Hypotensive Anesthesia for Orthognathic Surgery

A Comparison of Dexmedetomidine, Nicardipine, and Labetalol to Induce Hypotensive Anesthesia and Their Effects on Surgeon Visibility, Blood Loss, Hemodynamic Parameters, Operation Time, and Adverse Events During Orthognathic Surgery

The overall objective of this double blinded, randomized controlled trial (RCT) is to compare specific outcomes of three medications (Dexmedetomidine, Nicardipine, and Labetalol) which are routinely used to lower blood pressure used during general anesthesia for orthognathic (jaw) surgery. The outcome measures for the study will be surgical field visibility, estimated blood loss, hemodynamic parameters, operation time, and adverse events.

The specific objectives of this study are to compare:

1. Dexmedetomidine, Nicardipine, and Labetalol's effect on the quality of the surgical field. (Primary Outcome)
2. Dexmedetomidine, Nicardipine, and Labetalol's effect on estimated blood loss.
3. Dexmedetomidine, Nicardipine, and Labetalol's effect on hemodynamic parameters including systolic blood pressure, mean arterial pressure, and heart rate.
4. Dexmedetomidine, Nicardipine, and Labetalol's effect on operation time.
5. Dexmedetomidine, Nicardipine, and Labetalol's effect on adverse events.

The investigators will evaluate healthy adult male and female patients who require jaw surgery at Boston Medical Center. The anticipated 90 participants will be randomized into three groups: ) A Labetalol group in which the patients receive hypotensive anesthesia with the aid of labetalol, 2) A Nicardipine group in which the patients receive hypotensive anesthesia with the aid of nicardipine, and 3) A Dexmedetomidine group in which the patients receive hypotensive anesthesia with the aid of dexmedetomidine.

The time it will take for each individual participant ranges from 1-3 months. This time includes the pre-operative visit, the surgical procedure, a 1-week post-operation visit, and then followed for 30 days post-operatively after which the patient's participation in the study will conclude.

Inclusion Criteria:

• Adult patients undergoing orthognathic surgery [Le Fort I, Surgically Assisted Rapid Palatal Expansion (SARPE), Bilateral Sagittal Split Osteotomy (BSSO), or a combination these surgeries] at Boston Medical Center with Dr. Mehra
• Healthy, American Society of Anesthesiologists (ASA) physical status classification system I or II

Exclusion Criteria:

• Patients on a home beta blocker
• Patients on home calcium channel blocker
• Patients on home alpha 2 agonists
• Patients with an allergy to one or more of the intervention medications
• Does not speak English
• Pregnant patients (this is assessed day of surgery per standard care with a urine pregnancy test)
• Patients who have contraindications to induced hypotensive anesthesia