Evaluation of the Daily Change in PaO2/FiO2 Ratio as a Predictor of Abnormal Chest X-rays in Intensive Care Unit Patients Post Mechanical Ventilation Weaning: A Retrospective Cohort Study.

Won-Gun Kwack

doi:10.3390/medicina58020303

Abstract

Background and Objectives: The routine daily chest X-ray (CXR) strategy is no longer recommended in intensive care unit (ICU) patients. However, it is difficult for intensivists to collectively accept the on-demand CXR strategy because of the ambiguous clinical criteria for conducting CXRs. This study evaluated the predictive value of the change in PaO2/FiO2 (PF ratio) for abnormal CXR findings in ICU patients after mechanical ventilation (MV). Materials and Methods: A retrospective cohort study was conducted between January 2016 and March 2021 on ICU patients with MV who had at least 48 h of MV, and stayed at least 72 h in the ICU post-MV. Routine daily CXRs and daily changes in the PF ratios were investigated during the three days post-MV. Results: The 186 patients included in the study had a median age of 77 years (interquartile range: 65–82), and 116 (62.4%) were men. One hundred and eight (58.1%) patients had abnormal CXR findings, defined as one or more abnormal CXRs among the daily CXRs during the three days post-extubation. The reintubation rate was higher in the abnormal CXR group (p = 0.01). Of the 558 CXRs (normal = 418, abnormal = 140) and PF ratios, the daily change in PF ratio had a significant predictive accuracy for abnormal CXR findings (AUROC = 0.741, p < 0.01). Conclusions: The change in PF ratio (the Youden index point: ≤−23) had a sensitivity of 65.7%, and a specificity of 79.9%. Based on these results, the daily change in the PF ratio could be utilized as a predictive indicator of abnormal CXRs in ICU patients after MV treatment.

Highlights

Routine daily anterior–posterior chest X-ray (CXR) is a common practice for patients in intensive care units (ICUs) to monitor the improvement or deterioration of a disease, or to detect medical intervention-induced complications, especially in patients receiving mechanical ventilation (MV) [1]
This study evaluated the correlation between the daily change in the PF ratio and aggravating CXR changes in ICU patients after weaning from ventilator support and extubation
The Youden index cut-off for abnormal CXRs was a change in PF ratio ≤ −23

Summary

Introduction

Routine daily anterior–posterior chest X-ray (CXR) is a common practice for patients in intensive care units (ICUs) to monitor the improvement or deterioration of a disease, or to detect medical intervention-induced complications, especially in patients receiving mechanical ventilation (MV) [1]. A low PaO2 /FiO2 (PF ratio) at ICU admission has been associated with poor ICU patient outcomes, including higher ICU mortality and longer hospital stays [7,8]. It is difficult for intensivists to collectively accept the on-demand CXR strategy because of the ambiguous clinical criteria for conducting CXRs. This study evaluated the predictive value of the change in PaO2 /FiO2 (PF ratio) for abnormal CXR findings in ICU patients after mechanical ventilation (MV). Conclusions: The change in PF ratio (the Youden index point: ≤−23) had a sensitivity of 65.7%, and a specificity of 79.9% Based on these results, the daily change in the PF ratio could be utilized as a predictive indicator of abnormal CXRs in ICU patients after MV treatment

Methods

Results

Conclusion