to a high dose of hydrocortisone only, recovery from neuromuscular blockade was delayed. Delayed recovery from neuromuscular blockade is not always plausible when sugammadex is pre-exposed to steroidal drugs.

Efficacy and Safety of Sugammadex versus Neostigmine in Reversing Neuromuscular Blockade in Morbidly Obese Adult Patients: A Systematic Review and Meta-Analysis

Context:

Sugammadex is known to reverse neuromuscular blockade (NMB) more rapidly and reliably than neostigmine. However, data remain limited in bariatric patients. In this review, we systematically evaluated the efficacy and safety of sugammadex versus neostigmine in reversing NMB in morbidly obese (MO) patients undergoing bariatric surgery.

Aims:

Our primary objective was to determine the recovery time from drug administration to a train-of-four (TOF) ratio >0.9 from a moderate or deep NMB.

Settings and Design:

This systematic review and meta-analysis (SR and MA) was conducted in accordance with the Preferred Items for SRs and MAs guidelines.

Subjects and Methods:

A systematic search was conducted within multiple databases for studies that compared sugammadex and neostigmine in MO patients.

Statistical Analysis Used:

We reported data as mean difference (MD) or odds ratios (OR) and corresponding 95% confidence interval (CI) using random-effects models. A two-sided P < 0.05 was considered statistically significant.

Results:

Seven studies with 386 participants met the inclusion criteria. Sugammadex significantly reduced the time of reversal of moderate NMB-to-TOF ratio >0.9 compared to neostigmine, with a mean time of 2.5 min (standard deviation [SD] 1.25) versus 18.2 min (SD 17.6), respectively (MD: −14.52; 95% CI: −20.08, −8.96; P < 0.00001; I² = 96%). The number of patients who had composite adverse events was significantly lower with sugammadex (21.2% of patients) compared to neostigmine (52.5% of patients) (OR: 0.15; 95% CI: 0.07–0.32; P < 0.00001; I² = 0%).

Conclusions:

Sugammadex reverses NMB more rapidly with fewer adverse events than neostigmine in MO patients undergoing bariatric surgery.

Application of carbohydrates in approved small molecule drugs: A review

Carbohydrates are an important energy source and play numerous key roles in all living organisms. Carbohydrates chemistry involved in diagnosis and treatment of diseases has been attracting increasing attention. Carbohydrates could be one of the major focuses of new drug discovery. Currently, however, carbohydrate-containing drugs account for only a small percentage of all drugs in clinical use, which does not match the important roles of carbohydrates in the organism. In other words, carbohydrates are a relatively untapped source of new drugs and therefore may offer exciting novel therapeutic opportunities. Here, we presented an overview of the application of carbohydrates in approved small molecule drugs and emphasized and evaluated the roles of carbohydrates in those drugs. The potential development direction of carbohydrate-containing drugs was presented after summarizing the advantages and challenges of carbohydrates in the development of new drugs.

Decrease in heart rate following the administration of sugammadex in adults

Background and Aims:

Sugammadex is a novel agent for reversal of steroidal neuromuscular blocking agents (NMBAs) with potential advantages over acetylcholinesterase inhibitors. In preclinical trials, there have been rare instances of bradycardia with progression to cardiac arrest. To better define this issue, its incidence and mitigating factors, we prospectively evaluated the incidence of bradycardia after sugammadex administration in adults.

Material and Methods:

Patients ≥ 18 years of age who received sugammadex were included in this prospective, open label trial. After administration, heart rate (HR) was continuously monitored. HR was recorded every minute for 15 minutes and then every five minutes for the next 15 minutes or until patient was transferred out of the operating room. Bradycardia was defined as HR less than 60 beats/minute (bpm) or decrease in HR by ≥ 10 beats per minute (bpm) if the baseline HR was <70 bpm.

Results:

The study cohort included 200 patients. Bradycardia was observed in 13 cases (7%; 95% confidence interval: 4, 11), occurring a median of 4 minutes after sugammadex administration (IQR: 4, 9, range: 2-25). Among patients developing bradycardia, two (15%) had cardiac comorbid conditions. One patient received treatment for bradycardia with ephedrine. No clinically significant blood pressure changes were noted. On bivariate analysis, patients receiving a higher initial sugammadex dose were more likely to develop bradycardia. On multivariable logistic regression, initial sugammadex dose was not associated with the risk of bradycardia.

Conclusion:

The incidence of bradycardia after administration of sugammadex in our study was low and not associated with significant hemodynamic changes.

