Behaviour of Intravenous Solutions in Obese Patients Under General Anesthesia

Study Overview
=================
Brief Summary
-----------------
There is no objective evidence of how long intravenous solutions remain inside venous blood vessels after they have been administered, therefore there is no definite guideline of how to administer them in the preoperative setting. Besides, obese patients represent a particular group of subjects as they theoretically with-hold a constant inflammatory response and that would modify the way solutions behave intravenously, that is how long they remain inside. Having said this, we wish to describe the way colloid solutions behave in this group of patients by taking serial blood samples in 12 obese patients after a colloid infusion, to calculate plasma dilution curves based on hemoglobin dilution and therefore infer the time it remains intravascularly. All this in the hope this information will help, in the near future, to establish a more objective way to use these solutions and avoid possible complications due to over-administration.

Official Title
-----------------
Colloid Volume Kinetics in Morbidly Obese Patients Under General Anaesthesia

Conditions
-----------------
Obesity, Obesity, Morbid

Intervention / Treatment
-----------------
* Other: Tetrastarch (130/0.4)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: clinical diagnosis of obesity (IMC >35kg/m2) that will be treated with gastrojejunal laparoscopic bypass Exclusion Criteria: Renal failure KDOQI >3 Cardiac failure NYHA III-IV Sepsis Allergy to tetrastarch Allergy to any of the anesthetic medication that is to be used in the protocol previously established Patients in which vasoactive drugs are used Patients in which the blood samples are completed.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Tetrastarch (130/0.4)<br>In obese patients candidates to laparoscopic gastrojejunal bypass an infusion of Tetrastarch (130/0.4)) of 15mL/kg (of corrected weight) will be initiated after protocoled induction of general anesthesia. Blood samples will be taken at time 0 (after induction of anesthesia and before initiating infusion) and then every 5 minutes for half an hour and then every 15 minutes up to 90 minutes. Blood samples will be processed in the Institution's laboratory. Urine will be measured at the end of the intervention. With these data kinetic parameters will be estimated for each patient. | Other: Tetrastarch (130/0.4)<br> <br> * Other names: Voluven 6%;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| description of colloid volume kinetics in obese patients after the infusion of Tetrastarch (130/0.4) | different kinetic parameters will be used to asses the behavior of the colloid solution | 90 minutes after beginning of the infusion | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
general anesthesia, volume kinetics