Vecuronium-induced Neuromuscular Block Research Articles

Required dose of sugammadex or neostigmine for reversal of vecuronium-induced shallow residual neuromuscular block at a train-of-four ratio of 0.3.

Residual shallow neuromuscular block (NMB) is potentially harmful and contributes to critical respiratory events. Evidence for the optimal dose of sugammadex required to reverse vecuronium‐induced shallow NMB is scarce. The aims of the present study were to find suitable doses of sugammadex and neostigmine to reverse a residual vecuronium‐induced NMB from a time of flight (TOF) ratio of 0.3–0.9 and evaluate their safety and efficacy. In total, 121 patients aged 18–65 years were randomly assigned to 11 groups to receive placebo, sugammadex (doses of 0.125, 0.25, 0.5, 1.0, or 2.0 mg/kg), or neostigmine (doses of 10, 25, 40, 55, or 70 μg/kg). The reversal time of sugammadex and neostigmine to antagonize a vecuronium‐induced shallow residual NMB (i.e., TOF ratio of 0.3) and related adverse reactions were recorded. Several statistical models were tested to find an appropriate statistical model to explore the suitable doses of sugammadex and neostigmine required to reverse a residual vecuronium‐induced NMB. Based on a monoexponential model with the response variable on a logarithmic scale, sugammadex 0.56 mg/kg may be sufficient to reverse vecuronium‐induced shallow residual NMB at a TOF ratio of 0.3 under anesthesia maintained with propofol. Neostigmine may not provide prompt and satisfactory antagonism as sugammadex, even in shallow NMB.

A randomized trial evaluating the safety profile of sugammadex in high surgical risk ASA physical class 3 or 4 participants

BackgroundThe aim of this randomized, double-blind trial was to evaluate the safety and tolerability profile, including cardiac safety, of sugammadex-mediated recovery from neuromuscular block in participants undergoing surgery who met the American Society of Anesthesiologists (ASA) Physical Class 3 or 4 criteria. Specifically, this study assessed the impact of sugammadex on cardiac adverse events (AEs) and other prespecified AEs of clinical interest.MethodsParticipants meeting ASA Class 3 and 4 criteria were stratified by ASA Class and NMBA (rocuronium or vecuronium) then randomized to one of the following: 1) Moderate neuromuscular block, sugammadex 2 mg/kg; 2) Moderate neuromuscular block, neostigmine and glycopyrrolate (neostigmine/glycopyrrolate); 3) Deep neuromuscular block, sugammadex 4 mg/kg; 4) Deep neuromuscular block, sugammadex 16 mg/kg (rocuronium only). Primary endpoints included incidences of treatment-emergent (TE) sinus bradycardia, TE sinus tachycardia and other TE cardiac arrhythmias.ResultsOf 344 participants randomized, 331 received treatment (61% male, BMI 28.5 ± 5.3 kg/m2, age 69 ± 11 years). Incidence of TE sinus bradycardia was significantly lower in the sugammadex 2 mg/kg group vs neostigmine/glycopyrrolate. The incidence of TE sinus tachycardia was significantly lower in the sugammadex 2 and 4 mg/kg groups vs neostigmine/glycopyrrolate. No significant differences in other TE cardiac arrythmias were seen between sugammadex groups and neostigmine/glycopyrrolate. There were no cases of adjudicated anaphylaxis or hypersensitivity reactions in this study.ConclusionsCompared with neostigmine/glycopyrrolate, incidence of TE sinus bradycardia was significantly lower with sugammadex 2 mg/kg and incidence of TE sinus tachycardia was significantly lower with sugammadex 2 mg/kg and 4 mg/kg. These results support the safety of sugammadex for reversing rocuronium- or vecuronium-induced moderate and deep neuromuscular block in ASA Class 3 or 4 participants.Trial registrationClinicalTrials.gov Identifier: NCT03346057.

Retraction Note to: Monitoring of vecuronium-induced neuromuscular block at the sternocleidomastoid muscle in anesthetized patients

The Editor-in-Chief has retracted this article [1] because the three studies included in the meta-analysis [2,3 and 4] (cited as references 16, 17 and 18) have been retracted due to concerns regarding the data, which has rendered the results of this meta-analysis invalid.

