The combination of IV and perineural dexamethasone prolongs the analgesic duration of intercostal nerve blocks compared with IV dexamethasone alone

Abstract

Objective. The use of multiple-level, single-injection intercostal nerve blocks for pain control following video-assisted thorascopic surgery (VATS) is limited by the analgesic duration of local anesthetics. This study examines whether the combination of perineural and intravenous (IV) dexamethasone will prolong the duration of intraoperatively placed intercostal nerve blocks following VATS compared with IV dexamethasone and a perineural saline placebo. Design. Prospective, double-blind, randomized placebo-controlled trial. Setting. Single level-1 academic trauma center. Subjects. Forty patients undergoing a unilateral VATS under the care of a single surgeon. Methods. Patients were randomly assigned to two groups and received an intercostal nerve block containing 1) 0.5% bupivacaine with epinephrine and 1ml of 0.9% saline or 2) 0.5% bupivacaine with epinephrine and 1ml of a 4 mg/ml dexamethasone solution. All patients received 8mg of IV dexamethasone. Results. Group 2 had lower NRS-11 scores at postoperative hours 8 (5.05, SD52.13 vs 3.50, SD52.50; p50.04), 20 (4.30, SD52.96 vs 2.26, SD52.31; p50.02), and 24 (4.53, SD51.95 vs 2.26, SD52.31; p50.02). Equianalgesic opioid requirement was decreased in group 2 at 32 hours (5.78 mg, SD55.77 vs 1.67 mg, SD53.49; p50.02). Group 2 also had greater FEV1 measured at 8, 12, 24, and 44 hours; greater FVC at 24 hours; greater PEF at 28 through 48 hours; and greater FEV1/FVC at 8 and 36 hours. Conclusions. The combination of IV and perineural dexamethasone prolonged the duration of a singleinjection bupivacaine intercostal nerve block as measured by NRS-11 compared with IV dexamethasone alone at 24 hours. Reduced NRS-11 at other times, reduced opioid requirements, and increased PFTs were observed in group 2.