Emergency ultrasound-based algorithms for diagnosing blunt abdominal trauma

Background Ultrasonography is regarded as the tool of choice for early diagnostic investigations in patients with suspected blunt abdominal trauma. Although its sensitivity is too low for de finite exclusion of abdominal organ injury, proponents of ultrasound argue that ultrasound-based clinical pathways enhance the speed of primary trauma assessment, reduce the number of computed tomography scans and cut costs. Objectives To assess the efficiency and effectiveness of trauma algorithms that include ultrasound examinations in patients with suspected blunt abdominal trauma. Search strategy We searched MEDLINE, EMBASE, CENTRAL, CCMED, publishers' databases, controlled trials registers and the Internet. Bibliographies of identified articles and congress abstracts were handsearched. Trials were obtained from the Cochrane Injuries Group's trials register. Authors were contacted for further information and individual patient data. Selection criteria Participants: patients with blunt torso, abdominal or multiple trauma undergoing diagnostic investigations for abdominal organ injury. Interventions: diagnostic algorithms comprising emergency ultrasonography ( US). Controls: diagnostic algorithms without US ultrasound examinations ( e. g. primary computed tomography [CT] or diagnostic peritoneal lavage [DPL]). Outcome measures: mortality, use of CT and DPL, cost-effectiveness, laparotomy and negative laparotomy rates, delayed diagnoses, and quality of life. S tu dies: randomised controlled trials (RCTs) and quasi-randomised trials (qRCTs). Data collection and analysis Two reviewers independently selected trials for inclusion, assessed methodological quality and extracted data. Where possible, data were pooled and relative risks (RRs), risk differences (RDs) and weighted mean differences, each with 95% confidence intervals (CIs), were calculated by fixed-or random-effects modelling, as appropriate. Main results We identified two RCTs with US in the experimental arm and another with US in the control group. We also considered two qRCTs. Overall, trials were of moderate methodological quality. Few authors responded to our written inquiries seeking to resolve controversial issues and to obtain individual patient data. We were able to pool data from two trials comprising 1037 patients for primary endpoint analysis (i.e. mortality). The relative risk in favour of the no-US arm was 1.4 ( 95% CI 0.94 to 2.08). Because of a lack of details, the meaning of this observation remains unclear. There was a marginal bene fit with US-based pathways in reducing CT scans ( random-effects RD-0.46; 95% CI -1.00 to 0.13), offset by trials of higher methodological rigour. No differences were observed in DPL and laparotomy rates. Authors' conclusions There is insufficient evidence from RCTs to justify promotion of ultrasound-based clinical pathways in diagnosing patients with suspected blunt abdominal trauma.