Evaluation of Diagnostic Accuracy of HACOR Score in Predicting the Success Rate of CPAP in Patients with COVID-19-Induced Hypoxemia

 In coronavirus disease 2019 (COVID-19)-associated hypoxemic acute respiratory failure (ARF) may require continuous positive airway pressure (CPAP), and having an appropriate criterion for early diagnosis and prediction of CPAP failure or success can significantly reduce the mortality of these patients.

 This study was conducted to evaluate the diagnostic accuracy of heart rate, acidosis, consciousness, oxygenation, and respiratory rate (HACOR) score in predicting the success rate of CPAP in patients with COVID-19 induced hypoxemia.

 This retrospective cross-sectional study was conducted on 200 adult patients aged 63.23 ± 16.23 years with mild to moderate acute respiratory failure (COVID-19), partial pressure of oxygen in arterial blood (PaO2) < 300 mmHg, and partial pressure of carbon dioxide in arterial blood (PaCO2) < 45 mmHg from March 21 to November 21, 2021. The patients were admitted to the respiratory intensive care unit (RICU) of Khatam Al-Anbia (PBUH) Hospital in Shoushtar (southwestern Iran) and were subjected to CPAP for respiratory support. The HACOR score was calculated one hour after the CPAP onset. Data were analyzed by SPSS software (version 22) using Kolmogorov-Smirnov, t-test, pair t-tests, receiver operating characteristic (ROC) curve, sensitivity, specificity, and predictive value indices were used to determine the diagnostic performance of the method. The significance level was set at P ≤ 0.05.

 The mean HACOR score one hour after the onset of CPAP was 3.50 ± 1.57 (P < 0.001), with a mean of 153.84 ± 27.42 mmHg PaO2/fraction of inspired oxygen (FiO2) ratio (P < 0.001). The cut-off point for the HACOR score one hour after CPAP was 5, which had a sensitivity of 98.06% (94.45% - 99.60%) and a specificity of 83.33% (68.64% - 93.03%). Out of 200 patients, 157 patients (78.5%) had CPAP failure, and 43 patients (21.5%) underwent treatment. The diagnostic accuracy values of the HACOR score and PaO2/FiO2 ratio for predicting CPAP failure were 94.92% and 95.96%, respectively.

 Our findings support that although the HACOR score had a good diagnostic performance in predicting the success rate of CPAP in patients with COVID-19-induced hypoxemia, PaO2/FiO2 ratio was also shown to be a good predictor of success.