Diagnostic performance of prehospital ultrasound diagnosis for traumatic pneumothorax by a UK Helicopter Emergency Medical Service.

Objective: Up to 20% of major trauma patients may sustain a pneumothorax. Traumatic pneumothoraces can be difficult to diagnose on scene. Although the use of handheld ultrasound (HHUS) is becoming increasingly widespread, there remains uncertainty about its efficacy as a diagnostic tool in the prehospital setting. The aim of this study was to determine the diagnostic performance of prehospital chest HHUS in trauma patients.

Method: Retrospective review of trauma patients who received a prehospital chest HHUS and subsequently conveyed to the Royal Sussex County Hospital (RSCH) between 1 July 2013 and 24 September 2018. Data including patient age, sex, mechanism of injury and clinical interventions were obtained. Prehospital ultrasound findings were compared with the computer tomography (CT) scan performed on arrival at the hospital.

Results: Four hundred eleven patients were conveyed to RSCH, the single largest group being following road traffic collisions. The majority of HHUS (66%) were performed by doctors. Three hundred sixty-one patients (88%) subsequently had a CT scan. Of these, 98 patients (27%) were found to have pneumothoraces. For pneumothorax diagnosis, prehospital HHUS had a sensitivity of 28% [95% confidence interval (CI): 19-37%] and specificity of 98% [95% CI: 97-99%].

Conclusion: In this retrospective study, sensitivity of prehospital HHUS for diagnosing a pneumothorax was lower than is often reported in in-hospital studies. This suggests that caution should be exercised in using HHUS for the exclusion of pneumothorax in the prehospital setting.