ROX Index for Intubation after HFNC
Predicts failure of high-flow nasal cannula (HFNC) in patients with acute hypoxaemic respiratory failure. ROX <3.85 at 12h predicts HFNC failure and need for intubation.
Score interpretation
ROX <2.85 — very high risk of HFNC failure
→ Prepare for intubation; call anaesthesia/ICU urgently; optimise NIV bridge if time permits
ROX 2.85–3.84 — high risk of HFNC failure
→ Reassess within 2 hours; escalation likely; ICU senior review required
ROX 3.85–4.87 — intermediate risk; monitor closely
→ Continue HFNC; reassess every 2 hours; no safe prediction of success or failure at this range
ROX ≥4.88 — HFNC likely to succeed
→ Continue HFNC; standard monitoring; reassess at 2h, 6h, 12h post-initiation
Interpretation bands for the ROX Index. Apply clinical judgement and local guidance.
References
- Roca O 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.
Related
Curated clinical cross-links plus same-class fallbacks.
- Hydroxocobalamin (High-Dose — Cyanide Antidote) · Cyanide Antidote (Vitamin B12 Precursor at High Dose)
- Doxapram hydrochloride · Respiratory stimulant
- Dobutamine (Acute HF / Stress Echo) · Inotrope / Acute Heart Failure
- Milrinone · Inodilator / Acute Heart Failure
- Vericiguat · Heart Failure
- Ferric Carboxymaltose · Heart Failure
- Acute Asthma in Adults · BTS/SIGN British Guideline on Asthma 2019; NICE NG80
- Pulmonary Embolism Assessment · NICE NG158; ESC 2019 PE Guidelines
- Acute Exacerbation of COPD (AECOPD) · NICE NG115; GOLD 2024
- Spontaneous Pneumothorax (Adult) · BTS Pleural Disease 2023
- Atypical Pneumonia (Legionella / Mycoplasma / Chlamydophila) · BTS 2023; IDSA
- COPD Exacerbation Management · NICE NG115 / GOLD 2024
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.