Antagonism of cisatracurium and rocuronium block at a tactile train-of-four count of 2: should quantitative assessment of neuromuscular function be mandatory?

THYROID SURGERY, IONM AND SUGAMMADEX SODIUM RELATIONSHIPS: BENEFITS IN SUGAMMADEX SODIUM USE FOR IONM

Background

It is important to protect recurrent laryngeal nerve (RLN) during thyroid surgery. Thus, intra- operative neuromonitoring (IONM) has got popularity. But, the half life of neuromuscular blocking agents used has a reverse correlation with reliability and effectiveness of IONM. This study aimed to research the effect of Sugammadex Sodium, a specific nemuromuscular blocking agent antagonist, on nerve conduction and IONM.

Materials and methods

Twenty patients who underwent thyroidectomy under IONM followed an enhanced NMB recovery protocol-rocuronium 0.6 mg/kg at anesthesia induction and sugammadex 2 mg/kg at the beginning of operation. To prevent laryngeal nerve injury during the surgical procedures, all patients underwent intraoperative monitoring. At the same time, the measurement of TOF-Watch acceleromyograph of the adductor pollicis muscle response to ulnar nerve stimulation was performed; recovery was defined as a train-of-four (TOF) ratio ≥ 0.9. Age, sex, recurrent laryngeal nerve transmission speeds prior to and after operation, BMI, duration of surgery, the change in nerve transmission after drug administration and complications were analyzed.

Results

The mean age and the mean BMI were 47.6±11.82 years and 28.74±3.20, respectively. The mean operation duration was 52.65±5.51 minutes. There was no difference in either right or left RLN monitoring values before and after surgery. Following the drug injection, the TOF guard measurements on the 1^st, 2^nd, 3^rd and 4^th minutes were 23.5±4.90; 69.5±6.86; 88±4.1 and 135.9±10.62, respectively.

Conclusion

Neuromuscular blocking antagonist use and monitoring nerve transmission speed with TOF-guard can provide a safer resection.

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

OBJECTIVES

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

REVIEW METHODS

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

RESULTS

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

CONCLUSIONS

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

Effect of intraoperative neuromonitoring on efficacy and safety using sugammadex in thyroid surgery: randomized clinical trial

Purpose

The use of nondepolarizing neuromuscular blocking agents (NMBAs) may affect intraoperative neuromonitoring (IONM) during anesthesia used during thyroid and parathyroid surgery.

Methods

The use of sugammadex was evaluated in a prospective clinical study during thyroid surgery. Between July 2018 and January 2019, 129 patients were prospectively randomized to either the sugammadex group (group B) or the control group (group A). Group A patients underwent standardized IONM during thyroidectomy, while group B patients used an NMBA-reversal protocol comprised of rocuronium (0.6 mg/kg) in anesthesia induction and sugammadex (2 mg/kg) after first vagal stimulation (V0). A peripheral nerve stimulator was used to monitor the neuromuscular transmission.

Results

In our clinical study, it took 26.07 ± 3.26 and 50.0 ± 8.46 minutes to reach 100% recovery of laryngeal electromyography at injection of the sugammadex group (2 mg/kg) and the control group, respectively (P < 0.001). The train-of-four ratio recovered from 0 to >0.9 within 4 minutes after administering 2 mg/kg of sugammadex at the beginning of resection. Surgery time was significantly shorter in group B than in group A (P < 0.001). Transient recurrent laryngeal nerve (RLN) paralysis was detected in 4 patients from group A and in 3 patients from group B (P = 0.681). There was no permanent RLN paralysis in the 2 groups.

Conclusion

Our clinical study showed that sugammadex effectively and rapidly improved the inhibition of neuromuscular function induced by rocuronium. The implementation of the nondepolarizing neuromuscular block recovery protocol may lead to tracheal intubation as well as favorable conditions for IONM in thyroid surgery.

Neostigmine-based reversal of intermediate acting neuromuscular blocking agents to prevent postoperative residual paralysis: A systematic review

BACKGROUND

Neostigmine is widely used to antagonise residual paralysis. Over the last decades, the benchmark of acceptable neuromuscular recovery has increased progressively to a train-of-four (TOF) ratio of at least 0.9. Raising this benchmark may impact on the efficacy of neostigmine.

