ED AAA Ultrasound Alone vs AAA Ultrasound Plus FAST for Diagnosing Ruptured AAA
Date First Published:
October 3, 2025
Last Updated:
October 3, 2025
Report by:
Anoopkishore Chidambaram, ED Consultant (Queen Alexandra Hospital Portsmouth)
Search checked by:
Joe Schrieber and Aaron Razack, ED Consultant and Clinical Librarian
Three-Part Question:
In [adults in the ED with suspected ruptured AAA], does [AAA scan ultrasound plus a FAST exam] compared with [AAA scan ultrasound alone] [improve diagnostic accuracy for rupture and facilitate faster safe transfer to definitive care]?
Clinical Scenario:
A 74-year-old man at a district general hospital ED has sudden onset abdominal and back pain, hypotension, and a pulsatile abdominal mass. You perform a POCUS scan and identify an AAA. CT imaging is not working. You wonder if doing a FAST exam to look for free intraperitoneal fluid (an indicator of rupture) will increase confidence in the diagnosis of rupture and help expedite transfer to a vascular surgery center.
Search Strategy:
Medline (PubMed), EMBASE, and Cochrane (2010–2025) were searched using: (“abdominal aortic aneurysm” AND “rupture”) AND (“point of care” OR “POCUS” OR “emergency ultrasound” OR “FAST”) AND (“diagnostic accuracy” OR “sensitivity” OR “specificity”) AND (“emergency department”). Guidelines reviewed: RCEM Ultrasound in Emergency Medicine (2022); ACEP Emergency Ultrasound Policy (2016); UK Vascular Society transfer recommendations (2021). Date of last search: 14 August 2025.
Search Details:
Search limited to human adults, English language, ED setting. Guidelines reviewed: RCEM Ultrasound in Emergency Medicine (2022); ACEP Emergency Ultrasound Policy (2016); UK Vascular Society transfer recommendations (2021).
Outcome:
A total of 9 relevant sources were identified: comparative ED studies of AAA ultrasound with and without FAST, systematic reviews, and national guidelines/policies.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Prospective study of emergency ultrasound for the diagnosis of ruptured abdominal aortic aneurysm Tayal VS, et al. 2003 USA | ED patients with suspected AAA | Single-centre prospective study evaluating ED-performed AAA ultrasound and FAST | Sensitivity and specificity for rupture diagnosis | Addition of FAST improved sensitivity for rupture and reduced time to transfer decisions | Early 2000s, older technology, non-UK, small single-centre study |
| Enhancing clinical outcomes: Point of care ultrasound in the precision diagnosis and Management of Abdominal Aortic Aneurysms in emergency medicine: A systematic review and meta-analysis Eman E Shaban 1, Yavuz Yigit 2, Baha Alkahlout 2, Ahmed Shaban 3, Amira Shaban 4, Benny Ponappan 1, Mohammed Abdurabu 1, Hany A Zaki 1 5 2024 Sep 29 International | Patients with suspected AAA across EDs | Systematic review & meta-analysis (9 ED studies) | Sensitivity/specificity of POCUS for AAA and rupture detection | AAA POCUS sensitivity ~98%, specificity ~99.8%; ~25% of detected AAAs were ruptured | Focused on AAA detection; did not measure incremental value of adding FAST |
| Accuracy of emergency medicine ultrasound in the evaluation of abdominal aortic aneurysm Thomas G Costantino 1, Eric C Bruno, Neal Handly, Anthony J Dean 2005 Nov;29 USA | Community hospital ED patients with suspected AAA | Comparative study | Diagnostic specificity when AAA + free fluid visualised | If both AAA and free fluid seen, rupture was virtually certain; no false positives | Small sample, US-based, operator skill dependent |
| Systematic review: emergency department bedside ultrasonography for diagnosing suspected abdominal aortic aneurysm Elizabeth Rubano 1, Ninfa Mehta, William Caputo, Lorenzo Paladino, Richard Sinert 2013 Feb USA | Patients with suspected AAA across ED settings | Systematic review of diagnostic studies | Pooled sensitivity/specificity, effect on clinical management | Sensitivity of bedside US (about 97%); supports ED US use for rapid AAA exclusion | Focused on AAA not rupture; heterogeneity |
| RCEM Ultrasound Education & Training Curriculum RCEM Ultrasound Working Group 2022 UK | ED patients with suspected ruptured AAA | National guideline / expert consensus | Role of AAA POCUS and FAST | FAST and PoCUS recommended for suspected ruptured AAA in ED, clarify transfer and management | Expert consensus, no new clinical trial data |
