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Background and Aims The large surgical incisions and manipulation of internal organs in open gastrectomy cause severe postoperative pain. Intrathecal morphine (ITM) has been evidenced to provide effective analgesia in abdominal surgeries. Erector spinae plane block (ESPB) has the potential to provide both somatic and visceral sensory block. This study aimed to compare the analgesic efficacy of ESPB and ITM in open gastrectomy.

Methods Adult patients with American Society of Anesthesiologists physical status II-III undergoing elective open gastrectomy surgery were randomly assigned to either the ESPB or ITM groups. Before induction of anesthesia, patients received either 200 mcg ITM or bilateral ESPB using 20 mL of 0.25% bupivacaine. The primary outcome was to compare first postoperative 24-hour total opioid consumption, while secondary outcomes included evaluating postoperative pain using NRS scores and CAPA Tool, requirement for rescue analgesia, and assessing postoperative complications.

Results Sixty-three patients were included in the analysis. 24-hour opioid consumption was similar in ESPB and ITM groups (mean 24.5 ± 17.56 and 23.33 ± 16.3 respectively) (p = 0.831). Intraoperative remifentanyl consumption was lower in ESPB group (p = 0.002). NRS scores were <4/10 at all time intervals and similar among the groups. ITM group experienced notably superior comfort levels at 2nd hour (p = 0.008) and better pain management at 2nd and 6th hours compared to the ESPB group (p = 0.025; p = 0.006, respectively) according to CAPA Tool.

Conclusions Ultrasound-guided ESPB resulted in similar total opioid consumption with ITM at the first 24 hour after open gastrectomy.