ROX Index Management Guidelines for HFNC
Background information:
• Ratio of oxygen saturation as measured by pulse oximetry, FIO2, and respiratory rate
• Formula:
spO2/RR x FiO2
Predictors of HFNC success include:
• ROX ≥4.88 at 2, 6 and 12 hours after HFNC initiation was associated with a lower risk for intubation
Predictors of HFNC failure include:
• ROX <2.85 at 2 hours
• ROX <3.47 at 6 hours
• ROX <3.85 at 12 hours
Management Guidelines:
Upon Initiation of HFNC a ROX Index should be measured at:
• 2 hours
• 6 hours
• 12 hours
• If any of the measured values are below those listed above this triggers an automatic ICU consultation
Thereafter a ROX Index should be measured:
• Every 12 hours
• PRN if there is a change in the patient’s respiratory status concerning for the need of intubation
Note: ROX score <3.85 is 100% predictive of failure at 12 hours for HFNC. This requires an automatic ICU consultation
Note: ROX Scores between 3.85 and 4.88 at 12hrs and thereafter requires clinical judgement and an automatic ICU consultation
References:
Roca: Am J Respir Crit Care Med. 2019;199(11):1368-1376
Intensive Care Med (2020) 46:2238–2247
