Effects of 6% hydroxyethyl starch and 3% modified fluid gelatin on intravascular volume and coagulation during intraoperative hemodilution.

In the perioperative period, artificial colloids are most often infused in doses of 500-1000 mL intravenously. This randomized study compared the effects on intravascular volume and coagulation of approximately 2000 mL of two isooncotic artificial colloids: 6% hydroxyethyl starch (HES; MW 200,000; substitution ratio 0.40-0.55) and 3% modified fluid gelatin (GEL). We hypothesized more pronounced hypocoagulation with HES and a weaker intravascular volume effect of GEL. Forty-two patients, scheduled for primary total hip replacement, were allocated randomly to receive HES or GEL during acute normovolemic hemodilution and subsequent further intraoperative hemodilution. Blood samples were taken before and after 500 mL and 1000 mL of acute normovolemic hemodilution; intraoperatively after 20 mL/kg of artificial colloid and at the end of colloid infusion; on arrival in the recovery room; and 3 h later. We quantified: 1) coagulation variables; 2) blood loss; 3) hemodynamic stability; 4) necessary infusion volume; 5) interstitial extravasation, calculated from plasma volunteers measured using albumin marked with technetium-99m and iodine-125, respectively; 6) percentage volume effect at the end of the study as well as hematocrit, total serum protein, and colloid osmotic pressure. Intraoperative volume therapy was guided by radial systolic pressure and systolic pressure variation, mixed venous hemoglobin saturation in the pulmonary artery, and pulmonary capillary occlusion pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

A simple method for calculating component dilution during fluid resuscitation: the Leuven approach.

STUDY OBJECTIVES: To test the reliability of the Leuven approach, a balance between oversimplified empiric rules and more complex calculations requiring the use of nomograms or computers, to determine blood component dilution during large transfusions. To present schemes for blood component dilution and stabilization, as well as four examples showing the practicability of the method. DESIGN: Prospective study. SETTING: Orthopedic operating rooms at a university hospital. PATIENTS: 108 patients undergoing total hip replacement with expected large blood loss. INTERVENTIONS: Component concentrations were measured after patient arrival in the recovery room. Blood loss was followed clinically. MEASUREMENTS AND MAIN RESULTS: Preset target component concentrations [hematocrit (Hct) 31%; total serum protein (TSP) 5.0 g/dl; prothrombin time (PT) 50%; blood platelets (BLPL) 50,000/microliters)] were compared with concentrations measured on arrival in recovery after dilution and stabilization, according to the transfusion scheme. Average blood loss was 3,226 +/- 1,600 ml (mean +/- SD). End component concentrations were Hct, 33.4% +/- 3.3%; TSP, 5.2 +/- 0.5 g/dl; PT, 52% +/- 12%; BLPL, 97,000/microliters. Hct and TSP showed significant (p < 0.05) but clinically unimportant differences from target concentrations. Possible reasons for variability in end concentrations are discussed. CONCLUSION: The Leuven approach produces reliable blood component concentrations after extensive transfusions. It allows the clinician to decide for himself or herself, in accordance with general consensus and the patient's individual needs, when to stabilize blood components.