Medications that provide a neuromuscular blockade (NMB) are routinely administered in major surgeries and procedures to facilitate airway intubation and maintain surgical status ¹. Although reversal agents are generally successful at reversing neuromuscular blockade following surgery, a degree of residual NMB may persist in certain cases. The occurrence of postoperative pulmonary complications varies with age, surgery type, comorbidity, and general anesthesia, but incomplete NMB reversal (residual NMB) contributes to increased risk. Postoperative pulmonary complications include hypoxia, postoperative pneumonia, airway obstruction, atelectasis, and pulmonary infection ². While estimated incidences range from 1-23%, postoperative pulmonary complications have been linked to higher short-term and long-term mortality rates in patients following major surgery ^2,3. As such strategies to minimize this risk have been probed.

First, neuromuscular blocking agents must be properly dosed in order to minimize complications. Second, improvements in neuromuscular transmission monitoring and its interpretation may be required. As such, one study concluded that the proper use of neostigmine guided by neuromuscular transmission monitoring results may help reduce the incidence of postoperative respiratory complications ⁴.

A key factor leading to postoperative pulmonary complications is ostensibly residual NMB linked to NMB reversal agents. Traditionally, the acetylcholinesterase inhibitor neostigmine has been used to decrease the likelihood of postoperative pneumonia ⁵; however, its reversal of deep NMB tends to be inefficient. In this context, sugammadex, a novel cyclodextrin, the first in a new class of selective relaxant binding agents, has emerged as an important innovation and was approved by the Food and Drug Administration in 2015 ⁶. In particular, sugammadex lowers the incidence of residual paralysis ⁷, incurs a more rapid and efficient reversal ⁸, and minimizes hospital readmissions ⁹.

Though a large, retrospective study did not find a difference in postoperative pulmonary complications related to neostigmine versus sugammadex¹⁰, the general consensus is that sugammadex is the superior NMB reversal agent overall. A 2021 meta-analysis of 14 randomized controlled trials was carried out to compare the incidence of postoperative pulmonary complications between patients who received sugammadex versus the traditionally used agent neostigmine. Compared with neostigmine, the use of sugammadex for NMB reversal was associated with a lower risk of postoperative pulmonary complications, mainly due to a lower incidence of postoperative respiratory failure ¹¹. This may be attributed to the quicker and more complete NMB reversal achieved by sugammadex compared with neostigmine.

However, the study was limited by its lack of clinical homogeneity with regard to patient background, surgery type, and NMB reversal agent administration regimen. The influence of these factors on the effectiveness and optimal sugammadex administration protocol remain to be explored

The NMB reversal agent sugammadex, which is continuing to be assessed clinically, is very promising for its ability to reduce postoperative pulmonary complications ¹². In the future, however, further investigations are required in order to fully validate rapidly emerging findings and develop proper, contextually appropriate usage guidelines. Additional assessments across risk subgroups for postoperative pulmonary complications and targeting the cost-effectiveness of the use of sugammadex are also warranted.

References

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2. Raval, A. D. et al. Epidemiology and outcomes of residual neuromuscular blockade: A systematic review of observational studies. Journal of Clinical Anesthesia (2020). doi:10.1016/j.jclinane.2020.109962
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8. Hristovska, A. M., Duch, P., Allingstrup, M. & Afshari, A. Efficacy and safety of sugammadex versus neostigmine in reversing neuromuscular blockade in adults. Cochrane Database of Systematic Reviews (2017). doi:10.1002/14651858.CD012763
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