Serratus Anterior Block for Rib Fractures: A Systematic Review and Meta-analysis

Abstract

Background: Effective analgesia is the mainstay of the management of traumatic rib fractures. Serratus anterior block is a newer regional anaesthesia technique used in traumatic rib fractures which may have a favourable safety profile compared to other regional techniques. There is currently a lack of evidence for serratus anterior block and its role in the improvement of mortality, pain, duration of stay and pulmonary complications in patients with traumatic rib fractures in comparison to other regional anaesthesia techniques. Methods: Web of Science and PubMed were searched from inception until April 2022 for studies reporting on the use of a serratus anterior block compared to another therapy for the management of traumatic rib fractures. Primary outcomes were measures of analgesic efficacy. Secondary outcomes were the incidence of intervention related adverse events, hospital length of stay, intensive care unit length of stay and mortality. Results: Seven studies with 649 patients were included. No significant difference was found between serratus anterior block and intravenous opiates in terms of resting pain scores and achievement of mild or no pain after the chosen intervention(p>0.05). There was a statistically, but not clinically significant difference post block pain scores compared to other regional techniques (WMD= 0.63; 95% CI= 0.45 to 0.80; p< 0.00001). Significant differences were found in favour of blocks, specifically thoracic epidural and paravertebral blocks over serratus anterior block in terms of achieving mild or no pain after the block (OR= 0.54; 95% CI=0.32 to 0.90; I2= 0%; p= 0.02). No significant difference was found for any other outcomes. Conclusions: Current literature comparing the serratus anterior block to alternative analgesic options is limited by the end points assessing block success. No data was available assessing the effect on pain during deep inspiration and coughing. This meta-analysis demonstrated similar analgesic efficacy to other regional anaesthesia techniques but a lower incidence of mild or no pain post block compared to traditional epidural or paravertebral techniques. Future studies need to be directed towards important outcomes such as dynamic pain scores and respiratory complication rates. Keywords: Rib fractures, Serratus Anterior, Chest trauma