A prospective, randomized, blinded (investigator) clinical trial is currently underway at Galway University Hospital in Ireland to compare the efficacy of two regional analgesia techniques—Erector Spinae Plane Block (ESB) and Serratus Anterior Plane Block (SAPB)—for postoperative pain management following Laparoscopic Sleeve Gastrectomy (LSG). The study, which commenced recruitment on March 6, 2023, aims to determine if one technique provides superior pain relief and recovery compared to the other in patients undergoing elective LSG surgery.
Study Design and Patient Population
The trial involves patients presenting for elective LSG surgery. Key inclusion criteria involve patients undergoing elective LSG surgery, while exclusion criteria include inability to provide informed consent, pre-existing infection at the block site, severe coagulopathy, allergy to local anesthesia, pre-existing chronic pain condition, baseline use of opioid analgesics, previous history of opioid dependence/abuse, predicted inability to cooperate with completion of QoR-15 score on postoperative day 1, predicted admission to ICU for prolonged ventilation postoperatively, and patients with body weight < 100 kg.
Participants are randomized to one of two groups: Group A receives preoperative bilateral ESB under ultrasound guidance at the level of the T7 transverse process, while Group B receives a left-sided SAPB plus bilateral subcostal Transversus Abdominis Plane (TAP) block at the end of surgery, prior to emergence from general anesthesia. Both groups receive the same dose of local anesthetic.
Intervention Details
Patients in the ESB group receive bilateral ultrasound-guided ESB with 40 ml of 0.75% ropivacaine, diluted to 60 ml with 20 ml 1% lignocaine with adrenaline, injected at the T7 transverse process bilaterally (30 ml each side). Patients in the SAPB plus subcostal TAP block group receive ultrasound-guided left-sided SAPB and bilateral subcostal TAP block with the same total dose of ropivacaine and lignocaine solution (20 ml per injection).
All blocks are performed under full aseptic conditions by or under the direct supervision of the same consultant anesthesiologist, who is not involved in patient recruitment, randomization, or postoperative data collection.
Outcome Measures
The primary outcome is the quality of recovery at 24 hours postoperatively, as measured by the QoR-15 score. Secondary outcomes include pain scores at rest and on movement at 24 hours using a verbal response scale, time to first analgesia postoperatively, total opioid consumption in the first 24 hours postoperatively, incidence of nausea and vomiting and use of antiemetic rescue, incidence and severity of postoperative complications using the Comprehensive Complication Index (CCI) score, and length of hospital stay.
Rationale for Comparator Choice
LSG surgery involves multiple trocar incisions in the anterior abdominal wall, and the choice of regional analgesia technique should be tailored to the specific incision sites used. This trial compares bilateral ESB to cover all incision sites with a tailored approach of left-sided SAPB combined with bilateral subcostal TAP blockade to cover specific trocar sites.
Statistical Analysis and Sample Size
The study aims to recruit 70 patients in total (35 in each group). The sample size calculation is based on an established minimum clinically important difference in QoR-15 of 6.0, with an assumed standard deviation of 8. Statistical analysis will involve appropriate tests (unpaired t-test or Mann-Whitney U test) based on the distribution of the data.
Ethical Considerations and Data Management
The trial is overseen and monitored by the Galway University Hospital Clinical Research Ethics Committee. Data is collected by blinded research team members using paper proformas with study numbers only, stored in locked filing cabinets, and uploaded onto a password-protected study spreadsheet. Patient consent forms are stored separately, and identifiable data is stored on an enrolment log by the principal investigator, who has no role in data collection.
