Efficacy of ultrasound-guided erector spinae plane block on analgesia and quality of recovery after minimally invasive direct coronary artery bypass surgery: protocol for a randomized controlled trial

Abstract

Background: Minimally invasive direct coronary artery bypass (MIDCAB) surgery offers an effective option for coronary artery disease (CAD) patients with the avoidance of median sternotomy and fast postoperative recovery. However, MIDCAB is still associated with significant postoperative pain which may lead to delayed recovery. The erector spinae plane block (ESPB) is a superficial fascial plane block. There have not been randomized controlled trials evaluating the effects of ESPB on analgesia and patient recovery following MIDCAB surgery. We therefore designed a double-blind prospective randomized placebo-controlled trial, aiming to prove the hypothesis that ESPB reduces postoperative pain scores in patients undergoing MIDCAB surgery.

Methods: The study protocol has been reviewed and approved by the Ethical Review Committee of Peking University People's Hospital. Sixty adult patients of either sex scheduled for MIDCAB surgery under general anesthesia (GA) will be included. Patients will be randomly allocated to receive either a preoperative single-shot ESPB with 30 mL of ropivacaine 0.5% (ESPB group) or normal saline 0.9% (control group). The primary outcomes are the difference between the two groups in numeric rating scale (NRS) scores at rest at different time points (6, 12, 18, 24, 48 h) after surgery. The secondary outcomes include NRS scores on deep inspiration within 48 h, postoperative hydromorphone consumption, and quality of patient recovery at 24 h and 48 h, using the Quality of Recovery-15 (QoR-15) scale. The other outcomes include intraoperative fentanyl requirements, the need for additional postoperative rescue analgesics, time to tracheal extubation and chest tube removal after surgery, incidence of postoperative nausea and vomiting (PONV) and postoperative cognitive dysfunction (POCD), intensive care unit (ICU) length of stay (LOS), hospital discharge time, and 30-day mortality. Adverse events will be also evaluated.

Discussion: This is a novel randomized controlled study evaluating a preoperative ultrasound-guided single-shot unilateral ESPB on analgesia and quality of patient recovery in MIDCAB surgery. The results of this study will characterize the degree of acute postoperative pain and clinical outcomes following MIDCAB. Our study may help optimizing analgesia regimen selection and improving patient comfort in this specific population.

Trial registration: The study was prospectively registered with the Chinese Clinical Trial Registry (trial identifier: ChiCTR2100052810). Date of registration: November 5, 2021.

Keywords: Erector spinae plane block; Minimally invasive; Nerve block; Postoperative pain; Randomized controlled trial.

Fig. 1

Flowchart of the trial. −t₁, preoperative; t₁, before induction of general anesthesia; t₂, completion of surgery; t₃, ICU admission; t₄, 6 h after surgery; t₅, 12 h after surgery; t₆, 18 h after surgery; t₇, 24 h after surgery; t₈, 48 h after surgery days after surgery; t₉, 30 days after surgery; ESPB, erector spinae plane block; NRS, numeric rating scale; QoR, quality of recovery