Does a normal screening ultrasound of the abdominal aorta reduce the likelihood of rupture in emergency department patients?

Does Patient Weight, Age, or Gender Correlate With the Ability to Visualize the Distal Aorta on Bedside Aortic Ultrasounds in the Emergency Department?

INTRODUCTION

Abdominal aortic aneurysms (AAA) have a varied presentation, which often makes the diagnosis difficult. The most common location for an AAA is in the infra-renal or distal aorta, which can be difficult to visualize using bedside ultrasound.  Objective: This study was designed to identify if a patient's weight, gender, or age influenced our ability to visualize the distal aorta on bedside abdominal aortic ultrasound scans.  Methods: All aortic scans completed in the Emergency Department (ED) from September 2010 to September 2013 were retrospectively evaluated. Patients 21 years and older were included. Scans missing age, gender, or self-reported weight were excluded.  Results: 500 aortic scans were included. The distal aorta was visualized in 393 scans (78.6%). The mid aorta was visualized in 417 scans (83.4%). The proximal aorta was visualized in 454 scans (90.8%). For the distal aorta, the average weight for visualized versus not visualized was 75.7 kg versus 79.7 kg. For the proximal aorta, the average weight for visualized versus not visualized was 75.8 kg versus 84.0 kg. Weight significantly predicted the ability to visualize the proximal aorta (unadjusted p=0.0098, adjusted p=0.0095) and marginally predicted the ability to visualize the distal aorta (unadjusted p=0.071, adjusted p=0.019). Neither age (unadjusted p=0.13, adjusted p=0.052) nor gender (unadjusted p=0.74, adjusted p=0.40) was significantly associated with visualization.

CONCLUSION

There is no clinically significant difference in the ability to visualize a patient's distal aorta with bedside ultrasound based on a patient's body weight, gender, or age.

Identification of the main determinants of abdominal aorta size: a screening by Pocket Size Imaging Device

Background

Ultrasound exam as a screening test for abdominal aorta (AA) can visualize the aorta in 99% of patients and has a sensitivity and specificity approaching 100% in screening settings for aortic aneurysm. Pocket Size Imaging Device (PSID) has a potential value as a screening tool, because of its possible use in several clinical settings. Our aim was to assess the impact of demographics and cardiovascular (CV) risk factors on AA size by using PSID in an outpatient screening.

Methods

Consecutive patients, referring for a CV assessment in a 6 months period, were screened. AA was visualized by subcostal view in longitudinal and transverse plans in order to determine the greatest anterior-posterior diameter. After excluding 5 patients with AA aneurysm, 508 outpatients were enrolled. All patients underwent a sequential assessment including clinical history with collection of CV risk factors, physical examination, PSID exam and standard Doppler echoc exam using a 2.5 transducer with harmonic capability, both by expert ultrasound operators, during the same morning. Standard echocardiography operators were blinded on PSID exam and viceversa.

Results

Diagnostic accuracy of AA size by PSID was tested successfully with standard echo machine in a subgroup (n = 102) (rho = 0.966, p < 0.0001). AA diameter was larger in men than in women and in ≥50 -years old subjects than in those <50 -years old (both p < 0.0001). AA was larger in patients with coronary artery disease (CAD) (p < 0.0001). By a multivariate model, male sex (p < 0.0001), age and body mass index (both p < 0.0001), CAD (p < 0.01) and heart rate (p = 0.018) were independent predictors of AA size (cumulative R² = 0.184, p < 0.0001).

Conclusion

PSID is a reliable tool for the screening of determinants of AA size. AA diameter is greater in men and strongly influenced by aging and overweight. CAD may be also associated to increased AA diameter.