An ultrasound-guided serratus anterior plane block with continuous local anaesthetic infusion and epidural analgesia for rib fracture pain.

BACKGROUND: We compared analgesia with an ultrasound (US)-guided serratus anterior plane block (SAPB) to thoracic epidural analgesia (EA) with continuous local anaesthetic infusion in patients with unilateral multiple traumatic rib fractures. EA often carries contraindications in patients with multiple rib fractures (MRFs), whereby having alternative effective methods to treat rib fracture pain remains important to patient care. Thus, we hypothesised that both regional anaesthetic techniques would provide effective pain relief.

METHODS: In this study, we included 59 patients with unilateral MRFs and a numerical rating scale (NRS) pain score ≥4 at rest or upon movement. Patients were randomised to receive a US-guided SAPB or continuous infusion EA with 2 mg/mL ropivacaine. Patients were given a patient-controlled analgesia (PCA) device with intravenous oxycodone boluses for rescue medication. The primary outcome was a change in the NRS score at rest and upon movement from baseline to Day 2 following the block. We also measured the forced expiratory volume in 1 s of expiration (FEV1) and FEV1% at the same time points when NRS was measured. The total consumption of oxycodone with PCA was measured at 24 and 48 h after the block.

RESULTS: We detected a significant reduction (≥2) in NRS for both groups; however, EA associated with a greater reduction in NRS upon movement after block initiation. The mean reduction in NRS upon movement within 1 h was 3 (1.8, p < .01) in the SAPB group versus 4.7 (2.4, p < .01) in the EA group. We found no significant difference between groups in pain scores on Days 1 and 2 following the block. In the EA group, FEV1% increase in the first 12 h from baseline. Finally, PCA oxycodone consumption did not differ between groups.

CONCLUSIONS: SAPB with continuous local anaesthetic infusion is an effective alternative to treat rib fracture pain when EA is contraindicated. We found that SABP significantly reduces pain in patients with unilateral MRFs, although EA achieves better analgesia over the first 12 h following the block.