Sugammadex and postoperative pulmonary complications after upper gastrointestinal endoscopy

Tsai et al. report that sugammadex use was associated with fewer postoperative pulmonary complications than neostigmine following upper gastrointestinal endoscopy [1]. These findings contribute to the growing body of evidence supporting the respiratory benefits of sugammadex compared with neostigmine [2, 3]. However, we question whether the reported associations reflect the pharmacological effect of sugammadex accurately or are influenced by the choice of primary outcome and the potential for residual confounding in observational database analyses. The primary outcome was defined as postoperative mechanical ventilation or tracheal reintubation occurring within 30 days of the procedure. Although residual neuromuscular blockade is a plausible contributor to early postoperative respiratory compromise, it becomes increasingly difficult to establish a causal pathway linking an intra-operative reversal agent to respiratory failure occurring days or weeks after surgery [4]. Late respiratory events are more likely to reflect disease progression; hospital-acquired complications; subsequent interventions; or other intercurrent illnesses. A sensitivity analysis restricted to respiratory complications occurring within the first 24–72 h postoperatively would help determine whether the association persists during the period in which residual neuromuscular blockade is biologically relevant. Furthermore, the substantial reduction in postoperative ventilatory failure observed by Tsai et al. contrasts with the absence of significant differences in aspiration events; hypoxaemia; need for non-invasive ventilation; or mortality. These are all outcomes that might reasonably be expected to improve if residual neuromuscular blockade were the primary mechanism underlying the observed benefit. Because quantitative neuromuscular monitoring and train-of-four recovery strongly influence both the choice of antagonist and risk of pulmonary complications, failure to account for these variables leaves substantial potential for residual confounding. Current consensus recommendations emphasise the importance of quantitative neuromuscular monitoring and objective assessment of recovery from neuromuscular blockade when evaluating antagonist strategies [5]. Consequently, the comparison may reflect broader differences in peri-operative care rather than the antagonist drug itself.