Retraction

AnaesthesiaVolume 73, Issue 4 p. 526-526 RetractionFree Access Retraction This article retracts the following: Retracted: The effect of ulinastatin pre-treatment on vecuronium-induced neuromuscular block in patients with hepatic cirrhosis Y. Saitoh, K. Kaneda, M. Murakawa, Volume 57Issue 3Anaesthesia pages: 218-222 First Published online: March 5, 2002 First published: 27 February 2018 https://doi.org/10.1111/anae.14240AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Retracted: Saitoh Y, Kaneda K, Murakawa M. The effect of ulinastatin pre-treatment on vecuronium-induced neuromuscular block in patients with hepatic cirrhosis. Anaesthesia 2002; 57: 218–22. DOI: 10.1046/j.0003-2409.2001.02468.x The above article 1 from Anaesthesia, published online on 5 March 2002 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor in Chief, Dr A. Klein and John Wiley & Sons. The retraction has been agreed due to non-submission of research study for ethical approval before undertaking research and concerns about the data 2. References 1Saitoh Y, Kaneda K, Murakawa M. The effect of ulinastatin pre-treatment on vecuronium-induced neuromuscular block in patients with hepatic cirrhosis. Anaesthesia 2002; 57: 218– 22. DOI: 10.1046/j.0003-2409.2001.02468.X 2Carlisle JB, Loadsman JA. Evidence for non-random sampling in randomised, controlled trials by Yuhji Saitoh. Anaesthesia 2017; 72: 17– 27. DOI: 10.1111/anae.13650. Volume73, Issue4April 2018Pages 526-526 ReferencesRelatedInformation

Speed of reversal of vecuronium neuromuscular block with different doses of neostigmine in anesthetized dogs

ObjectivesNeostigmine is routinely used to reverse non-depolarizing neuromuscular block. Given its indirect mechanism, a plateau may exist whereby increasing doses of neostigmine do not result in clinical benefit. This study was designed to measure the speed of reversal of vecuronium-induced neuromuscular block in isoflurane-anesthetized dogs after the administration of three doses of neostigmine as used in clinical practice. Study designProspective, crossover, randomized study. AnimalsSeven adult, mixed-breed dogs with a mean ± standard deviation (SD) age of 2.0 ± 0.8 years and weight of 19.1 ± 9.1 kg. MethodsDogs were anesthetized on three occasions with isoflurane and administered vecuronium (0.1 mg kg–1) intravenously (IV). The train-of-four (TOF) ratio was measured on the pelvic limb with acceleromyography. When the second twitch of the TOF had returned spontaneously, atropine (0.03 mg kg–1) and neostigmine (0.02, 0.04 or 0.07 mg kg–1) were administered IV. Time to reach a TOF ratio of ≥0.9 after neostigmine administration was recorded. ResultsIncreasing the dose of neostigmine from 0.02 mg kg–1 to 0.04 mg kg–1 and 0.07 mg kg–1 resulted in significant reductions in mean ± SD reversal times (10.5 ± 2.3, 7.4 ± 1.1 and 5.4 ± 0.5 minutes, respectively) (p < 0.0001) and smaller coefficients of variation (22%, 15% and 10%, respectively). Conclusions and clinical relevanceIncreasing the dose of neostigmine from 0.02 mg kg–1 to 0.04 mg kg–1 and 0.07 mg kg–1 produced faster and less variable reversal of vecuronium-induced neuromuscular block in isoflurane-anesthetized dogs. No ceiling effect was observed at this dose range.

Post-tetanic burst count and train-of-four during recovery from vecuronium-induced intense neuromuscular block under different types of anaesthesia

Post-tetanic burst count and train-of-four during recovery from vecuronium-induced intense neuromuscular block under different types of anaesthesia

Recovery of train-of-four ratio to 0.70 and 0.90 is delayed in type 2 diabetes with vecuronium-induced neuromuscular block

