Point-of-Care Ultrasound Correlates of Pulmonary Capillary Wedge Pressure and Right Atrial Pressure

Volume assessment remains a challenging bedside practice that is highly dependent on patient factors, comorbid conditions, physical exam, and point-of-care ultrasound (POCUS) techniques. POCUS is increasingly used to assist with diuretic decision-making for patients with suspected volume overload. While developing evidence suggests that POCUS allows for rapid and safe evaluation of volume status, limited data exist regarding which POCUS assessments correlate best to filling pressure measurements obtained from rightheart catheterization (RHC).

A single-center observational exploratory study conducted at Oregon Health & Science University investigated POCUS volume assessment in adult patients scheduled to undergo RHC. Multiple POCUS measurements were performed directly prior to RHC in 28 patients to investigate correlations between POCUS and RHC measurements, specifically mean right atrial pressure (mRAP) and pulmonary capillary wedge pressure (PCWP).

POCUS measurements that correlated (either positively or negatively) with mRAP as measured by RHC included qualitative RV function assessment and tricuspid annular plane of systolic excursion (TAPSE) (r^S = -0.421, p = 0.032, effect size = -0.699-0.047). Left atrial diameter measurement (r^P = 0.651, p = <0.001, effect size = 0.359-0.826), mitral valve inflow velocity (E) (r^S = 0.394, p = 0.050, effect size = 0.053-0.711), E/A ratio (r^S = 0.446, p = 0.025, effect size = 0.048-0.708), total B-line score (r^S = 0.407, p = 0.031, effect size = -0.159-0.615), combined LA diameter and mitral valve inflow velocity (r^P = 0.383, p = 0.044, effect size = 0.011-0.661), and combined E/e' and E/A ratio (r^P = 0.418, p = 0.027, effect size = 0.053-0.684) all correlated with PCWP.

Some correlation exists between POCUS measurements and RHC assessment of PCWP and mRAP. Larger prospective studies are needed to fully understand this correlation, particularly in the context of pre/post intervention and specific disease processes.