Evaluation of the Adverse Effects of Chronic Exposure to Donepezil (An Acetylcholinesterase Inhibitor) in Adult Zebrafish by Behavioral and Biochemical Assessments

Donepezil (DPZ) is an acetylcholinesterase inhibitor used for the clinical treatment of mild cognitive impairment. However, DPZ has been reported to have adverse effects, including causing abnormal cardiac rhythm, insomnia, vomiting, and muscle cramps. However, the existence of these effects in subjects without Dementia is unknown. In this study, we use zebrafish to conduct a deeper analysis of the potential adverse effects of DPZ on the short-term memory and behaviors of normal zebrafish by performing multiple behavioral and biochemical assays. Adult zebrafish were exposed to 1 ppm and 2.5 ppm of DPZ. From the results, DPZ caused a slight improvement in the short-term memory of zebrafish and induced significant elevation in aggressiveness, while the novel tank and shoaling tests revealed anxiolytic-like behavior to be caused by DPZ. Furthermore, zebrafish circadian locomotor activity displayed a higher reduction of locomotion and abnormal movement orientation in both low- and high-dose groups, compared to the control group. Biomarker assays revealed that these alterations were associated with an elevation of oxytocin and a reduction of cortisol levels in the brain. Moreover, the significant increases in reactive oxygen species (ROS) and malondialdehyde (MDA) levels in muscle tissue suggest DPZ exposure induced muscle tissue oxidative stress and muscle weakness, which may underlie the locomotor activity impairment. In conclusion, we show, for the first time, that chronic waterborne exposure to DPZ can severely induce adverse effects on normal zebrafish in a dose-dependent manner. These unexpected adverse effects on behavioral alteration should be carefully addressed in future studies considering DPZ conducted on zebrafish or other animals.

Heart Rate Changes Following the Administration of Sugammadex to Infants and Children With Comorbid Cardiac, Cardiovascular, and Congenital Heart Diseases

Background

Sugammadex is a novel, rapidly-acting pharmacologic agent to reverse steroidal neuromuscular blocking agents with demonstrated advantages over acetylcholinesterase inhibitors. However, anecdotal reports have noted rare instances of bradycardia and even cardiac arrest. The current study examined heart rate (HR) changes in infants and children with comorbid cardiac, cardiovascular, and congenital heart diseases.

Methods

Patients less than 18 years of age, who had a comorbid cardiac, cardiovascular, or congenital heart disease and were to receive sugammadex, were included in this prospective observational study. After sugammadex administration, HR was continuously monitored and recorded every minute for the first 15 min, and then every 5 min for the next 15 min or until the patient was transferred from the operating room. The primary outcome, bradycardia, was defined as HR below the fifth percentile for age. Secondary outcomes included greatest decrease in HR from baseline for each patient and interventions required for bradycardia.

Results

The study cohort included 99 patients (58 male and 41 female) with a median age of 3 years. Bradycardia was noted in 20 of 99 patients (20%); however, six of these patients were bradycardic prior to the administration of sugammadex. Older patients, male patients, and patients with higher body weight were the most likely to experience bradycardia. None of the patients required treatment for bradycardia.

Conclusions

The incidence of bradycardia following the administration of sugammadex was low, even in patients with congenital heart disease. Bradycardia was not associated with clinically significant hemodynamic changes and no treatment was required.

Effects of Sugammadex on Post-Operative Pulmonary Complications in Laparoscopic Gastrectomy: A Retrospective Cohort Study

The use of sugammadex can reduce post-operative residual neuromuscular blockade, which is known to increase the risk of post-operative respiratory events. However, its effect on post-operative pulmonary complications is not obvious. This study was performed to evaluate the effects of sugammadex on post-operative pulmonary complications in patients undergoing laparoscopic gastrectomy between 2013 and 2017. We performed propensity score matching to correct for selection bias. Post-operative pulmonary complications (i.e., pneumonia, respiratory failure, pleural effusion, atelectasis, pneumothorax, and aspiration pneumonitis) were evaluated from the radiological and laboratory findings. We also evaluated admission to the intensive care unit after surgery, re-admission or an emergency room visit within 30 days after discharge, length of hospital stay, re-operation, and mortality within 90 days post-operatively as secondary outcomes. In the initial cohort of 3802 patients, 541 patients were excluded, and 1232 patients were analyzed after propensity score matching. In the matched cohort, pleural effusion was significantly reduced in the sugammadex group compared to the neostigmine group (neostigmine 23.4% vs. sugammadex 18%, p = 0.02). Other pulmonary complications and secondary outcomes were not significantly different between the groups. In comparison to neostigmine, the use of sugammadex was associated with a lower incidence of post-operative pleural effusion in laparoscopic gastrectomy.

A multicenter survey on the use of neuromuscular blockade in Greece. Does the real-world clinical practice indicate the necessity of guidelines?

Background and Aims

The aim of this study was to investigate the current status of clinical practice regarding neuromuscular blocking drugs and their antagonists in Greece.