The recovery profile of train-of-four ratio to more than 0.70 in patients with diabetes mellitus has not been well investigated. Our primary objective was to evaluate the spontaneous recovery profile of neuromuscular block by vecuronium until train-of-four ratio more than 0.90 in patients with type 2 diabetes mellitus compared with controls, using first dorsal interosseous electromyography. Single-centre prospective case-control study. The operating theatres of Fukuoka University Hospital. Fourteen adults with type 2 diabetes mellitus (diabetes mellitus group) and 14 control patients (control group) were included in this study. Evoked responses to train-of-four stimuli were measured by electromyography at the first dorsal interosseous muscle. General anaesthesia was induced with propofol, fentanyl and remifentanil. Vecuronium (0.1 mg kg) was administered to all patients. Anaesthesia was maintained with propofol, fentanyl and remifentanil. The neuromuscular block was assessed until spontaneous recovery to train-of-four ratio more than 0.90. Recovery times to train-of-four ratio 0.70 and 0.90. Recovery times to train-of-four ratio 0.70 and 0.90 were significantly longer in the diabetes mellitus group than the control group (P = 0.041 and P = 0.027, respectively). The time from train-of-four ratio 0.25 to 0.90 was also significantly longer in the diabetes mellitus group than the control group (P = 0.029). In five of 14 patients in the diabetes mellitus group, the time from train-of-four ratio 0.25 to 0.90 was longer than 60 min, which is longer than the duration of action of neostigmine. The time from train-of-four ratio 0.25 to 0.90 was longer than 60 min in only one of 14 in the control group. Recovery times to train-of-four ratio 0.70 and 0.90 were delayed in patients with type 2 diabetes mellitus. Neuromuscular block by vecuronium should be carefully monitored in patients with type 2 diabetes mellitus until recovery of train-of-four ratio to a safe level is confirmed.

Sugammadex reversal of rocuronium-induced neuromuscular blockade in two types of neuromuscular disorders: Myotonic dystrophy and spinal muscular atrophy

Neuromuscular disorders like myotonic dystrophy (dystrophia myotonica or Steinert's disease) and spinal muscular atrophy are associated with perioperative complications related to muscle weakness. These patients have an increased sensitivity to non-depolarising neuromuscular blocking agents, which can lead to postoperative residual curarization (PORC) and its associated respiratory complications. Adequate reversal of neuromuscular blockade is essential to prevent this. Sugammadex is the first selective relaxant binding agent and it reverses rocuronium- and vecuronium-induced neuromuscular block. Two cases are reported in which the patients received sugammadex to reverse a rocuronium-induced neuromuscular block. Reversal of the rocuronium-induced neuromuscular block (NMB) in both cases was fast, effective and without recurarization, and no safety concerns were observed.

Reversal of profound rocuronium or vecuronium-induced neuromuscular block with sugammadex in isoflurane-anaesthetised dogs

This study evaluated the use of sugammadex for reversal of profound neuromuscular blockade induced with rocuronium or vecuronium in dogs. Anaesthesia was induced and maintained with isoflurane in oxygen in eight dogs on two occasions. Neuromuscular blockade was monitored using peroneal nerve stimulation and acceleromyography. Rocuronium 0.6 mg/kg or vecuronium 0.1mg/kg was administered intravenously (IV), followed 5 min later by sugammadex 8 mg/kg IV. Lag and onset time of rocuronium and vecuronium, lag time from sugammadex injection to recovery of first twitch response, recovery of T1/T0 to 25% and 75%, recovery index, and time to recovery of the train-of-four ratio (T4/T1) to 0.9 were recorded. Cardiovascular and respiratory parameters were also noted. Statistical analysis was performed using one-way ANOVA. Onset time for rocuronium (37 ± 18s; [mean ± SD]) was significantly shorter than for vecuronium (62 ± 15s) (P<0.04). No other significant differences were found between the two groups. After both rocuronium and vecuronium blockade, T4/T1 recovered to 0.9 in under 2 min after sugammadex (58.1 ± 67.8s and 98.1 ± 70.3s, respectively; P<0.32). Sugammadex can reverse profound neuromuscular blockade induced by vecuronium or rocuronium safely and rapidly in isoflurane-anaesthetised dogs.

Effect of Epidural Levobupivacaine on Recovery from Vecuronium-Induced Neuromuscular Block in Patients Undergoing Lower Abdominal Surgery

The aim of this study was to evaluate the effect of epidural levobupivacaine on recovery from vecuronium-induced neuromuscular block. Ninety patients undergoing lower abdominal surgery were randomised into two groups after an epidural test dose: the epidural group (n = 45) received a bolus of 15 ml of 0.5% levobupivacaine whereas the control group (n = 45) did not. Anaesthesia was induced and maintained with propofol, fentanyl, vecuronium and nitrous oxide. Neuromuscular block was induced with vecuronium 0.1 mg/kg and monitored with acceleromyographic train-of-four at the adductor pollicis. Patients in each group received neostigmine at 25% recovery of the first twitch of train-of-four during recovery from anaesthesia. The effect of epidural levobupivacaine on the speed of recovery of neuromuscular function was evaluated. The lag time, onset time and time from vecuronium administration until 25% T1 recovery did not differ between the groups. The times of the recovery index (the time from 25% to 75% recovery of T1) and of the DUR 25-train-of-four 90 (time from 25% T1 to train-of-four ratio of 0.9) in the epidural group were significantly longer than those for the control group (5.2 [2.1] vs 3.04 [1.02] minutes and 10.8 [3.3] vs 8.2 [2.3] minutes, P < 0.001). This study shows that epidural levobupivacaine significantly delays the train-of-four recovery from vecuronium-induced block. Although the interaction is small in the clinical setting, anaesthetists should take this interaction into consideration when combining general and epidural anaesthesia during surgery.

