The clinical relevance of the COVID-19-associated hyperinflammatory syndrome score in the ICU: A single-center retrospective observational study

Objectives The COVID-19-associated hyperinflammatory syndrome (cHIS) score has been proposed as a tool for identifying patients at risk of clinical deterioration. This study evaluated the predictive accuracy of the admission cHIS score for invasive mechanical ventilation and ICU mortality in critically ill COVID-19 patients. Methods We conducted a single-center retrospective observational study including 85 adults with laboratory-confirmed COVID-19 who were admitted to the ICU. The cHIS score was calculated on admission, and patients were stratified into two groups (<3 and ≥3). Associations with mechanical ventilation and ICU mortality were examined using ROC curve analysis and multivariable logistic regression, adjusted for age and comorbidity burden. Results An admission cHIS score ≥3 demonstrated moderate discrimination for ICU mortality (AUROC = 0.70; sensitivity = 0.76; specificity = 0.66) and mechanical ventilation (AUROC = 0.71; sensitivity = 0.73; specificity = 0.65). Higher cHIS scores were significantly associated with both outcomes in unadjusted analyses. After adjustment, the associations were attenuated and became borderline for mortality and mechanical ventilation, suggesting potential confounding by age and underlying comorbidities. Key inflammatory markers within the cHIS score—CRP, LDH, and D-dimer—showed the strongest individual associations with adverse outcomes. Kaplan–Meier analysis demonstrated significantly reduced survival probabilities in patients with cHIS ≥3. Conclusion The admission cHIS score reflects the degree of systemic hyperinflammation and is associated with greater illness severity, ICU mortality, and the need for mechanical ventilation. Although its predictive value diminishes after adjusting for age and comorbidities, the score remains a useful adjunct for early risk stratification in critically ill COVID-19 patients. Larger multicenter studies are needed to determine its independent prognostic utility.