Residual neuromuscular block in the postanaesthesia care unit: a single-centre prospective observational study and systematic review.

Background: Concerns regarding residual neuromuscular block (RNMB) have persisted since the introduction of neuromuscular blocking agents, with reported incidences in the 21st century up to 50%. Advances in neuromuscular transmission (NMT) monitoring and the introduction of sugammadex have addressed this issue, but the impact of these developments remains unclear.

Methods: This prospective observational study evaluated RNMB in 500 surgical patients in a large Dutch teaching hospital with readily available quantitative NMT monitoring and reversal agents. The anaesthetic technique and intraoperative NMT monitoring were independently chosen by the attending anaesthesiologist. Acceleromyography was performed upon arrival in the PACU for patients who received nondepolarising neuromuscular blocking agents. RNMB was defined as a train-of-four ratio (TOFR) <0.9. A systematic review was conducted to analyse trends in RNMB in contemporary practice.

Results: Out of 500 patients, 11 (2.2%) had a TOFR <0.9. Intraoperative NMT monitoring was performed in 77.6% of patients, and sugammadex was administered to 38% of patients. No patient received neostigmine. The only difference was an automatically recorded TOFR ≥0.9 at the end of surgery in 61.1% in the non-RNMB group compared with 18.2% in the RNMB group (P=0.009). Our systematic review identified incidences ranging from 3.5% to 53.3% since 2000, with a decreasing trend in Europe and North America.

Conclusions: The incidence of residual neuromuscular block in the PACU was 2.2%. This suggests significant improvement in the prevention of residual neuromuscular block and stresses the importance of rigorous neuromuscular transmission monitoring and adequate use of reversal agents.