Sugammadex reverses neuromuscular block induced by 3-desacetyl-vecuronium, an active metabolite of vecuronium, in the anaesthetised rhesus monkey

3-Desacetyl-vecuronium is an active metabolite of the neuromuscular blocking agent (NMBA) vecuronium, which might lead to residual paralysis after prolonged administration of vecuronium in critically ill patients with renal failure. This study investigated the ability of sugammadex to reverse 3-desacetyl-vecuronium-induced neuromuscular block (NMB) in the anaesthetised rhesus monkey. Experiments were performed in anaesthetised female rhesus monkeys. After bolus intravenous injection of vecuronium (n = 8) or 3-desacetyl-vecuronium (n = 8) 10 μg kg(-1) (ED90), a continuous infusion of the same NMBA was started to maintain the first twitch of the train-of-four (TOF) at 10% of baseline value. The infusion was stopped and NMB recovered spontaneously. The procedure was repeated, but immediately after stopping the infusion, an intravenous bolus dose of sugammadex 0.5 or 1.0 mg kg(-1) was given. For each NMBA, four placebo experiments were performed, in which the second recovery from NMB was also spontaneous. For all experiments, time to recovery of the TOF ratio to 90% was retrieved. After administration of sugammadex for reversal of 3-desacetyl-vecuronium-induced NMB, recovery was significantly faster than spontaneous recovery. Mean time to recovery of TOF to 90% was 3.2 min (sugammadex 0.5 mg kg(-1)) and 2.6 min (1.0 mg kg(-1)), compared to spontaneous recovery (17.6 min). For vecuronium-induced NMB, mean time to recovery of TOF to 90% was 17.1 min (0.5 mg kg(-1)) and 4.6 min (1.0 mg kg(-1)), compared to spontaneous recovery (23.4 min). Sugammadex rapidly and effectively reversed 3-desacetyl-vecuronium-induced NMB in the rhesus monkey, at a lower dose than that needed to reverse vecuronium-induced NMB.

Sugammadex rapidly reverses moderate rocuronium- or vecuronium-induced neuromuscular block during sevoflurane anaesthesia: a dose–response relationship

Sugammadex rapidly reverses moderate rocuronium- or vecuronium-induced neuromuscular block during sevoflurane anaesthesia: a dose–response relationship

Sugammadex rapidly reverses moderate rocuronium- or vecuronium-induced neuromuscular block during sevoflurane anaesthesia: a dose–response relationship

BackgroundSugammadex shows a dose–response relationship for reversal of neuromuscular block (NMB) during propofol anaesthesia. Sevoflurane, unlike propofol, can prolong the effect of neuromuscular blocking agents (NMBAs), increasing recovery time. This open-label, randomized, dose-finding trial explored sugammadex dose–response relationships, safety, and pharmacokinetics when administered for reversal of moderate rocuronium- or vecuronium-induced NMB during sevoflurane maintenance anaesthesia. MethodsAfter anaesthesia induction with propofol, adult patients were randomized to receive single-dose rocuronium 0.9 mg kg−1 or vecuronium 0.1 mg kg−1, with maintenance doses as needed. Anaesthesia was maintained with sevoflurane. NMB was monitored using acceleromyography. After the last dose of NMBA, at reappearance of T2, single-dose sugammadex 0.5, 1.0, 2.0, or 4.0 mg kg−1 or placebo was administered. The primary efficacy variable was time from the start of sugammadex administration to recovery of T4/T1 ratio to 0.9. Safety assessments were performed throughout. ResultsThe per-protocol population comprised 93 patients (rocuronium, n=46; vecuronium, n=47). A statistically significant dose–response relationship was demonstrated for mean recovery times of T4/T1 ratio to 0.9 with increasing sugammadex dose with both NMBAs: rocuronium, 96.3 min (placebo) to 1.5 min (sugammadex 4.0 mg kg−1); vecuronium, 79.0 min (placebo) to 3.0 min (sugammadex 4.0 mg kg−1). Plasma sugammadex concentrations indicated linear pharmacokinetics, independent of NMBA administered. No study drug-related serious adverse events occurred. Evidence of reoccurrence of block was reported in seven patients [sugammadex 0.5 mg kg−1 (suboptimal dose), n=6; 2.0 mg kg−1, n=1]. ConclusionsDuring sevoflurane maintenance anaesthesia, sugammadex provides well-tolerated, effective, dose-dependent reversal of moderate rocuronium- and vecuronium-induced NMB.

