Summary
ROX index for predicting early intubation in patients with COVID-19 treated with low-flow oxygen
Affiliation of the authors
DOI
Quote
Monroy Hernández JE, Sosa Jurado F, Ortega Rosado C. ROX index for predicting early intubation in patients with COVID-19 treated with low-flow oxygen. Rev Esp Urg Emerg. 2024;3:221–4
Summary
OBJECTIVE. To determine a cut point for the ROX index (ratio of peripheral oxygen saturation to the fraction of inspired oxygen) as a predictor of early intubation in patients with COVID-19 in treatment with a low-flow oxygen oxygen system.
METHODS. Retrospective case-control study of patients hospitalized for SARS-CoV-2 requiring treatment with low-flow oxygen. Case patients were those who later required intubation; control patients were those who did not. We collected demographic and clinical data, including blood gas variables for calculating the ROX index. Descriptive and inferential statistics were also calculated. The ROX index cut point at 6 hours of low-flow oxygen supplementation was determined by Youden’s J statistic on the receiver operating characteristic (ROC) curve.
RESULTS. Of 192 patients reviewed, 144 (62 cases and 82 controls) met the inclusion criteria. A ROX index cut point of 5.71 was selected. At that point, sensitivity was 84% (95% CI, 73.2-92.5) and specificity was 90.3% (95% CI, 81.6-95.6). The positive and negative predictive values, respectively, were 78% (95% CI, 68%-87%) and 97% (95% CI, 89%-99%). The area under the ROC was 0.94 (95% CI, 0.90-0.97) for predicting that a patient on low-flow oxygen would come to need more advanced airway management.
CONCLUSIONS. The ROX index proved to be a useful tool for predicting progression to advanced airway management in patients with SARS-CoV-2 treated with low-flow oxygen. The cut point of 5.71 was higher than the established point for switching to highflow
nasal cannula systems.