ED point-of-care ultrasonography is associated with earlier drainage of pericardial effusion: A retrospective cohort study.

Objectives: To determine the association between emergency department point-of-care cardiac ultrasonography (POCUS) utilization and time to pericardial effusion drainage during an 8-year period when the emergency ultrasound program was established at our institution.

Methods: We performed a single-center retrospective cohort study in patients undergoing pericardiocentesis or other procedure for evacuation of pericardial effusion. Data was collected using both direct queries to the electronic health record database and two-examiner chart review. The primary outcome was time to intervention for pericardial effusion drainage. Multivariable Cox regression, with and without inverse probability weighting for likelihood to receive POCUS, was used to determine the association between POCUS and time to intervention. Secondary outcomes included 28-day mortality.

Results: 257 patient encounters were included with 137 receiving POCUS and 120 who did not. The proportion of patients receiving POCUS increased from 18.5% to 69.5% during the early to late periods of the study. POCUS was associated with an earlier median time to intervention of 21.6 h (95% CI 17.2, 24.2) compared to 34.6 h (27.0, 50.5) in the No POCUS group. After adjustment for patient demographics, anticoagulation, time of presentation and hemodynamic instability, POCUS was associated with earlier intervention (HR 2.08 [95% CI 1.56, 2.77]). POCUS use was not associated with a difference in 28-day mortality, which was evaluated as a secondary outcome. However, diagnosis of pericardial effusion by the ED physician using any means (POCUS or other imaging) was associated with decreased 28-day mortality (9.7% vs. 26.0%, -16.3% for POCUS [95% CI -29.1, -3.5]).

Conclusion: POCUS was associated with an earlier time to intervention for pericardial effusions after adjustment for multiple confounding factors. Failure to diagnose pericardial effusion in the ED using any diagnostic testing including POCUS, was associated with increased 28-day mortality.