Reversal of profound vecuronium-induced neuromuscular block under sevoflurane anesthesia: sugammadex versus neostigmine

BackgroundAcetylcholinesterase inhibitors cannot rapidly reverse profound neuromuscular block. Sugammadex, a selective relaxant binding agent, reverses the effects of rocuronium and vecuronium by encapsulation. This study assessed the efficacy of sugammadex compared with neostigmine in reversal of profound vecuronium-induced neuromuscular block under sevoflurane anesthesia.MethodsPatients aged ≥18 years, American Society of Anesthesiologists class 1-4, scheduled to undergo surgery under general anesthesia were enrolled in this phase III, multicenter, randomized, safety-assessor blinded study. Sevoflurane anesthetized patients received vecuronium 0.1 mg/kg for intubation, with maintenance doses of 0.015 mg/kg as required. Patients were randomized to receive sugammadex 4 mg/kg or neostigmine 70 μg/kg with glycopyrrolate 14 μg/kg at 1-2 post-tetanic counts. The primary efficacy variable was time from start of study drug administration to recovery of the train-of-four ratio to 0.9. Safety assessments included physical examination, laboratory data, vital signs, and adverse events.ResultsEighty three patients were included in the intent-to-treat population (sugammadex, n = 47; neostigmine, n = 36). Geometric mean time to recovery of the train-of-four ratio to 0.9 was 15-fold faster with sugammadex (4.5 minutes) compared with neostigmine (66.2 minutes; p < 0.0001) (median, 3.3 minutes with sugammadex versus 49.9 minutes with neostigmine). No serious drug-related adverse events occurred in either group.ConclusionsRecovery from profound vecuronium-induced block is significantly faster with sugammadex, compared with neostigmine. Neostigmine did not rapidly reverse profound neuromuscular block (Trial registration number: NCT00473694).

RETRACTED ARTICLE: Monitoring of vecuronium-induced neuromuscular block at the sternocleidomastoid muscle in anesthetized patients

To assess the degree of neuromuscular block acceleromyographically at the sternocleidomastoid muscle. Eighteen adult patients scheduled for air-oxygen-sevoflurane-fentanyl and epidural anesthesia were studied. In the patients, the right accessory nerve and the sternocleidomastoid muscle were stimulated and the contraction of the sternocleidomastoid muscle was evaluated acceleromyographically. Simultaneously, the response of the adductor pollicis muscle was measured electromyographically. Supramaximal stimulating current, degree of maximum neuromuscular block after vecuronium 0.1mg/kg, and onset of or recovery from vecuronium-induced neuromuscular block were compared between the two muscles. The supramaximal stimulating current at the sternocleidomastoid muscle was significantly higher than that at the adductor pollicis muscle (54.8±7.1 vs. 33.7±10.3mA, mean±SD, P<0.001). The onset of neuromuscular block at the sternocleidomastoid muscle did not significantly differ from that at the adductor pollicis muscle (214±117 vs. 161±87s, P=0.131). The degree of maximum neuromuscular block at the sternocleidomastoid muscle was significantly less than that at the adductor pollicis muscle (93.6±3.1 vs. 99.2±2.5%, P<0.001). During recovery from neuromuscular block, T1/control and train-of-four ratio measured at the sternocleidomastoid muscle were significantly higher than those at the adductor pollicis muscle 10-30 and 40-120min after vecuronium, respectively (P<0.05). The sternocleidomastoid muscle is more resistant to vecuronium than the adductor pollicis muscle. Recovery from neuromuscular block is faster at the sternocleidomastoid muscle than at the adductor pollicis muscle.

