# A modified CO-related EIT parameter was used to evaluate pulmonary ventilation-perfusion ratio during prone position and inhaled nitric oxide therapy: a case report

## TL;DR

A modified EIT parameter was used to assess lung function in a patient with severe lung disease during treatments that improve oxygen levels.

## Contribution

A new EIT-derived parameter was introduced to evaluate ventilation-perfusion ratios during prone positioning and nitric oxide therapy.

## Key findings

- The modified EIT parameter showed improved consistency with oxygenation index compared to conventional indicators.
- The patient's oxygenation and ventilation-perfusion ratio improved during prone positioning and inhaled nitric oxide therapy.

## Abstract

Assessment of the V/Q ratio is crucial for understanding the pathophysiology of iNO therapy and prone position in ARDS patients. Recently, the concept of the absolute V/Q ratio measured by EIT has emerged. In this study, we first describe a case where a modified EIT parameter was employed to clinically monitor the absolute V/Q ratio in an ARDS patient during both prone positioning and iNO therapy.

This report describes the case of a 69-year-old ARDS patient with refractory hypoxemia who underwent prone position and iNO therapy. The patient exhibited a positive response to the treatment, showing improved oxygenation and absolute V/Q. A modified EIT-derived parameter, the cardiac output (CO)-related V/Q match index, was utilized to evaluate the absolute V/Q ratio, demonstrating improved consistency with the oxygenation index compared to conventional indicators.

This case elucidates the significance of the EIT-derived parameter—CO-related V/Q match index, revealing its benefits in evaluating the V/Q ratio under the various treatment strategies when compared to traditional ones.