Incidence and impact of respiratory tract infections on outcomes in patients with status epilepticus: A 20-year longitudinal observation.

OBJECTIVE: This study was undertaken to identify the incidence of respiratory tract infections (RTIs) in a large cohort of adult patients with status epilepticus (SE) and to characterize their associations with clinical features and outcome determinants. METHODS: This was a retrospective observational study in the intensive care unit (ICU) at the University Hospital of Basel, Switzerland from 2005-2024. All adult patients treated for SE at the ICU were included. We recorded the incidence of RTI diagnosed during or 48 h after SE termination and clinical characteristics. Outcome characteristics potentially complicated by RTI (i.e., SE duration, hospital stay, survival with return to premorbid neurological function at hospital discharge, and mortality) were secondary objectives. RESULTS: Among 818 patients (median age = 68 years, 49% female), 34.2% required mechanical ventilation. RTIs were diagnosed in 12.0% (98/818), rising to 34.3% (96/280) among ventilated patients, with 21.4% (21/98) meeting ventilator-associated pneumonia criteria. Characteristics associated with subsequent RTI included nonconvulsive SE (NCSE) with coma, unconsciousness at onset, and early intubation (odds ratio [OR] = 1.8-2.6); 53.4% (31/58) of patients with all three features developed RTIs. Patients with RTI had higher maximal median markers of inflammation (C-reactive protein with RTI 81 mg/L vs. without RTI 23 mg/L, p < .001; leukocytes with RTI 11 × 109/L vs. leukocytes without RTI 10 × 109/L, p = .002). After adjusting for age, etiology, and SE severity, RTI remained associated with an 8.44-day increase in SE duration (95% confidence interval [CI] = 5.31-11.56), a 54% reduced likelihood of full neurologic recovery (OR = .46; 95% CI = .26-.81), and more than double the risk of in-hospital mortality (OR = 2.12, 95% CI = 1.13-4.00). SIGNIFICANCE: RTIs affect more than one third of mechanically ventilated patients with SE and approximately every second intubated patient with NCSE and coma. RTIs were associated with coma, early intubation, higher mortality, and longer SE duration. Prospective studies are needed to clarify the direction of these associations and whether preventing RTIs improves outcomes.