Preoperative frailty tendency predicts delirium occurrence in older people undergoing spinal surgery

This prospective cohort study focused on the predictive value of frailty or pre-frailty assessed by Edmonton Frailty Scale (EFS) for postoperative delirium in spinal surgery patients. The primary outcome measurement was postoperative delirium (POD) evaluated by Confusion Assessment Method at day 1, day 2, and day 3 after the surgery. Secondary outcomes included severity and duration of POD, severe postoperative pain measured by Faces Pain Scale-Revised. Patients scheduled for elective spinal surgery were enrolled and assessed for frailty by EFS before surgery. Demographic data, preoperative, intraoperative, and postoperative information were collected. 231 out of 325 patients were enrolled and analyzed in this study at last. The cohort with 36.8% being frail and 28.5% being vulnerable. Postoperative delirium was detected in 41 in 231 patients. Multivariate logistic regression analysis revealed that vulnerable to frailty (OR = 4.681, 95% CI: 1.199 to 18.271, P = 0.026), after adjusted duration of surgery more than 3 h, using flumazenil at the end of surgery, using butorphanol only in postoperative patient-controlled intravenous analgesia, moderate-to-severe pain at day 1 and 2, is a strong predictor of postoperative delirium. Frailty was associated with longer duration (frailty vs. fit, P = 0.364) and stronger severity of postoperative delirium in the first two days (P < 0.001). High EFS score was independent risk factor of severe postoperative pain (Frailty vs. Fit: OR = 5.007, 95% CI: 1.903 to 13.174, P = 0.001; Vulnerable vs. Fit: OR = 2.525, 95% CI: 1.008 to 6.329, P = 0.048). In stratified tests, Sufentanil regimen in intravenous PCA significantly increase the proportion of POD in vulnerable group (P = 0.030), instead of frailty group (P = 0.872) or fit group (P = 0.928). Frailty can increase the risk, severity, duration of delirium and severe postoperative pain in the first 3 days after surgery of patients. The protocol of this study has been approved by the Ethic Committee of Shanghai Changzheng Hospital (Approval file number: 2022SL044) and informed consent was obtained from all the patients. The trial was retrospectively registered at chictr.org.cn (ChiCTR2300073306) on 6th July 2023.