Point-of-care ultrasound: Uniting cardiology and nephrology at the bedside.

Cardiorenal syndrome reflects a complex interplay between cardiac and renal dysfunction, often compounded by fragmented management between cardiology and nephrology. Traditional phrases such as "the heart likes it dry and the kidneys like it wet" oversimplify care and perpetuate misconceptions about diuretic use and fluid management. Emerging evidence points to venous congestion rather than reduced cardiac output as a key driver of worsening renal function and adverse outcomes in heart failure. This article blends current evidence with the authors' perspective and clinical experience to explore the role of point-of-care ultrasound (POCUS) in the hemodynamic assessment of cardiorenal dysfunction, highlighting practical frameworks and tools. Conventional bedside assessment tools are limited, and static markers such as serum creatinine and physical signs can be misleading. POCUS provides a dynamic, physiology-based evaluation by integrating focused cardiac imaging, venous Doppler, lung ultrasound, and abdominal views. Frameworks such as "pump, pipes, and leaks" and scoring systems like venous excess ultrasound enable real-time visualization and quantification of congestion, shifting practice from assumption-based to data-driven care and fostering alignment between specialties. As training opportunities expand and supporting evidence grows, POCUS should be regarded as a core clinical skill in the management of cardiorenal dysfunction, with the potential to improve diagnostic precision and guide targeted therapy.