High HACOR Score Predicts Non-invasive Ventilation Failure in COPD

Photo Credit: PatrikSlezak

Patient’s HACOR scores can help physicians determine the likelihood of NIV failure in a patient with COPD and how effective these predictions are.

Current guidelines recommend that healthcare professionals treating patients with chronic obstructive pulmonary disease (COPD) in respiratory failure should intervene using non-invasive ventilation (NIV). Although NIV decreases the use of intubation, NIV failure increases the probability of mortality. A prognostic tool that can be applied to determine the likelihood of NIV failure in a patient with COPD is the heart rate, acidosis, consciousness, oxygenation, and respiratory rate (HACOR) score.

To evaluate the effectiveness of HACOR score as a tool for predicting NIV failure, Raghuveer Singh, MD, and colleagues developed a hospital-based prospective observational study. The Journal of the Association of Physicians of India published the results.

Non-invasive Ventilation

The patients with COPD selected for participation in the study all experienced acute respiratory failure and all received NIV. The attending physician chose NIV as the appropriate course of treatment based on the following criteria: respiratory distress during rest, arterial blood pH at a reading of less than 7.40, partial pressure of arterial carbon dioxide (PaCO₂)  greater than 45 mm Hg, and partial pressure of arterial oxygen (PaO₂) less than 60 on oxygen support. The researchers used a face mask with bi-level positive airway pressure to execute NIV. They defined NIV failure as progression to the use of a mechanical ventilation device or death.

The researchers analyzed 100 patients with COPD on NIV in this study. Among these participants, the mean age was 65.34 years (SD 8.19). Researchers noted that age did not affect NIV outcome (p-value: 0.19). There were 81 male patients in the cohort with similar NIV outcomes noted among males and females. 89% of the cohort smoked and smoking status did not significantly influence NIV outcomes. The patients avoided invasive intubation in 87% of the cases due to effective NIV intervention. NIV failure occurred in 13% of the patient cohort.

HACOR Score

The patients observed in the study had their HACOR score assessed before NIV methods were applied and then at 1 to 2 hours after NIV application, 12 hours after application, and 24 hours after application. The median score for the testing before NIV, was three (interquartile: 2, 4). Seventeen patients in the cohort had a HACOR score of greater than or equal to five prior to NIV application. NIV failure in patients with a HACOR score of  greater than or equal to five at the start of NIV had a higher rate. Furthermore, the area under the curve (AUC) had the highest for the HACOR score at the time of NIV application. The researchers determined that the sensitivity of the HACOR score is greatest at the application of NIV and lowest at 24 hours post-application. Of the 100 participants in the study, seven died during their hospitalization. Out of these seven deaths, six patients had a HACOR score greater than five at the application of NIV.

Dr. Singh and colleagues shared the applicability of their findings in the article sharing the details of the study, “Obtaining the HACOR score at bedside makes it convenient for assessing the efficacy of NIV in patients with COPD.” They also said,  “In high-risk patients identified by a HACOR score of greater than or equal to five, assessed at the initiation of treatment, elective and early intubation will result in increased hospital mortality.”