Material and Methods

This is a multicenter survey, including a questionnaire based on previous studies, which was translated and modified by a Task Force of the Hellenic Society of Anaesthesiology. It was completed on a web-based database after invitation via e-mail and was left online for a period of 2 months.

Results

A total of 1,100 questionnaires were sent, with a response rate of 7.9%. 13.7% stated that they do not use neuromuscular monitoring. Rocuronium was most commonly used for intubation ["often" stated by 19 (21.8%) and "very often" by 62 (71.2%)], followed by cis-atracurium, atracurium, and succinylcholine. Neostigmine and sugammadex were both used, with reversal not always administered by 23 (26.4%). Both agents were mostly used at fixed doses and not calculated based on TOF monitoring or body weight. Sugammadex was preferred in special patient groups and in operations of short duration. Reversal was most often administered based on clinical signs of neuromuscular recovery rather than objective monitoring. A significant percentage of respondents used an inadequate TOF ratio for extubation [37 (43.2%) used a TOF ratio <90%]. The reported incidence of observed residual neuromuscular blockade (RNMB) was 44.8%.

Conclusion

Great variability was observed in Greek clinical practice regarding the use of neuromuscular blockade, which indicates serious issues that must be addressed. The needs for educating anesthesia providers and developing official guidelines are obvious in order to improve patient outcomes.

Reevaluation and update on efficacy and safety of neostigmine for reversal of neuromuscular blockade

Postoperative residual neuromuscular block is a serious threat which endangers the patient safety. Neostigmine has been the most commonly used anticholinesterase for the pharmacological reversal of neuromuscular blockade. Although newer agents have been introduced recently, neostigmine has some irreplaceable advantages, including broad-spectrum reversal of all nondepolarizing neuromuscular blocking drugs, low cost, and availability of more related data for clinical practice to refer to. Neostigmine is also noticed to have some drawbacks, such as the inability to reverse profound and deep blockade, potential induction of muscle weakness, cardiovascular adverse effects, and so on. Data on the usage of neostigmine in the geriatric and the pediatric population are still insufficient. Some discrepancies are observed in the results from previous studies which need further investigation. However, recent studies offer some renewed information. Regarding both efficacy and safety, the key for successful reversal of neuromuscular blockade is to use neostigmine “appropriately,” optimizing the dosage and timing of administration under close monitoring.

Monitoring of Sugammadex Dosing at a Large Tertiary Care Pediatric Hospital

Introduction:

Anesthesiologists use sugammadex to reverse neuromuscular blockade (NMB) produced by rocuronium and vecuronium. Its mechanism involves encapsulation of the neuromuscular blocking agent. Sugammadex dosing is based on the depth of NMB, assessed by measuring the train-of-four (TOF).

Methods:

We retrospectively reviewed procedures under general anesthesia in patients older than 1 year of age if they included sugammadex reversal of rocuronium-induced NMB. Documentation of TOF monitoring before and after reversal was noted, along with the dose of sugammadex administered. TOF was considered correctly documented if the anesthesia provider recorded the number of twitches before and after NMB reversal, or if they recorded 4 twitches before NMB reversal. We defined appropriate sugammadex dosing if it was within 10% of the recommended dose for the depth of NMB. We repeated this review after staff education and creating a reminder in the electronic health record system.

Results:

We included 100 patients in the preintervention analysis, of whom 30% had correct TOF documentation. Among patients with TOF assessment before sugammadex administration, the dose was appropriate in 34 of 40 cases. In the postintervention analysis, we reviewed 75 cases and found that correct documentation improved to 45% (P = 0.024). Among postintervention cases with TOF documented before sugammadex administration, sugammadex dosing was appropriate in 62 patients.

Conclusion:

Documentation of TOF was low (30%) before intervention and improved to only 45% after the interventions, suggesting that additional interventions are needed. Even before the intervention, with or without TOF documentation, the dose of sugammadex was generally consistent with recommendations.

Sepsis decreases the activity of acetylcholinesterase by reducing its expression at the neuromuscular junction

