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

Abstract

Background

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.

Methods

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.

Results

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.

Conclusions

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.

Clinical trial registration

NCT04648774.