OPTIMAL PREOPERATIVE TITRATED DOSAGE OF HYPERTONIC HYPERONCOTIC SOLUTIONS IN CARDIAC RISK PATIENTS

Hypertonic-iso/hyperoncotic solutions have been the subject of numerou s studies, mostly used in a fixed dosage (4 mL/kg bw or 250 mL). Nearl y no study exists to prove whether this is the appropriate dosage espe cially in cardiac risk patients with accompanying diseases. We have co mpared preoperative volume loading with either 10% hydroxyethyl-starch /7.5% NaCl (HHT-HES) or 10% hydroxyethyl-starch/.9% NaCl (HES) in 50 m t bolus infusions. Volume loading was done with either HES or HHT-HES in 2 x 20 patients before aortic aneurysmectomy. The endpoint of stepw ise infusion represented the highest cardiac index (CI) at the lowest possible wedge pressure (PCWP) (turning point of each individual Frank Starling relation). 167.5 mt (+/- 45.5 mL = 2.41 mL/kg bw) of HHT-HES and 440 mL (+/- 26.15 mL = 6.33 mL/kg bw) of HES were necessary. We o bserved a significant higher increase of the CI in the HHT-HES group. Significant increases of PCWP, pulmonary artery pressure, and central venous pressure occurred within the groups without any significant dif ferences between the groups (p <.05). Results of the study showed: 1) The commonly used fixed dosage of 4 mL/kg bw of HHT-HES is too high in cardiac risk patients with slight hypovolemia. 2) HHT-HES shoud be gi ven in an individual titration. 3) In the HHT-HES group we observed a positive inotropic effect (higher CI). 4) With the individual titratio n of HHT-HES no negative side effects occurred (especially no hypotens ion).