Our previous study demonstrated that sepsis may decrease the activity of acetylcholinesterase (AChE) at the neuromuscular junction (NMJ) of the diaphragm at 24 h, and thus improve the antagonistic action of neostigmine on rocuronium. The present study aimed to determine the effects of sepsis on AChE activity over 2 weeks, which is a more clinically relevant time period. Furthermore, the present study aimed to elucidate the association between AChE activity and its expression at the NMJ during sepsis. Male adult Sprague‑Dawley rats were randomly divided into the sham or sepsis groups. Sepsis was induced by cecal ligation and puncture. On days 1, 3, 7 and 14 after surgery, AChE activity at the NMJ of the diaphragm was detected using a modified Karnovsky and Roots method. Furthermore, AChE expression levels at the NMJ, and in the whole muscle fibers of the diaphragm, were detected by immunohistofluorescence staining and western blot analysis, respectively. AChE activity was significantly decreased in the sepsis group, with its lowest level detected on day 7; however, its activity had partially recovered on day 14 (P<0.01). AChE activity was positively correlated (r=0.975, P=0.025) with its expression at the NMJ, which showed a similar trend over 2 weeks of sepsis. The protein expression levels of AChE in the whole muscle fibers of the diaphragm were significantly decreased on days 1, 3 and 7 in the sepsis group (P<0.01), with the lowest level observed on day 3. In conclusion, sepsis decreased AChE activity by reducing its expression at the NMJ over 14 days; the reduced expression of AChE at the NMJ might be as a result of its reduced muscular production.

Efficacy and safety of sugammadex versus neostigmine in reversing neuromuscular blockade in adults

BACKGROUND

Acetylcholinesterase inhibitors, such as neostigmine, have traditionally been used for reversal of non-depolarizing neuromuscular blocking agents. However, these drugs have significant limitations, such as indirect mechanisms of reversal, limited and unpredictable efficacy, and undesirable autonomic responses. Sugammadex is a selective relaxant-binding agent specifically developed for rapid reversal of non-depolarizing neuromuscular blockade induced by rocuronium. Its potential clinical benefits include fast and predictable reversal of any degree of block, increased patient safety, reduced incidence of residual block on recovery, and more efficient use of healthcare resources.

OBJECTIVES

The main objective of this review was to compare the efficacy and safety of sugammadex versus neostigmine in reversing neuromuscular blockade caused by non-depolarizing neuromuscular agents in adults.

SEARCH METHODS

We searched the following databases on 2 May 2016: Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE (WebSPIRS Ovid SP), Embase (WebSPIRS Ovid SP), and the clinical trials registries www.controlled-trials.com, clinicaltrials.gov, and www.centerwatch.com. We re-ran the search on 10 May 2017.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) irrespective of publication status, date of publication, blinding status, outcomes published, or language. We included adults, classified as American Society of Anesthesiologists (ASA) I to IV, who received non-depolarizing neuromuscular blocking agents for an elective in-patient or day-case surgical procedure. We included all trials comparing sugammadex versus neostigmine that reported recovery times or adverse events. We included any dose of sugammadex and neostigmine and any time point of study drug administration.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts to identify trials for eligibility, examined articles for eligibility, abstracted data, assessed the articles, and excluded obviously irrelevant reports. We resolved disagreements by discussion between review authors and further disagreements through consultation with the last review author. We assessed risk of bias in 10 methodological domains using the Cochrane risk of bias tool and examined risk of random error through trial sequential analysis. We used the principles of the GRADE approach to prepare an overall assessment of the quality of evidence. For our primary outcomes (recovery times to train-of-four ratio (TOFR) > 0.9), we presented data as mean differences (MDs) with 95 % confidence intervals (CIs), and for our secondary outcomes (risk of adverse events and risk of serious adverse events), we calculated risk ratios (RRs) with CIs.

MAIN RESULTS

We included 41 studies (4206 participants) in this updated review, 38 of which were new studies. Twelve trials were eligible for meta-analysis of primary outcomes (n = 949), 28 trials were eligible for meta-analysis of secondary outcomes (n = 2298), and 10 trials (n = 1647) were ineligible for meta-analysis.We compared sugammadex 2 mg/kg and neostigmine 0.05 mg/kg for reversal of rocuronium-induced moderate neuromuscular blockade (NMB). Sugammadex 2 mg/kg was 10.22 minutes (6.6 times) faster then neostigmine 0.05 mg/kg (1.96 vs 12.87 minutes) in reversing NMB from the second twitch (T2) to TOFR > 0.9 (MD 10.22 minutes, 95% CI 8.48 to 11.96; I2 = 84%; 10 studies, n = 835; GRADE: moderate quality).We compared sugammadex 4 mg/kg and neostigmine 0.07 mg/kg for reversal of rocuronium-induced deep NMB. Sugammadex 4 mg/kg was 45.78 minutes (16.8 times) faster then neostigmine 0.07 mg/kg (2.9 vs 48.8 minutes) in reversing NMB from post-tetanic count (PTC) 1 to 5 to TOFR > 0.9 (MD 45.78 minutes, 95% CI 39.41 to 52.15; I2 = 0%; two studies, n = 114; GRADE: low quality).For our secondary outcomes, we compared sugammadex, any dose, and neostigmine, any dose, looking at risk of adverse and serious adverse events. We found significantly fewer composite adverse events in the sugammadex group compared with the neostigmine group (RR 0.60, 95% CI 0.49 to 0.74; I2 = 40%; 28 studies, n = 2298; GRADE: moderate quality). Risk of adverse events was 28% in the neostigmine group and 16% in the sugammadex group, resulting in a number needed to treat for an additional beneficial outcome (NNTB) of 8. When looking at specific adverse events, we noted significantly less risk of bradycardia (RR 0.16, 95% CI 0.07 to 0.34; I2= 0%; 11 studies, n = 1218; NNTB 14; GRADE: moderate quality), postoperative nausea and vomiting (PONV) (RR 0.52, 95% CI 0.28 to 0.97; I2 = 0%; six studies, n = 389; NNTB 16; GRADE: low quality) and overall signs of postoperative residual paralysis (RR 0.40, 95% CI 0.28 to 0.57; I2 = 0%; 15 studies, n = 1474; NNTB 13; GRADE: moderate quality) in the sugammadex group when compared with the neostigmine group. Finally, we found no significant differences between sugammadex and neostigmine regarding risk of serious adverse events (RR 0.54, 95% CI 0.13 to 2.25; I2= 0%; 10 studies, n = 959; GRADE: low quality).Application of trial sequential analysis (TSA) indicates superiority of sugammadex for outcomes such as recovery time from T2 to TOFR > 0.9, adverse events, and overall signs of postoperative residual paralysis.

