Hypotensive Anesthesia for Orthognathic Surgery

Study Overview
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Brief Summary
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The overall objective of this double blinded, randomized controlled trial (RCT) is to compare specific outcomes three medications (Dexmedetomidine, Nicardipine, and Labetalol) which are routinely used to lower blood pressure used during general anesthesia for orthognathic (jaw) surgery. The investigators will evaluate healthy adult male and female patients who require jaw surgery at Boston Medical Center which will be performed by the principal investigator. The anticipated 90 participants will be randomized into three groups: Dexmedetomidine group, Nicardipine group, and Labetalol group. All medications will be given intravenously during their operation. Several outcomes (surgical field visibility, estimated blood loss, hemodynamic parameters -including systolic blood pressure, mean arterial pressure, and heart rate, operation time, and adverse events will be compared among the three groups. Each participant will be enrolled in the study for approximately 1-3 months. This time includes the pre-operative visit, the surgical procedure, and a 1-week post-operative visit. Each participant will be followed for 30 days post-operatively. These visits are part of the standard of care, and no additional visits will be required specifically for research purposes only.

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

Conditions
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Hypotensive Anesthesia, Orthognathic Surgery

Intervention / Treatment
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* Drug: Dexmedetomidine
* Drug: Nicardipine
* Drug: Labetalol


Participation Criteria
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Eligibility Criteria
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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)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dexmedetomidine group<br>Participants randomized into this group will be given Dexmedetomidine to lower their blood pressure during jaw surgery. | Drug: Dexmedetomidine<br>* 1 mcg/kg will be administered intravenously over 10 minutes; followed by maintenance infusion of 0.2 to 1 mcg/kg/hour.<br>* Other names: Dexmedetomidine Injection;|
| Experimental: Nicardipine group<br>Participants randomized into this group will be given Nicardipine to lower their blood pressure during jaw surgery. | Drug: Nicardipine<br>* 1 mg will be administered intravenously and increase by 0.5-1 mg if the initial dose is ineffective, to a maximum of 15 mg / hour or<br>* Other names: Nicardipine Hydrochloride Injection;|
| Experimental: Labetalol group<br>Participants randomized into this group will be given Labetalol to lower their blood pressure during jaw surgery. | Drug: Labetalol<br>* 20 - 80 mg will be administered intravenously at 10-minute intervals to maximum of 300 mg;<br>* Other names: Labetalol hydrochloride injection;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Surgical field visibility | Surgical field visibility will be assessed using the Fromme's scale (0 = no bleeding, virtually bloodless field, 1 = bleeding, so mild it was not even a surgical nuisance, 2= moderate bleeding, a nuisance but without interference with accurate dissection, 3 = moderate bleeding that moderately compromised surgical dissection, 4 = bleeding, heavy but controllable, that significantly interfered with dissection, 5 = massive uncontrollable bleeding). This data will be obtained from the surgeon in the form of an electronic survey, and the mean value will be recorded. | immediately after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Estimated blood loss | This outcome will be calculated by the volume in suction minus the volume of irrigating fluid. | immediately after surgery | 
| Mean systolic blood pressure during surgery | This outcome will be automatically recorded in the electronic medical record every 5 minutes during surgery. | throughout surgery every 5 minutes | 
| Mean arterial pressure | This outcome will be automatically recorded in the electronic medical record every 5 minutes during surgery. | throughout surgery every 5 minutes | 
| Mean heart rate | This outcome will be automatically recorded in the electronic medical record every 5 minutes during surgery. | throughout surgery every 5 minutes | 
| Operation time | Operation time will be measured from time of first incision to procedure end, as recorded in electronic medical record. | immediately after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Nicardipine, Labetalol, Surgeon visibility, Blood loss, Hemodynamic parameters, Operation time, Dexmedetomidine