Detection of Type B Aortic Dissection in the Emergency Department with Point-of-Care Ultrasound

Abstract

Aortic dissection (AD) is a rare, time-sensitive, and potentially fatal condition that can present with subtle signs requiring timely diagnosis and intervention. Although definitive diagnosis is most accurately made through computed tomography angiography, this can be a time-consuming study and the patient may be unstable, thus preventing the study’s completion. Chest radiography (CXR) signs of AD are classically taught yet have poor diagnostic reliability. Point-of-care ultrasound (POCUS) is increasingly used by emergency physicians for the rapid diagnosis of emergent conditions, with multiple case reports illustrating the sonographic signs of AD. We present a case of Stanford type B AD diagnosed by POCUS in the emergency department in a patient with vague symptoms, normal CXR, and without aorta dilation. A subsequent review of CXR versus sonographic signs of AD is described.

Ultrasound diagnosis of dissecting thoracic aortic aneurysms: procedure with a handheld device and a video-illustrated case

“…In addition, unlike POCUS, simple radiography cannot identify an intimal flap or wall motion abnormality. 9…”

“…This risk score, which has since been validated, is included in free online medical calculation apps. 9 Nearly 96% of patients with ADD were identified by one or more clinical risk markers (Table 1). Although a normal-width mediastinum on chest radiograph cannot rule out an AAD, adding that criterion to the ADD risk score slightly increased its sensitivity.…”

“…8 the presentation of patients may also be confusing when they have had or seem to have an associated myocardial infarction, cerebrovascular accident, renal, spinal cord, or bowel ischemia or infarction. 9 The large International Registry of Acute Aortic Dissection (IRAD) database found a median time from emergency hospital admission to diagnosis of 4.3 h. While critically ill patients (e.g. those with hypotension, tamponade, pulse deficits/limb ischemia or altered mental status) are diagnosed earlier, studies show that longer delays more commonly occur in women, those presenting with atypical, gradual-onset or painless symptoms, 6,10 patients with prior cardiac surgery 11 or those seen at a non-tertiary care hospital.…”

“…In addition, unlike POCUS, simple radiography cannot identify an intimal flap or wall motion abnormality. 9 AAD is more rapidly diagnosed when using ultrasonography or computed tomography (CT) rather than magnetic resonance imaging (MRI) or an aortogram. 12 Table 2 lists the ultrasound findings with which to diagnose an AAD.…”

Predictors of adverse events in uncomplicated type B aortic dissection: a systematic review with meta-analysis

“…However, these values may underestimate the real magnitude of the problem 2 . Timely evaluation and management are crucial given its potentially life-threatening outcomes 3 . Up to 30% of all aortic dissections are Type B Aortic Dissections (TBAD) 1,4 , with an in-hospital mortality estimated at 10.7% 5 .…”