Utility of Point-of-Care Ultrasonography (POCUS) in Guiding Clinical Decision-Making

Introduction: Point-of-care ultrasound (POCUS) refers to ultrasound utilized by healthcare providers at the bedside for immediate clinical decisions, in contrast to consultative ultrasonography. POCUS is becoming more utlized in routine clinical practice across various medical specialties. In nephrology, POCUS has myriad applications, including rapid assessment of genitourinary tract, assessing volume and dialysis access, and differentiating causes of hypotension. POCUS also has utility across the spectrum of patient care, ranging from outpatient to inpatient to the dialysis unit. We present a case in which POCUS was used in the dialysis unit to personalize care and avioid harm. Case Description: A 62-year-old woman with ESRD from HTN/DM on hemodialysis, CAD, and PVD developed progressive dyspnea. Echocardiogram demonstrated preserved LVEF but decreased RV function and elevated estimated PASP. Her cardiologist diagnosed presumed volume overload and recommended to decrease her target weight. The patient's dry weight was decreased but this resulted in worsening intradialytic hypotension and cramping. Nephrologist-performed POCUS in the dialysis unit demonstrated an IVC diameter < 2.1 cm with over 50% collapse with inspiration, suggesting low right atrial pressure. While RV dysfunction can cause plethoric IVC even without hypervolemia, on the contrary, small and collapsible IVC in this setting was felt to be reliable evidence of hypovolemia. The patient's estimated dry weight was increased, and intradialytic hypotension improved. A right heart catheterization demonstrated a right atrial pressure of 3 mmHg, a pulmonary artery pressure of 75/26 and a PCWP of 7mmHg, indicating normal LV filling pressures. She had no evidence of autoimmune etiologies, primary pulmonary etiology, or pulmonary embolism. Her diagnosis is presumed WHO type V pHTN from dialysis and is scheduled for follow up at a pHTN referral center. Discussion: The integration of POCUS into nephrology practice provides additional tool for rapid and personalized patient assessment. In this case, nephrologist-performed POCUS in the dialysis unit mitigated harm by correcting an inappopriate dry weight reduction. Furthermore, an understanding of the strengths and limitations of cardiac ultrasonography avoided excess reliance on other providers' assessments, in this case a presumptive dry weight reduction based on an echocardiographic finding of pulmonary hypertension.