rox_index_score: ROX Index for Intubation Risk after HFNC

In cliot: Clinical Indices and Outcomes Tools

ROX Index for Intubation Risk after HFNC

Description

Calculates the ROX Index (Respiratory rate-Oxygenation) to predict the success or failure of High-Flow Nasal Cannula (HFNC) therapy in patients with acute hypoxemic respiratory failure. The index is defined as the ratio of SpO2/FiO2 to Respiratory Rate. A lower score (< 2.85 to 4.88) indicates a higher risk of HFNC failure and the need for intubation.

Usage

rox_index_score(spo2_percent, fio2_percent, respiratory_rate)

Arguments

spo2_percent	Numeric. Oxygen saturation percentage (0-100).
fio2_percent	Numeric. Fraction of Inspired Oxygen (can be entered as percent 21-100 or decimal 0.21-1.0).
respiratory_rate	Numeric. Respiratory rate in breaths per minute.

Value

A list containing:

ROX_Index	The calculated index value.
Interpretation	Clinical interpretation based on risk thresholds (e.g., < 2.85, < 3.85, < 4.88, >= 4.88).

References

Roca O, Messika J, Caralt B, et al. Predicting success of high-flow nasal cannula in pneumonia patients with hypoxemic respiratory failure: The utility of the ROX index. J Crit Care. 2016;35:200-205. doi:10.1016/j.jcrc.2016.05.022 Roca O, Caralt B, Messika J, et al. An Index Combining Respiratory Rate and Oxygenation to Predict Outcome of Nasal High-Flow Therapy. Am J Respir Crit Care Med. 2019;199(11):1368-1376.

Examples

# Example 1: High Risk of Failure
# SpO2 88%, FiO2 1.0 (100%), RR 35
# Ratio = 88 / 1.0 = 88. Index = 88 / 35 = 2.51
rox_index_score(88, 100, 35)

# Example 2: Success Likely
# SpO2 95%, FiO2 0.4 (40%), RR 20
# Ratio = 95 / 0.4 = 237.5. Index = 237.5 / 20 = 11.88
rox_index_score(95, 40, 20)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.