Admission Acute Brain Dysfunction and In-ICU Mortality in a Single-Center Pre-Vaccination Romanian COVID-19 Cohort:A Retrospective Observational Analysis.

BACKGROUND: Critically ill COVID-19 patients frequently develop organ dysfunction and acute brain dysfunction with features overlapping sepsis-associated encephalopathy (SAE). Real-world cohorts from Eastern European intensive care during the pre-vaccination period are scarce. METHODS: We retrospectively analysed 389 consecutive adults with RT-PCR-confirmed SARS-CoV-2 admitted to a single regional Romanian tertiary ICU during 2020-2021, entirely preceding population-level vaccination. Organ dysfunction was defined as admission SOFA≥2, and acute brain dysfunction was op-erationalised from admission Glasgow Coma Scale and neurological SOFA (the acute brain dysfunction [ABD] proxy). Associations with in-ICU mortality were examined descriptively, with pre-specified sensitivity analyses restricted to non-ventilated pa-tients to address sedation confounding. RESULTS: In-ICU mortality was 65.8%. The ABD proxy was present in 49.6% of the cohort; mortality was 96.9% in ABD-proxy-positive patients versus 45.9% in those with preserved consciousness, an absolute difference of 51.0 percentage points, which was of similar magnitude (49.4 points) in non-ventilated patients, arguing against sedation as the sole explanation. Higher inflammatory markers accompanied the ABD proxy, and the association between admission acute brain dys-function and mortality was consistent across analyses. CONCLUSIONS: Admission acute brain dysfunction was strongly associated with in-ICU mortality, and this association persisted in non-ventilated patients. The findings are descriptive associations within an extreme, single-center pre-vaccination cohort under surge conditions; they are not causal, and should not be generalised to vaccinated or contemporary critical care.