Hand dominance affects recovery measurements during neuromuscular monitoring

Practice guidelines recommend monitoring neuromuscular responses at the adductor pollicis (AP), although clinicians may use the abductor digiti minimi (ADM) because electrode placement can be convenient. This prospective randomized study enrolled 44 patients undergoing general anesthesia and recorded electromyographic responses simultaneously from both muscles. Outcomes included time from rocuronium administration to a train-of-four (TOF) count of zero, and recovery after sugammadex to TOF ratios of at least 0.9 and 1.0.

Overall, the study found no significant differences between ADM and AP measurements for onset or recovery. However, recovery differed according to the hand monitored. In the right hand, ADM readings indicated recovery to a TOF ratio of at least 0.9 a mean 93 seconds earlier than AP readings, and recovery to 1.0 a mean 105 seconds earlier. No corresponding difference was found when monitoring the left hand.

The findings suggest that ADM and AP measurements may be comparable in some settings, but recovery readings from the dominant hand may not be interchangeable. The study was small, and the reported differences concern monitoring measurements; the source does not establish whether they affect clinical outcomes or management.