A Randomized Double-Blind Controlled Trial to Assess the Efficacy of Ultrasound-Guided Erector Spinae Plane Block in Cardiac Surgery

Abstract

Cardiac surgical pain is of moderate-to-severe intensity. Ineffective pain control may lead to increased cardiopulmonary complications and poor surgical outcomes. This study aimed to assess the efficacy of ultrasound-guided erector spinae plane block in providing analgesia in adult cardiac surgeries. Prospective, randomized, double-blinded clinical trial. Single-center, tertiary care hospital with university affiliation. Thirty patients of either sex, aged 18-to-60 years, body mass index 19-to-30 kg/m2, undergoing elective on-pump single-vessel coronary artery bypass grafting or valve replacement under general anesthesia. Patients were randomly categorized into two groups of 15 patients each to receive bilateral erector spinae plane block with 20 mL per side of 0.25% levobupivacaine (group E) or sham block with 20 mL of normal saline (group C). Mean analgesic requirement in terms of fentanyl equivalents (µg) in the first 24 hours postoperatively was 225 ± 112 in group E and 635 ± 145 in group C (95% confidence interval, 313.10-506.90; p < 0.05). Mean time to first rescue analgesia was 356.9 ± 34.5 in group E and 123.9 ± 13.1 minutes in group C (p < 0.05). Cox proportional hazard ratio for rescue analgesic requirement in group E-to-group C was 5.0. Duration of mechanical ventilation was 88.4 ± 17 and 103.5 ± 18 minutes in groups E and C, respectively (p < 0.05). Ramsay sedation score at six hours postextubation was 1.45 ± 0.53 in group E and 3.19 ± 0.62 in group C (p < 0.05). Mean numerical rating score was 3.67 ± 1.41 in group E and 4.50 ± 1.00 in group C (p = 0.17). No significant differences were observed in the incidences of postoperative nausea vomiting, pruritus, and erector spinae plane block-related infection and pneumothorax. Single-shot erector spinae plane block provides superior analgesia as compared with sham block. It decreased the first 24-hour postoperative analgesic consumption by 64.5% and risk of pain by five times in the authors' population. It also reduced the sedation and duration of mechanical ventilation in postcardiac surgery patients.