Blood Volume, Extravasation Clinical Trial
Official title:
Blood Volume and Fluid Kinetics in Patients Undergoing Extracorporal Circulation
In patients undergoing extracorporal circulation during cardiac operation, the hemoglobin is subjected to large changes. The purpose of this study is to see if it is possible with the help of volume kinetic techniques to use these variations to measure blood volume and fluid escape from the intravascular volume.
In many clinical situations, such as extensive surgery, it is of value to determine blood
volume and rate of fluid loss from the intravascular space, since hypo- and hypervolemia are
combined with increased morbidity and mortality. In this study we which to use the large
variations in hemoglobin during extracorporal to calculate both these variables.
Hemoglobin is measured every 5 minutes during one hour beginning shortly before start of the
heart-lung machine. When the extracorporal circulation begins the hemoglobin decreases due
to the quick mix and dilution of the priming fluid from the heart-lung machine with the
patients blood.
From the amount of priming fluid and the fall of the hemoglobin, the blood volume can be
calculated. If no further fluid is given the next 20 to 30 minutes, the hemoglobin
concentration will in most cases increase as a result of the fluid loss from the vascular
space. This increase in combination with the diureses can be used to calculate the
intravascular fluid loss to the interstitium during surgery.
Sodium concentration will also be measured in parallel with the hemoglobin concentration.
The Sodium concentrations in combination with given and excreted (urine)Sodium can be used
in a mass balance to calculate if intracellular edema is induced.
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Observational Model: Cohort, Time Perspective: Prospective