Reversal of neuromuscular blockade: "identification friend or foe".

T he article by McLean et al.2 builds on a burgeoning body of literature that for more than 50 yr has described potential complications associated with the use of neuromuscular-blocking agents (NMBAs). There seem to be two themes: The first irrefutable finding is affirmation that the use of NMBAs is associated with postoperative residual weakness that may lead to significant morbidity and, rarely, mortality. Although the second theme is also supported by good science, it is more controversial as it appears to “fly in the face” of the typical anesthesiologist who feels that administration of neostigmine to induce pharmacologic reversal is routinely and reliably sufficient to ensure adequate postoperative neuromuscular function (and thus avoid respiratory complications). however, both the anesthesia and the critical care medicine literature is replete with studies documenting that with or without neostigmine, a significant proportion of our patients exhibits significant residual neuromuscular block (defined as train-of-four [TOF] ratio <0.90) when tested objectively in the postanesthesia care unit (PACU).3 In a sense, NMBAs are similar to opioids—they are both “life-saving” and “complicationproducing” drugs. When used appropriately, NMBAs allow the performance of surgical procedures that would be much more difficult and sometimes impossible without the induced paralysis. Similarly, opioids allow the performance of surgical procedures that would otherwise induce a more significant physiologic trespass with increased risks and complications. But both NMBAs and opioids have significant, sometimes deadly, side effects unless monitored appropriately. Monitoring the depth of analgesia and respiratory depression produced by opioids can be difficult, inexact, and unreliable. Unlike opioids, however, the depth of neuromuscular block, and the adequacy of reversal, can and should be measured— easily, predictably, and routinely. We have the technology, and we have the proof—so far, we have just not had the resolve. It is inexplicable that monitoring of the depth of NMBA block and adequacy of pharmacologic reversal are still not used routinely, and several previous editorials have pointed out the lack of understanding of clinicians of, and perhaps interest in, neuromuscular monitoring.4,5 Why should this be? We believe that a host of factors6 provide some explanation and should include medical heuristics. These heuristics are mental shortcuts used to assist our everyday decisionmaking during patient care, but in essence these are educated Reversal of Neuromuscular Blockade