# Elevated international normalized ratio contributes to poor prognosis in patients with traumatic lung injury

## TL;DR

High international normalized ratio (INR) is linked to worse outcomes in patients with traumatic lung injury, suggesting it could be used as an early warning sign.

## Contribution

Identifies elevated INR as a strong predictor of poor prognosis in traumatic lung injury patients using machine learning and statistical analysis.

## Key findings

- INR ≥1.36 is associated with an 8.5 times higher 28-day mortality risk in traumatic lung injury patients.
- INR showed strong predictive value with an area under the ROC curve of 0.826 for 28-day mortality.
- Machine learning models confirmed INR as a key risk factor for poor outcomes in these patients.

## Abstract

To investigate the pivotal determinants contributing to the adverse prognosis in patients afflicted with traumatic lung injury (TLI), with an aim to mitigate the elevated mortality rate associated with this condition.

A retrospective analysis was carried out on 106 TLI patients who were admitted to the intensive care unit of a comprehensive hospital from March 2018 to November 2022. The patients were categorized into two groups based on their 28-day outcome: the survival group (n = 88) and the death group (n = 18). Random forest model, least absolute shrinkage and selection operator (LASSO) regression and support vector machine recursive feature elimination (SVM-RFE) were utilized to pinpoint the primary factors linked to poor prognosis in TLI patients. The Receiver Operating Characteristic (ROC) curve analysis was utilized to ascertain the predictive value of INR in forecasting the prognosis of TLI patients. Based on the cut-off value of INR, patients were categorized into two groups: INR ≥ 1.36 group (n = 35) and INR < 1.36 group (n = 71). The 28-day survival rate was then compared using Kaplan–Meier analysis.

Random forest model, LASSO, and SVM-RFE jointly identified International standardization ratio (INR) as a risk factor for TLI patients. The area under the ROC curve for INR in predicting the 28-day mortality of TLI patients was 0.826 (95% CI 0.733–0.938), with a cut-off value of 1.36. The 28-day mortality risk for TLI patients with an INR ≥ 1.36 was 8.5 times higher than those with an INR < 1.36.

Traumatic lung injury patients with elevated INR have a poor prognosis. An INR of ≥1.36 can be used as an early warning indicator for patients with traumatic lung injury.