Incidence of Postoperative Residual Neuromuscular Blockade at the Postanesthesia Care Unit Following General Anesthesia

Objective: This study aimed to investigate residual neuromuscular blockade (RNMB) and respiratory adverse events and identify risk factors for RNMB. Material and Methods: A prospective observational study enrolled 377 elective adult patients with American Society of Anesthesiologists (ASA) classifications 1–3 who underwent GA with NMBAs. At the conclusion of surgery, endotracheal tubes were removed once clinical extubation criteria were met. The Train-of-Four (TOF) ratio was immediately measured upon the patients’ arrival in the post-anesthesia care unit (PACU), with RNMB defined as a TOF ratio < 0.9. Respiratory adverse events were documented. Results: The incidence of RNMB was 40.8% upon PACU arrival, with a median TOF ratio of 0.92 (interquartile range [IQR], 0.85–0.98). Cisatracurium was the primary NMBA used (98.1%). The incidence of respiratory adverse events was 6.6%, including hypoxemia (2.9%) and tachypnea (3.7%). No cases of reintubation or unplanned ICU admission occurred. The ophthalmologic surgery emerged as the only significant risk factor for RNMB, adjusted OR 2.44 (95% CI, 1.16-4.38, p = 0.02). Conclusion: The incidence of RNMB after GA in the PACU was common, though no serious adverse events were observed. The type of surgery was identified as the sole significant risk factor for RNMB.