SPIP vs ESP Block in Cardiac Surgery

Overview

This multicentre, randomized, assessor-blinded, non-inferiority trial will compare the analgesic efficacy of bilateral superficial parasternal intercostal plane (SPIP) block with bilateral erector spinae plane (ESP) block in adults undergoing first-time on-pump cardiac surgery through median sternotomy. Participants will be randomly assigned in a 1:1 ratio to receive either SPIP or ESP block before induction of general anesthesia, in addition to standardized perioperative multimodal analgesia. The primary outcome is cumulative intravenous morphine milligram equivalent (IV-MME) consumption from extubation to 24 hours after extubation. The study will evaluate whether SPIP block is non-inferior to ESP block using a prespecified non-inferiority margin of 3 mg IV-MME.

This multicenter, parallel-group, randomized controlled non-inferiority trial will compare bilateral SPIP block with bilateral ESP block for postoperative analgesia in adults undergoing first-time on-pump cardiac surgery through median sternotomy. Patients aged 18-80 years will be enrolled across tertiary cardiac surgery centres in Türkiye and randomly assigned in a 1:1 ratio, stratified by center, to receive either bilateral SPIP block or bilateral ESP block. Both interventions will be performed before induction of general anesthesia. Participants in the SPIP group will receive ultrasound-guided injection between 4th and 5th ribs, whereas participants in the ESP group will receive bilateral ultrasound-guided injection at the T5 transverse process. Perioperative anesthesia, postoperative multimodal analgesia, and patient-controlled morphine analgesia will be standardised across participating centers. Postoperative outcome assessors will remain blinded to treatment allocation. Block success will be assessed using cold sensation testing before induction. The primary outcome is cumulative opioid consumption from extubation to 24 hours after extubation, expressed as intravenous morphine milligram equivalents (IV-MME). The primary objective is to determine whether SPIP block is non-inferior to ESP block using a prespecified non-inferiority margin of 3 mg IV-MME. Secondary outcomes include time-weighted average pain intensity at rest and during coughing over the first 24 hours after extubation, Quality of Recovery-15 scores at 24 hours and hospital discharge, and the incidence of chronic postsurgical pain at 3 months. Exploratory outcomes include rescue analgesic requirements, postoperative nausea and vomiting and other opioid-related adverse effects, time to extubation, intensive care unit and hospital length of stay, block failure, and block-related complications. The primary non-inferiority analysis will be performed in both the intention-to-treat and per-protocol populations. The between-group location shift in 24-hour IV-MME consumption will be estimated using the Hodges-Lehmann method with a two-sided 95% confidence interval. Non-inferiority will be concluded if the upper bound of the confidence interval for the SPIP minus ESP difference is less than 3 mg IV-MME.