Residual neuromuscular block after rocuronium or cisatracurium

Residual neuromuscular block in the post-anesthetic recovery unit (PACU) may increase postoperative morbidity from 0% to 93%. This study aimed at evaluating the incidence of residual neuromuscular block in the PACU.

Participated in this study 93 patients submitted to general anesthesia with cisatracurium or rocuronium. After PACU admission, neuromuscular function was objectively monitored (acceleromyography - TOF GUARD). Residual neuromuscular block was defined as TOF < 0.9.

From 93 patients, 53 received cisatracurium and 40 rocuronium. Demographics, procedure length and the use of antagonists were comparable between groups. Residual neuromuscular block was 32% in subgroup C (cisatracurium) and 30% in subgroup R (rocuronium). Residual neuromuscular block was unrelated to dose, age and use of antagonists, but was related to procedure length. In subgroup C, mean procedure length was 135 minutes for patients with neuromuscular block and 161 minutes for patients without (p < 0.029). In subgroup R, mean surgery length was 122 and 150 minutes, respectively (p < 0.039).

Both groups had high incidence of residual neuromuscular block in the PACU. Residual postoperative curarization is still a problem even with new intermediary action neuromuscular blockers. It is highly important to objectively monitor all patients submitted to general anesthesia with neuromuscular blockers.