Minimum local analgesic concentration of ropivacaine and bupivacaine in continuous axillary brachial plexus block for postoperative active mobilization of flexor tendon
- VernacularTitle:屈肌腱松解术后功能锻炼患者罗哌卡因或布比卡因臂丛阻滞的最低镇痛浓度
- Author:
Changzhi YAO
;
Wei ZHANG
;
Li FANG
- Publication Type:Journal Article
- Keywords:
Amides;
Bupivacaine;
Brachial plexus;
Never block;
Tendon injuries;
Dose-response relationship, drug
- From:
Chinese Journal of Anesthesiology
1994;0(06):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To determine and compare the minimum local analgesic concentration(MLAC) of ropivacaine and bupivacaine in continuous block of axillary brachial plexus for postoperative active mobilization of flexor tendon. Methods Seventy ASA Ⅰ or Ⅱ patients undergoing relaxation of flexor tendon were randomly allocated into 2 groups (n = 35 each): ropivacaine group (group R) and bupivacaine group (group B). A catheter was inserted into axillary sheath using B. Braun stimulating intraducer, 24-48 h after operation. 30 min before functional exercise 20 ml of ropivacaine or bupivacaine was injected through catheter. The minimum local analgesic concentration of both local anesthetics was determined by up-and-down sequential test. The first concentration of both local anesthetics was 0.1%. The next concentration of local anesthetic was determined by response of the previous patient. The analgesia efficacy was assessed using 100 mm VAS score (0 = no pain, 100 mm = worst possible pain) . Increase/decrease in VAS by 10 mm was defined as effective. An effective result resulted in increase/decrease by 0.01% in the next patient. The motor block was also recorded.Results The two groups were comparable with regard to age, sex, body weight and baseline VAS score. The MLAC of ropivacaine was 0.133% [95% confidence interval (CI), 0.128%-0.138%] and MLAC of bupivacaine was0.121% (95%CI, 0.116%-0.126%). The analgesic potency of ropivacaine was 10% less than that of bupivacaine. The potency ratio of ropivacaine to bupivacaine was 0.91. The degree of motor block is higher with bupivacaine than with ropivacaine. Conclusion The results of our study show that the analgesic potency of ropivacaine is 10% less than that of bupivacaine. The degree of motor block is higher with bupivacaine than with ropivacaine.
