Routine screening for asymptomatic abdominal aortic aneurysm in high-risk patients is not recommended in emergency departments that are frequently crowded.
OBJECTIVE
The objectives were to examine the feasibility of offering abdominal aortic aneurysm (AAA) screening to consecutive, asymptomatic high-risk patients in a busy emergency department (ED) and to compare the prevalence of undetected AAA among ED patients to the prevalence among similarly aged men from the general population.


METHODS
A prospective cohort study was conducted at an academic community ED with an annual census of 58,000 patients. Dedicated study coordinators attempted to approach all consecutive male ED patients >50 years who presented in June-August 2007 during hours of high patient volume. To be eligible, older males had to have a smoking history or a family history of AAA. Patients were excluded if they presented with AAA symptoms, had a previous history of AAA screening or repair, had hemodynamic instability, or had an altered mental status. Study coordinators completed a brief interview with all enrolled subjects to obtain demographic and health information. A credentialed ED provider performed the ultrasound (US) screening exam and documented all findings. The US director reviewed representative images of the sonographic exam for correct visualization and measurement during quality assurance. The ED sonographers also completed a survey regarding their attitudes toward AAA screening in the ED. The primary study outcomes were the feasibility of AAA screening in the ED (screening rate, enrollment rate, US success rate, and providers' opinions) and the prevalence of AAA (aortic diameter of > or =3.0 cm) in the study sample.


RESULTS
During the 12-week study period, the study coordinators successfully approached 96% (700/729) of males > 50 years who were in the ED during study enrollment hours. Of those approached, 278 were eligible (40%), 25% were ineligible, 20% were not at high risk, and for 15% we could not determine risk factor status because of altered mental status. Of the 278 eligible, 196 (70%) underwent an US exam; 10% were not scanned because the providers were too busy, and 20% declined participation. Of those scanned, the ED sonographer was able to completely visualize and correctly measure the abdominal aortas of 71% of subjects. The prevalence rate of AAA in the study sample was 5.7% (95% confidence interval [CI] = 1.9% to 9.6%), similar to reported rates of 6 or 7% in other studies. More than half of the ED sonographers reported that US screening for AAA improved the quality of ED care (58%) and patient satisfaction (63%). However, 47% reported that AAA screening reduced ED efficiency, and 74% felt that the ED was not an appropriate setting for routine AAA screening.


CONCLUSIONS
Routine screening for asymptomatic AAA required substantial ED resources for a relatively low success rate of completed screens. The prevalence rate of AAA in our ED sample was not significantly different than prevalence estimates obtained from older men in the general population. ED sonographers reported benefits of screening in terms of improving the quality of emergency care and patient satisfaction, but also reported that it reduced operational efficiency. For EDs that have problems with crowding, we do not recommend implementing a routine screening program for AAA, even among high-risk patients.
Hoffmann
Beatrice
B
Department of Emergency Medicine, Johns Hopkins University, Hopkins Bayview Medical Center, Baltimore, MD, USA. bhoffma8@jhmi.edu
Um
Patrick
P
Bessman
Edward S
ES
Ding
Ru
R
Kelen
Gabor D
GD
McCarthy
Melissa L
ML
D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003955:Diagnostic Tests, Routine / Q000706:statistics & numerical data; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005240:Feasibility Studies; D006764:Hospitals, Community / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data*; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D018570:Risk Assessment; D014463:Ultrasonography