Ultrasound-guided erector spinae plane block for postoperative analgesia in patients undergoing minimally invasive direct coronary artery bypass surgery: a double-blinded randomized controlled trial

Purpose Minimally invasive direct coronary artery bypass (MIDCAB) surgery is associated with significant postoperative pain. We aimed to investigate the efficacy of ultrasound-guided erector spinae plane block (ESPB) for analgesia after MIDCAB.Methods We conducted randomized controlled trial in 60 patients undergoing MIDCAB who received either a single-shot ESPB with 30 mL of ropivacaine 0.5% (ESPB group, n = 30) or normal saline 0.9% (control group, n = 30). The primary outcome was numerical rating scale (NRS) pain scores at rest within 48 hr postoperatively. The secondary outcomes included postoperative NRS pain scores on deep inspiration within 48 hr, hydromorphone consumption, and quality of recovery-15 (QoR-15) score at 24 and 48 hr.Results Compared with the control group, the ESPB group had lower NRS pain scores at rest at 6 hr (estimated mean difference, -2.1; 99% confidence interval [CI], -2.7 to -1.5; P < 0.001), 12 hr (-1.9; 99% CI, -2.6 to -1.2; P < 0.001), and 18 hr (-1.2; 99% CI, -1.8 to -0.6; P < 0.001) after surgery. The ESPB group also showed lower pain scores on deep inspiration at 6 hr (-2.9; 99% CI, -3.6 to -2.1; P < 0.001), 12 hr (-2.3; 99% CI, -3.1 to -1.5; P < 0.001), and 18 hr (-1.0; 99% CI, -1.8 to -0.2; P = 0.01) postoperatively. Patients in the ESPB group had lower total intraoperative fentanyl use, lower 24-hr hydromorphone consumption, a shorter time to extubation, and a shorter time to intensive care unit (ICU) discharge.Conclusion Erector spinae plane block provided early effective postoperative analgesia and reduced opioid consumption, time to extubation, and ICU discharge in patients undergoing MIDCAB.