Neuromuscular monitoring, residual blockade, and reversal: Time for re-evaluation of our clinical practice

Abstract

Even with the advent of shorter-acting muscle relaxants, the risk of residual blockade continues to persist. Consequently, in daily practice, we are confronted with the following contradiction, namely, how best to combine muscular relaxation throughout the operative procedure without exposing patients to the risk of residual blockade at the end of the case. A Continuing Professional Development (CPD) module concerning residual blockade is published in this issue of the Journal. Why was it necessary to publish a CPD module on this topic when a number of related studies and surveys reports are already available? While many clinicians are convinced about the benefits of both neuromuscular monitoring and reversal in current practice, nevertheless, reality seems to differ. Anesthesiologists are well trained in the use of neuromuscular blocking agents. In fact, anesthesiology is the only specialty where these drugs are routinely used. And yet, many clinicians tend not to follow the basic recommendations for using both neuromuscular monitoring and reversal agents. The circumstances leading to this state of affairs are likely more complex. The last updated version of the American Society of Anesthesiologists’ (ASA) Practice Guidelines for Postanesthetic Care states that: ‘‘Assessment of neuromuscular function primarily includes physical examination and, on occasion, may include neuromuscular blockade monitoring’’. With such an assertion regarding the potential for occasional use of neuromuscular monitoring, it would, in all likelihood, be difficult to convince our colleagues regarding the benefits of neuromuscular monitoring and modify existing behaviour. Clinical methods for determining signs of residual blockade may not have the degree of sensitivity to detect partial paralysis. For example, residual paralysis is likely in patients who are able to maintain a sustained head lift. It is only with objective neuromuscular monitoring that one can exclude residual blockade. Clearly, the ASA Task Force on Postanesthetic Care developed their recommendation based on data lacking in sufficient evidence. This is also the basis for SpO2 monitoring. Pedersen et al. from the Cochrane Collaboration updated the systematic review on the use of pulse oximetry during the perioperative period. The authors’ conclusions are comparable with two previous reviews published by the same group. Even if the use of pulse oximetry helped decrease the frequency of hypoxemic episodes, it does not influence patient outcome on major end points (e.g., death and cardiovascular, respiratory, or neurological complications). Even when we consider these evidence-based data on pulse oximetry, can any one of us imagine starting a case without its use? This depiction reveals the limits of evidence-based medicine. This topic has previously been addressed with humour in a study on whether or not there are benefits to using a parachute to prevent death during free fall. Residual blockade remains a specific concern in daily anesthesia practice. The use of neuromuscular blocking drugs has facilitated major progress in performing additional and more complex surgical procedures. This view was first addressed by Dr. Harrold Griffith et al. 70 years ago when Benoit Plaud is consultant for MSD France and MSD International and has participated in the clinical development of sugammadex (Bridion ).