OBJECTIVE(S)

The systematic review evaluates the efficacy of neostigmine to antagonise neuromuscular block to attain a TOF ratio of at least 0.9.

DESIGN

We performed a systematic search of the literature from January 1992 to December 2015.

DATA SOURCES OR SETTING

PubMed, EMBASE and the Cochrane Controlled Clinical Trials database were searched for randomised controlled human studies. Search was performed without language restrictions, using the following free text terms: 'neostigmine', 'sugammadex', 'edrophonium' or 'pyridostigmine' AND 'neuromuscular block', 'reversal' or 'reverse'.

ELIGIBILITY CRITERIA

Studies were accepted for inclusion if they used quantitative neuromuscular monitoring and neostigmine as the reversal agent. Selected trials were checked by two of the authors for data integrity. Trials relevant for inclusion had to report the number of patients included, the type of anaesthetic maintenance, the type of neuromuscular blocking agent used, the reversal agent and dose used, the depth of neuromuscular block when neostigmine was administered and the reversal time (time from injection of neostigmine until a TOF ratio ≥0.9 was attained).

RESULTS

19 trials were eligible for quantitative analysis. In patients with deep residual block [T1 (first twitch height) <10%] 70 μg kg neostigmine was used (five trials, 118 patients), and the mean reversal time was 17.1 min (95% confidence interval (CI) [12.4 to 21.8]). In patients with moderate residual block (T1 10% to <25%) the mean neostigmine dose was 56 μg kg (seven trials, 342 patients), and the mean reversal time was 11.3 min (95% CI [9.2 to 13.4]). In patients with a shallow residual block (T1 ≥ 25%) the mean neostigmine dose was 40 μg kg (13 trials, 535 patients), and the mean reversal time was 8.0 min (95% CI [6.8 to 9.2]).

CONCLUSION

Based on the findings of this systematic review, we recommend that the administration of neostigmine be delayed until an advanced degree of prereversal recovery has occurred (i.e. a T1 >25% of baseline), or that a recovery time longer than 15 min be accepted.

Optimal dose of combined rocuronium and cisatracurium during minor surgery: A randomized trial

BACKGROUND

Combined rocuronium and cisatracurium have synergistic effects. We investigated whether reduced doses are effective during coadministration, by monitoring neuromuscular relaxation during surgery.

METHODS

This randomized, controlled clinical trial was registered at http://clinicaltrials.gov (registration number NCT02495038). The participants were 81 patients scheduled for elective mastoidectomy and tympanoplasty. Participants were assigned to groups, including the intubating dose group (Group I, n = 27; combined ED95 rocuronium and ED95 cisatracurium), the small reduction group (Group S, n = 27; dose reduced by 10% of each ED95), or the large reduction group (Group L, n = 27; dose reduced by 20% of each ED95). Drugs were administered to patients and a timer was started using TOF-Watch monitoring. TOF (train-of-four) was monitored at the ulnar nerve, at a setting of 2 Hz/12 s. We recorded the time to TOF ratio = 0 (onset), time to first TOF ratio > 25% (duration 25%), and TOF 25-75% (recovery index) under total intravenous anesthesia. One-way analysis of variance was used for statistical analyses (α = 0.05, β = 0.2).

RESULTS

There were no significant demographic differences between groups. Group L had a longer duration to onset (mean ± standard deviation, 399.3 ± 147.8 seconds) and shorter duration 25% (39.4 ± 6.8 minutes) compared to Group I (212.8 ± 56.0 s and 51.3 ± 8.47 minutes, respectively) and Group S (230.7 ± 60.6 s and 47.9 ± 10.7 minutes, respectively). There were no other significant differences between groups.

CONCLUSION

Our findings contribute to determining clinically effective combinations of rocuronium and cisatracurium, as well as to predicting the pharmacokinetic characteristics of the synergistic effects. We suggest that reducing doses of both drugs by approximately 10% of their respective ED95 values is sufficient to maintain neuromuscular relaxation during minor surgery.

The Impact of Residual Neuromuscular Blockade, Oversedation, and Hypothermia on Adverse Respiratory Events in a Postanesthetic Care Unit: A Prospective Study of Prevalence, Predictors, and Outcomes

BACKGROUND

Residual neuromuscular blockade (RNMB) has been linked to adverse respiratory events (AREs) in the postanesthetic care unit (PACU). However, these events are often not attributed to RNMB by anesthesiologists because they may also be precipitated by other factors including obstructive sleep apnea, opioids, or hypnotic agents. Many anesthesiologists believe RNMB occurs infrequently and is rarely associated with adverse outcomes. This study evaluated the prevalence and predictors of RNMB and AREs.

