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Suspected ruptured abdominal aortic aneurysm with non-diagnostic bedside ultrasound — MRCEM SBA MCQ

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HardProcedures, imaging and diagnosticsSuspected ruptured abdominal aortic aneurysm with non-diagnostic bedside ultrasoundMRCEM SBA

A 76-year-old man attends a district general hospital with abrupt severe back pain and a brief collapse. An abdominal aortic aneurysm measuring 5.8 cm was documented six months ago. He is alert, with a pulse of 122/min and blood pressure of 88/54 mmHg. Intravenous access and monitoring are established. Immediate bedside aortic ultrasound is non-diagnostic because bowel gas obscures the aorta. The regional vascular centre is 20 minutes away and can assess him on arrival. Ambulance transfer can begin within 10 minutes; local CT angiography would delay departure by at least 45 minutes. What is the most appropriate diagnostic and disposition plan?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: D — Discuss immediately with the vascular service and arrange transfer without further local imaging.

Abrupt back pain, collapse, hypotension and a previously documented large abdominal aortic aneurysm make rupture a major concern. The bedside scan is **non-diagnostic**, not negative: failure to visualise the aorta cannot resolve that concern. NICE recommends immediate discussion with a regional vascular service when ultrasound is non-diagnostic and an aneurysm is still suspected. Once accepted for emergency assessment, a patient should leave the referring unit within 30 minutes of the transfer decision. Here, local CT angiography would substantially delay that pathway; it can be considered as part of assessment for repair without making it a prerequisite for transfer. ([nice.org.uk](https://www.nice.org.uk/guidance/ng156/chapter/Recommendations)) A repeat bedside scan (A) or formal ultrasound (C) might establish aortic anatomy, but neither justifies deferring this available transfer. CT angiography (B) is attractive because it can define rupture and repair anatomy; its **45-minute delay before departure** is the decisive disadvantage in this case. A free-fluid scan (E) would not clarify the obscured aortic finding and should not delay vascular assessment. Arrange urgent transfer after immediate vascular discussion while continuing appropriate monitoring and resuscitation. ([nice.org.uk](https://www.nice.org.uk/guidance/ng156/chapter/Rationale-and-impact))

Reference: Abdominal aortic aneurysm: diagnosis and management — Recommendations (19 March 2020) — https://www.nice.org.uk/guidance/ng156/chapter/Recommendations Abdominal aortic aneurysm: diagnosis and management — Recommendations (19 March 2020) — https://www.nice.org.uk/guidance/ng156/chapter/Recommendations Abdominal aortic aneurysm: diagnosis and management — Recommendations (19 March 2020) — https://www.nice.org.uk/guidance/ng156/chapter/Recommendations