·To observe pharmacodynamics of cisatracurium intravenously infused in infants and young children with end-stage liver disease during living donor liver transplantation.

·Sixteen patients of American Society of Anesthesiologists (ASA) physical status Ⅲ and Ⅳ, aged 6－24 months, with end-stage liver disease, undergoing liver transplantation were studied. Neuromuscular transmission was monitored by the responses of the adductor pollicis to train-of-four (TOF) stimulation of ulnar nerve, using the accelerography (TOF-Watch). Endotracheal intubation was performed after intravenous injection of 0.15 mg/kg cisatracurium, with T₁ being the maximum inhibitory degree. After recovery of T₁ to 3%, cisatracurium was infused at an initial rate of 2 μg/(kg·min). The infusion rate was adjusted to maintain a constant 90% to 95% neuromuscular paralysis until the end of the operation. The onset time, no reaction period of TOF, the dosage of cisatracurium given during paleo-phepatic phase, an-hepatic phase and neo-hepatic phase, the time to 25% recovery of T₁, recovery index (25%?75%), and the time for the TOF ratio (TOFr) to reach 0.9 were recorded respectively.

·The infusion rate was (1.37±0.46) μg/(kg·min). The average infusion rate of drugs in the three different periods showed a downward trend, but there was no statistical difference (P=0.110). The onset time of cisatracurium was (242.63±46.74) s. The no reaction period of TOF was (34.02±7.71) min. Following termination of the infusion, the time to 25% recovery of T₁ was (12.80±3.49) min, and the recovery index (25%?75%) was (15.12±4.59) min. The time of TOFr=0.9 was (40.27±7.03) min.

·The pharmacodynamical characteristics of muscle relaxants should be fully understood during living donor liver transplantation in infants and young children with end-liver disease. When cisatracurium (0.15 mg/kg) is used for anesthesia induction, endotracheal intubation should be performed 4 min after administration. In the maintenance stage of anesthesia, the infusion dose requirement of cisatracurium is basically unchanged in the three different periods,and the infusion rate of 1.4 μg/(kg·min) can provide satisfactory muscle relaxation effect.