METHODS

This prospective cohort study included 599 adult patients undergoing general anesthesia who received neuromuscular blocking agents. Baseline demographic, surgical, and anesthetic variables were collected. RNMB was defined as a train-of-four ratio below 0.90 measured by electromyography on admission to the PACU. AREs were defined based on the modified Murphy's criteria.

RESULTS

RNMB was present in 186 patients (31% [95% confidence interval (CI), 27%-35%]) on admission to the PACU. One or more AREs were experienced by 97 patients (16% [95% CI 13-19]). AREs were more frequent in patients with RNMB (21% vs 14%, P = .033). RNMB was significantly associated with age (adjusted relative risk [RR], 1.17 [95% CI, 1.06-1.29] per 10-year increase), type of operation (adjusted RR, 0.59 [95% CI, 0.34-0.99] for laparoscopic surgery compared with open abdominal surgery), and duration of operation (adjusted RR, 0.59 [95% CI, 0.39-0.86] for ≥90 minutes compared with <90 minutes). Using multivariate logistic regression, AREs were found to be independently associated with decreased level of consciousness (adjusted RR, 4.76 [95% CI, 1.49-6.76] for unrousable/unconscious compared with alert/awake) and lower core temperature (adjusted RR, 1.43 [95% CI, 1.04-1.92] per 1°C decrease). Although univariate analysis found a significant association between AREs and RNMB, the significance became borderline after adjusting for other covariates (adjusted RR, 1.46 [95% CI, 0.99-2.08]).

CONCLUSIONS

The prevalence of RNMB in the PACU was >30%. Older age, open abdominal surgery, and duration of operation <90 minutes were associated with increased risk of RNMB in our patients. Our RR estimate for AREs was highest for depressed level of consciousness. When AREs occur in the PACU, potentially preventable causes including RNMB, hypothermia, and reduced level of consciousness should be readily identified and treated appropriately. Delaying extubation until the patient is awake and responsive may reduce AREs.

Use of neuromuscular blockers and neostigmine for general anesthesia and its association with neuraxial blockade: A retrospective study

This research aimed to assess the use of neuromuscular blockers (NMB) and its reversal, associated or not with neuraxial blockade, after general anesthesia.This retrospective study analyzed 1295 patients that underwent surgery with general anesthesia at Prof. Dr. José Aristodemo Pinotti Hospital in 2013. The study included patients aged >1 year, with complete, readable medical charts and anesthetic records.Rocuronium (ROC) was the most used NMB (96.7%), with an initial dose of 0.60 (0.52-0.74) mg/kg and total dose of 0.38 (0.27-0.53) mg/kg/h. In 24.3% of the cases, neuraxial blockade was associated with a significantly longer anesthesia (P < .001) than in cases without neuraxial block, regardless of technique (total intravenous (TIV) vs intravenous and inhalational (IV+IN)). In 71.9% of the cases, a single dose of NMB was used. Patients under TIV general anesthesia associated with neuraxial blockade had a lower total dose of ROC (mg/kg/h) in comparison with TIV GA alone (0.30 (0.23-0.39) and 0.42 (0.30-0.56) mg/kg/h, respectively, P < .001). The same was observed for patients under IV+IN GA (0.32 (0.23-0.41) and 0.43 (0.31-0.56) mg/kg/h, respectively, P < .001). The duration of anesthesia was longer according to increasing number of additional NMB doses (P < .001). Dose of neostigmine was 2.00 (2.00-2.00) mg or 29.41 (25.31-33.89) μg/kg. The interval between neostigmine and extubation was >30 minutes in 10.9% of cases.The most widely used NMB was ROC. Neuroaxial blockade (spinal or epidural) was significantly associated with reduced total dose of ROC (mg/kg/h) during general anesthesia, even in the absence of neuromuscular monitoring and regardless of general anesthetic technique chosen. In most cases, neostigmine was used to reverse neuromuscular block. The prolonged interval between neostigmine and extubation (>30 minutes) was neither associated with total doses of ROC or neostigmine, nor with the time of NMB administration. This study corroborates the important role of quantitative neuromuscular monitors and demonstrates that neuraxial blockade is associated with reduced total ROC dose. Further studies are needed to evaluate the possible role of neuraxial blockade in reducing the incidence of postoperative residual curarization.

