Common biomarkers of physiologic stress and associations with delirium in patients with intracerebral hemorrhage.

PURPOSE:To examine associations between physiologic stress and delirium in the setting of a direct neurologic injury. MATERIALS AND METHODS:We obtained initial neutrophil-to-lymphocyte ratio (NLR), glucose, and troponin in consecutive non-comatose patients with non-traumatic intracerebral hemorrhage (ICH) over 1 year, then used multivariable regression models to determine associations between each biomarker and incident delirium. Delirium diagnoses were established using DSM-5-based methods, with exploratory analyses further categorizing delirium as first occurring <24 h ("early-onset") or > 24 h after presentation ("later-onset"). RESULTS:Of 284 patients, delirium occurred in 55% (early-onset: 39% [n = 111]; later-onset: 16% [n = 46]). Patients with delirium had higher NLR (mean 9.0 ± 10.4 vs. 6.4 ± 5.5; p = 0.01), glucose (mean 146.5 ± 59.6 vs. 129.9 ± 41.4 mg/dL; p = 0.008), and a higher frequency of elevated troponin (>0.05 ng/mL; 21% vs. 10%, p = 0.02). In adjusted models, elevated NLR (highest quartile: OR 3.4 [95% CI 1.5-7.8]), glucose (>180 mg/dL: OR 3.1 [95% CI 1.1-8.2]), and troponin (OR 3.0 [95% CI 1.2-7.2]) were each associated with delirium, but only initial NLR was specifically associated with later-onset delirium and with delirium in non-mechanically ventilated patients. CONCLUSIONS:Stress-related biomarkers corresponding to multiple organ systems are associated with ICH-related delirium. Early NLR elevation may also predict delayed-onset delirium, potentially implicating systemic inflammation as a contributory delirium mechanism.