Prognostic Nutritional Index (PNI) in patients with severe encephalitis as a useful prognostic indicator:a multivariate analysis

Abstract Background The prognostic impact of poor nutritional status in severe encephalitis is not clearly understood. We aim to investigate the relationship between the prognostic nutritional index (PNI) and poor outcomes of severe encephalitis. Method We conducted a retrospective study involving patients with severe encephalitis to determine whether the nutritional and inflammatory biomarker is linearly related to the prognosis of encephalitis. The PNI was calculated as follows: 10×serum albumin (g/L) + 5×total lymphocyte count (109/L). The PNI scores were analyzed as continuous variables and categorical variables divided by quartiles from top to bottom. Restricted cubic splines and logistic regression were applied. Result In this study, 307 patients were enrolled. We found that the advanced age(＜0.001), respiratory failure(＜0.001), status epilepticus(＜0.001) and GCS<8(＜0.001) were significantly higher in the poor-prognosis group. The relationship between PNI score and poor prognosis of severe encephalitis was linear. According to a logistic regression model, a lower PNI score had a poorer prognosis for encephalitis. [per 1-point decrement; adjusted OR=1.10; 95% CI, 1.05-1.14; compared with Quartile 1 (PNI ≥ 50.36), Quartile 4 (PNI < 40.15), unadjusted OR =3.60, 95% CI:1.67-7.74; and adjusted OR=3.33, 95% CI:1.46-7.62 ] Conclusion According to our study, lower PNI score was correlated with poorer outcome in severe encephalitis patients. It suggested that PNI is a useful prognostic indicator in patients with severe encephalitis.