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.

Comparison of Sugammadex versus Neostigmine Costs and Respiratory Complications in Patients with Obstructive Sleep Apnoea

OBJECTIVE

To compare sugammadex and neostigmine regarding the efficacy in reversing rocuronium-induced neuromuscular block, the incidence of post-operative respiratory complications and costs in patients undergoing surgery for the treatment of obstructive sleep apnoea (OSA).

METHODS

After obtaining ethical approval and patient consent, 74 patients in ASA physical status I or II were randomised into two groups to receive 2-mg kg(-1) sugammadex (Group S) or 0.04-mg kg(-1) neostigmine+0.5-mg atropine (Group N). Groups were compared regarding time to TOF (train-of-four) 0.9, operating room time, post-anaesthesia care unit (PACU) stay, post-operative respiratory complications, costs related to neuromuscular block reversal, anaesthesia care and complication treatment.

RESULTS

Patient demographics, anaesthesia, surgical data and total rocuronium doses were similar between groups. Time to TOF 0.9 was shorter for group S [Group N: 8 (5-18) min; Group S: 2 (1.5-6) min (p<0.001)]. Operating room time [Group S: 72.4±14.3 min; Group N: 96.6±22.8 min (p<0.001)] and PACU stay [Group S: 22.9±10.1 dk; Group N: 36.3±12.6 dk (p<0.001)] were also shorter in Group S. After extubation, desaturation was observed in 12 (32.4%) patients in group N and in 4 (8%) patients in group S (p=0.048). In group N, three patients were reintubated; there were eight (21.6%) unplanned intensive care unit (ICU) admissions. There was one unplanned ICU admission in group S. Negative pressure pulmonary oedema was observed in one patient in group N. The results regarding costs were as follows. The reversal cost was higher in the sugammadex group (vial cost 98.14 TL) than that in the neostigmine group (ampoule cost 0.27 TL; total 6147.88 TL vs. 3569.5 TL); however, complication treatment cost and total cost were lower in group S than those in group N (199.5 TL vs. 3944.6 TL) (staff anaesthesia doctor cost was 0.392 TL per min and the cost of nurse anaesthetist was 0.244 TL per min).

CONCLUSION

This study confirmed the efficacy of sugammadex over neostigmine for the reversal of rocuronium-induced neuromuscular block. Sugammadex decreases the incidence of post-operative respiratory complications and related costs in patients with OSA.

Timing of reversal with respect to three nerve stimulator end-points from cisatracurium-induced neuromuscular block

After elective ear surgery with cisatracurium neuromuscular blockade, 48 adults were randomly assigned to receive neostigmine: (a) at appearance of the fourth twitch of a 'train-of-four'; (b) at loss of fade to train-of-four; or (c) at loss of fade to double-burst stimulation, all monitored using a TOF-Watch SX® on one arm. For each of these conditions, the recovery from train-of-four (TOF) ratio was measured in parallel objectively using a TOF-Watch SX placed on the contralateral arm. The median (IQR [range]) time from administration of reversal to a train-of-four ratio ≥ 0.9 was 11 (9-15.5 [2-28]) min, 8 (4-13.5 [1-25]) min and 7 (4-10 [2-15]) min in the three groups, respectively. This recovery time was significantly shorter when reversal was given at loss of fade to double-burst stimulation (c), than when given at the appearance of the fourth twitch (a), p = 0.046. However, the total time to extubation may be unaffected as it takes longer for fade to be lost after double-burst stimulation than for four twitches subjectively to appear.

Sugammadex: clinical development and practical use

Sugammadex is belonging to a new class of drugs: the selective relaxant binding agents. Sugammadex can reverse residual paralysis by encapsulating free circulating non depolarizing muscle relaxants. The mains advantages of sugammadex when compared with conventional anticholinesterase agents are a much faster recovery time and the unique ability, for the first time, to reverse rapidly and efficiently deep levels of neuromuscular blockade. However it only works for reversal of rocuronium or vecuronium-induced neuromuscular blockade. When administered 3 min after rocuronium the use of a large dose (16 mg/kg) can even reverse rocuronium significantly faster than the spontaneous recovery after succinylcholine.

