[Colloidal hypertonic solutions in cardiac surgery].

Abstract

The ideal solution for volume therapy is still under discussion. In cardiac surgery, hemodynamic efficacy as well as the influence of cardiopulmonary bypass (CPB) are of major interest when administering volume. Hypertonic sodium (HS) solutions which have been advocated for resuscitation from hemorrhagic shock may also be of benefit in cardiac surgery patients. Hypertonic saline solution (7.5%) prepared in 6% hydroxyethyl starch solution (HS-HES) were infused in patients undergoing aortocoronary bypass grafting to double reduced baseline pulmonary capillary wedge pressure (PCWP < 4 mmHg). Volume replacement was carried out before (within 15 min), during (within 2 min), and after CPB (within 15 min). Significantly less HS-HES solution than standard 6% HES solution was necessary to double baseline PCWP. Cardiac index (CI) increased more and systemic vascular resistance (SVR) decreased more pronounced in the HS-HES group than in the 6% HES-patients. Fluid requirements in the patients having received hypertonic solution preoperatively were significantly less during CPB. Pulmonary function (paO2, Qs/Qt) was less changed in the HS-HES patients indicating avoidance of (interstitial) fluid overload in these patients. Infusion of HS-HES after weaning from CPB resulted in overall more improved hemodynamics than volume replacement with 6% HES. Rapid infusion of HS-HES during CPB (within 2 min) was followed by a significant, but shortlasting decrease in MAP (-40 mm Hg) and an increase in the oxygenator volume. Preoperative infusion of HS-HES resulted in a significant improvement in skin capillary microcirculation assessed by lased Doppler technique during and after CPB.(ABSTRACT TRUNCATED AT 250 WORDS)