Comparative Evaluation of Deep Versus Superficial Erector Spinae Plane Blocks for Postoperative Analgesia in Modified Radical Mastectomy.

Background and aims The erector spinae plane (ESP) block is a popular technique for postoperative analgesia across various surgical procedures. This study aimed to compare two different approaches - the superficial ESP (SES) block and deep ESP (DES) block - for the duration and quality of analgesia in women undergoing modified radical mastectomy (MRM). Materials and methods This prospective, double-blind, randomized comparative study was conducted on 44 American Society of Anesthesiologists (ASA) physical status I/II patients aged 18-65 years and posted for MRM. Patients were randomly assigned to either Group DES or Group SES. Following induction of anesthesia, patients were turned lateral, and the ultrasound-guided blocks were performed at the level of the fourth thoracic vertebra (T4) with 20 mL of 0.25% bupivacaine and 6 mg dexamethasone, as per group allocation. Time to first request of supplemental analgesia, postoperative numeric rating scale (NRS) scores, and total analgesic consumption over 24 hours postoperatively were recorded. Results There was no significant difference in time to first request for supplemental analgesia between the two groups. Group DES demonstrated a lower percentage of patients requesting supplemental analgesia compared to Group SES (18.2% vs. 63.6%, p = 0.002). Additionally, Group DES had significantly lower total postoperative analgesic consumption (17.05 ± 39.63 mg vs. 51.14 ± 42.59 mg of diclofenac, p = 0.004) and reduced NRS scores at 12 hours (0.55 ± 1.224 vs. 1.86 ± 1.885, p = 0.01) as compared to Group SES. Conclusion The ESP block is an effective regional anesthetic technique for the provision of postoperative analgesia in patients undergoing MRM. The DES block provided better quality of analgesia compared with the SES block.