Serratus Anterior Plane and PECS II Blocks After Coronary Artery Bypass Grafting

Yuzuncu Yil University243 enrolled

Overview

This prospective randomized placebo-controlled trial was designed to evaluate the effects of ultrasound-guided bilateral pectoralis (PECS II) and serratus anterior plane (SAP) blocks on postoperative recovery in adult patients undergoing elective coronary artery bypass grafting (CABG). Patients were randomized to receive bilateral PECS II block, bilateral SAP block, or bilateral sham fascial plane injections in addition to standardized systemic analgesia. The study evaluated postoperative pain intensity using the Visual Analog Scale (VAS), opioid consumption, postoperative nausea and vomiting (PONV), block-related complications, duration of mechanical ventilation, time to first mobilization, and intensive care unit (ICU) length of stay.

This prospective, randomized, placebo-controlled trial evaluated the postoperative analgesic efficacy of ultrasound-guided bilateral serratus anterior plane (SAP) block and bilateral PECS II block in adult patients undergoing elective coronary artery bypass grafting (CABG). Participants were randomly assigned to one of three groups: bilateral SAP block, bilateral PECS II block, or bilateral sham fascial plane injections (placebo comparator). All participants received the same standardized postoperative systemic analgesic regimen. To preserve allocation concealment and blinding, an investigator not involved in patient management prepared identical coded syringes according to the randomization sequence. The physician performing the ultrasound-guided procedures was unaware of syringe contents. All participants underwent bilateral injections at both the PECS II and SAP fascial planes; depending on group allocation, each fascial plane received either 0.25% bupivacaine or 0.9% saline. Postoperative outcome assessment was performed by investigators blinded to treatment allocation. The primary outcome was postoperative pain intensity measured using the Visual Analog Scale (VAS) at predefined time points after extubation. Secondary outcomes included cumulative opioid consumption during the first 24 postoperative hours, postoperative nausea and vomiting (PONV), and block-related complications. Additional recovery-related outcomes included duration of mechanical ventilation, time to first mobilization, and intensive care unit (ICU) length of stay. These recovery outcomes were analyzed as exploratory endpoints because ICU clinicians were not blinded and important perioperative factors influencing recovery were not systematically collected.

Study Type

INTERVENTIONAL

Allocation

Interventions

Bilateral Serratus Anterior Plane BlockPROCEDURE

Ultrasound-guided bilateral serratus anterior plane (SAP) block performed using 20 mL of 0.25% bupivacaine on each side after ICU admission while patients remained intubated following elective coronary artery bypass grafting.

Bilateral PECS II BlockPROCEDURE

Ultrasound-guided bilateral PECS II block was performed using the standard two-injection technique after ICU admission while patients remained intubated following elective coronary artery bypass grafting. On each side, a total of 20 mL of 0.25% bupivacaine was injected between the pectoralis major and minor muscles and between the pectoralis minor and serratus anterior muscles.

Sham Fascial Plane ProcedurePROCEDURE

Ultrasound-guided bilateral sham fascial plane procedure was performed after ICU admission while patients remained intubated following elective coronary artery bypass grafting. On each side, 20 mL of 0.9% saline was injected at both the PECS II and serratus anterior plane injection sites using identical coded syringes to maintain study blinding.

Eligibility

Sex: ALLMin age: 20 Years

Medical Language ↔ Plain English

Inclusion Criteria: Adults aged 20 years and older ASA physical status II-IV Scheduled for elective coronary artery bypass grafting (CABG) via median sternotomy Extubated in the intensive care unit after surgery Provided written informed consent Exclusion Criteria: Refusal to participate or inability to provide informed consent Pregnancy Known allergy or contraindication to bupivacaine or other amide local anesthetics Coagulopathy or ongoing anticoagulation precluding regional anesthesia Local infection at the planned injection site Severe hepatic or renal failure Pre-existing chronic opioid use or chronic pain requiring opioid treatment Pre-existing neurological disorders affecting pain assessment Requirement for emergency surgery or concomitant cardiac procedures other than isolated CABG Reoperation for postoperative bleeding before outcome assessment

Outcomes

Primary Outcomes

Postoperative pain intensity assessed using the Visual Analog Scale (VAS)

Postoperative pain intensity will be assessed using a 10-cm Visual Analog Scale (VAS), where 0 indicates no pain and 10 indicates the worst imaginable pain. Higher scores indicate greater pain intensity. Assessments will be performed at 4, 8, 12, and 24 hours after extubation.

Time frame: 4, 8, 12, and 24 hours after extubation

Secondary Outcomes

Postoperative nausea and vomiting (PONV)

The occurrence of postoperative nausea and/or vomiting will be recorded during the first 24 hours after surgery.

Time frame: Within 24 hours after surgery

Block-related complications

Block-related complications, including local anesthetic systemic toxicity, hematoma, infection, pneumothorax, vascular puncture, nerve injury, or other procedure-related adverse events, will be recorded.

Time frame: During hospitalization

Length of intensive care unit (ICU) stay

Length of stay in the intensive care unit (ICU), measured in hours from ICU admission to ICU discharge.

Time frame: From ICU admission to ICU discharge (assessed up to 30 days).

Time to first mobilization

Time from ICU admission to first mobilization, measured in hours.

Time frame: From ICU admission to first mobilization (assessed up to 7 days).

Duration of mechanical ventilation

Duration of mechanical ventilation, measured as the time from ICU admission to successful extubation, in hours.

Time frame: From ICU admission to successful extubation (assessed up to 7 days).

Total tramadol and pethidine consumption within the first 24 postoperative hours

Cumulative intravenous tramadol and pethidine doses administered during the first 24 postoperative hours will be recorded and reported separately in milligrams.

Time frame: Within the first 24 postoperative hours