Current Status of Neuromuscular Reversal and Monitoring: Posttetanic Neuromonitoring and Other Considerations

Authors: Hilary P. Grocott, M.D., F.R.C.P.C., F.A.S.E.

Anesthesiology 10 2017, Vol.127, 723-724.

To the Editor:

The recent comprehensive review article by Drs. Brull and Kopman¹ outlines the challenges and opportunities of the current status of neuromuscular reversal and monitoring. Their superlative and informative review is clearly destined to be a go-to reference on the subject. Importantly, it should serve as a rallying point for advancing future neuromuscular blockade (NMB) and function monitoring.

Several aspects of this article do warrant additional comment, however. First, the article deals with many important concepts in NMB monitoring and reversal, including not only perioperative considerations, but issues pertinent to the intensive care unit (ICU) where residual neuromuscular blockade, and associated patient awareness, has occasionally been reported.²  Given that the article will rightly take its place as a definitive article on the subject, and as an advocate for postpublication peer-review, I was curious as to why the section discussing awareness from residual paralysis in the ICU included a reference to an article on hypothermia in the ICU (that does not actually mention awareness at all).³  That minor irregularity aside, the excellent text, tables, and figures make for an easy to understand description of all the important concepts in NMB monitoring.

A second issue that was particularly interesting was in the discussion of posttetanic count (PTC) as it pertains to posttetanic facilitation. Although the important information the authors provided was accurate, it incompletely addressed an often-misunderstood PTC concept—that is, the time period following a tetanic stimulus that the neuromuscular junction is affected and that subsequent train-of-four (TOF) monitoring might be impaired. Indeed, Hakim et al.⁴  recently dispelled the common misconception that PTC impairs the NMB for a protracted period of time, showing that TOF responses are reliable as early as one minute after a PTC. I think it is worthwhile bringing this to the readers’ attention, particularly in a definitive and comprehensive article.

Lastly, both Brull and Kopman, as well as the accompanying editorial by Naguib and Johnson,⁵  highlight the importance of moving forward the “state of the art” of NMB monitoring. Importantly, the editorial highlights the American Society of Anesthesiologists’ significant gap in providing guidance on neuromuscular blockade monitoring, particularly when compared with other similar anesthesia societies.^6,7  Articles such as this one from Brull and Kopman will, we can hope, encourage the American Society of Anesthesiologists to take a more progressive stance on the subject and advocate for the use of NMB monitoring whenever neuromuscular blocking drugs are used.

Hilary P. Grocott, M.D., F.R.C.P.C., F.A.S.E., University of Manitoba, Winnipeg, Manitoba, Canada. hgrocott@sbgh.mb.ca

References

Brull, SJ, Kopman, AF . Current status of neuromuscular reversal and monitoring: Challenges and opportunities. Anesthesiology 2017; 126:173–90

Roy, M, Morissette, N, Girard, M, Robillard, N, Beaulieu, P . Postoperative awake paralysis in the intensive care unit after cardiac surgery due to residual neuromuscular blockade: A case report and prospective observational study. Can J Anaesth 2016; 63:725–30

Polderman, KH, Herold, I . Therapeutic hypothermia and controlled normothermia in the intensive care unit: Practical considerations, side effects, and cooling methods. Crit Care Med 2009; 37:1101–20

Hakim, D, Drolet, P, Donati, F, Fortier, LP . Performing post-tetanic count during rocuronium blockade has limited impact on subsequent twitch height or train-of-four responses. Can J Anaesth 2016; 63:828–33

Naguib, M, Johnson, KB . Innovative disruption in the world of neuromuscular blockade: What is the “state of the art?” Anesthesiology2017; 126:12–5

Merchant, R, Chartrand, D, Dain, S, Dobson, G, Kurrek, MM, Lagace, A, Stacey, S, Thiessen, B, Chow, L, Sullivan, P . Guidelines to the practice of anesthesia—Revised edition 2016. Can J Anesth 2016; 63:86–112

Checketts, MR, Alladi, R, Ferguson, K, Gemmell, L, Handy, JM, Klein, AA, Love, NJ, Misra, U, Morris, C, Nathanson, MH, Rodney, GE, Verma, R, Pandit, JJ ; Association of Anaesthetists of Great Britain and Ireland: Recommendations for standards of monitoring during anaesthesia and recovery 2015: Association of Anaesthetists of Great Britain and Ireland. Anaesthesia 2016; 71:85–93