A Retrospective Study of the Respiratory Rate Oxygenation and Respiratory Rate Oxygenation-Heart Rate Indexes in Predicting the Results of Conventional Oxygen Therapy in Patients with Acute Respiratory Failure.

BACKGROUND

Conventional oxygen therapy is a first-line treatment for acute respiratory failure, but accurately predicting which patients will require escalated respiratory support remains a critical clinical challenge.

OBJECTIVE

To explore the clinical significance of the respiratory rate oxygenation (ROX) and ROX-heart rate (ROX-HR) indexes in forecasting outcomes of standard oxygen therapy in patients with acute respiratory failure (ARF).

METHODS

This retrospective study analyzed 262 ARF patients admitted to the emergency department between June 2021 and May 2023. Patients were categorized into a Success group (n = 153) and a Failure group (n = 109) based on their response to standard oxygen therapy. ROX and ROX-HR indexes were compared between groups at baseline 0 h and 1 h, and we assessed the predictive efficacy by Receptor Operator Characteristic (ROC) curves, Area under the ROC curve (AUROC), and multivariable Logistic regression.

RESULTS

The Success group had significantly higher ROX and ROX-HR indexes at both 0 h and 1 h compared to the Failure group (all p < 0.001). At 0 h, the AUROC for the ROX-HR index outperformed the ROX index at 0.76 (95% CI 0.70-0.81), and 0.75 (95% CI 0.69-0.81) respectively. The ROX-HR-0 was found to be an independent predictor of successful response to oxygen therapy in a multivariate analysis (odds ratio [OR] = 0.48, 95% CI 0.27-0.86, p = 0.013).

CONCLUSIONS

The ROX and ROX-HR indexes were associated with the outcome of standard oxygen therapy in patients with ARF, with the ROX-HR index showing a good AUROC. Further validation in larger patient populations is warranted to confirm their utility as dynamic monitoring tools.