Dexmedetomidine was safely used for sedation during spinal anesthesia in a very elderly patient

We safely administered dexmedetomidine (DEX) for sedation during spinal anesthesia in a very elderly patient. The patient was a 98-year-old woman who had hypertension, renal failure, and first-grade atrioventricular block. She was scheduled to undergo internal fixation for fracture of the femoral neck. Initially, DEX (6.0 mu g/kg/h) was administered over 10 min, followed by continuous infusion at a dose of 0.7 mu g/kg/h. Consequently, her Ramsay sedation score (RSS) increased to 5, and the patient did not grimace in pain while being turned to the lateral position. Epidural catheterization and spinal anesthesia were performed under sedation without any problem. The DEX dose was adjusted to maintain the RSS within 3-4. The surgical operation was performed smoothly without any problem. Since the hemodynamic condition was stable, administration of ephedrine (5 mg) was required only once during surgery. Percutaneous oxygen saturation was maintained at 98% or more; respiratory rate was within 15-21 tpm, and no ventilatory assistance was required. The maximum predicted plasma concentration (pCp) of DEX was 1.56 ng/mL, and the mean pCp of DEX during surgery was approximately 0.45 ng/mL. We found that DEX can be safely used for sedation during spinal anesthesia in a very elderly patient.