ABSTRACT
Introduction: APACHE II severity scoring system has been successfully used for mortality risk assessment in the ICU, however its validity in the subgroup of COVID-19 patients has been questionable. We aimed to examine the predictive value of APACHE II score in a cohort of critically ill COVID-19 patients. Method(s): We performed a retrospective analysis of prospectively collected data in a cohort of COVID-19 patients admitted to our 50-bed ICU between October 2020 and April 2022. Using a ROC analysis we assessed the performance of APACHE II score and identified the optimal cut-off value for mortality prediction. Result(s): Our cohort included 783 patients (66% male) with positive PCR forSARS-Cov-2 and respiratory failure. Mean age was 66 years. Invasive mechanical ventilation was used in 92%of patients and 89.3% had at least one comorbidity. The mean APACHE II score of the whole cohort was 20.3 (+/- 8.5). ICU mortality was 44.7%. Death rate was similar between sexes but significantly higher in those who were older and those suffering from COPD, chronic renal or heart failure, atrial fibrillation or any kind of malignancy. Non-survivors had a significantly higher APACHE II score compared to survivors (25.2 +/- 7.9 vs 16.3 +/- 6.7, p < 0.001). ROC analysis showed an AUC 0.81 (95% CI 0.78-0.84, p < 0.001). At a cut-off value of 19.5 APACHE II score could predict death with a sensitivity of 77.1% (95% CI 72.4-81.4%), a specificity of 70.7% (95% CI 66.1-74.9%), PPV 68% (95% CI 63.2-72.6%) and NPV 79.3% (95% CI 74.9-83.2%). Conclusion(s): APACHE II score is an effective tool for mortality prediction in critically ill COVID-19 patients. A cut-off value of 19.5 can be used for risk stratification in this patient population.