ROX index

Q: What is ROX index?

Answer: (SpO2/FiO2)/RR

ROX Index predicts the Risk of intubation, particularly in patients who are not tachypneic but may require higher oxygen demand such as High Flow Nasal Cannula (HFNC).The ROX index is calculated as 

(peripheral arterial oxygen saturation/fraction of inspired oxygen [expressed as a percentage]/respiratory rate) 

A ROX index of >4.88 at 2, 6, and 12 hours post-initiation of HFNC indicated a less likely need for endotracheal intubation. 

The ROX index may be very useful in patients who gets admitted to ICU with impending respiratory failure. It's best utility lies where it is combined with overall clinical picture.

#pulmonary

#ventilators

References:

1. Li A, Cove ME, Phua J, et al. Expanding the utility of the ROX index among patients with acute hypoxemic respiratory failure. PLoS One 2022; 17:e0261234.

2. Junhai Z, Jing Y, Beibei C, Li L. The value of ROX index in predicting the outcome of high flow nasal cannula: a systematic review and meta-analysis. Respir Res 2022; 23:33.

3. Zhou X, Liu J, Pan J, et al. The ROX index as a predictor of high-flow nasal cannula outcome in pneumonia patients with acute hypoxemic respiratory failure: a systematic review and meta-analysis. BMC Pulm Med 2022; 22:121.