Comparison of the effects of volume resuscitation with Dextran 60 vs. Ringer's lactate on central hemodynamics, regional blood flow, pulmonary function, and blood composition during hyperdynamic endotoxemia.

In hyperdynamic porcine endotoxemia the pulmonary as well as macro-and microcirculatory effects of volume substitution using 6% Dextran 60 (DX) vs. Ringer's lactate (RL) were analyzed. Endotoxemia was induced by continuous i.v. infusion of S. abortus equi endotoxin over 3.5 hr. Pulmonary capillary wedge pressure (PCWP) was maintained by titrated infusion of either DX (n = 6) or RL (n = 6). Regional blood flow was analyzed in 290 samples from 12 organs by means of the radioactive microspheres technique (diameter 15 microns). Lung function was impaired in both groups, as reflected by an increase of airway resistance and a decrease of O2 index. More than three times the volume of RL had to be substituted as compared to DX for maintenance of left ventricular filling pressure: cardiac output, however, remained higher with DX treatment (P < 0.05). In both groups, blood flow to the spleen decreased, while liver blood flow (hepatic artery) increased (P < 0.05); cerebral blood flow remained unchanged. In contrast, blood flow to kidneys, gastric mucosa, and intestine was preserved at significantly higher values upon treatment with DX as compared to RL (P < 0.05). It is concluded that volume replacement with 6% Dextran 60 sufficient to maintain stable left ventricular filling pressure is superior to Ringer's lactate infusion in acute endotoxemia; it effectively restores intravascular volume at constant plasma colloid osmotic pressure and--together with its positive rheological properties--favors high cardiac output and high nutritional blood flow.