Mortality and Neurologic Sequelae in Influenza-Associated Encephalopathy: Retrospective Multicenter PICU Cohort in France.

OBJECTIVES To describe and estimate the mortality rate of severe influenza-associated encephalopathy/encephalitis among children admitted to PICUs. DESIGN Multicenter retrospective study. SETTING Twelve French PICUs. PATIENTS All children admitted for influenza-associated encephalopathy/encephalitis between 2010 and 2018 with no severe preexisting chronic neurologic disorders and no coinfection potentially responsible for the disease. INTERVENTION None. MEASUREMENTS AND MAIN RESULTS We collected the clinical presentation; laboratory, electroencephalographic, and MRI findings; and treatments used in the PICU. The primary outcome was mortality. The secondary outcomes included sequelae at discharge and last follow-up. We included 41 patients with a median (interquartile range) age of 4.7 years (2.5-8.2 yr). The main reasons for admission were altered consciousness (59%) and status epilepticus (34%); 48% of patients had meningitis, and one third had acute necrotizing encephalopathy on MRI. Mechanical ventilation was required in 73% of patients and hemodynamic support in 24%. The use of specific treatments was variable; steroids were given to 49% of patients. Seven patients (17%) died in the PICU. Median (interquartile range) PICU stay length was 7 days (2-13 d), and total hospital length of stay was 23 days (7-33 d). On hospital discharge, 49% (n = 20) had neurologic sequelae, with 27% (n = 11) having severe disabilities defined by modified Rankin Score greater than or equal to 4. CONCLUSIONS Children requiring PICU admission for influenza-associated encephalopathy/encephalitis have high mortality and morbidity rates. The management remains highly variable due to the lack of guidelines.