AUTHORS' CONCLUSIONS

Review results suggest that in comparison with neostigmine, sugammadex can more rapidly reverse rocuronium-induced neuromuscular block regardless of the depth of the block. Sugammadex 2 mg/kg is 10.22 minutes (˜ 6.6 times) faster in reversing moderate neuromuscular blockade (T2) than neostigmine 0.05 mg/kg (GRADE: moderate quality), and sugammadex 4 mg/kg is 45.78 minutes (˜ 16.8 times) faster in reversing deep neuromuscular blockade (PTC 1 to 5) than neostigmine 0.07 mg/kg (GRADE: low quality). With an NNTB of 8 to avoid an adverse event, sugammadex appears to have a better safety profile than neostigmine. Patients receiving sugammadex had 40% fewer adverse events compared with those given neostigmine. Specifically, risks of bradycardia (RR 0.16, NNTB 14; GRADE: moderate quality), PONV (RR 0.52, NNTB 16; GRADE: low quality), and overall signs of postoperative residual paralysis (RR 0.40, NNTB 13; GRADE: moderate quality) were reduced. Both sugammadex and neostigmine were associated with serious adverse events in less than 1% of patients, and data showed no differences in risk of serious adverse events between groups (RR 0.54; GRADE: low quality).

Sepsis Strengthens Antagonistic Actions of Neostigmine on Rocuronium in a Rat Model of Cecal Ligation and Puncture

Background:

The antagonistic actions of anticholinesterase drugs on non-depolarizing muscle relaxants are theoretically related to the activity of acetylcholinesterase (AChE) in the neuromuscular junction (NMJ). However, till date the changes of AChE activity in the NMJ during sepsis have not been directly investigated. We aimed to investigate the effects of sepsis on the antagonistic actions of neostigmine on rocuronium (Roc) and the underlying changes of AChE activity in the NMJ in a rat model of cecal ligation and puncture (CLP).

Methods:

A total of 28 male adult Sprague-Dawley rats were randomized to undergo a sham surgery (the sham group, n = 12) or CLP (the septic group, n = 16). After 24 h, the time-response curves of the antagonistic actions of 0.1 or 0.5 μmol/L of neostigmine on Roc (10 μmol/L)-depressed diaphragm twitch tension were measured. Meanwhile, the activity of AChE in the NMJ was detected using a modified Karnovsky and Roots method. The mRNA levels of the primary transcript and the type T transcript of AChE (AChE_T) in the diaphragm were determined by real-time reverse transcription-polymerase chain reaction.

Results:

Four of 16 rats in the septic group died within 24 h. The time-response curves of both two concentrations of neostigmine in the septic group showed significant upward shifts from those in the sham group (P < 0.001 for 0.1 μmol/L; P = 0.009 for 0.5 μmol/L). Meanwhile, the average optical density of AChE in the NMJ in the septic group was significantly lower than that in the sham group (0.517 ± 0.045 vs. 1.047 ± 0.087, P < 0.001). The AChE and AChE_T mRNA expression levels in the septic group were significantly lower than those in the sham group (P = 0.002 for AChE; P = 0.001 for AChE_T).

Conclusions:

Sepsis strengthened the antagonistic actions of neostigmine on Roc-depressed twitch tension of the diaphragm by inhibiting the activity of AChE in the NMJ. The reduced content of AChE might be one of the possible causes of the decreased AChE activity in the NMJ.

