Working Knowledge for Fluid Management

Abstract

  Thinking of three compartments (intracellular, interstitial, and intravascular compartment) is necessary for fluid therapy during surgery. As Hartman's solution is hypotonic, we prefer the extracellular fluids which contain sugars (except glucose), because they have high osmolarity and then high volume effect and diuretic effect. Hydroxyethyl starch (HES) is an appropriate intravascular fluid when acute fluid resuscitation is needed. When we think about colloid osmotic pressure, the characteristics of measured membrane, organ specificity of endothelium, and comprehension of pathological condition should be considered. HES has anti-inflammatory effects and can maintain proper blood viscosity and, consequently maintain peripheral microcirculation. HES70 has the lowest molecular weight among HES products and thus has the least side effects of renal function and coagulation system. Urine output is the most clinical and useful monitor for fluid management. The assessment of volume challenge using a transesophageal echocardiogram is a new idea for monitoring fluid load. The mixed venous saturation and the plasma lactate measurement are important comprehensive monitors which also offer the direction of fluid management for patients under unstable oxygen metabolism.