Serratus anterior plane block improves pain and incentive spirometry volumes in trauma patients with multiple rib fractures: a prospective cohort study.

Background: Rib fractures are common injuries associated with considerable morbidity, long-term disability, and mortality. Early, adequate analgesia is important to mitigate complications such as pneumonia and respiratory failure. Regional anesthesia has been proposed for rib fracture pain control due to its superior side effect profile compared with systemic analgesia. Our objective was to evaluate the effect of emergency physician-performed, ultrasound-guided serratus anterior plane block (SAPB) on pain and respiratory function in emergency department patients with multiple acute rib fractures. Methods: This was a prospective observational cohort study of adult patients at a level 1 trauma center who had two or more acute unilateral rib fractures. Eligible patients received a SAPB if an emergency physician trained in the procedure was available at the time of diagnosis. Primary outcomes were the absolute change in pain scores and percent change in expected incentive spirometry volumes from baseline to 3 hours after rib fracture diagnosis. Results: 38 patients met eligibility criteria, 15 received the SAPB and 23 did not. The SAPB group had a greater decrease in pain scores at 3 hours (-3.7 vs. -0.9; p=0.003) compared with the non-SAPB group. The SAPB group also had an 11% (CI 1.5% to 17%) increase in percent expected spirometry volumes at 3 hours which was significantly better than the non-SAPB group, which had a -3% (CI -9.1% to 2.7%) decrease (p=0.008). Conclusion: Patients with rib fractures who received SAPB as part of a multimodal pain control strategy had a greater improvement in pain and respiratory function compared with those who did not. Larger trials are indicated to assess the generalizability of these initial findings.