# Point-of-Care Ultrasound for the Diagnosis of Congestive Kidney Due to Severe Acidemia: A Case Report

## TL;DR

A patient with severe acidemia and kidney injury was correctly diagnosed with congestive kidney using ultrasound, avoiding incorrect treatment.

## Contribution

Demonstrates the utility of venous excess ultrasound (VExUS) in diagnosing acidemia-induced congestive kidney over prerenal causes.

## Key findings

- VExUS score improved with acidemia treatment, confirming congestive kidney as the cause of AKI.
- Fluid therapy and acidemia correction led to rapid improvement in kidney function.
- Correct diagnosis via VExUS avoided unnecessary hypovolemia treatment.

## Abstract

A 51-year-old woman with mitochondrial myopathy and congestive heart failure with reduced left ventricular ejection fraction was admitted due to loss of appetite and progressive frailty. She presented with acute kidney injury (AKI) and severe acidemia. Given her medical history and physical examination (jugular vein distention was not obvious), prerenal causes (hypovolemia/hypotension) of AKI were considered most likely. However, with a significantly elevated N-terminal pro-b-type natriuretic peptide level of 14,700 pg/mL, a congestive kidney was also considered. Bedside echocardiography showed no evidence of low output syndrome, whereas venous excess ultrasound (VExUS) score was assessed as Grade 2 (moderate congestion). In addition to administering fluids for the suspected prerenal causes (hypovolemia/hypotension), sodium bicarbonate was administered suspecting a negative impact of severe acidemia on cardiac function. With the improvement of acidemia and only a small volume of fluid therapy, there was a rapid improvement in AKI with the normalization of the VExUS score. This suggested that the main cause of AKI was congestive kidney. In this case, VExUS helped us make a correct diagnosis of acidemia-induced congestive kidney rather than hypovolemia as a cause of AKI, leading to the appropriate treatment.