230 Ultrasound-Guided Serratus Anterior Plane Block Improves Pain Control in Patients With Rib Fractures

Abstract

The serratus anterior plane block (SAPB) is an ultrasound-guided compartment block; limited data suggest that it can decrease pain in patients with rib fractures or chest wall pain. We sought to determine the effect of SAPB on pain and incentive spirometry maximal vital capacity in adult patients with rib fractures. We enrolled a prospective cohort of adult patients ages 18 or above with at least 2 unilateral rib fractures in the anterior or lateral aspect of ribs 2-9, who were being admitted to the trauma service for pain control. The SAPB was performed by six emergency medicine residents, ultrasound fellows, and attending physicians who completed a one hour didactic and hands-on training in performing SAPB under ultrasound guidance. We used a standard dose of 20mL 0.5% bupivacaine with 10mL of normal saline for the block. We measured the effect of SAPB on chest wall pain at rest and during incentive spirometry using a 11-point Numeric Rating Scale (NRS-11), as well as maximum vital capacity. Measurements were obtained 15 and 60 minutes after SABP. We followed patients for 24 hours to evaluate for complications attributable to SABP including pneumothorax, cardiac arrhythmia, local anesthetic systemic toxicity, allergic reaction, infection or hematoma at SAPB site, or clinically significant bleeding. 20 patients (ages 33 to 95, median age 60) were enrolled (Table 1). The median number of rib fractures was four. SABP consistently decreased pain scores. Compared to pre-block pain scores at rest, mean and median pain scores decreased by 1.8 (SD 2.17, 95% CI:0.79-2.81) and 2.0 points (95% CI:0-3.0), respectively, at 15 minutes, and 2.5 (SD 2.69, 95% CI:1.24-3.76) and 2.0 points (95% CI:1.00-3.00), respectively, at 60 minutes (Figure 1a). Compared to pre-block pain scores during incentive spirometry use, mean and median pain scores decreased by 1.95 (SD 1.99, 95% CI:1.02-2.88) and 2.0 points (95% CI:1.00-3.00), respectively, at 15 minutes, and 2.4 (SD 2.42, 95% CI:1.27-3.53) and 2.0 points (95% CI:1.00-3.00), respectively, at 60 minutes (Figure 1b). Mean and median maximum vital capacity increased by 13mL (SD 672, 95% CI:-311-337) and 0mL (95% CI:0-250), respectively, at 15 minutes and 232mL (SD 406, 95% CI:36-427) and 100mL (95% CI:0-250), respectively, at 60 minutes (Figure 2). Zero complications attributable to SAPB were identified in our study population in the 24 hours following enrollment. In patients with multiple rib fractures, SAPB reduced pain scores at rest and during incentive spirometry, and increased maximal vital capacity. The SABP is a safe and effective modality for pain control in trauma patients with multiple rib fractures.View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT)