Low TT4 as a predictor of poor outcomes in severe encephalitis: a multivariate analysis of 94 patients

Abstract

Background: To investigate the prognostic value of acute thyroid function in patients with severe encephalitis.

Methods: We retrospectively analyzed information from patients with severe encephalitis from June 2012 to June 2017. Using multivariate logistic regression analysis, we examined predictors of poor outcomes in these patients after 6 months.

Results: A total of 94 patients with severe encephalitis were included in the study. Univariate analysis showed that patients with good or poor outcomes had significantly different total thyroxine (TT4) (P = 0.012) and free triiodothyronine (FT3) (P = 0.049) levels, mechanical ventilation requirements (P < 0.001), pulmonary infection complications (P = 0.001), lengths of neurological intensive care unit (P = 0.003) and total hospital (P = 0.012) stay, and Acute Physiology and Chronic Health Evaluation (APACHE II) (P = 0.005) and Glasgow Coma Scale (GCS) (P = 0) scores. The results of multivariate analysis suggested the following factors to be associated with a poor outcome: a low TT4 level (OR 0.303, 95% CI 0.100-0.923) and a low GCS score (OR 0.683, 95% CI 0.506-0.923).

Conclusions: Low TT4 has a predictive value for the adverse outcomes of severe encephalitis; further study is needed for verification.

Keywords: Encephalitis; neurological intensive care unit; outcome; predictor; total thyroxine.