Preoperative detection of serum phosphorylated neurofilament heavy chain subunit predicts postoperative delirium: a prospective observational study

Abstract

Background & Aims. Elderly surgical patients are susceptible to de-velopment of postoperative delirium. Interventions for postoperative delirium have little effect on its progression, indicating the importance of early detection and prevention. This study investigated preoperative biomarkers to predict postoperative delirium. Methods. Delirium-related serum biomarkers were measured before the start of surgery in patients who underwent esophageal cancer surgery and were compared between patients who did and did not devel-op postoperative delirium. Results. Fifteen of 96 patients (15.6%) developed postoperative de-lirium. Brain-derived phosphorylated neurofilament heavy subunit was preoperatively detected in 80% of patients with postoperative delirium. The preoperative interleukin-6 (IL-6) concentration was significantly higher whereas the concentrations of plasminogen activator inhibitor-1 (PAI-1) was significantly lower in patients with postoperative delirium. Detection of phosphorylated neurofilament heavy subunit was associated with postoperative delirium independent of age (adjusted odds ra-tio, 5.86; 95% confidence interval, 1.60-29.03; p = 0.0064). The sensi-tivity and specificity of postoperative delirium detection was increased when age was combined with detection of phosphorylated neurofila-ment heavy subunit. Conclusions. Preoperative evaluation of phosphorylated neurofilament heavy subunit can predict postoperative delirium independent of age. Early detection of serum phosphorylated neurofilament heavy subunit before surgery may enable clinicians to identify patients at risk for postoperative delirium and start early intervention.