ABSTRACT
Background: The aim of this study was to measure serum brain injury biomarkers in patients with COVID-19 admitted to intensive care unit (ICU), without evidence of brain impairment, and to determine potential correlations with systemic inflammatory markers, illness severity, and outcome. Methods: In patients admitted to the ICU with COVID-19, without clinical evidence of brain injury, blood S100 calcium-binding protein B (S100B), neuron-specific enolase (NSE) and interleukin-6 (IL-6) were measured on admission. Clinical, routine laboratory data and illness severity were recorded. Comparisons between 28-day survivors and non-survivors and correlations of neurological biomarkers to other laboratory data and illness severity, were analyzed. Results: We included 50 patients, median age 64 [IQR 58-78] years, 39 (78%) males, 39 (78%) mechanically ventilated and 11 (22%) under high flow nasal oxygen treatment. S100B and NSE were increased in 19 (38%) and 45 (90%) patients, respectively. S100B was significantly elevated in non-survivors compared to survivors: 0.15 [0.10-0.29] versus 0.11 [0.07-0.17] µg/L, respectively, (p = 0.03), and significantly correlated with age, IL-6, arterial lactate, noradrenaline dose, illness severity and lymphocyte count. IL-6 was significantly correlated with C-reactive protein, noradrenaline dose and organ failure severity. NSE was correlated only with lactate dehydrogenase. Conclusion: Brain injury biomarkers were frequently elevated in COVID-19 ICU patients, in the absence of clinical evidence of brain injury. S100B was significantly correlated with IL-6, low lymphocyte count, hypoperfusion indices, illness severity, and short-term outcome. These findings indicate a possible brain astrocytes and neurons involvement, also suggesting a broader role of S100B in systemic inflammatory response.
ABSTRACT
BACKGROUND: Although older adults are at high risk for severe coronavirus disease 2019 (COVID-19) requiring intensive care unit (ICU) admission, age is often used as a selection criterion in case of ICU beds scarcity. We sought to compare the proportion, clinical features and mortality between patients ≥70 years old and younger ICU patients with COVID-19. METHODS: All patients, consecutively admitted to our COVID ICU, where age was not used as an admission criterion, from March 2020 through April 2021, were included. Demographics, clinical and laboratory characteristics were recorded. Illness severity and Charlson comorbidity Index (CCI) were calculated. Patients≥70 years old were compared to youngers. RESULTS: Of 458 patients (68 [59-76] years, 70% males), 206 (45%) were ≥70 years old. Compared to younger, older patients had higher illness severity scores (APACHE II 18 [14-23] versus 12 [9-16], P<0.001, SOFA 8 [6-10] versus 6 [2-8], P<0.001, CCI 5 [4-6] versus 2 [1-3], P<0.001), increased need for mechanical ventilation (92% vs. 72%, P<0.001) and ICU mortality (74% versus. 29%, P<0.001). Age (HR: 1.045, CI: 1.02-1.07, P=0.001), CCI (HR: 1.135, CI: 1.037-1.243, P=0.006) and APACHE II (HR: 1.070, CI: 1.013-1.130, P=0.015) were independently associated with mortality. Among comorbidities, obesity, chronic pulmonary disease and chronic kidney disease were independent risk factors for death. CONCLUSIONS: When age is not used as criterion for admission to COVID ICU, patients ≥70 years old represent a considerable proportion and, compared to younger ones, they have higher mortality. Age, severity of illness and CCI, and certain comorbidities are independent risk factors for mortality.