Updated Hacor Score for Early Prediction of Noninvasive Ventilation Failure in Hypoxemic Respiratory Failure: A Prospective Observational Study

Background: Noninvasive ventilation (NIV) is widely used in acute hypoxemic respiratory failure to avoid endotracheal intubation and complications related to invasive mechanical ventilation. However, delayed recognition of NIV failure is associated with increased mortality. The HACOR score, comprising Heart rate, Acidosis, Consciousness, Oxygenation, and Respiratory rate, has been validated as a bedside tool for predicting NIV failure. Duan et al. subsequently developed the Updated HACOR score by incorporating baseline clinical variables including acute respiratory distress syndrome (ARDS), septic shock, immunosuppression, cardiogenic pulmonary edema, pneumonia, and Sequential Organ Failure Assessment (SOFA) score. Data evaluating its performance in Indian ICU settings remain limited.

Objectives: To evaluate the predictive ability of the Updated HACOR score for NIV failure in patients with hypoxemic respiratory failure and compare its performance with the original HACOR score.

Methods: A prospective observational study was conducted in the intensive care unit of a tertiary care teaching hospital between July 2023 and December 2024. Sixty-three adult patients with hypoxemic respiratory failure requiring NIV were enrolled. Baseline demographic and clinical data were recorded. Original and Updated HACOR scores were calculated at baseline, 1–2 hours, 12 hours, and 24 hours after NIV initiation. NIV failure was defined as the need for endotracheal intubation and invasive mechanical ventilation. Receiver operating characteristic (ROC) analysis was performed to assess predictive performance.

Results: The mean age of participants was 53.8±15 years and 61.9% were males. Septic shock was present in 36.5% and ARDS in 42.9% of patients. NIV failure occurred in 15.9%, 19.0%, 31.4%, and 2.9% of patients at baseline, 1–2 hours, 12 hours, and 24 hours respectively. At 1–2 hours, the Updated HACOR score demonstrated superior predictive ability compared with the Original HACOR score (AUC 0.904 vs 0.889). At 12 hours, predictive accuracy further improved (AUC 0.957 vs 0.862). A cutoff value of 15.5 for the Updated HACOR score yielded sensitivity of 91% and specificity of 86%.

Conclusion: The Updated HACOR score significantly improves early prediction of NIV failure compared with the Original HACOR score and may facilitate timely clinical decision-making in patients with hypoxemic respiratory failure.