| ACEP Ultrasound Guidelines: Emergency, Point-of-care, and Clinical Ultrasound Guidelines ACEP Emergency Ultrasound Section 2016 USA | ED patients, suspected ruptured AAA | Clinical policy / guideline | Recommendations for use of AAA POCUS and FAST in ED | FAST can expedite detection of free fluid in suspected rupture; increases diagnostic certainty | Broad, not UK-relevant, no new data through 2016 |
| The Provision of Services for Patients with Vascular Disease Vascular Society of Great Britain & Ireland 2021 UK | Patients with suspected or confirmed ruptured AAA | National policy recommendations | Guidance for ED transfer and AAA management | Endorses emergency ultrasound (PoCUS/FAST) in initial ED workup and transfer decision | Policy-level, not primary data |
| Accuracy of presenting symptoms, physical examination, and imaging for diagnosis of ruptured abdominal aortic aneurysm: Systematic review and meta-analysis Fernando SM, Tran A, Cheng W, et al. 2022 Canada | Patients with suspected ruptured AAA in ED/acute care | Systematic review and meta-analysis | Diagnostic accuracy of clinical and imaging features (including FAST) | FAST high sensitivity for AAA, less for rupture; imaging (CTA) is gold standard | Data heterogeneity, FAST cannot exclude rupture |
Author Commentary:
Performing a FAST examination in addition to an AAA ultrasound increases diagnostic confidence for ruptured AAA by identifying intraperitoneal free fluid in a patient with a known aneurysm. This combined approach is particularly valuable in haemodynamically unstable patients and when definitive imaging (CT angiography) is unavailable or would cause delay. Evidence from single-centre studies, systematic reviews and guideline statements indicates that AAA + FAST improves sensitivity for detecting rupture (by detecting intra-abdominal haemorrhage) and increases specificity when both an AAA and free fluid are seen. Current guidance and expert consensus (RCEM, ACEP, Vascular Society UK) support FAST as an adjunct to AAA ultrasound to expedite transfer decisions. A negative FAST does not exclude rupture because bleeding may be retroperitoneal; if an AAA is visualised and the patient is unstable, transfer should not be delayed by a negative FAST. No large prospective UK RCTs exist; the evidence base is dominated by observational ED cohorts and expert consensus.
Bottom Line:
In a patient with suspected ruptured AAA, an ED-performed FAST exam in addition to AAA POCUS can improve the diagnostic accuracy for rupture and increase the emergency physician’s confidence when arranging urgent surgical transfer. The combination of AAA visualisation and free fluid on FAST strongly suggests rupture and should prompt immediate transfer to a vascular center if not already in progress. However, a normal FAST does not exclude a rupture (e.g. contained retroperitoneal bleeds), so the absence of free fluid should not unduly delay transfer in a clinically suspicious case. Use the combined ultrasound approach especially in unstable patients or when CT is unavailable or will cause delays.
Level of Evidence:
Level 1: Recent well-done systematic review was considered or a study of high quality is available
References:
- Tayal VS, et al.. Prospective study of emergency ultrasound for the diagnosis of ruptured abdominal aortic aneurysm
- Eman E Shaban 1, Yavuz Yigit 2, Baha Alkahlout 2, Ahmed Shaban 3, Amira Shaban 4, Benny Ponappan 1, Mohammed Abdurabu 1, Hany A Zaki 1 5. Enhancing clinical outcomes: Point of care ultrasound in the precision diagnosis and Management of Abdominal Aortic Aneurysms in emergency medicine: A systematic review and meta-analysis
- Thomas G Costantino 1, Eric C Bruno, Neal Handly, Anthony J Dean. Accuracy of emergency medicine ultrasound in the evaluation of abdominal aortic aneurysm
- Elizabeth Rubano 1, Ninfa Mehta, William Caputo, Lorenzo Paladino, Richard Sinert. Systematic review: emergency department bedside ultrasonography for diagnosing suspected abdominal aortic aneurysm
- RCEM Ultrasound Working Group. RCEM Ultrasound Education & Training Curriculum
- ACEP Emergency Ultrasound Section. ACEP Ultrasound Guidelines: Emergency, Point-of-care, and Clinical Ultrasound Guidelines
- Vascular Society of Great Britain & Ireland. The Provision of Services for Patients with Vascular Disease
- Fernando SM, Tran A, Cheng W, et al.. Accuracy of presenting symptoms, physical examination, and imaging for diagnosis of ruptured abdominal aortic aneurysm: Systematic review and meta-analysis