Goal-Directed Fluid Therapy for Patients Undergoing Oro-Maxillofacial Surgery

Study Overview
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Brief Summary
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Orthognathic surgery, one kind of Oro-maxillofacial surgery, is a complicate surgery that undergoes several hours with nasotracheal intubation general anesthesia. To limit blood loss during operation, the patients are often under intentional hypotension. However, the intentional hypotension may confuse with hypovolemic induced low blood pressure. The hypothesis is using flotrac (to measure stroke volume variation) to keep the patients hemodynamics stable under Tridil and propofol infusion and avoid over-infusion of crystalloid or colloid and prevent hypovolemia induced postoperative nausea and vomiting.

Detailed Description
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Orthognathic surgery, one kind of oro-maxillofacial surgery, is a complicated surgery that undergoes several hours with nasotracheal intubation general anesthesia. Patients without premedication undergo orthognathic surgery with nasotracheal intubation general anesthesia. Patients without premedications Monitoring of patients with entropy for consciousness, ECG, with noninvasive BP and invasive blood pressure through redial artery, train-of-four monitor, target controlled infusion of propofol, infusion Tridil, and sevoflurane for mainly anesthesia maintenance. Ventilator setting as volume control (8-12ml/kg), frequency respiratory rate (8-12/min), I/E ratio: 1/2, positive end expiratory pressure: 4 mmHg, Fraction inspiratory O2: 60%. To maintain the MAP >60-55 mmHg, urine output 0.5-1ml/kg, and body core temperature > 36 Celsius degree. Closely observation of patients postoperatively for adverse events or complications.

Official Title
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Kaohsiung Medical University Chung-Ho Memorial Hospital

Conditions
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Blood Pressure, Low

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients undergo orthognathic surgery, ASA I III, 20 to 65 years old, no mouth limitation Exclusion Criteria: ankylosing spondylitis, limited mouth opening < 3 cm, liver or renal disease, obese patients (BMI>35kg/m2), patients refused

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 65 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| group surgery<br>using medications to maintain low stable blood pressure | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| blood loss measurement | to maintain low blood pressure (MAP > 55mmHg) to limit blood loss | 10hrs | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| assessment of inappropriate fluid infusion | count the fluid given by stroke volume variation but fixed time administration | 10hours | 
| postoperative adverse events | adequate medications to maintain low stable BP to decrease tissue edematous change | 2 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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oromaxillofacial surgery, nasotracheal intubation, stroke volume variation