Dynamic changes in serum neuregulin-1 and their association with postoperative delirium after laparoscopic gastrointestinal surgery in elderly patients.

OBJECTIVE

Postoperative delirium is a frequent complication in older adults following gastrointestinal surgery, and perioperative inflammatory activation has been implicated in its pathogenesis. This study investigated whether perioperative serum neuregulin-1 levels were associated with postoperative delirium and evaluated the discriminative performance for postoperative risk stratification of neuregulin-1.

METHODS

In this prospective cohort study, 512 patients aged ≥65 years undergoing elective laparoscopic gastrointestinal surgery were enrolled. Postoperative delirium was assessed twice daily during the first 3 postoperative days using the Confusion Assessment Method and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria. Serum neuregulin-1, interleukin-6, interleukin-17, tumor necrosis factor-α, and C-reactive protein were measured preoperatively and at 6 hours, 24 hours, and 72 hours postoperatively. Receiver operating characteristic curves and multivariable logistic regression were used to assess discriminative value and independent associations.

RESULTS

Postoperative delirium occurred in 93 of 512 patients (18.2%). Compared with non-postoperative delirium patients, those who developed postoperative delirium had lower preoperative Mini-Mental State Examination scores and higher American Society of Anesthesiologists class, longer operation and anesthesia durations, greater intraoperative blood loss, and a higher incidence of intraoperative hypothermia. Serum neuregulin-1 levels were significantly lower in postoperative delirium patients compared with non-postoperative delirium patients at 6 hours, 24 hours, and 72 hours after surgery. Receiver operating characteristic curve analysis showed that neuregulin-1 at 24 hours after surgery showed the best discriminative performance for postoperative delirium risk stratification with an area under the curve of 0.750 (95% confidence interval, 0.701-0.799), a cutoff value of 251.55 pg/mL, sensitivity of 67.1%, and specificity of 64.5%. In the multivariate logistic regression analysis, lower neuregulin-1 at 24 hours (odds ratio, 0.964; 95% confidence interval, 0.954-0.975; P < .001) was independently associated with postoperative delirium.

CONCLUSION

Lower perioperative serum neuregulin-1 levels, particularly at 24 hours after surgery, were strongly associated with postoperative delirium in elderly patients undergoing gastrointestinal surgery. Measurement of neuregulin-1 at 24 hours after surgery may serve as a practical postoperative biomarker for risk stratification and closer clinical surveillance in elderly patients undergoing gastrointestinal surgery.