Obesity and Goal-directed Intraoperative Fluid Therapy

Study Overview
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Brief Summary
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The purpose of the study is to compare non-obese patients (BMI≤ 30 kg/m2)versus obese patients (BMI> 30 kg/m2) in regard of their respective needs for intraoperative fluid therapy during laparoscopic surgery. Specifically the investigators will test the hypothesis that subcutaneous tissue oxygenation (PsqO2)is increased in obese patients when fluid management is optimized by means of esophageal Doppler monitoring compared to obese patients undergoing standard fluid management. Furthermore the investigators will test the hypothesis that PsqO2 is decreased in obese patients undergoing conventional fluid therapy compared to non-obese patients when fluid management is optimized. Thus the investigators assume that PsqO2 is similar in obese and non-obese patients when fluid management is optimized in both groups.

Detailed Description
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Hemodynamic stability and normovolemia are critical determinants of tissue perfusion and oxygenation. Adequate tissue oxygenation is essential to maintain normal physiologic functions and to reduce complications, such as wound infections. Fat tissue is relatively hypoperfused and, therefore, poorly oxygenated. Subcutaneous tissue oxygenation in the obese is thus critically low and even supplemental oxygen only slightly increases subcutaneous oxygenation.It is likely that poor subcutaneous oxygenation in the obese surgical patients results in part from inadequate intraoperative fluid replacement. It remains unknown how to hydrate obese surgical patients best. The most physiologic approach for perioperative fluid replacement is now thought to be goal-directed management, using stroke volume as the treatment parameter.

Official Title
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Intraoperative Goal-directed Fluid Management in Non-Obese and Obese Patients Undergoing Laparoscopic Surgery

Conditions
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Obesity

Intervention / Treatment
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* Other: Goal directed fluid therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Non-obese (BMI≤ 30kg/m2) and obese patients (BMI > 30 kg/m2) undergoing laparoscopic elective fundoplication or elective bariatric surgery Exclusion Criteria: decompensate heart failure documented coronary artery disease renal insufficiency severe chronic obstructive pulmonary disease symptoms of infection or sepsis esophageal disease (excepting gastro-esophageal reflux without any other esophageal alteration).

Ages Eligible for Study
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Minimum Age: 18 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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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: obese control<br> | |
| Active Comparator: obese goal-directed<br> | Other: Goal directed fluid therapy<br>* Fluid will be administered to reach maximal stroke volume during the intraoperative period.<br>|
| Active Comparator: non-obese goal directed<br> | Other: Goal directed fluid therapy<br>* Fluid will be administered to reach maximal stroke volume during the intraoperative period.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Subcutaneous tissue oxygenation |  | intraoperative and 2 postoperative hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obesity, Esophageal Doppler monitoring, tissue oxygen tension