Comparison on the pulmonary effects of rapid infusion of a crystalloid and a colloid solution.

The cardio-pulmonary effects of a rapid infusion of a crystalloid (Ringer's lactate) and a colloid solution (Dextran 40) were compared in healthy dogs. The colloid solution produced a long lasting volume expansion and hemodilution. The improved circulation in this group was reflected in an increased cardiac output and arterial blood pressure. The ventilation/perfusion ratios were reduced and the pulmonary vascular resistance was significantly lower in the colloid group in comparison both to the crystalloid group as well as to the control animals. The total oxygen consumption increased slightly in the colloid group but decreased in the crystalloid group. The postmortem extravascular lung water content did not differ in the groups.