The following is a summary of “Daily ROX index can predict transitioning to mechanical ventilation within the next 24 h in COVID-19 patients on HFNC,” published in the November 2023 issue of Emergency Medicine by Carvalho, et al.

High-flow nasal cannula (HFNC) has emerged as a valuable tool in preventing invasive ventilation in patients with COVID-19-associated hypoxemia. The respiratory rate-oxygenation (ROX) index has been recognized for predicting HFNC failure in COVID-19 pneumonia cases, especially during the initial hours of therapy. However, the clinical trajectory of patients in the intensive care unit (ICU) may undergo substantial changes in the early days of admission.

For a study, researchers sought to assess whether the ROX index, measured within the first four days of ICU admission, could reliably predict the subsequent need for invasive respiratory support within 24 hours.

The retrospective cross-sectional study analyzed a database comprising adult patients with COVID-19 pneumonia admitted to the ICU. Patients were monitored daily from ICU admission, and the ROX index was calculated during HFNC therapy. Receiver operating characteristics curves (ROCs) were utilized for predictive assessments.

About 249 patients were included, 48% eventually requiring mechanical ventilation (MV). The area under the ROC for the pooled 4-day ROX index values, predicting the transition from HFNC to MV within 24 hours, was 0.86 (95%CI 0.83 to 0.88, P < 0.001), with a cutoff point of 4.06.

In COVID-19 patients receiving high-flow nasal cannula, daily measurements of the ROX index within the first four days of ICU admission proved effective in predicting the transition to mechanical ventilation within the subsequent 24 hours.

Source: sciencedirect.com/science/article/abs/pii/S0735675723004631