Induction with Ciprofol Decreases Propofol Requirement During Propofol-Remifentanil Total Intravenous Anesthesia Maintenance in Elderly Patients Undergoing Total Knee Arthroplasty: A Prospective, Double-Blind, Randomized Controlled Trial

Xiaoxiang Chen,* Yu Lai,* Yuekun Shen, Shan Gao, Xiongqing Huang, Lu Yang, Wei Xiong Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, People’s Republic of China*These authors contributed equally to this workCorrespondence: Wei Xiong, Department of Anesthesiology, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, 510080, People’s Republic of China, Email [email protected] Lu Yang, Department of Anesthesiology, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, 510080, People’s Republic of China, Email [email protected]: Elderly patients are susceptible to dose-dependent perioperative hypotension caused by propofol. This study investigates whether general anesthesia induction with ciprofol reduces subsequent propofol maintenance requirements and improves hemodynamic stability compared to propofol induction in elderly patients undergoing total knee arthroplasty (TKA).Participants and Methods: In this prospective, double-blind, randomized controlled trial, 52 elderly participants (≥ 65 years, ASA I-III) undergoing TKA were randomly allocated to receive propofol (2 mg/kg) or ciprofol (0.4 mg/kg) for anesthesia induction. All participants received standardized anesthesia protocol for maintenance. The primary outcome was the average propofol infusion rate. Secondary outcomes included intraoperative norepinephrine utilization, mean arterial pressure (MAP) fluctuations, time to extubation, and postoperative modified Aldrete scores. Data were analyzed using t-tests, Wilcoxon rank-sum, or Chi-square/Fisher’s exact tests as appropriate.Results: The mean age was 70.62 ± 3.86 years in the ciprofol group and 69.08 ± 3.52 years in the propofol group with balanced sex distribution. During anesthesia maintenance, the ciprofol group required a significantly lower propofol infusion rate than the propofol group (2.70 ± 0.75 mg/kg/h vs. 4.18 ± 1.66 mg/kg/h; mean difference, − 1.48 mg/kg/h; [95% confidence interval, − 2.19 to − 0.77], P = 0.009). Additionally, the ciprofol group presented with a lower norepinephrine utilization rate (46.2% vs. 84.6%, P = 0.004) and a reduced median norepinephrine infusion rate (0 [interquartile range (IQR), 0– 0.05] μg/kg/min vs. 0.05 [IQR, 0.01– 0.08] μg/kg/min, P = 0.030). Norepinephrine initiation was significantly delayed in the ciprofol group (P = 0.047). No significant differences were observed in MAP variability or postoperative modified Aldrete scores.Conclusion: In relatively healthy elderly patients undergoing total knee arthroplasty, anesthesia induction with ciprofol is associated with reduced propofol maintenance requirements and decreased intraoperative norepinephrine utilization. Ciprofol may represent a promising alternative for anesthesia induction in this population, although further multicenter validation is warranted.Keywords: ciprofol, propofol, elderly patients, hypotension, total knee arthroplasty