To compare the onset and spontaneous recovery from rocuronium-induced neuromuscular block between the adductor pollicis (hand) and flexor hallucis brevis (foot) muscles in pediatric patients younger than two years.

Patients younger than two years undergoing elective surgery under general anesthesia were enrolled. A TetraGraph electromyography monitor was applied to each of the ulnar and posterior tibial nerves to monitor train-of-four (TOF) responses of the hand and foot. Spontaneous recovery following rocuronium 0.6 mg/kg was observed until the end of surgery. Endotracheal intubation was performed when a TOF count (TOFC) = 0 was observed at the foot. The primary outcome was the time from administration of rocuronium to TOFC = 1. Secondary outcomes included onset time, other recovery parameters, and intubating conditions. Data were analyzed using the paired t-test, with statistical significance set at p < 0.05.

No significant differences were observed in onset and recovery times to TOFC = 1, 2, or 4; or to a TOF ratio of 0.4, between the hand and foot. Intubating conditions, including the ease of laryngoscopy, position of the vocal cords, and reaction to insertion of the endotracheal tube, were rated as excellent in all patients.

In patients younger than two years, neuromuscular recovery from rocuronium did not differ between the hand and foot. This finding suggests that the foot may be a reasonable alternative site for neuromuscular monitoring and that TOFC = 0 at the foot represents an appropriate timing for endotracheal intubation.