Use of Dexmedetomidine for Sedation during Spinal Anesthesia in Very Elderly Patients.

We used dexmedetomidine (DEX) for sedation dur- ing spinal anesthesia in 3 elderly patients above 90 years of age. They were scheduled to undergo open reduction and internal fixation or bipolar hip arthro- plasty for femoral neck fractures. A loading dose of DEX (6 tg - kg-' - hr-1) was infused after performing spinal anesthesia in 2 patients, and sufficient sedation was attained within 5 min in 1 of the patients and 2 min in the other. In another patient, DEX was started with an initial dose of 3ttg - kg-1 - hr-1, and she attained a sedative state within 5 min. Vasopressor was administered for hypotension in 1 patient, and oxygen saturation decreased in 2 patients ; however, these side effects were mild. We can conclude that DEX may be safely used for sedation during spinal anesthesia in very elderly patients ; however, careful observation is necessary because the effect of DEX may appear at very low concentrations. t.