Diagnosis of ruptured abdominal aortic aneurysm: a multicentre cohort study.

Objective: The aim of this study was to describe the presentation of patients with ruptured abdominal aortic aneurysm (rAAA) and identify factors contributing toward misdiagnosis.

Methods: This was an observational study of cases with a final diagnosis of rAAA assessed at nine Emergency Departments and managed at one of two regional vascular centres in the UK.

Results: Eighty-five consecutive cases were included. Seventeen [20.0%, 95% confidence interval (CI) 11.5-28.5%] patients reported important symptoms up to 3 weeks before index presentation. In the Emergency Department, most patients complained of abdominal and/or back pain, seven (8.2%, 95% CI 2.4-14.0%) additionally reported atypical pain and ten (11.8%, 95% CI 4.9-18.7%) denied pain altogether. Hypotension (36.5%, 95% CI 26.3-46.7%), tachycardia (18.8%, 95% CI 10.5-27.1%) and syncope (36.5%, 95% CI 26.3-46.7%) were documented in a minority of cases. Distracting symptoms were present in 33 (38.8%, 95% CI 28.4-49.2%) patients. The median time to diagnosis was 17.5 min (range immediate-12 days), and 21 (25.6%, 95% CI 16.3-34.9%) patients were misdiagnosed during clinical assessment.

Conclusion: The classical signs and symptoms or rAAA are not always present and patients frequently show additional features that may confound the diagnosis. A high level of suspicion should be adopted for rAAA alongside a low threshold for immediate computed tomography. Further research is required to develop an objective clinical risk score or predictive tool for characterizing patients at risk.