Accidental Epidural Injection of Rocuronium in a Pediatric Patient: A Case Report and Literature Review

Accidental administration of non-epidural drugs into the epidural or subarachnoid spaces may be associated with unexpected pain, morbidity, adverse effects, increased level of care, prolonged hospital stay, and mortality. We describe a 12-month-old admitted for secondary-stage hypospadias reconstruction. General anesthesia was induced with sevofiurane and a peripheral catheter was placed. Instead of ropivacaine, rocuronium (80 mg; 6.3 mg/kg) was injected into the epidural space by the caudal route. Surgery was uneventful and was completed 160 minutes after rocuronium was given. The patient exhibited paralysis with 1 of 4 twitches to the train-of-four with some posttetanic potentiation at the end of surgery. He was transferred to the pediatric intensive care unit for supportive ventilation and recovery. He did not experience oxygen desaturation or hypoventilation between the time of rocuronium administration and intubation. He was hemodynamically stable, without respiratory insufficiency, and his neurologic exam was normal, without motor or sensorial block. The patient was discharged home on the morning of the first postoperative day. Clinical examination 1 week after surgery revealed no lasting sequelae from the error.

Neostigmine for reversal of neuromuscular block in paediatric patients

BACKGROUND

Residual neuromuscular block is associated with serious postoperative complications. Some anaesthesiologists use neostigmine to reverse neuromuscular blockade for all paediatric surgical patients. However, the incidence of residual neuromuscular block may be lower in paediatric patients than in adults. The use of neostigmine has also caused complications, such as postoperative nausea, vomiting, excessive salivation and bradycardia. Therefore, whether neostigmine should be used routinely to reverse neuromuscular blockade in each paediatric patient is an important question for paediatric anaesthesiologists.

OBJECTIVES

To assess the necessity of routine usage of neostigmine in preventing residual neuromuscular blockade in paediatric patients following the use of muscle relaxants.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) 2013, Issue 8, part of The Cochrane Library; MEDLINE via Ovid (1946 to August 2013); EMBASE via Ovid SP (1974 to August 2013); ClinicalTrials.gov (18 August 2013) and Chinese Clinical Trial Registry (18 August 2013) with no language restrictions.

SELECTION CRITERIA

We planned to include randomized controlled trials (RCTs) comparing neostigmine versus placebo in American Society of Anaesthesiologists (ASA) I or II paediatric surgical participants (younger than 12 years of age, including newborns) who had received non-depolarizing muscle relaxants.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the studies for inclusion.

MAIN RESULTS

We found no study that satisfied the inclusion criteria. We found one study awaiting classification.

AUTHORS' CONCLUSIONS

No RCTs were found that supported, or argued against, the routine use of neostigmine to reverse neuromuscular block in paediatric patients.

Donepezil provides positive effects to patients treated with gabapentin for neuropathic pain: an exploratory study

BACKGROUND

The first-line medication gabapentin and the acetylcholinesterase inhibitor donepezil represent a new promising combination to improve treatment outcomes for patients with severe neuropathic pain. The drugs have previously shown synergism following co-administration in nerve-injured rats.

METHODS

The clinical relevance of adding donepezil to existing gabapentin treatment in patients with post-traumatic neuropathic pain was explored in this open-label study. The study comprised two consecutive periods of minimum 6 weeks: (1) titration of gabapentin to the highest tolerable dose or maximum 2400 mg daily, and (2) addition of donepezil 5 mg once daily to the fixed gabapentin dose. Efficacy and tolerability were assessed by ratings of pain intensity, questionnaires for pain and health-related quality of life, and reporting of adverse events. Pain scores were also analysed using mixed-effects analysis with the software NONMEM to account for intersubject variability.

RESULTS

Eight patients commenced treatment with donepezil, of which two withdrew because of adverse events. Addition of donepezil resulted in clinically relevant reductions of pain (> 11 units on a 0-100 scale) and improved mental wellness in three of six patients. The remaining three patients had no obvious supplemental effect. Mixed-effects analysis revealed that pain scores were significantly lower during co-administration (P < 0.0001 combination vs. monotherapy).

CONCLUSION

Donepezil may provide additional analgesia to neuropathic pain patients with insufficient pain relief from gabapentin as monotherapy. The promising results support controlled clinical trials of the drug combination. The usefulness of mixed-effects analysis in small-scale trials and/or for data with high intersubject variability was also demonstrated.

Cucurbit[n]uril type hosts for the reversal of steroidal neuromuscular blocking agents

The ideal neuromuscular blocking agent (NMBA) is regarded as being a non-depolarizing equivalent of succinylcholine, having a rapid onset and short duration of action, with minimal side effects. In the absence of a single drug, the administration of an aminosteroid NMBA, such as rocuronium, followed by reversal using an acetylcholinesterase inhibitor, such as neostigmine, is commonly employed. A different and safer approach to rapidly reversing the action of the NMBA, by encapsulating it with a macrocyclic or acyclic host molecule, such as the cyclodextrin sugammadex or more recently, cucurbituril-type hosts such as cyclic cucurbit[7]uril and the acyclic glycoluril tetramer calabadion 1, is described.

Calabadion

Introduction:

To evaluate whether calabadion 1, an acyclic member of the Cucurbit[n]uril family of molecular containers, reverses benzylisoquinoline and steroidal neuromuscular-blocking agent effects.

Methods:

A total of 60 rats were anesthetized, tracheotomized, and instrumented with IV and arterial catheters. Rocuronium (3.5 mg/kg) or cisatracurium (0.6 mg/kg) was administered and neuromuscular transmission quantified by acceleromyography. Calabadion 1 at 30, 60, and 90 mg/kg (for rocuronium) or 90, 120, and 150 mg/kg (for cisatracurium), or neostigmine/glycopyrrolate at 0.06/0.012 mg/kg were administered at maximum twitch depression, and renal calabadion 1 elimination was determined by using a 1H NMR assay. The authors also measured heart rate, arterial blood gas parameters, and arterial blood pressure.

Results:

After the administration of rocuronium, resumption of spontaneous breathing and recovery of train-of-four ratio to 0.9 were accelerated from 12.3 ± 1.1 and 16.2 ± 3.3 min with placebo to 4.6 ± 1.8 min with neostigmine/glycopyrrolate to 15 ± 8 and 84 ± 33 s with calabadion 1 (90 mg/kg), respectively. After the administration of cisatracurium, recovery of breathing and train-of-four ratio of 0.9 were accelerated from 8.7 ± 2.8 and 9.9 ± 1.7 min with placebo to 2.8 ± 0.8 and 7.6 ± 2.1 min with neostigmine/glycopyrrolate to 47 ± 13 and 87 ± 16 s with calabadion 1 (150 mg/kg), respectively. Calabadion 1 did not affect heart rate, mean arterial blood pressure, pH, carbon dioxide pressure, and oxygen tension. More than 90% of the IV administered calabadion 1 appeared in the urine within 1 h.

Conclusion:

Calabadion 1 is a new drug for rapid and complete reversal of the effects of steroidal and benzylisoquinoline neuromuscular-blocking agents.

Residual paralysis: a real problem or did we invent a new disease?

PURPOSE

Over the past three decades, many studies have shown a high proportion of patients in the recovery room with residual neuromuscular blockade after anesthesia. The purpose of this Continuing Professional Development module is to present the physiological consequences of residual paralysis, estimate the extent of the problem, and suggest solutions to prevent its occurrence.

PRINCIPAL FINDINGS

Residual paralysis is defined as a train-of-four ratio (TOFR) < 0.9 at the adductor pollicis. While tidal volume and, to a lesser extent, vital capacity are well preserved as the intensity of blockade increases, the probability of airway obstruction, impaired swallowing, and pulmonary aspiration increases markedly as TOFR decreases. In recent studies, incidences of residual paralysis from 4-57% have been reported, but surveys indicate that anesthesiologists estimate the incidence of the problem at 1% or less. The decision to administer neostigmine or sugammadex should be based on the degree of spontaneous recovery at the adductor pollicis muscle (thumb), not on recovery at the corrugator supercilii (eyebrow). The most important drawback of neostigmine is its inability to reverse profound blockade, which is a consequence of its ceiling effect. When spontaneous recovery reaches the point where TOFR > 0.4 or four equal twitch responses are seen, reduced doses of neostigmine may be given. The dose of sugammadex required in a given situation depends on the intensity of blockade.

CONCLUSION

Careful monitoring and delaying the administration of neostigmine until four twitches are observed at the adductor pollicis can decrease the incidence of residual paralysis. The clinical and pharmacoeconomic effects of unrestricted sugammadex use are unknown at this time.

Neuromuscular blocking agents for electroconvulsive therapy: a systematic review

Electroconvulsive therapy (ECT) is the transcutaneous application of small electrical stimuli to the brain to induce generalised seizures for the treatment of selected psychiatric disorders. The clinical indications for ECT as an effective therapeutic modality have been considerably expanded since its introduction. Anaesthesia and neuromuscular blocking agents (NMBAs) are required to ensure patients' safety during ECT. The optimal dose of muscle relaxant for ECT reduces muscle contractions without inducing complete paralysis. Slight residual motor convulsive activity is helpful in ascertaining that a seizure has occurred, while total paralysis prolongs the procedure unnecessarily. Suxamethonium is commonly used, but nondepolarising NMBAs are indicated in patients with certain comorbidities. In this review, we summarise current concepts of NMBA management for ECT.