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Reversal of rocuronium‐induced profound neuromuscular block by sugammadex in Duchenne muscular dystrophy

A case is reported in which a child with Duchenne muscular dystrophy received a dose of sugammadex to reverse a rocuronium-induced profound neuromuscular block. Sugammadex is the first selective relaxant binding agent and reverses rocuronium- and vecuronium-induced neuromuscular block. A fast and efficient recovery from profound neuromuscular block was achieved, and no adverse events or other safety concerns were observed.

Effective Reversal of Moderate Rocuronium- or Vecuronium-Induced Neuromuscular Block With Sugammadex, a Selective Relaxant Binding Agent

Survey of Anesthesiology: August 2008 - Volume 52 - Issue 4 - p 187-188 doi: 10.1097/SA.0b013e31817c5bb0

Safety and tolerability of single intravenous doses of sugammadex administered simultaneously with rocuronium or vecuronium in healthy volunteers

Sugammadex rapidly reverses rocuronium- and vecuronium-induced neuromuscular block. To investigate the effect of combination of sugammadex and rocuronium or vecuronium on QT interval, it would be preferable to avoid the interference of anaesthesia. Therefore, this pilot study was performed to investigate the safety, tolerability, and plasma pharmacokinetics of single i.v. doses of sugammadex administered simultaneously with rocuronium or vecuronium to anaesthetized and non-anaesthetized healthy volunteers. In this phase I study, 12 subjects were anaesthetized with propofol/remifentanil and received sugammadex 16, 20, or 32 mg kg(-1) combined with rocuronium 1.2 mg kg(-1) or vecuronium 0.1 mg kg(-1); four subjects were not anaesthetized and received sugammadex 32 mg kg(-1) with rocuronium 1.2 mg kg(-1) or vecuronium 0.1 mg kg(-1) (n=2 per treatment). Neuromuscular function was assessed by TOF-Watch SX monitoring in anaesthetized subjects and by clinical tests in non-anaesthetized volunteers. Sugammadex, rocuronium, and vecuronium plasma concentrations were measured at several time points. No serious adverse events (AEs) were reported. Fourteen subjects reported 23 AEs after study drug administration. Episodes of mild headache, tiredness, cold feeling (application site), dry mouth, oral discomfort, nausea, increased aspartate aminotransferase and gamma-glutamyltransferase levels, and moderate injection site irritation were considered as possibly related to the study drug. The ECG and vital signs showed no clinically relevant changes. Rocuronium/vecuronium plasma concentrations declined faster than those of sugammadex. Single-dose administration of sugammadex 16, 20, or 32 mg kg(-1) in combination with rocuronium 1.2 mg kg(-1) or vecuronium 0.1 mg kg(-1) was well tolerated with no clinical evidence of residual neuromuscular block, confirming that these combinations can safely be administered simultaneously to non-anaesthetized subjects. Rocuronium and vecuronium plasma concentrations decreased faster than those of sugammadex, reducing the theoretical risk of neuromuscular block developing over time.

Epidurally administered mepivacaine delays recovery of train-of-four ratio from vecuronium-induced neuromuscular block

The aim of this study was to examine the efficacy of epidurally administered mepivacaine on recovery from vecuronium-induced neuromuscular block. Eighty patients were randomly assigned to one of two study groups. They were either given epidurally a bolus of 0.15 ml kg(-1) of mepivacaine 2%, followed by repetitive injections of 0.1 ml kg(-1) h(-1) throughout the study, or were not given epidurally. General anaesthesia was induced and maintained with fentanyl, propofol and nitrous oxide. Neuromuscular block was induced with vecuronium 0.1 mg kg(-1) and monitored using acceleromyographic train-of-four (TOF) at the adductor pollicis. Patients in each treatment group were randomized to receive neostigmine 0.04 mg kg(-1) at 25% recovery of the first twitch of TOF or to recover spontaneously to a TOF ratio of 0.9. The effect of epidural mepivacaine on speed of spontaneous and facilitated recovery of neuromuscular function was evaluated. The time from administration of vecuronium to spontaneous recovery to a TOF ratio of 0.9 was significantly longer in the epidural mepivacaine group [105.4 (14.2) min] as compared with the control group [78.5 (9.1) min, P < 0.01]. Neostigmine administered at 25% of control in T1 shortened recovery from neuromuscular block, however the time required for facilitated recovery to a TOF ratio of 0.9 in the epidural group was significantly longer than that in the control group [7.6 (1.6) min vs 5.8 (2.1) min, P < 0.01]. In clinical anaesthesia, it should be recognized that epidurally administered mepivacaine delays considerably the TOF recovery from neuromuscular block.