Reversal of profound neuromuscular blockade with sugammadex after failure of rapid sequence endotracheal intubation: a case report

BACKGROUND AND OBJECTIVES

Sugammadex is a reversal agent that acts as a selective antagonist of neuromuscular blockade induced by rocuronium and vecuronium. This is a case report of an elderly female patient who had sugammadex just after rocuronium induction.

CASE REPORT

An 88-year-old female patient, 34 kg, presented a femoral fracture and had to undergo general anesthesia after spinal anesthesia failure. Induction was performed with propofol 1.5mg.kg(-1), rocuronium 1.2mg.kg(-1), fentanyl 100 mcg, and lidocaine 2mg.kg(-1). There was no success in either tracheal intubation or laryngeal mask positioning maneuvers. The use of sugammadex at a dose of 16 mg.kg(-1) was required and respiratory function returned to normal.

CONCLUSION

Literature recommends sugammadex at a dose of 16 mg.kg(-1) for patients with profound blockade. It was used in our patient with rapid and effective reversal of neuromuscular blockade allowing the patient to undergo another procedure to ensure the airway patency without clinical impairment of her general condition.

Effect of isoflurane versus propofol-remifentanil anesthesia on neuromuscular blockade and hemodynamic responses by cisatracurium bolus injection

BACKGROUND

Inhalational anesthetics potentiate nondepolarizing muscle relaxants. Cisatracurium is a recently introduced neuromuscular blocker in Korea. We studied the effect of inhalational anesthesia and total intravenous anesthesia (TIVA) on neuromuscular blockades and hemodynamic responses by cisatracurium bolus injection.

METHODS

Forty patients undergoing elective surgery were randomly divided into isoflurane and propofol-remifentanil groups. A bolus dose of cisatracurium of 0.15 mg/kg (3 × ED(95)) was administered after induction and the onset time and clinical duration of action were recorded. The nueromuscular blockade was monitored using train-of-four (TOF) stimulation. Hemodynamic parameters were also recorded.

RESULTS

Onset time was 194.0 ± 39.1 sec in the isoflurane group and 226.5 ± 62.2 sec in the propofol-remifentanil group. Clinical duration of action was 49.2 ± 9.0 min in the isoflurane group and 43.0 ± 9.2 min in the propofol-remifentanil group. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) immediately before intubation decreased in the propofol-remifentanil group. Heart rate (HR), SBP and DBP 1 and 3 min after tracheal intubation increased in the isoflurane group.

CONCLUSIONS

Onset time was similar between isoflurane and propofol-remifentanil anesthesia. Clinical duration of action was significantly longer in isoflurane anesthesia. SBP and DBP immediately before intubation and HR, SBP and DBP 1 and 3 min after tracheal intubation were significantly different between the two groups.

Sugammadex reversal of rocuronium-induced neuromuscular block in Caesarean section patients: a series of seven cases

Sugammadex is a selective relaxant-binding agent, which reverses rocuronium-induced neuromuscular blocks of any depth by chemical encapsulation of rocuronium in the plasma in various groups of patients. We reported seven Caesarean section cases, undergoing general anaesthesia with thiopental (6 mg kg⁻¹) and rocuronium (0.6 mg kg⁻¹) who were given desflurane and fentanyl for maintenance of anaesthesia after delivery. The action of rocuronium may be prolonged in pregnant women. At the end of the operation, all patients had a significant degree of neuromuscular block. In five patients, there was no single twitch response and no TOF ratio, one patient had one twitch detectable, and in one patient, a TOF ratio of 3% was detected. The recommended dose of sugammadex for reversal of profound block (4 mg kg⁻¹) or moderate block (2 mg kg⁻¹) was given. In all patients, sugammadex provided rapid and sufficient reversal to TOF >0.9 within 2 min. All patients were monitored after operation, and no signs of recurarization occurred in any patient and no signs of neuromuscular weakness were observed.

