Background and aim:

Dyspnea is a common reason for emergency department (ED) visits and is associated with poor prognosis. Point-of-care ultrasound (PoCUS) improves the diagnosis of dyspneic ED patients, but the impact of serial PoCUS on prognosis remains uncertain. This study aimed to investigate temporal changes in serial PoCUS findings in dyspneic ED patients and examine their association with short-term mortality and hospitalization.

Methods and material:

This substudy was part of a randomized, controlled, blinded-outcome multicenter trial in Denmark. Patients ≥ 18 years with a primary complaint of dyspnea were included and allocated to a serial ultrasound or control group. PoCUS examinations were performed at two-hour intervals. The main study showed that treatment guided by serial PoCUS significantly reduced the degree of dyspnoea compared to usual care. In this secondary analysis, we examined if the PoCUS findings changed within the first 5 hours in the ED. Associations between the sum of B-lines, inferior vena cava collapsibility index (IVC-CI), tricuspid annular plane systolic excursion (TAPSE), right ventricular dilatation, and ejection fraction (EF) and 30-day all-cause mortality and 30-day hospitalization after discharge were examined with a multivariable logistic regression model.

Results:

A total of 206 patients were included. PoCUS findings remained stable during the initial ED stay, except for decreasing B-lines. Thirty-day all-cause mortality was 4.3%, and hospitalization rate was 22.8%. PoCUS findings were not associated with mortality or hospitalization. Age over 80 years was the strongest predictor of prognosis.
Discussion and Conclusion:

Discussion and conclusion: PoCUS is valuable in the initial diagnostic workup of dyspneic patients. B-lines showed dynamic changes in the short term. However, PoCUS parameters did not provide prognostic information. A larger sample size is needed to draw definitive conclusions. Nonetheless, serial focused lung ultrasound and monitoring B-line trajectories have the potential as a tool to tailor treatment alongside standard care.