Ultrasound-guided deep versus superficial continuous serratus anterior plane block for pain management in patients with multiple rib fractures: A prospective randomized double-blind clinical trial.

Background: Efficient analgesia is the cornerstone in multiple rib fractures (MRFs) management. The serratus anterior plane block (SAPB) shows promising outcomes. However, it is still provocative whether the superficial or deep approach is more effective in the SAPB procedure. We hypothesized that the deep approach of ultrasound (US)-guided continuous SAPB could be superior for MRFs pain management.

Methods: Sixty-two adult patients having unilateral MRFs, were randomized into two groups to receive continuous superficial SAPB (group S, n = 31) or continuous deep SAPB (group D, n = 31). As a primary outcome, we compared pain numeric rating scale (NRS), while total analgesic consumption, incentive spirometer volume (IS-V), lung ultrasound score (LUSS), basal and 24-h serum beta-endorphin (BE) levels, and any adverse events were secondary outcomes.

Results: There was a significant reduction in NRS in favor of group D when compared to group S at 30 minutes ( = 0.001) until 12 hours ( = 0.029); total analgesic consumption was significantly lower in group D ( = 0.005). A significant increase in the median IS-V in group D compared to group S at 90 minutes ( = 0.02) and 12h postblock ( = 0.004) LUSS was significantly lower in D group at 90 min, 12 h, and 24 h ( = 0.04, 0.001, 0.031). No significant differences as regards serum BE levels. No adverse events were noted.

Conclusion: Either superficial or deep continuous SAPB can be used safely and effectively in managing pain related to MRFs. Notably, the deep approach offered superior analgesia and improved deep breathing compared to the superficial.