Incidence of Residual Neuromuscular Blockade in a Post-Anaesthetic Care Unit

We conducted a prospective observational study to assess the incidence of residual neuromuscular blockade (RNMB) in a post-anaesthetic care unit (PACU) of a tertiary hospital. The subjects were 102 patients undergoing general anaesthesia with neuromuscular blockade (NMB). The procedural anaesthetists were unaware of their patients’ inclusion in the study, and the choice of muscle relaxant and use of reversal agents were at the anaesthetists’ discretion. On arrival to the PACU, the train-of-four ratio was assessed using electromyography, repeated every five minutes until the train-of-four ratio exceeded 0.9. RNMB was defined as a train-of-four ratio < 0.9. The requirement for airway support, incidence of desaturation while in the PACU and time to eligibility for PACU discharge were recorded. The mean interval between the last dose of relaxant and arrival in the PACU for patients with RNMB was 81 minutes. An intermediate-acting muscle relaxant had been used for most patients. Despite this, RNMB was observed in 31% (95% confidence interval 25 to 47%) of patients. Our findings suggest that RNMB in the PACU is common. As RNMB may predispose to postoperative complications, anaesthetists should utilise quantitative monitoring to assess neuromuscular blockade and optimise reversal use. Anaesthetists should be aware that intervals between the last dose of relaxant of well over one hour do not exclude the possibility of RNMB, even when using intermediate-acting neuromuscular blockade agents.

Neuromuscular monitoring and postoperative residual curarisation: a meta-analysis

We conducted a meta-analysis to examine the effect of intraoperative monitoring of neuromuscular function on the incidence of postoperative residual curarisation (PORC). PORC has been considered present when a patient has a train-of-four (TOF) ratio of < 0.7 or < 0.9. We analysed data from 24 trials (3375 patients) that were published between 1979 and 2005. We excluded data on mivacurium from this meta-analysis because only three studies had examined the incidence of PORC associated with its use. Long- and intermediate-acting neuromuscular blocking drugs had been given to 662 and 2713 patients, respectively. Neuromuscular function was monitored in 823 patients (24.4%). A simple peripheral nerve stimulator was used in 543 patients, and an objective monitor was used in 280. The incidence of PORC was found to be significantly lower after the use of intermediate neuromuscular blocking drugs. We could not demonstrate that the use of an intraoperative neuromuscular function monitor decreased the incidence of PORC.

Sugammadex reversal of rocuronium-induced neuromuscular blockade: a comparison with neostigmine-glycopyrrolate and edrophonium-atropine

BACKGROUND

Sugammadex is a modified [gamma] cyclodextrin compound, which encapsulates rocuronium to provide for a rapid reversal of residual neuromuscular blockade. We tested the hypothesis that sugammadex would provide for a more rapid reversal of a moderately profound residual rocuronium-induced blockade than the commonly used cholinesterase inhibitors, edrophonium and neostigmine.

METHODS

Sixty patients undergoing elective surgery procedures with a standardized desflurane-remifentanil-rocuronium anesthetic technique received either sugammadex, 4 mg/kg IV (n = 20), edrophonium, 1 mg/kg IV and atropine, 10 microg/kg IV (n = 20), or neostigmine, 70 microg/kg IV and glycopyrrolate, 14 microg/kg IV (n = 20) for reversal of neuromuscular blockade at 15 min or longer after the last dose of rocuronium using acceleromyography to record the train-of-four (TOF) responses. Mean arterial blood pressure and heart rate values were recorded immediately before and for 30 min after reversal drug administration. Side effects were noted at discharge from the postanesthesia care unit.

RESULTS

The three groups were similar with respect to their demographic characteristics and total dosages of rocuronium prior to administering the study medication. Although the initial twitch heights (T1) at the time of reversal were similar in all three groups, the time to achieve TOF ratios of 0.7 and 0.9 were significantly shorter with sugammadex (71 +/- 25 and 107 +/- 61 s) than edrophonium (202 +/- 171 and 331 +/- 27 s) or neostigmine (625 +/- 341 and 1044 +/- 590 s). All patients in the sugammadex group achieved a TOF ratio of 0.9 < or =5 min after reversal administration compared with none and 5% in the edrophonium and neostigmine groups, respectively. Heart rate values at 2 and 5 min after reversal were significantly higher in the neostigmine-glycopyrrolate group compared with that in sugammadex. Finally, the incidence of dry mouth was significantly reduced in the sugammadex group (5% vs 85% and 95% in the neostigmine and edrophonium groups, respectively).

