Abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: Frailty can increase the risk, severity, duration of delirium and severe postoperative pain in the first 3 days after surgery of patients. TRIAL REGISTRATION: 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.