To the Editor:
The American Society of Anesthesiologists (ASA) and the European Society of Anaesthesiology and Intensive Care (ESAIC) recently published, independently from one another, their respective Practice Guidelines for the Management of Neuromuscular Blockade. The ASA guideline provides evidence-based recommendations regarding appropriate monitoring and antagonism of neuromuscular blockade. The ESAIC guideline presents aggregated and evidence-based recommendations regarding the role of neuromuscular blocking agents to facilitate airway management and to improve surgical conditions, as well as strategies for the diagnosis and prevention of residual paralysis. Both societies’ guidelines recommend the use of quantitative neuromuscular monitoring at the adductor pollicis to guide antagonism. Accordingly, sugammadex is recommended for deep, moderate, and shallow levels of neuromuscular blockade that is induced by rocuronium or vecuronium; neostigmine is a reasonable alternative for minimal blockade; and patients with a calibrated and normalized train-of-four ratio greater than or equal to 0.9 do not require pharmacologic antagonism.
Current data indicate a high incidence of inappropriate management of neuromuscular block, with a high rate of residual paralysis and relaxant-associated postoperative complications. Indeed, a recent survey addressed the practice of neuromuscular block management in Europe. In this survey, 17,150 patients were exposed to a neuromuscular blocking agent, but neuromuscular monitoring was not employed in more than 10,000 of them, the timing of extubation was based solely on clinical criteria in approximately 12,000 patients, and more than 8,300 patients did not receive any reversal agent at the end of surgery. Finally, only 16.5% of patients (2,839 of 17,150) were extubated with a documented train-of-four ratio greater than or equal to 0.9. Unsurprisingly, this very high incidence of inappropriate management of neuromuscular block increased the rate of residual paralysis and relaxant-associated postoperative pulmonary complications. Unfortunately, the practice of neuromuscular management did not fundamentally differ in the United States. These findings are concerning, because the available neuromuscular monitoring, as well as neuromuscular blocking agents and their antagonists, basically allows safe management of neuromuscular blockade. Moreover, convincing evidence strongly suggests that residual paralysis worsens patients’ outcomes and increases the risk of adverse respiratory events during early recovery; these adverse events can be reduced by intraoperative quantitative neuromuscular monitoring.
Hence, in light of the above-mentioned description of the practice of neuromuscular blockade management and with the intention to improve patient safety, the ASA and the ESAIC each created a guideline task force to critically appraise the current literature in the field and to provide a graded and evidence-based set of practice guidelines for the management of neuromuscular blockade. Both task forces chose an acknowledged, transparent, and reproducible methodology to develop their respective recommendations.
Neither task force was aware of the existence or mission of the other. Both acted independently (the COVID-19 pandemic with limited international meetings and congresses in 2020 and 2021 may have contributed to this). Despite this, the published practice guidelines are almost identical, further strengthening both the applied methodology and the set of recommendations developed.
From our perspective, the recommendations with perhaps the greatest impact on quality of practice, patient care, and patient outcome are:
- To use ulnar nerve stimulation and quantitative neuromuscular monitoring at the thumb
- To recommend sugammadex over neostigmine at deep, moderate, and shallow neuromuscular blockade induced by rocuronium
- To use neostigmine as a reasonable alternative to sugammadex for minimal neuromuscular blockade (train-of-four ratio of 0.4 to less than 0.9) induced by rocuronium
- To consider neostigmine for a depth of block deeper than minimal, depending on clinical judgment and in the context of quantitative monitoring, with the understanding that deeper blocks will require more time to attain a train-of-four ratio greater than or equal to 0.9
The recommendations were developed after a systematic review of the literature. They are evidence-based, straightforward, and clinically sound: the data show it is impossible to accurately predict the depth of neuromuscular block or the adequacy of reversal by using clinical tests or qualitative assessment of the responses to a peripheral nerve stimulator. Objective confirmation of a train-of-four ratio of 0.9 or higher obtained at the adductor pollicis muscle after ulnar nerve stimulation is critical before tracheal extubation.
However, implementation of these guidelines in current clinical practice is crucial to meaningfully improve patient care and outcomes. Hence, both the ASA and the ESAIC further support, with this joint letter, the routine use of quantitative neuromuscular monitoring for patients receiving neuromuscular blocking agents. The exact strategies employed by any given practice may vary, but a systematic approach may include restructuring the clinical environment by placing quantitative monitors in all anesthetizing locations, educational efforts on the departmental and individual levels utilizing different mediums, and performance feedback on the departmental and individual levels. Finally, the presence of a local champion who is supported by the departmental and institutional leaders is paramount to support a change in the current practice.