Dose of intravenously infused cisatracurium for maintenance of deep neuromuscular blockade during thoracic surgery / 中华麻醉学杂志

ABSTRACT

Objective:To investigate the dose of intravenously infused cisatracurium for the maintenance of deep neuromuscular blockade during thoracic surgery.Methods:Patients of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, aged 18-64 yr, scheduled for elective thoracic surgery under general anesthesia, were studied.The patients were connected to a muscle relaxation monitor after entering the operating room.After the completion of muscle relaxant calibration and anesthesia induction, cisatracurium was intravenously infused at a constant rate to maintain deep neuromuscular blockade (post-tetanic count [PTC]≤5 ). The infusion rate was calculated by modified Dixon up-and-down method.The first patient received cisatracurium at 0.12 mg·kg -1·h -1.If the PTC was 0 or was maintained≤5 continuously, the infusion rate was decreased 0.01 mg·kg -1·h -1 in the next patient, until PTC was >5 during operation.The mean dose for the patient was used as initial dose.Then the infusion rate was increased/decreased by 0.005 mg·kg -1·h -1.The 95% effective dose of cisatracurium (ED 95) was the median of 6 thresholds. Results:A total of 22 cases completed the study.The ED 95 of continuous intravenous infusion of cisatracurium for the maintenance of deep neuromuscular blockade was 0.108 mg·kg -1·h -1(95% confidence interval 0.105-0.125 mg·kg -1·h -1). Conclusion:The dose of intravenous infusion of cisatracurium for the maintenance of deep neuromuscular blockade during thoracic surgery is 0.108 mg·kg -1·h -1.