Spectrum and Outcome of Acute Infectious Encephalitis/encephalopathy in an Intensive Care Unit from India

Purpose: To evaluate the spectrum of acute infectious encephalitis/encephalopathy syndrome (AIES) in intensive care unit (ICU) and the predictors of mechanical ventilation (MV) and outcome of these patients.

Methods: AIES patients diagnosed on the basis of fever, altered sensorium, seizure and cerebrospinal fluid pleocytosis admitted to the neurology ICU were prospectively included. The demographic and clinical details, hematological, biochemical, MRI and etiological findings of the patients were noted. Need of MV, death in hospital and 3-month functional outcome were analyzed.

Results: One hundred sixty-four out of 258 (64%) AIES patients needed ICU admission. Their median age was 35 (2-85) years and 71 (43%) were females. The etiology was viral in 44 (herpes and Japanese encephalitis in 12 each, dengue in 17, mumps, measles and varicella in 1 patient each), non-viral in 64 (scrub typhus in 48, falciparum malaria in 6, leptospira in 3 and bacterial in 7) and undetermined etiology in 56 (34%) patients. Sixty-nine (42%) patients needed MV. On multivariate analysis, Glasgow Coma Scale (GCS) score, Sequential Organ Failure Assessment (SOFA) score and raised intracranial pressure were independent predictors of MV. Forty-three (26%) patients died, and all were in the MV group. Higher SOFA score and untreatable etiology were independent predictors of mortality. At 3-month follow-up, 14% had poor and 86% had good outcome. Low GCS score, focal weakness and status epilepticus independently predicted poor outcome.

Conclusion: Twenty-six percent patients with AIES died in ICU, and 86% had good recovery at 3 months. Admission SOFA scores and untreatable etiology predicted mortality.