CONCLUSION

Sugammadex, 4 mg/kg IV, more rapidly and effectively reversed residual neuromuscular blockade when compared with neostigmine (70 microg/kg IV) and edrophonium (1 mg/kg IV). Use of sugammadex was associated with less frequent dry mouth than that with the currently used reversal drug combinations.

CISATRACURIUM VS. ROCURONIUM: A PROSPECTIVE, COMPARATIVE, RANDOMIZED STUDY IN ADULT PATIENTS UNDER TOTAL INTRAVENOUS ANAESTHESIA

AIMS

To compare the pharmacodynamics of cisatracurium and rocuronium-induced neuromuscular block following single dose, allowing either spontaneous or neostigmine-accelerated complete recovery.

METHODS

Following the ethics committee approval and informed consent, 120 patients scheduled for elective surgery under TIVA with tracheal intubation were randomized into 4 groups with different cisatracurium (CIS, 0.10 or 0.15 mg.kg(-1)) or rocuronium (ROC, 0.60 or 0.90 mg.kg(-1)) doses administered. For each patient, the onset time for 95 % depression of T1, clinical duration until 25 % recovery, recovery index (T1 from 25 to 75 %) and time from T1 25 % to TOF-ratio 0.9 were determined allowing either spontaneous or induced recovery.

RESULTS

The onset times were 277 (SD 58), 220 (46), 91 (16) and 77 (16) s for the CIS 0.10, CIS 0.15, ROC 0.60 and ROC 0.90 groups (p < 0.05), respectively, with lower variability in both ROC groups (p < 0.05). The clinical durations were 42 (7), 52 (7), 35 (11) and 52 (12) min, respectively (p < 0.05 for lower doses). Recovery index was identical in all groups allowing either spontaneous recovery - 15.9 (1.8), 15.5 (1.7), 16.1 (3.7) and 16.1 (4.0) min, or following neostigmine administration - 4.4 (0.9), 4.5 (0.8), 4.3 (0.8) and 4.7 (0.7) min for respective groups. During spontaneous recovery, the variability of DUR25-TOF90 was twice as great for ROC than CIS groups (p < 0.05), while after neostigmine administration it was uniform in all groups.

CONCLUSIONS

For equipotent doses, the onset times for CIS were approximately three times longer than for ROC. The average clinical duration for both relaxants ranged from 35 to 52 min with acceptable variability. Neostigmine administration accelerated the recovery and reduced its variability. When allowing for spontaneous recovery, less scatter was demonstrated for both CIS groups than for ROC ones.

Pharmacodynamics of rocuronium 0.3 mg kg(-1) in adult patients with and without renal failure

BACKGROUND AND AIM

The neuromuscular effects of a bolus dose of rocuronium 0.6 mg kg(-1) under propofol anaesthesia in renal failure patients are prolonged compared to healthy patients. The present study aims to describe the neuromuscular effects of 0.3 mg kg(-1) rocuronium under propofol anaesthesia in patients with renal failure and to compare these effects with healthy control patients.

METHODS

With institutional approval and informed consent, 18 healthy patients and 18 patients with renal failure took part in this prospective open label study. The renal failure patients were undergoing either renal transplantation or insertion of a shunt. Rocuronium 0.3 mg kg(-1) was given intravenously after induction of anaesthesia with propofol 1-2 mg kg(-1) and fentanyl 2 microg kg(-1). Propofol 6-12 mg kg(-1) h(-1) was used for maintenance of anaesthesia. Four acceleromyographic responses of the thumb after supramaximal stimulation of the ulnar nerve using surface electrodes at 2 Hz every 15 s were measured and recorded. The onset time, the time to recovery of the first twitch to 25% recovery and the time to a train-of-four ratio of 0.7 were all recorded. Wilcoxon rank sum testing was used to compare the pharmacodynamics and to see if medication, gender or electrolytes influenced the duration of the block. P < 0.05 was significant.

RESULTS

No statistical differences were seen in the neuromuscular blocking effects of rocuronium between the two groups but there was a significant difference (P < 0.00001) in the variability of the total duration of the block.

CONCLUSIONS

Rocuronium 0.3 mg kg(-1) is suitable for use in patients with renal failure when endotracheal intubation and neuromuscular block for a short period of time are needed. Tracheal intubation is facilitated within 4 min and the block can be antagonized within 20 min.

