Safety and Duration of Low-Dose Adjuvant Dexamethasone in Regional Anesthesia for Upper Extremity Surgery: A Prospective, Randomized, Controlled Blinded Study.

ABSTRACT

BACKGROUND: Orthopedic procedures concerning the upper extremity commonly use a brachial plexus nerve block to achieve postoperative analgesia. The addition of dexamethasone to peripheral nerve blocks has been shown to significantly prolong its effect. We hypothesize that 1 mg doses of dexamethasone will prolong brachial plexus nerve block with similar efficacy to 4 mg and better than ropivacaine alone. METHODS: Seventy-nine patients who received a brachial plexus nerve block prior to undergoing upper extremity surgery were randomized to 1 of 4 treatment groups group 1 received only 30 mL of 0.5% ropivacaine without dexamethasone (control); groups 2, 3, and 4 received 4, 2, and 1 mg of dexamethasone, respectively, added to 30 mL of 0.5% ropivacaine. RESULTS: Comparison of block duration, specifically "first signs of the block wearing off" to the 0-mg group, referencing the 1-, 2-, and 4-mg groups (P = .02, .04, and .01, respectively) that received steroid adjuvant therapy demonstrated a significant increase in time until the block began to wear off. All study groups receiving steroids also demonstrated a significant increase in duration of the block prior to its effects being completely gone when compared with the control group (P < .01 for all groups). CONCLUSIONS: Our findings demonstrate that adjuvant dexamethasone can prolong brachial plexus nerve blocks effectively at low doses compared with high doses, in addition to prolonging analgesia compared with local anesthetic alone.