Quantitative assessment of residual neuromuscular blockade in post-anesthesia care unit

Objectives: Residual neuromuscular blockade (RNMB) is a critical factor contributing to post-operative respiratory complications, even when traditional extubation criteria are met. This study aimed to assess the incidence of residual neuromuscular blockade (RNMB) using train of four ratios and identify associated risk factors in post-surgical patients. Material and Methods: After ethical permission and written informed consent, this prospective observational study was undertaken in tertiary care hospital in 80 American Society of Anesthesiologists (ASA) Grade I and II patients aged 18–60 years undergoing surgery of duration more than 2 h. Patients with renal or liver disease, neuromuscular disorders, or hemodynamic instability were excluded. During the operation under general anesthesia, data on total drug usage, hemodynamic parameters, blood loss, urine output, and temperature were all recorded. Following extubation, RNMB was evaluated serially using train-of-four (TOF) watch acceleromyography, with the first measurement recorded at extubation (T0), at 5-min until the TOF ratio >0.9 was obtained. Statistical analysis was performed with the Statistical Package for the Social Sciences, with P < 0.05 considered significant. Results: The incidence of RNMB was 28.8%. Patients with RNMB were mainly female (69.6%), older (average age 42.61 years), and had a higher body mass index (BMI) (26.00 kg/m 2 ) compared to those without RNMB. Prolonged surgery duration, increased muscle relaxant dosage, and intraoperative use of labetalol and tranexamic acid were significantly associated with RNMB. No significant association was observed with ASA grades, hypertension, diabetes, or type of surgery. Conclusion: Residual neuromuscular blockade (RNMB) remains a significant post-operative risk, particularly in females, older patients, and those with higher BMI. Quantitative neuromuscular monitoring is crucial for complete recovery and reducing complications. While clinical extubation criteria work well for ASA I and II patients, intraoperative TOF monitoring is recommended for those with higher BMI, longer surgeries, or significant blood loss. This study supports the reliability of clinical criteria in low-risk groups and calls for further research on higher-risk populations, such as ASA III and IV patients.