Ketamine–Midazolam Improves Sedation Experience in Interventional Radiology: Study
USA: A study published in the journal Radiology has found that combining ketamine and midazolam for sedation during image-guided procedures improved patient experience without increasing complications. The findings suggest that this combination could offer an alternative to the commonly used opioid–benzodiazepine regimen for sedation and analgesia in interventional radiology.
The randomized clinical trial was conducted by Amy R. Deipolyi, MD, PhD, FSIR, Interventional Radiology, Department of Surgery, Charleston Area Medical Center, Charleston, West Virginia, and colleagues. The investigators compared ketamine/midazolam with fentanyl/midazolam to assess pain control and patient experience during image-guided procedures.
Opioid-benzodiazepine combinations are widely used for procedural sedation administered by radiologists. However, concerns remain regarding opioid-related respiratory effects and the adequacy of analgesia. Ketamine, which provides analgesic and dissociative effects, may represent an alternative approach.
The single-center trial was conducted between June 2025 and February 2026. It included adults undergoing image-guided lung or bone biopsy or abscess drainage. A total of 264 procedures involving 260 participants were randomized equally to receive either fentanyl/midazolam or ketamine/midazolam administered by interventional radiologists. Procedures were guided using ultrasound, CT, CT fluoroscopy, or combined CT and ultrasound.
The primary outcome was the maximum pain experienced during the procedure, measured on a 0-to-10 Numeric Rating Scale. Researchers also evaluated sedation depth, physiological parameters, oxygen desaturation, patient-reported experience, and procedure- or sedation-related complications.
Key findings included:
- Maximum intraprocedural pain was significantly lower with ketamine/midazolam, with a mean difference of −1.4 points compared with fentanyl/midazolam.
- Pain scores above 4 occurred in 2.3% of procedures with ketamine/midazolam versus 17% with fentanyl/midazolam.
- Oxygen saturation at its lowest point was higher with ketamine/midazolam, with a mean difference of 1.4 percentage points.
- Oxygen desaturation below 90% occurred less frequently with ketamine/midazolam than with fentanyl/midazolam (2.3% versus 9.8%).
- Patients receiving ketamine/midazolam experienced deeper sedation, higher intraprocedural systolic blood pressure, and fewer recollections of the procedure, while reporting greater overall comfort and adequate sedation.
- Hallucinations were more common with ketamine/midazolam, occurring in 11.4% versus 3.8% with fentanyl/midazolam.
- Procedure-related and sedation-related complications were comparable between the two groups.
The study has several limitations, including its single-center design, lack of physician blinding, individualized ketamine dosing, and insufficient sample size to detect rare serious adverse events. Outcomes were limited to the immediate procedural period, with no assessment of long-term complications or economic impact. The findings may also not generalize to longer or more painful procedures.
The investigators concluded that radiologist-administered ketamine/midazolam provided better analgesia and patient-reported procedural experience, while reducing hypoxemic events without increasing complications. The findings suggest that ketamine-based sedation could be considered as an alternative to opioid-benzodiazepine regimens in selected image-guided interventional radiology procedures.
Reference: https://doi.org/10.1148/radiol.260671
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