Perineural dexamethasone as an adjuvant to erector spinae plane block for acute and chronic pain after cardiac surgery

Abstract

Abstract Pain control after cardiac surgery remains suboptimal. The erector spinae plane (ESP) block offers a safer regional alternative to neuraxial techniques, but its duration is limited. We tested whether perineural dexamethasone added to bilateral ESP blocks reduces acute postoperative pain intensity and attenuates chronic post surgical pain (CPSP) after coronary artery bypass grafting (CABG). In this randomized, double-blind trial (NCT04313959), 43 patients undergoing elective CABG received bilateral ESP blocks with 0.2% ropivacaine alone (control, n  = 21) or ropivacaine plus 8 mg perineural dexamethasone (dexamethasone, n  = 22). Primary outcome: pain intensity at rest on postoperative day 1, measured using the numerical rating scale (NRS). Pre-specified secondary outcomes were mechanical ventilation duration, 48-hour opioid consumption, and pain interference at 30, 60, and 90 days measured using the Brief Pain Inventory (BPI). The primary outcome was not significantly different between groups: NRS pain at rest on day 1 was 1.35 ± 1.95 (control) vs. 1.57 ± 2.27 (dexamethasone), p  = 0.781 (Fig. 1). Acute pain scores and 48-hour opioid consumption were comparable (Fig. 3). Mechanical ventilation was shorter in the dexamethasone group (median 11.6 vs. 14.7 h; p  = 0.041; Table 2). At 30 days, no significant between-group differences were found in any BPI domain (all p  > 0.05; Table 3). At 60 days, pain intensity scores were lower in the dexamethasone group (composite score 0.47 ± 0.88 vs. 1.21 ± 1.28; p  = 0.019; Table 3; Fig. 2). By 90 days, all outcomes were comparable (all p  > 0.05). One procedure-related adverse event occurred (pneumothorax, control group). Addition of dexamethasone to ropivacaine did not add to the reduction of acute pain. The secondary exploratory findings of shorter mechanical ventilation time and lower pain intensity at 60 days are hypothesis-generating and should be evaluated using larger, adequately powered multicenter trials with intraoperative blinding and a systemic comparator arm. Trial registry: NCT04313959.