An Open-label Trial of Clevidipine for Controlled Hypotension During Spinal Fusion

This would basically be an observational study without a significant change in our current practice. There would be no change in the standard and usual anesthetic care including premedication, anesthetic induction, intraoperative anesthetic management, and intraoperative monitoring. Our usual anesthetic routine includes:

1. Intravenous or oral premedication with midazolam
2. Inhalational or intravenous induction based on the preference of the patient
3. Facilitation of endotracheal intubation with a dose of rocuronium with placement of intraoperative monitors including an arterial cannula
4. Maintenance anesthesia to include desflurane titrated to maintain the bispectral index at 40-60, fentanyl 2-4 µg/kg followed by a remifentanil infusion to maintain the mean arterial pressure at 55-65 mmHg.
5. Tranexamic acid to limit intraoperative bleeding
6. As needed, agent to control blood pressure to maintain the MAP at 55-65 mmHg if remifentanil in doses up to 0.3 µg/kg/min are ineffective.

As needed, clevidipine will be started at 1 µg/kg/min and titrated up in 1 µg/kg/min every 1-2 minutes to achieve an MAP at 55-65mmHg. Vital signs including heart rate will be recorded every 1 minute until the target MAP is achieved and then at 15 minute increments after that.