Continuous serratus anterior block for sternotomy analgesia after cardiac surgery: a single-centre feasibility study.

Abstract

Moderate-to-severe pain is common after cardiac surgery, peaking during the first and second postoperative days. Several nerve blocks for sternotomy have been described; however, the optimal location for continuous catheters has not been established. This study assessed the feasibility of a larger trial evaluating the efficacy of serratus anterior plane (SAP) catheter analgesia for sternotomy pain. This double-blinded trial included patients undergoing cardiac surgery via sternotomy. Bilateral SAP catheters were placed in all participants, and randomised to ropivacaine or placebo. We assessed feasibility based on predetermined endpoints: (1) average recruitment rate >4 per month; (2) protocol adherence rate >90%; (3) primary outcome measurement rate >90%; and (4) significant catheter-related adverse event rate ≤2%. The quality of recovery index (QoR-15) was compared using an independent t-test. Of 52 participants randomised, feasibility data were available for 50. A definitive study was deemed 'not feasible' in our standalone centre owing to a low recruitment rate (2.4 per month) and a high adverse event rate (pneumothorax rate 12%). There were no major protocol deviations but minor deviations in 12% of participants. Pain, opioid consumption, complications, and quality of recovery were not different between groups. Long-term pain at 3 months was low in both groups. A single-centre trial was deemed not feasible for our setting. With limited data, the quality of recovery was not different with ropivacaine dosing of bilateral SAP catheters for sternotomy pain. NCT04648774.