Beatrice Hoffmann

Emergency ultrasonography is a frequently used imaging tool in the bedside diagnosis of the acute abdomen. Classic indications include imaging for acute abdominal aneurysm, acute cholecystitis, hydronephrosis, and free intra-abdominal fluid in patients with trauma or suspected vascular or ectopic pregnancy rupture. Point-of-care sonographic imaging often emphasizes the diagnostic utility of fluid and edema, both as a significant finding and as a desirable adjunct for improved imaging. Conversely, the finding of sonographic intra-abdominal air is commonly 'tolerated' as a necessary evil that can foil image acquisition. This is in stark contrast to the accepted diagnostic utility of air in other imaging modalities for the acute abdomen, such as computed tomography and conventional radiography. Countering the bias against air as a deterrent for diagnostic ultrasound's accuracy are several published studies suggesting that abnormal air patterns can be used with high precision to diagnose pneumoperitoneum. These studies advocate that sonographic findings of abnormal air can be straightforward and can become crucial for increasing the diagnostic yield of bedside ultrasound of the acute abdomen. They suggest that practitioners should familiarize themselves with the findings and techniques to gain the experience required to make the diagnosis with confidence. This article will discuss four groups of abnormal air patterns found in the abdomen and the retroperitoneum and the respective scanning techniques, with a focus on the use of ultrasound for diagnosing pneumoperitoneum and a suggested scanning approach in the emergency setting.

Background The aims of this study were to examine the association between emergency department (ED) providers' experience with bedside ultrasound after achieving credentialing for abdominal aortic aneurysm (AAA) sonography, and their successful visualisation rate of the abdominal aorta among consecutive patients who presented asymptomatically but with risk factors for AAA. Methods Study coordinators enrolled asymptomatic men >50 years presenting to a single ED with AAA risk factors. One of 20 AAA credentialed ED sonographers screened each subject for AAA. Screening forms and ultrasound images were reviewed for quality assurance. Multivariate logistic regression was used to estimate OR of visualisation and correct measurement among providers with varying experience, adjusted for bowel gas and body mass index (BMI). Results During the 12 week enrolment, 278 patients were eligible and 196 (70%) enrolled. ED sonographers accurately visualised the entire abdominal aorta of 140 subjects (71.4%), did not completely visualise 40 (20.4%) and incorrectly measured 16 (8.2%). After controlling for bowel gas and BMI, providers with 3 years experience. Conclusion AAA sonography performance varied markedly among a diverse group of already credential ED sonographers. The most experienced providers demonstrated best performance. The present results suggest that some providers might require >25 proctored scans to ensure competency and training, and training on technically difficult patients should be part of the credentialing process.

Objectives:  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 ≥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.