Assessment of the ROX index as a predictor of invasive ventilation in patients with community-acquired pneumonia

Abstract

Aims: Community-acquired pneumonia (CAP) is a significant cause of morbidity and mortality worldwide, particularly among elderly patients and those with comorbid conditions. CAP can lead to severe respiratory failure, often necessitating invasive mechanical ventilation (IMV). Early identification of patients at high risk for intubation is crucial for optimizing management and improving outcomes. The ROX index, which incorporates respiratory rate, oxygen saturation, and fraction of inspired oxygen, has emerged as a potential tool for predicting the need for IMV in patients with respiratory distress. This study aims to evaluate the effectiveness of the ROX index in predicting IMV in patients hospitalized with CAP. Methods: This retrospective cohort study included patients diagnosed with CAP who were admitted to a tertiary healthcare institution between January 1, 2019, and January 1, 2024. The ROX index was calculated at hospital admission using respiratory rate, oxygen saturation (SpO₂), and fraction of inspired oxygen (FiO₂). Severe pneumonia was defined as pneumonia severity index (PSI) class IV or V, and subgroup analyses were conducted for these patients to evaluate the diagnostic performance of the ROX index. The primary outcome was the requirement for IMV, and the predictive ability of the ROX index was evaluated. Results: A total of 416 patients were included, with 30 (7.2%) requiring invasive mechanical ventilation. The mean ROX index was significantly lower in the intubation group (14.4±4.5) compared to the non-intubation group (23.8±5.4) (p<0.001). A ROX index ≤18.7 was identified as the optimal cutoff for predicting IMV, with an AUROC of 0.908. Among patients with severe pneumonia, the ROX index demonstrated an AUROC of 0.831, indicating strong predictive performance in this subgroup. Conclusion: The ROX index is a valuable tool for predicting the need for invasive mechanical ventilation in patients with CAP, particularly in those with severe pneumonia, making it a useful tool for early risk stratification and clinical decision-making.

Keywords

• Critical care
• mechanical ventilation
• pneumonia

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