HACOR Score for NIV Failure Risk
Heart rate, Acidosis, Consciousness, Oxygenation, and Respiratory rate (HACOR) score predicts the risk of non-invasive ventilation (NIV) failure and need for intubation in patients with acute respiratory failure. Assessed at 1-2 hours after NIV initiation. Score above 5 predicts NIV failure with 72% sensitivity and 89% specificity. Validated by Liu et al. 2017 in 449 patients.
Score interpretation
HACOR at or below 5 -- NIV likely to succeed; continue and reassess
→ Continue NIV; re-assess HACOR at 1-2 hours and 4-6 hours; optimise NIV settings (increase IPAP/EPAP if inadequate oxygenation/ventilation); ensure patient-ventilator synchrony; document ABG trends; if patient improving: wean NIV gradually; ensure backup plan for intubation available (anaesthetic team aware); nursing-to-patient ratio appropriate for NIV; monitor for mask intolerance and skin pressure injury.
HACOR 6-9 -- moderate NIV failure risk; close monitoring and early intubation plan
→ Reassess in 30-60 minutes; discuss with senior clinician (SpR or Consultant); anaesthetic pre-assessment for intubation (anticipate difficult airway if obese/OSA); optimise NIV: check mask seal, adjust IPAP up to 20-24 cmH2O, EPAP 5-8 cmH2O, FiO2 to keep SpO2 above 94%; treat underlying cause urgently (antibiotics if infection, diuresis if fluid overload); if not improving: early intubation plan -- safer to intubate controlled vs emergency; escalate to ICU if deteriorating.
HACOR above 9 -- high NIV failure risk; early intubation strongly recommended
→ Urgent anaesthetic/intensivist review; intubation and mechanical ventilation should be planned immediately (unless patient has DNAR/CEILING of treatment); pre-oxygenate with BVM; RSI drugs ready; difficult airway anticipated -- videolaryngoscope preferred; ICU admission for invasive mechanical ventilation; if patient has advance directive refusing intubation: palliative symptom management (opioids, benzodiazepines for dyspnoea); if HFNC trialled: monitor ROX index (HACOR and ROX complementary tools); document decision clearly including ceiling of treatment discussion.
Interpretation bands for the HACOR Score. Apply clinical judgement and local guidance.
References
- Liu J et al. Early predictors of noninvasive ventilation failure in patients with severe community-acquired pneumonia. Respir Care. 2017;62(10):1271-1279.
- Scala R, Pisani L. Noninvasive ventilation in acute respiratory failure: which recipe for success? Eur Respir Rev. 2018;27(149):180029.
Related
Curated clinical cross-links plus same-class fallbacks.
- Dobutamine (Acute HF / Stress Echo) · Inotrope / Acute Heart Failure
- Milrinone · Inodilator / Acute Heart Failure
- Mannitol (Osmotic Diuretic — Renal/Neurological) · Acute Oliguric Renal Failure / Raised ICP
- Doxapram hydrochloride · Respiratory stimulant
- Glyceryl Trinitrate (Sublingual / IV) · Nitrate / Acute Angina
- Vericiguat · 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.