Residual Neuromuscular Blockade and Postoperative Pulmonary Complications in the Post-anesthesia Care Unit: A Prospective Observational Study.

Abstract

Background Neuromuscular blocking agents (NMBAs) are employed during general anesthesia induction for endotracheal intubation and to facilitate specific surgeries requiring muscle relaxation. However, residual neuromuscular blockade (RNMB) can lead to respiratory complications in post-anesthesia care units (PACUs). This study investigates RNMB incidence in PACUs and its association with postoperative airway and respiratory issues. Methods A prospective observational study on patients undergoing general anesthesia with NMBAs was conducted at the Department of Anesthesia, Salmaniya Medical Complex, Bahrain, over six months (April to September 2023). Train-of-four (TOF) ratios were calculated using an acceleromyograph upon PACU arrival. Data on demographics, perioperative variables, and postoperative complications were recorded. Results Among 82 patients, 30 (36.6%) had RNMB upon PACU arrival. RNMB incidence declined: 17.1% at 10 minutes, 6.1% at 20 minutes, and 2.4% at 30 minutes, resolving by 40 minutes. Demographics and procedure duration showed no correlation with RNMB. Postoperative respiratory complications affected 23.2% of patients, notably higher in those with RNMB (p = 0.001). Among patients with TOF <90% at PACU arrival, 46.7% experienced complications compared to 9.6% with TOF ≥90% (p<0.001). Participants without RNMB had a significantly higher weight (p = 0.046). Airway support was required for 30% of patients, all with TOF <90% (p<0.001). Conclusion This study emphasizes the importance of assessing and monitoring neuromuscular function to detect and prevent RNMB in PACUs. RNMB presence correlated with an increased susceptibility to postoperative respiratory complications. Regular quantitative neuromuscular monitoring is advisable in clinical practice to proactively mitigate RNMB incidence and its complications.