Background: Intraoperative monitoring of train-of-four (TOF) response is recommended to avoid inadequate dose of muscle relaxant and its antagonist. We have standardized monitoring of TOF response at the end of surgery in all the patients undergoing general anesthesia with rocuronium since October 2013.
Methods: TOF group comprised of 113 consecutive patients just after the standardization and we investigated the relationship between the dose of sugammadex and TOF count and also compared anesthetic factors in TOF group with those in control group which included 104 consecutive patients just before the standardization without TOF monitoring.
Results: Rate of the patients with TOF count 4 in TOF group approximately reached 70% and mean TOF ratio resulted in 0.56 ± 0.28. Mean dose of sugammadex in patients with TOF count 2-4 was 2.5 ± 0.9 mg x kg(-1), while the dose in patients with TOF count 0-1 was 3.6 ± 0.9 mg x kg(-1) and 6 patients among 11 patients with TOF count 0 was given less than 4 mg x kg(-1) of sugammadex. The percentage of the patients given 200 mg of sugammadex significantly decreased from 78% in control group to 48% in TOF group.
Conclusions: We conclude that standardization of TOF response at the end of surgery reduces dose of sugammadex in patients with slight residual neuromuscular block though the dose in patients under deep muscle relaxation seems to be insufficient.