Objectives: Undifferentiated dyspnea is a challenging emergency department presentation. In the acute setting, treatment decisions are often made prior to completion of a full work up. Providers are often forced to act with diagnostic uncertainty. Point of Care Ultrasonography (POCUS) is a rapid and effective tool to guide therapy in these patients. Prior studies show that a protocolized approach to ultrasound (US) performed by a trained sonographer aids in narrowing the differential diagnosis (DDx). These studies have may not be applicable in practice settings where clinicians do not have extensive US training or time time to perform a complete exam while guiding resuscitation. This study aims to evaluate the effectiveness of targeted POCUS in narrowing diagnostic uncertainty and guiding initial management when performed by the treating physician as opposed to when performed by trained ultrasonographers.
Methods: This is a multi-center, prospective, non inferiority cohort study investigating the effect of ultrasound on emergency physicians’ DDx in patients presenting with undifferentiated dyspnea. During the initial evaluation of these patients, the primary provider filled out a survey of their initial DDx. The provider, or a separate US team, then performed targeted US on the patient. After US, the treating provider completed a second survey of changes in DDx post US.
Results: This is a preliminary analysis of the initial 3 months of enrollment for a proposed 1 year trial. We enrolled 26 dyspneic cases (9 performed by US team). 41.2% of cases had a change in final diagnosis when US was performed by the provider, while 44.4% of cases had a change when performed by the US team. POCUS also significantly narrowed the providers’ DDx by 2 when performed by the US team, as compared to 1.88 when performed by the primary provider. If there is truly no difference between both groups, then 150 patients are required to be 80% sure that the upper limit of a one-sided 95% confidence interval will exclude a difference in favor of the US team of more than 20%.
Conclusion: Both POCUS performed by a dedicated US team, and by the primary provider resulted in a significant change in most likely diagnosis as well as change in the DDx, with no difference between the two groups. US appears to be a valuable tool in the initial evaluation of undifferentiated dyspneic patients.