Incidence of chronic postsurgical pain after cardiac surgery and the effect of bilateral erector spinae plane block: a randomized controlled trial

BACKGROUND: The effects of the erector spinae plane (ESP) block on chronic postsurgical pain (CPSP) after cardiac surgery remain unclear. This study evaluated the efficacy of bilateral ESP block in reducing the incidence and severity of CPSP after cardiac surgery. METHODS: This prospective, randomized, controlled, single-blind trial included 63 patients aged 18-80 years with American Society of Anesthesiologists physical status II-III, scheduled for elective cardiac surgery via median sternotomy. Participants received a bilateral ultrasound-guided ESP block or standard care without regional anesthesia. The primary outcome was the Brief Pain Inventory (BPI) score at 3 months postoperatively. Secondary outcomes included morphine consumption in the first 24 hours; Numerical Rating Scale (NRS) scores during rest/activity at 0, 3, 6, 12, and 24 hours; BPI scores at 6 months postoperatively; and Douleur Neuropathique 4 (DN4) and Hospital Anxiety and Depression Scale (HADS) scores at 3 and 6 months postoperatively. RESULTS: The BPI scores of the two groups did not differ significantly at 3 months postoperatively (median (IQR): 0(26) vs 12 (31), p=0.166). However, 24 hours postoperative morphine consumption (8 mg vs 10.5 mg, p<0.001) and NRS scores at multiple time points were significantly lower in the ESP block group. No significant differences were observed between the groups in terms of the BPI, DN4, or HADS scores at three or 6 months. CONCLUSIONS: The ESP block effectively reduced acute pain and opioid consumption; however, it had no significant effect on the incidence or severity of CPSP at 3 and 6 months.