Similar analgesic effect after popliteal fossa nerve blockade with 0.375% and 0.75% bupivacaine

Effect of Perineural Dexamethasone on the Duration of Single Injection Saphenous Nerve Block for Analgesia After Major Ankle Surgery: A Randomized, Controlled Study

BACKGROUND AND OBJECTIVES

Patients undergoing major elective ankle surgery often experience pain from the saphenous nerve territory persisting beyond the duration of a single-injection saphenous nerve block. We hypothesized that perineural dexamethasone as an adjuvant for the saphenous nerve block prolongs the duration of analgesia and postpones as well as reduces opioid-requiring pain.

METHODS

Forty patients were included in this prospective, randomized, controlled study. All patients received a continuous sciatic catheter and were randomized to receive a single-injection saphenous nerve block with 10 mL of 0.5% bupivacaine with 1:200,000 epinephrine with addition of 1 mL of saline or 1 mL of 0.4% (ie, 4 mg) dexamethasone. The primary outcome was duration of saphenous nerve block estimated as the time until the first opioid request. Secondary outcomes were opioid consumption and pain.

RESULTS

The mean (SD) duration of the saphenous nerve block until first opioid request was 29.4 (8.4) hours in the dexamethasone group and 23.2 (10.3) hours in the control group (P = 0.048). The median opioid consumption [interquartile range] during the first 24 hours was 0 mg [0-0] versus 1.5 mg [0-14.2] in the dexamethasone and control groups, respectively. Nonparametric comparison of opioid consumption from 0 to 24 hours was statistically significant. The opioid consumption was similar in the two groups in the time interval 24 to 48 postoperative hours.

CONCLUSION

Perineural dexamethasone as an adjuvant for the single-injection subsartorial saphenous nerve block can prolong analgesia and reduce opioid-requiring pain after major ankle surgery.

Addition of Dexamethasone and Buprenorphine to Bupivacaine Sciatic Nerve Block: A Randomized Controlled Trial

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 (IV) dexamethasone (4 mg) (control); control blocks + IV buprenorphine (150 μg) + IV dexamethasone (IV buprenorphine); and 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 versus control (45.6 vs 30.0 hours). Perineural patients had lower scores for "worst pain" versus control (median, 0 vs 2). Both IV buprenorphine and perineural groups were less likely to use opioids on the day after surgery versus control (28.6%, 28.6%, and 60.7%, respectively). Nausea after IV 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.

Is there a dose response of dexamethasone as adjuvant for supraclavicular brachial plexus nerve block? A prospective randomized double-blinded clinical study

STUDY OBJECTIVE

The study objective is to examine the analgesic effect of 3 doses of dexamethasone in combination with low concentration local anesthetics to determine the lowest effective dose of dexamethasone for use as an adjuvant in supraclavicular brachial plexus nerve block.

DESIGN

The design is a prospective randomized double-blinded clinical study.

SETTING

The setting is an academic medical center.

PATIENTS

The patients are 89 adult patients scheduled for shoulder arthroscopy.

INTERVENTIONS

All patients were randomly assigned into 1 of 4 treatment groups: (i) bupivacaine, 0.25% 30 mL; (ii) bupivacaine, 0.25% 30 mL with 1-mg preservative-free dexamethasone; (iii) bupivacaine, 0.25% 30 mL with 2-mg preservative-free dexamethasone; and (iv) bupivacaine, 0.25% 30 mL with 4-mg preservative-free dexamethasone. All patients received ultrasound-guided supraclavicular brachial plexus nerve blocks and general anesthesia.

MEASUREMENTS

The measurements are the duration of analgesia and motor block.

MAIN RESULTS

The median analgesia duration of supraclavicular brachial plexus nerve block with 0.25% bupivacaine was 12.1 hours; and 1-, 2-, or 4-mg dexamethasone significantly prolonged the analgesia duration to 22.3, 23.3, and 21.2 hours, respectively (P = .0105). Dexamethasone also significantly extended the duration of motor nerve block in a similar trend (P = .0247).

CONCLUSION

Low-dose dexamethasone (1-2 mg) prolongs analgesia duration and motor blockade to the similar extent as 4-mg dexamethasone when added to 0.25% bupivacaine for supraclavicular brachial plexus nerve block.

Clonidine and analgesic duration after popliteal fossa nerve blockade: randomized, double-blind, placebo-controlled study

BACKGROUND

We tested the hypothesis that 100 microg clonidine added to 0.375% bupivacaine would prolong the duration of analgesia from popliteal fossa nerve blockade.

METHODS

Ninety-nine patients scheduled for hospital admission after foot or ankle surgery entered this randomized, double-blind, placebo-controlled trial. Patients received a popliteal fossa block (nerve stimulator technique, via the posterior approach) using 30 mL 0.375% bupivacaine, with epinephrine. Patients were randomized to receive no clonidine, 100 microg clonidine IM, or 100 microg clonidine with bupivacaine for the popliteal block. Patients also received a combined spinal-epidural anesthetic, a saphenous nerve block, and postoperative IV patient-controlled analgesia. The primary outcome was patient-reported duration of analgesia.

RESULTS

Duration of analgesia was statistically longer in the block clonidine group (18 +/- 6 h for clonidine with bupivacaine vs 14 +/- 7 h for IM clonidine and 15 +/- 7 h for control, P = 0.016 for control vs clonidine with bupivacaine). Pain scores, analgesic use, and side effects attributable to pain management were similar among groups.

CONCLUSIONS

Clonidine significantly prolongs the analgesic duration after popliteal fossa nerve blockade with bupivacaine.