Addition of Dexamethasone and Buprenorphine to Bupivacaine Sciatic Nerve Block

Abstract

Background and Objectives Sciatic nerve block provides analgesia after foot and ankle surgery, but block duration may be insufficient. We hypothesized that perineural dexamethasone and buprenorphine would reduce pain scores at 24 hours. Methods Ninety patients received ultrasound-guided sciatic (25 mL 0.25% bupivacaine) and adductor canal (10 mL 0.25% bupivacaine) blockade, with random assignment into 3 groups (30 patients per group): control blocks + intravenous dexamethasone (4 mg) (control); control blocks + intravenous buprenorphine (150 mcg) + intravenous dexamethasone (intravenous buprenorphine); nerve blocks containing buprenorphine + dexamethasone (perineural). Patients received mepivacaine neuraxial anesthesia and postoperative oxycodone / acetaminophen, meloxicam, pregabalin, and ondansetron. Patients and assessors were blinded to group assignment. The primary outcome was pain with movement at 24 hours. Results There was no difference in pain with movement at 24 hours (median score 0). However, the perineural group had longer block duration vs control (45.6 vs 30.0 hr). Perineural patients had lower scores for “worst pain” vs control (median 0 vs 2). Both intravenous buprenorphine and perineural groups were less likely to use opioids on the day after surgery, vs control (28.6%, 28.6%, 60.7%, respectively). Nausea after intravenous buprenorphine (but not perineural buprenorphine) was severe, frequent, and bothersome. Conclusions Pain scores were very low at 24 hours after surgery in the context of multimodal analgesia and were not improved by additives. However, perineural buprenorphine and dexamethasone prolonged block duration, reduced the worst pain experienced, and reduced opioid use. Intravenous buprenorphine caused troubling nausea and vomiting. Future research is needed to confirm and extend these observations.

Efficacy of perineural dexamethasone with ropivacaine in adductor canal block for post-operative analgesia in patients undergoing total knee arthroplasty: A randomized controlled trial

“…Various additives have been used to prolong regional blockade. Dexamethasone has been extensively studied as an adjunct to local anesthetic in peripheral nerve blockade (15)(16)(17). The use of dexamethasone at doses of 4-12 mg via intravenous and perineural routes has been described in regional anesthesia and pain medicine textbooks (17), but to the best of our knowledge, no previous study has examined the use of perineural dexamethasone for ACB.…”

Ultrasound‐guided adductor canal block after arthroscopic anterior cruciate ligament reconstruction: Effect of adding dexamethasone to bupivacaine, a randomized controlled trial

“…Although the precise mechanism is unknown, dexamethasone is thought to function by altering the inflammatory response and may have a direct effect on nociceptive C‐fibres (Chong et al., ). When added to local anaesthetics, analgesia is prolonged either by inducing vasoconstriction and reducing the absorption of local anaesthetic or by increasing the activity of inhibitory potassium channels on nociceptive C‐fibres, decreasing their activity and prolonging sensory and motor blockade (YaDeau et al., ).…”

“…Although the precise mechanism is unknown, dexamethasone is thought to function by altering the inflammatory response and may have a direct effect on nociceptive C-fibres (Chong et al, 2017). When added to local anaesthetics, analgesia is prolonged either by inducing vasoconstriction and reducing the absorption of local anaesthetic or by increasing the activity of inhibitory potassium channels on nociceptive C-fibres, decreasing their activity and prolonging sensory and motor blockade (YaDeau et al, 2015). Chisholm et al (2017) concluded that the addition of dexamethasone (1 and 4 mg) to subsartorial saphenous nerve blocks significantly increased the duration of postoperative analgesia by 8-13 h following ACL reconstruction, which is longer than the time in this study.…”

Perineural Versus Intravenous Dexamethasone as an Adjuvant for Peripheral Nerve Blocks

“…1, PRISMA flow diagram). 5,6,8,[13][14][15][16][17][18][19][20] Notably, we excluded certain studies during our full-text review: 2 studies that compared IV/perineural clonidine and/or buprenorphine alongside dexamethasone, 21,22 one study where a continuous infusion was started prior to complete resolution of the sensory block, 23 one study where all patients received IV dexamethasone, 8 mg, 4 and finally one study where all patients received long-acting intrathecal narcotics. 24 …”