Impact of serratus plane block on pain scores and incentive spirometry volumes after chest trauma.

Background: Adequate pain control is difficult to achieve in patients with multiple rib fractures (MRF). Serratus plane block (SPB) is a novel technique for alleviating rib fracture pain. Several published case reports support this hypothesis. Purpose: The purpose of this study was to evaluate the use of SPB in MRF at our level 1 trauma center. Methods: Our hospital's Regional Anesthesia Registry was queried for all trauma patients with MRF who underwent SPB between August 2014 and January 2018. Data were compared in each patient as a matched pair for the time periods before and after undergoing SPB. Thirty-four patients with similar baseline characteristics were enrolled. Results: The median number of rib fractures was 7. Ordinal pain scores were found to be improved 4 hrs after SPB from median 7/10 to 3/10 ( P <0.001). Incentive spirometry (IS) volumes recorded 4 and 24 hrs postserratus plane block showed a median increase of 150 and 175 mL from baseline, respectively ( P <0.001). IS volumes recorded at 48 hrs showed a median increase of 300 mL from baseline ( P <0.001). Respiratory rate decreased from a median value of 24.5 to 16 breaths/min ( P <0.001). SpO2 was improved at 24 hrs from median 96% to 99% ( P <0.001). Conclusion: SPB improves pain scores and IS volumes in MRF. Because it is not limited by patient positioning or anticoagulation and has a better safety profile, it may offer a viable alternative to neuraxial techniques. Additional studies are necessary to evaluate its efficacy compared to neuraxial techniques.