Comparative studies, descriptive studies and case reports of prehospital ultrasound in trauma patients were eligible for inclusion. Relevant outcomes were survival, feasibility, time to hospital, changes to diagnosis, changes to therapy and changes to choice of receiving hospital.
Included study designs were trials, prospective observational studies, retrospective observational studies, case series, case reports and letters to the editor. All studies included patients who underwent prehospital ultrasound using echocardiography, focused abdominal sonography for trauma (FAST), ultrasound-guided access to large central veins or invasive procedures. Ultrasound administrators varied from trained physicians to untrained aircrew. There were no studies of radiologists.
Three reviewers performed study selection.