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

Abstract

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.

Incidence of postoperative residual neuromuscular blockade in the postanaesthesia care unit

“…In a clinical series of 350 patients undergoing elective surgical procedures at eight public hospitals which can be considered representative of the country because of their geographical location and the number of patients attending annually, the incidence of RNMB was 26%. This percentage is within the range reported in similar studies published in the literature, 1,5,9,17,19 and highlights the dimension of the problem of incomplete neuromuscular recovery in the PACU in our country.…”

“…Although other studies on this topic from different countries have been published, 3,5,17 it is important to have local data because differences do exist between countries and over time. This was an observational trial designed to assess the incidence of RNMB as the primary endpoint but endpoints did not include evaluating the rationale for using neuromuscular block reversal agents or the time since the last dose of neuromuscular blocker.…”

“…5 In an audit of RNMB from Australasia, 31% of patients exhibited RNMB on entry to the PACU (TOF ratio <0.9). 17 In a meta-analysis of 3375 patients, the pooled incidence of postoperative residual curarisation was 41.3% for intermediate-acting muscle relaxants with a TOF ratio less than 0.9. 18 In a review of studies published since 2000 reported by Murphy and Brull, 1 the incidence of RNMB defined as TOF ratio less than 0.9 and measured with acceleromyography varied widely between 3.5 and 83%.…”

Efficacy of Sugammadex for the Reversal of Moderate and Deep Rocuronium-induced Neuromuscular Block in Patients Pretreated with Intravenous Magnesium

“…[9][10][11] Prolongation of the duration of the neuromuscular blockade increases the risk of clinically relevant paralysis postoperatively and may thus compromise patient safety. 8,[12][13][14][15] To prevent residual neuromuscular block, reliable pharmacological reversal should be achieved before extubation of the trachea. Classically, anesthesiologists have administered cholinesterase inhibitors (for instance, neostigmine) at the end of surgery to antagonize residual effects of neuromuscular-blocking agents.…”

A Review of the Safety and Efficacy of Sugammadex in Anesthetic Practice

“…Yet, despite an ever-improving understanding of neuromuscular function and the clinical use of modern neuromuscular monitoring techniques, residual paralysis still remains a significant problem in post anesthesia care units (PACU). 1,2 In fact, Yip et al showed the incidence of patients arriving in the PACU with residual weakness (residual paralysis) to be 31%. Interestingly, in this study the incidence of residual weakness was not significantly lower in patients who received neostigmine, 1 suggesting that we may need to rethink our management of patients who receive neuromuscular blocking agents (NMBAs).…”