Median Effective Dose ( ED50) of Ropivacaine in Ultrasound-guided Transversus Abdominis Plane Block for Analgesia in Patients Undergoing Appendectomy / 医药导报

ABSTRACT

Objective To evaluate the median effective anesthetic dose of ropivacaine in ultrasound-guided transversus abdominis plane ( TAP ) block for analgesia in patients undergoing appendectomy. Methods Twenty-eight cases of appendectomy under general anesthesia were analyzed.After standardized general anaesthesia,a bilateral ultrasound-guided TAP block was performed on patients undergoing appendectomy using ropivacaine. Sequential method was applied. The initial dose of ropivacaine in first patient was 1.6 mg·kg-1,the dose adjustment interval was 0.2 mg·kg-1.Numerical Rating Scale was used to estimate the level of pain postoperatively. If NRS≤3, dosage of ropivacaine was decreased by 0. 2 mg·kg-1. The transversus abdominis plane block analgesia duration and incidences of postoperative adverse reactions were analyzed. Results Median effective dose (ED50) of ropivacaine in ultrasound-guided transversus abdominis plane block was 2.73 mg·kg-1.95%CI (1.94, 3.84) mg·kg-1. Conclusion The determination of ED50of ropivacaine in ultrasound-guided transversus abdominis plane block improved the anesthesia efficacy and safety.