Association of cerebral tissue oxygenation status and systemic inflammatory markers with delirium in mechanically ventilated intensive care unit patients

BACKGROUNDDelirium is a frequent complication among mechanically ventilated patients in the intensive care unit (ICU) and is associated with adverse clinical outcomes.Early cerebral hypoxia and systemic inflammation may contribute to its development; however, the relationships between regional cerebral oxygen saturation (rSO 2 ), routinely available inflammatory markers, and subsequent delirium in emergency ICU patients remain insufficiently characterized. AIMTo explore whether early rSO₂ and routinely available systemic inflammatory markers measured within the first 6 hours after initiation of invasive mechanical ventilation are associated with subsequent incident delirium in emergency ICU patients.This study was intended to identify exploratory associations rather than to develop a validated delirium prediction tool. METHODSThis single-center retrospective cohort study used routine-care records from a 20-bed emergency ICU at The First Affiliated Hospital of Anhui Medical University, Hefei, China, from June 1, 2025 to May 31, 2026.Consecutively screened adults receiving invasive mechanical ventilation were eligible.Baseline rSO₂ and laboratory markers were defined within the first 6 hours after ventilation initiation and before any positive Confusion Assessment Method for the ICU (CAM-ICU) assessment.CAM-ICU was scheduled twice daily and was performed when the Richmond Agitation-Sedation Scale (RASS) was ≥ -3; assessments were deferred when RASS was -4 or -5.Of 118 screened patients, 80 complete cases were analyzed (31 with incident delirium and 49 with no documented delirium during ICU observation), and every included patient had at least Key Words: Mechanical ventilation; Emergency intensive care unit; Delirium; regional cerebral oxygen saturation; Systemic inflammatory markers; Neutrophil-to-lymphocyte ratio Liang PP, Yang M. Association of cerebral tissue oxygenation status and systemic inflammatory markers with delirium in mechanically ventilated intensive care unit patients.