Different sensitivities of rat skeletal muscles and brain to novel anti-cholinesterase agents, alkylammonium derivatives of 6-methyluracil (ADEMS)

BACKGROUND AND PURPOSE

The rat respiratory muscle diaphragm has markedly lower sensitivity than the locomotor muscle extensor digitorum longus (EDL) to the new acetylcholinesterase (AChE) inhibitors, alkylammonium derivatives of 6-methyluracil (ADEMS). This study evaluated several possible reasons for differing sensitivity between the diaphragm and limb muscles and between the muscles and the brain.

EXPERIMENTAL APPROACH

Increased amplitude and prolonged decay time of miniature endplate currents were used to assess anti-cholinesterase activity in muscles. In hippocampal slices, induction of synchronous network activity was used to follow cholinesterase inhibition. The inhibitor sensitivities of purified AChE from the EDL and brain were also estimated.

KEY RESULTS

The intermuscular difference in sensitivity to ADEMS is partly explained caused by a higher level of mRNA and activity of 1,3-bis[5(diethyl-o-nitrobenzylammonium)pentyl]-6-methyluracildibromide (C-547)-resistant BuChE in the diaphragm. Moreover, diaphragm AChE was more than 20 times less sensitive to C-547 than that from the EDL. Sensitivity of the EDL to C-547 dramatically decreased after treadmill exercises that increased the amount of PRiMA AChE(G4), but not ColQ AChE(A12) molecular forms. The A12 form present in muscles appeared more sensitive to C-547. The main form of AChE in brain, PRiMA AChE(G4), was apparently less sensitive because brain cholinesterase activity was almost three orders of magnitude more resistant to C-547 than that of the EDL.

CONCLUSIONS AND IMPLICATIONS

Our findings suggest that ADEMS compounds could be used for the selective inhibition of AChEs and as potential therapeutic tools.

Current therapeutic uses, pharmacology, and clinical considerations of neuromuscular blocking agents for critically ill adults

OBJECTIVE

To summarize literature describing use of neuromuscular blocking agents (NMBAs) for common critical care indications and provide a review of NMBA pharmacology, pharmacokinetics, dosing, drug interactions, monitoring, complications, and reversal.

DATA SOURCES

Searches of MEDLINE (1975-May 2011), EMBASE (1980-May 2011), and Cumulative Index to Nursing and Allied Health Literature (1981-May 2011) were conducted to identify observational and interventional studies evaluating the efficacy or safety of NMBAs for management of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), status asthmaticus, elevated intracranial pressure (ICP), and therapeutic hypothermia.

STUDY SELECTION AND DATA EXTRACTION

We excluded case reports, animal- or laboratory-based studies, trials describing NMBA use during rapid sequence intubation or in the operating room, and studies published in languages other than English or French.

DATA SYNTHESIS

Clinical applications of NMBAs in intensive care include, but are not limited to, immobilizing patients for procedural interventions, decreasing oxygen consumption, facilitating mechanical ventilation, reducing intracranial pressure, preventing shivering, and management of tetanus. Recent data on ARDS demonstrated that early application of NMBAs improved adjusted 90-day survival for patients with severe lung injury. These results may lead to increased use of these drugs. While emerging data support the use of cisatracurium in select patients with ALI/ARDS, current literature does not support the use of one NMBA over another for other critical care indications. Cisatracurium may be kinetically preferred for patients with organ dysfunction. Close monitoring with peripheral nerve stimulation is recommended with sustained use of NMBAs to avoid drug accumulation and minimize the risk for adverse drug events. Reversal of paralysis is achieved by discontinuing therapy or, rarely, the use of anticholinesterases.

CONCLUSIONS

NMBAs are high-alert medications used to manage critically ill patients. New data are available regarding the use of these agents for treatment of ALI/ARDS and status asthmaticus, management of elevated ICP, and provision of therapeutic hypothermia after cardiac arrest. To improve outcomes and promote patient safety, intensive care unit team members should have a thorough knowledge of this class of medications.

Neuromuscular block and current treatment strategies for its reversal in children

Even though neuromuscular blocking agents are an essential part of balanced anesthesia and the risks of residual paralysis are well documented, many anesthetists seldomly monitor neuromuscular block. Classical reversal agent neostigmine is unable to antagonise a deep neuromuscular block and is rather slow to antagonise even a moderate block. These caveats may have introduced a practice to use muscle relaxants mainly for an endotracheal intubation. This review presents current views on the effects of muscle relaxants and their reversal agents in pediatric patients. This may help clinicians to reconsider the value of muscle relaxants during anesthesia in children.