Analgesic Effect of the Topical Use of Dexamethasone in Ultrasound-Guided Axillary Brachial Plexus Blockade: A Prospective, Randomized, Double-Blind, Placebo-Controlled Study

Abstract

Introduction

Increasing the duration of regional anesthesia in orthopedic surgery is of vital importance, as it prolongs postoperative analgesia, allowing faster rehabilitation of patients. Dexamethasone has been found to extend the block duration in animal and human studies. The aim of this study is the assessment of the effect of the addition of dexamethasone to ropivacaine on the onset and duration of axillary brachial plexus block, along with the intensity of postoperative pain.

Methods

Forty patients undergoing below-elbow surgery under ultrasound-guided axillary brachial plexus block were randomly allocated to receive either 30 mL ropivacaine 0.75% with 2 mL of saline (Group A, n = 20) or 30 mL ropivacaine 0.75% with 2 mL of dexamethasone (4 mg) (Group B, n = 20). Sensory and motor blockade were assessed, with the use of the pinprick test and the modified Bromage scale, at five, 10, 15, and 20 min after the block. The duration of analgesia, intensity of postoperative pain, postoperative opioid consumption, overall satisfaction, and perioperative complications were compared between the two groups.

Results

We found no difference at the mean onset time of the sensory and motor block between the two groups. The mean duration of postoperative analgesia was three hours higher in the dexamethasone group (15.85 ± 4.82 versus 11.75 ± 6.81, p-value = 0.035). Pain intensity was lower in the dexamethasone group, at six and 12 hours after surgery (3.45 ± 1.79 versus 4.65 ± 1.79, p-value = 0.040). Postoperative opioid consumption, patient overall satisfaction, and perioperative complications were not significantly different between groups.

Conclusions

Dexamethasone prolongs the duration of ropivacaine in an axillary brachial plexus block and decreases postoperative pain in patients subjected to below-elbow surgery.