High serum interleukin-6 level is associated with increased risk of delirium in elderly patients after noncardiac surgery: a prospective cohort study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The relationship between inflammation and delirium remains to be determined. The purposes of this study were to investigate the association between serum interleukin-6 levels and the occurrence of delirium in elderly patients after major noncardiac surgery.</p><p><b>METHODS</b>A total of 338 elderly patients (60 years of age and over) undergoing major noncardiac surgery were enrolled. Blood samples were obtained before anesthesia and in the first postoperative morning and serum interleukin-6 concentrations were measured. Delirium was assessed twice daily by the confusion assessment method for the Intensive Care Unit during the first three postoperative days. Survival analyses were performed to assess the relationship between the serum IL-6 level and the occurrence of postoperative delirium.</p><p><b>RESULTS</b>Postoperative delirium occurred in 14.8% (50 of 338) of patients. High serum interleukin-6 levelsafter surgery were significantly associated with increased risk of the occurrence of postoperative delirium (hazard ratio 1.514, 95% confidence interval 1.155-1.985, P = 0.003). Other independent predictors of delirium included increasing age, poor preoperative New York Heart Association classification, low preoperative Mini-Mental State Examination score, and high total postoperative Visual Analogue Scale pain score. Patients who developed delirium had a prolonged hospital stay after surgery.</p><p><b>CONCLUSIONS</b>Delirium is a frequent complication in elderly patients after noncardiac surgery. High serum interleukin-6 level after surgery is associated with increased risk of the occurrence of postoperative delirium.</p>

Serum proteomics of early postoperative cognitive dysfunction in elderly patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Studies on postoperative cognitive dysfunction (POCD) have attracted extensive attention and achieved significant progress. However, the diagnosis of POCD is not very satisfactory as no specific biomarkers have been classified. The aim of the present study was to evaluate differences in serum protein composition between POCD and Non-POCD patients, identify potential biomarkers associated with early POCD, and study the mechanism underlying POCD.</p><p><b>METHODS</b>Sixty-eight elderly patients (age ≥ 65 years) received isoflurane inhalation anesthesia for arthroplasty surgeries. One day before and seven days after the surgery, these patients were subjected to a neuropsychological test and venous blood sample collection. Postoperative cognitive dysfunction was determined using Z test scores. Based on the results, the patients were divided into POCD and non-POCD groups. Twenty-five randomly chosen blood samples obtained seven days after the surgery from each group were analyzed on a Bruker ultraFlex(TM) time of flight (TOF)/TOF mass spectrophotometer. The resulting peptide fingerprints were compared with those from the pre-surgery samples to identify differences in serum protein composition. The model designed to distinguish between a non-POCD group and a POCD group were established and validated. Three proteins with the most significant changes were selected for further characterization.</p><p><b>RESULTS</b>Thirty-three cases were diagnosed as POCD. Using the Clinprotools software, 58 polypeptides were found to display differential expression (P < 0.05). Using a support vector algorithm method, seven differential peaks were isolated to establish a diagnostic model to distinguish POCD patients from normal individuals. The prediction rate and recognition rate were 96.89% and 100%, respectively. Validation of this model showed that the accuracy rates were 100% and 85% using samples from the POCD and non-POCD groups, respectively. Protein analysis also led to the identification of fibrinopeptide A (FPA) as a potential biomarker for POCD.</p><p><b>CONCLUSIONS</b>Arthroplastic surgery under isoflurane inhalation anesthesia causes differential serum protein expression in elderly patients. These differentially expressed proteins may contribute to the diagnosis of early POCD, which may provide a basis for identifying the underlying mechanism of POCD development.</p>