Postoperative residual neuromuscular blockade is associated with impaired clinical recovery

In this investigation, we sought to determine the association between objective evidence of residual neuromuscular blockade (train-of-four [TOF] ratio <0.9) and the type, incidence, and severity of subjective symptoms of muscle weakness in the postanesthesia care unit (PACU).

TOF ratios of 149 patients were quantified with acceleromyography on arrival to the PACU. Patients were stratified into 2 cohorts: a TOF <0.9 group (n = 48) or a TOF ≥0.9 (control) group (n = 101). A standardized examination determined the presence or absence of 16 symptoms and 11 signs of muscle weakness on arrival to the PACU and 20, 40, and 60 minutes after admission.

The incidence of symptoms of muscle weakness was significantly higher in the TOF <0.9 group at all times (P < 0.001), as was the median (range) number of symptoms from PACU arrival (7 [3-6] TOF <0.9 group vs 2 [0-11] control group; difference 5, 99% confidence interval of the difference 4-6) until 60 minutes after admission (2 [0-12] TOF <0.9 group vs 0 [0-11] control group; difference 2, 99% confidence interval of the difference 1-2) (all P < 0.0001).

The incidence and severity of symptoms of muscle weakness were increased in the PACU in patients with a TOF <0.9.