Curarisation résiduelle

Despite the availability of modern neuromuscular blocking agents with short or intermediate duration of action, incidence of residual neuromuscular blockade remains very high. Evidences have been recently provided that residual curarization must be defined as a train-of-four ratio below 0.9 at the thumb adductor during the recovery period after anaesthesia. Residual curarization may be associated with serious adverse events related to respiratory depression, pharyngeal dysfunction, hypoxemia and prolongation of the length of stay in the recovery room. Appropriate choice of drugs, perioperative monitoring of neuromuscular function and large indications of pharmacological reversal may reduce the incidence of residual curarization and improve the patient's safety in the postoperative setting.

Residual Paralysis at the Time of Tracheal Extubation

Respiratory and pharyngeal muscle function are impaired during minimal neuromuscular blockade. Tracheal extubation in the presence of residual paresis may contribute to adverse respiratory events. In this investigation, we assessed the incidence and severity of residual neuromuscular block at the time of tracheal extubation. One-hundred-twenty patients presenting for gynecologic or general surgical procedures were enrolled. Neuromuscular blockade was maintained with rocuronium (visual train-of-four [TOF] count of 2) and all subjects were reversed with neostigmine at a TOF count of 2-4. TOF ratios were quantified using acceleromyography immediately before tracheal extubation, after clinicians had determined that complete neuromuscular recovery had occurred using standard clinical criteria (5-s head lift or hand grip, eye opening on command, acceptable negative inspiratory force or vital capacity breath values) and peripheral nerve stimulation (no evidence of fade with TOF or tetanic stimulation). TOF ratios were measured again on arrival to the postanesthesia care unit. Immediately before tracheal extubation, the mean TOF ratio was 0.67 +/- 0.2; among the 120 patients, 70 (58%) had a TOF ratio <0.7 and 105 (88%) had a TOF ratio <0.9. Significantly fewer patients had TOF ratios <0.7 (9 subjects, 8%) and <0.9 (38 subjects, 32%) in the postanesthesia care unit compared with the operating room (P < 0.001). Our results suggest that complete recovery from neuromuscular blockade is rarely present at the time of tracheal extubation.

Antagonism of profound cisatracurium and rocuronium block: the role of objective assessment of neuromuscular function

STUDY OBJECTIVE

The purpose of this study is to determine the incidence of significant (train-of-four [TOF] ratio <0.70), but clinically undetectable (TOF ratio >0.40), residual neuromuscular block after neostigmine antagonism of profound cisatracurium (CIS) or rocuronium (ROC) block.

DESIGN

Prospective, randomized, open-label study.

SETTING

University hospital.

PATIENTS

Forty ASA physical status I and II undergoing elective surgical procedures.

INTERVENTIONS

Anesthesia was induced with propofol 1.5 to 2.5 mg/kg IV plus fentanyl 2 to 4 mug/kg and maintained with N(2)O/desflurane plus narcotic supplementation. The electromyographic response of the adductor pollicis was recorded. Train-of-four stimulation was given every 20 seconds. Twitch height (T1) and TOF fade ratio were continuously recorded. In group 1 (n = 20), neuromuscular block was induced with CIS 0.10 mg/kg, and T1 was maintained at 5% of control by a constant infusion of CIS until the end of surgery. One minute after the termination of the infusion, neostigmine 0.05 mg/kg was administered. T1 and TOF values were monitored continuously for the next 20 minutes. Group 2 (n = 20) is identical to group 1 except that the initial drug was ROC 0.60 mg/kg, and paralysis was maintained with an infusion of ROC.

MEASUREMENTS AND MAIN RESULTS

There were no significant differences in the recovery patterns of CIS vs ROC. The duration (bolus to end of infusion) in both groups averaged 2.7 hours, and the mean cumulative dose of relaxant approximated 4 x the ED(95). T1 at the time of reversal was 6% (4%-10%) of control. Mean TOF ratios at 10, 15, and 20 minutes were 0.55, 0.71, and 0.0.81, respectively. Return to a TOF ratio >0.40 was always achieved in 15 minutes or less. However, at 20 minutes postreversal, 5 of 40 subjects had TOF ratios <0.70 and only 11 individuals had recovered to a TOF ratio of 0.90 or greater.

CONCLUSIONS

Most clinicians cannot detect tactile fade once the TOF ratio exceeds 0.40. When reversing profound block, an objective monitor of neuromuscular function is required if the extent of residual block is to be assessed with any confidence.