Accuracy of serum S-100β protein and neuron specific enolase level in prediction of postoperative delirium in different age patients

Abstract

Objective To investigate the accuracy of serum S-100β protein and neuron specific enolase (NSE) level in predication of postoperative delirium (PD) in patients of different ages.Methods Four hundred ASA Ⅰ -Ⅳ patients of both sexes weighing 40-82 kg undergoing abdominal surgery performed under general anesthesia were divided into 4 age groups:group Ⅰ 18-44 yr; group Ⅱ 45-59 yr; group Ⅲ 60-74 yr and group Ⅳ ≥75 yr.The diagnosis of PD was made by using confusion assessment method.The incidence of PD was recorded within 72 h after operation.Each group was further divided into PD and non-PD subgroups.Blood samples were taken at 1 day before operation (T1),during their stay in PACU (T2) and at 24 and 72 h after operation (T3,4 ) for determination of serum S-100β protein and NSE concentrations.The receiver operating characteristic (ROC) curve for serum S-100β protein concentration in determining the PD efficacy was plotted.Results The incidence of PD was significantly higher and the duration was significantly longer in groups Ⅲ and Ⅳ than in groups Ⅰ and Ⅱ,and in group Ⅳ than in group Ⅲ (P ＜ 0.05).There was no significant difference in the serum S-100β protein concentration between PD subgroup and non-PD subgroup in groups Ⅰ - Ⅲ ( P ＞ 0.05).Compared with that at T1 and in nonPD subgroup,the serum S-100β protein concentration was significantly increased in PD subgroup in group Ⅳ,and the serum NSE concentration was significantly decreased at T2,3 in PD subgroup in group Ⅰ (P ＜ 0.05).There was no significant difference in the serum NSE concentration between PD subgroup and non-PD subgroup in groups Ⅱ -Ⅳ.The analysis results of the ROC curve showed that:the area under the curve for the serum S-100β protein concentration and 95％ confidence interval were 0.329 (0.127-0.531),0.352 (0.168-0.536),0.619 (0.466- 0.772) and 0.921 (0.846-0.995),the sensitivity was 50％,50％,56％ and 88％,and the specificity was 29％,22％,46％ and 86％ in groups Ⅰ-Ⅳ respectively.Conclusion Increase in the serum S-100β protein concentration can be used in predicting the development of PD in patients ≥75 yr,but the serum NSE protein concentration can not be used. Key words: S100 proteins; Phosphopyruvate hydratase; Delirium; Postoperative complications