ROX Index for the Timing of Intubation in Nasal High Flow

"The thresholds of the ROX index for intubation are the following:~* After 2 hours of HFNC: ROX \<2.85.~* After 4 and 6 hours of HFNC: ROX \<3.47~* After 8, 10 and 12 hours of HFNC: ROX \<3.85 If the ROX index is between the abovementioned thresholds and 4.88, the NHF support will be also increased to the maximum tolerated flow (up to 60L/min) and FIO2 of 1 and subsequently titrated with the target SpO2. If the patient is already treated with to 60L/min) and FIO2 of 1 and no further increase could be done and the ROX index will be recalculated after 30 minutes of full NHF support. The ROX index will be recalculated in 30 minutes: 1) if the ΔROX is \<0 the patient will be intubated; 2) if the ΔROX is 0-0.5, the ΔROX will be reassessed in 20 minutes; and 3) if the ΔROX is \>0.5 the patient will not be intubated, NHF will be managed as protocolized and respiratory condition will be reassessed every two hours or at any new clinical deterioration."