Imaging strategies for detection of urgent conditions in patients with acute abdominal pain: diagnostic accuracy study

doi:10.1136/bmj.b2431

Published 26 June 2009, doi:10.1136/bmj.b2431
Cite this as: BMJ 2009;338:b2431

Research

Imaging strategies for detection of urgent conditions in patients with acute abdominal pain: diagnostic accuracy study

Wytze Laméris, research fellow ¹^,2, Adrienne van Randen, research fellow²^,1, H Wouter van Es, consultant radiologist³, Johannes P M van Heesewijk, consultant radiologist³, Bert van Ramshorst, consultant surgeon⁴, Wim H Bouma, consultant surgeon⁵, Wim ten Hove, consultant radiologist⁶, Maarten S van Leeuwen, consultant radiologist⁷, Esteban M van Keulen, consultant radiologist⁸, Marcel G W Dijkgraaf, methodologist⁹, Patrick M M Bossuyt, professor of clinical epidemiology⁹, Marja A Boermeester, consultant surgeon and clinical epidemiologist¹, Jaap Stoker, professor of radiology², on behalf of the OPTIMA study group

¹ Department of Surgery, Academic Medical Center, Amsterdam, Netherlands, ² Department of Radiology, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, ³ Department of Radiology, St Antonius Hospital, Nieuwegein, Netherlands, ⁴ Department of Surgery, St Antonius Hospital, Nieuwegein, ⁵ Department of Surgery, Gelre Hospitals, Apeldoorn, Netherlands, ⁶ Department of Radiology, Gelre Hospitals, Apeldoorn, ⁷ Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, ⁸ Department of Radiology, Tergooi Hospitals, Hilversum, Netherlands, ⁹ Department of Clinical Epidemiology, Biostatistics, and Bioinformatics, Academic Medical Center, Amsterdam

Correspondence to: J Stoker j.stoker{at}amc.uva.nl

Objective To identify an optimal imaging strategy for the accuratedetection of urgent conditions in patients with acute abdominalpain.

Design Fully paired multicentre diagnostic accuracy study withprospective data collection.

Setting Emergency departments of two university hospitals andfour large teaching hospitals in the Netherlands.

Participants 1021 patients with non-traumatic abdominal painof >2 hours’ and <5 days’ duration. Exclusioncriteria were discharge from the emergency department with noimaging considered warranted by the treating physician, pregnancy,and haemorrhagic shock.

Intervention All patients had plain radiographs (upright chestand supine abdominal), ultrasonography, and computed tomography(CT) after clinical and laboratory examination. A panel of experiencedphysicians assigned a final diagnosis after six months and classifiedthe condition as urgent or non-urgent.

Main outcome measures Sensitivity and specificity for urgentconditions, percentage of missed cases and false positives,and exposure to radiation for single imaging strategies, conditionalimaging strategies (CT after initial ultrasonography), and strategiesdriven by body mass index and age or by location of pain.

Results 661 (65%) patients had a final diagnosis classifiedas urgent. The initial clinical diagnosis resulted in many falsepositive urgent diagnoses, which were significantly reducedafter ultrasonography or CT. CT detected more urgent diagnosesthan did ultrasonography: sensitivity was 89% (95% confidenceinterval 87% to 92%) for CT and 70% (67% to 74%) for ultrasonography(P<0.001). A conditional strategy with CT only after negativeor inconclusive ultrasonography yielded the highest sensitivity,missing only 6% of urgent cases. With this strategy, only 49%(46% to 52%) of patients would have CT. Alternative strategiesguided by body mass index, age, or location of the pain wouldall result in a loss of sensitivity.

Conclusion Although CT is the most sensitive imaging investigationfor detecting urgent conditions in patients with abdominal pain,using ultrasonography first and CT only in those with negativeor inconclusive ultrasonography results in the best sensitivityand lowers exposure to radiation.

© Laméris et al 2009
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Rapid Responses:

Read all Rapid Responses

Likelihood ratios and conclusion?: Alexis Descatha
bmj.com, 3 Aug 2009 [Full text]
An inefficient and costly way of managing an acute abdomen.: Richard G Fiddian-Green
bmj.com, 30 Jun 2009 [Full text]
Re: An inefficient and costly way of managing an acute abdomen.: Wytze Lam�ris, et al.
bmj.com, 6 Jul 2009 [Full text]
Importance of repeated clinical examinations.: Richard G Fiddian-Green
bmj.com, 7 Jul 2009 [Full text]
Apples and oranges and opposing objectivess..: Richard G Fiddian-Green
bmj.com, 7 Jul 2009 [Full text]
A succession of examinations can be a very painful experience.: Richard G Fiddian-Green
bmj.com, 7 Jul 2009 [Full text]
Re. Imaging strategies for detection of urgent conditions in patients with acute abdominal pain: diagnostic accuracy study.: Masoom Muttalib, Waleed Al-Obaydi, Sobath Premaratne
bmj.com, 9 Jul 2009 [Full text]
Re: Re. Imaging strategies for detection of urgent conditions in patients with acute abdominal pain: diagnostic accuracy study.: Wytze Lameris, et al.
bmj.com, 13 Jul 2009 [Full text]
The limitations of non-blinded diagnostic studies in the context of imaging in acute abdominal pain.: Masoom Muttalib, et al.
bmj.com, 28 Jul 2009 [Full text]
Re: The limitations of non-blinded diagnostic studies in the context of imaging in acute abdominal pain.: Wytze Lam�ris, et al.
bmj.com, 20 Aug 2009 [Full text]
Re: Likelihood ratios and conclusion?: Wytze Lam�ris, et al.
bmj.com, 20 Aug 2009 [Full text]