Comparison of Sedation With Ketamine-Propofol Versus Propofol-Fentanyl for Elderly Patients Undergoing Prostate Biopsy: A Retrospective Observational Study

Background: Procedural sedation is increasingly used for elderly patients, but there is no established ideal method for elderly patients who are prone to respiratory and circulatory depression. This study aims to investigate the association of respiratory complications and the combination of ketamine-propofol versus fentanyl-propofol in elderly patients undergoing prostate biopsy requiring deep sedation. Methods: This was a single-center, retrospective, observational study conducted from April 2020 to March 2021. We included male patients aged 65 years and older scheduled for prostate biopsy under procedural sedation. Ketamine-propofol and fentanyl-propofol were administered at the discretion of the anesthesiologist. The primary outcome was the need for assisted ventilation. The secondary outcome was the duration of oxygen saturation (SpO(2)) below 90%. Results: We enrolled 120 patients over 65 years, and 92 patients were included in the final analysis. The anesthesiologist administered an initial dose of ketamine and propofol of 1:1 to 1:4 of 1.0 mg kg(-1) (interquartile range: 0.98 to 1.17) or administered an initial dose of fentanyl of 0.05 to 0.1 mg and a target-controlled infusion of propofol of 2.8 μg ml(-1) (interquartile range: 2.0 to 3.0) followed by additional doses at the discretion of the anesthesiologist. Ketamine-propofol was associated with a reduced need for assisted ventilation and a shorter duration of SpO2 below 90% than propofol-fentanyl (95.7% vs. 4.3%, P < 0.05; 0.64 minutes vs. 0.17 minutes, P = 0.26). Conclusions: Ketamine-propofol is associated with a significantly reduced need for assisted ventilation compared to propofol-fentanyl during procedural sedation and analgesia for procedures requiring deep sedation for the elderly.