Erector Spinae Nerve Block for the Management of Rib Fractures: A Retrospective Propensity Matched Cohort Study Protocol

Introduction: Rib fractures are the most common thoracic blunt trauma injury and constitute up to 55% of all thoracic blunt trauma injuries. They are a common cause of hospital admission and are associated with significant morbidity and mortality. Immediate causes of comorbidities and mortality that stem from complications of rib fractures include pneumothorax, haemothorax, pulmonary contusions, flail chest and acute respiratory distress syndrome; whilst more delayed complications include atelectasis, pneumonia, pulmonary embolism, empyema and respiratory failure. The higher the number of rib fractures, the higher the incidence of pulmonary morbidity and mortality. A fundamental contributor to delayed complications is hypoventilation secondary to pain from the facture(s) and thus, a key element in the prevention of post-fracture complications is optimal analgesia. Several neuraxial and regional techniques have been described in relation to systemic opioid analgesia with varying levels of evidence. One such strategy is the use of the Erector Spinae Block (ESB). This technique has never been described in relation to any other technique. The aim of this study will be to compare the ESB to systemic opioid analgesia with the hypothesis that patients receiving Erector Spinae Blocks will have a lower incidence of respiratory complications and thus a shorter length of stay in hospital and reduced mortality rates. Methods and Analysis: A retrospective cohort study with propensity matching will be performed. A retrospective analysis of patients with rib fractures managed by the Sunshine Coast Hospital and Health Service (SCHHS) Acute Pain Service (APS). Each patient’s electronic medical record (EMR) from their hospital admission will be reviewed for age, number of rib fractures, presence of a flail segment, comorbidities at the time of admission, management used (oral medications alone vs. ketamine infusion vs. patient controlled analgesia vs. regional complications (haemothorax/pneumothorax, pneumonia, pulmonary embolism, respiratory failure, requirement ventilatory support or ICU, number of days of ventilatory support, regional block failure or local anaesthetic related adverse effects), length of stay, discharge destination and mortality during admission. Ethics and Dissemination: Ethics approval for the study protocol and data collection has been approved LNR/2018/QPCH/45155). The study findings will be submitted for publication in a peer reviewed journal. Conclusion: There is currently no available literature to support the use of an ESB over other analgesic this cohort study will provide initial exploratory results to guide further randomised controlled trials.