Effect of intravenous dexamethasone on the duration of postoperative analgesia for popliteal sciatic nerve block: a randomized, double-blind, placebo-controlled study

• Published in: Korean journal of anesthesiology Vol. 74; no. 4; pp. 317 - 324
• Main Authors: Kim, Byung-Gun, Lee, Woojoo, Song, Jang Ho, Yang, Chunwoo, Heo, Gyung A, Kim, Hongseok
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Society of Anesthesiologists 01.08.2021; 대한마취통증의학회
• Subjects: analgesia; ankle; Clinical; dexamethasone; foot; intravenous injections; nerve block; pharmaceutic adjuvants; sciatic nerve; 마취과학; dexamethasone; intravenous; adjuvant; analgesia; ankle; nerve block; foot; sciatic nerve
• ISSN: 2005-6419; 2005-7563; 2005-7563
• DOI: 10.4097/kja.20640

BackgroundIntravenous (IV) dexamethasone prolongs the duration of a peripheral nerve block; however, there is little available information about its optimal effective dose. This study aimed to evaluate the effects of three different doses of IV dexamethasone on the duration of postoperative analgesia to determine the optimal effective dose for a sciatic nerve block.MethodsPatients scheduled for foot and ankle surgery were randomly assigned to receive normal saline or IV dexamethasone (2.5 mg, 5 mg, or 10 mg). An ultrasound-guided popliteal sciatic nerve block was performed using 0.75% ropivacaine (20 ml) before general anesthesia. The duration of postoperative analgesia was the primary outcome, and pain scores, use of rescue analgesia, onset time, adverse effects, and patient satisfaction were assessed as secondary outcomes.ResultsCompared with the control group, the postoperative analgesic duration of the sciatic nerve block was prolonged in groups receiving IV dexamethasone 10 mg (P < 0.001), but not in the groups receiving IV dexamethasone 2.5 mg or 5 mg. The use of rescue analgesics was significantly different among the four groups 24 h postoperatively (P = 0.001) and similar thereafter. However, pain scores were not significantly different among the four groups 24 h postoperatively. There were no statistically significant differences in the other secondary outcomes among the four groups.ConclusionsThis study demonstrated that compared to the controls, only IV dexamethasone 10 mg increased the duration of postoperative analgesia following a sciatic nerve block for foot and ankle surgery without the occurrence of adverse events.