Ketamine Plus Midazolam versus Fentanyl Plus Midazolam for Sedation and Analgesia during Image-guided Procedures in Interventional Radiology: Randomized Clinical Trial.

Background Opioid-benzodiazepine regimens remain common for radiologist-administered procedural sedation despite respiratory and analgesic effectiveness concerns. Purpose To compare intraprocedural pain and patient-reported experience between ketamine/midazolam and fentanyl/midazolam during image-guided procedural sedation. Materials and Methods This randomized clinical trial was conducted at a single academic center between June 2025 and February 2026. Adults undergoing image-guided lung or bone biopsy or abscess drainage were randomized to fentanyl/midazolam or ketamine/midazolam administered by interventional radiologists. Procedures were performed using US, CT, CT fluoroscopy, or combined CT and US guidance. The primary outcome was maximum intraprocedural pain (0-10 on the Numeric Rating Scale). Secondary outcomes included sedation depth, physiologic parameters, oxygen desaturation, patient-reported experience assessed using a modified Heidelberg questionnaire, and complications. Results Among 264 randomized procedures (132 procedures per group) in 260 participants (median age, 68 years [IQR, 61-75 years]; 135 [52%] female), ketamine/midazolam resulted in lower maximum intraprocedural pain than fentanyl/midazolam (mean difference, -1.4 points [95% CI: -2.0, -0.8]; P < .001). Pain scores greater than 4 occurred less frequently with ketamine/midazolam (2.3% vs 17%; absolute difference, 14 percentage points [95% CI: 8, 21]; P < .001). Ketamine/midazolam was associated with higher nadir oxygen saturation (mean difference, +1.4% [95% CI: 0.6, 2.2]; P = .001) and fewer oxygen desaturation events below 90% (three [2.3%] vs 13 [9.8%]; absolute difference, 7.6 percentage points [95% CI: 1.9, 13.3]; P = .02). Ketamine/midazolam produced deeper sedation and higher intraprocedural systolic blood pressure. Hallucinations occurred more frequently with ketamine/midazolam (15 [11.4%] vs five [3.8%]; absolute difference, 7.6 percentage points [95% CI: 1.3, 13.9]; P = .03), though overall procedural comfort, reduced recall, and perceived adequacy of sedation were improved. Procedure-related and sedation-related complications did not differ between groups. Conclusion Radiologist-administered ketamine/midazolam during image-guided procedural sedation improved analgesia and patient-reported experience with fewer hypoxemic events and no increase in complications compared with fentanyl/midazolam. Clinical trial registration no. NCT07040163