Focused Cardiac Ultrasound and Doppler Hemodynamics in Nephrology Practice

Point-of-care ultrasonography (POCUS) in nephrology is evolving beyond kidney imaging and procedural guidance toward integrated hemodynamic assessment. Distinguishing reduced forward flow from elevated filling pressures and venous congestion remains challenging in patients with acute kidney injury and cardiorenal syndromes. This educational review discusses the clinical reasoning behind incorporating basic and advanced cardiac POCUS into nephrology practice. We highlight the interpretation and limitations of ventricular size and function, inferior vena cava assessment, stroke volume and left ventricular outflow tract Doppler, left ventricular filling pressures, right-sided and pulmonary artery pressures, and right ventricular outflow tract Doppler, with emphasis on how these findings may influence fluid removal, volume administration, and vasoactive therapy. The complementary role of venous excess ultrasound (VExUS) in assessing the downstream consequences of systemic venous congestion is also discussed. Rather than relying on isolated sonographic parameters or rigid cutoffs, cardiac POCUS findings should be integrated with multisystem ultrasound and the broader clinical context. Familiarity with these principles can help nephrologists obtain focused, repeatable hemodynamic information at the bedside and translate sonographic findings into more physiologically informed clinical decisions.