Incidence of postoperative residual neuromuscular blockade - A multicenter, observational study in Portugal (INSPIRE 2).

BACKGROUND: Although the use of neuromuscular blocking agents (NMBAs) optimizes surgical conditions and facilitates tracheal intubation, it can lead to residual neuromuscular blockade (RNMB), with postoperative complications. This study aimed to assess RNMB incidence and management in Portugal.

METHODS: Prospective observational study of patients admitted for elective surgery requiring general anesthesia with nondepolarizing NMBAs between July 2018 and July 2019 at 10 Portuguese hospitals. The primary endpoint was the proportion of patients arriving at postanesthesia care unit (PACU) with a TOF ratio <0.9.

RESULTS: A total of 366 patients were included, with a median age of 59 years, and 89.1% classified as ASA II or III. Rocuronium was the most used NMBA (99.5%). A total of 96.2% of patients received a reversal agent, 96.6% of which sugammadex and 3.4% neostigmine. Twenty patients displayed a TOF ratio <0.9 at PACU arrival, representing an RNMB incidence of 5.5% (95% CI, 3.1%-7.8%). Only two patients displayed a TOF ratio <0.7. RNMB incidence was 16.7% with neostigmine and 5.3% with sugammadex ( P = .114). In patients with intraoperative neuromuscular blockade (NMB) monitoring, RNMB incidence was 5% (95% CI, 2%-8%), which varied significantly according to the type of monitoring ( P = .018). Incidence of adverse events was 3.3% (2 severe and 10 moderate).

CONCLUSIONS: The reported overall incidence of 5.5% is numerically lower than results from similar observational studies. An appropriate pharmacological neuromuscular reversal strategy, guided by quantitative neuromuscular monitoring, has the potential to achieve even better results, converting RNMB from an unusual to a very rare or even inexistent event.