抄録
The effect of hypothermia on circulating blood volume wasstudied using 9 dogs subjected to body surface and blood cooling. Toanalyze the movement of water between the vascular and interstitial fluidspaces, Ringer solution was infused during normothermia and hypothermia (30°C core temperature). During body cooling and infusionexperiments, blood volume, hematocrit, and colloid osmotic pressurewere monitored continuously. When body temperature was loweredto about 30°C within 2 hr, plasma volume decreased from 39.0±0.1 to36.2±5.3 ml/kg and colloid osmotic pressure increased from 16.4±0.2 to17.0±3.1 mmHg. The changes in blood volume, colloid osmotic pressure, and central venous pressure during the infusion of Ringer solution andrecovery periods, were used for a simulation analysis based on a two-compartmentmodel. The instantaneous and delayed compliances were determinedon the vascular space and on the interstitial fluid space togetherwith the transvascular filtration coefficient of water. Hypothermia to30°C increased vascular compliance, but decreased interstitial fluidspace. The transvascular filtration coefficient of water decreased in hypothermia.These results suggest that the redistribution of blood dueto hypothermia causes a reduction of capillary area available for fluidexchange. The transvascular filtration coefficient determined on thewhole body decreases due to reduction of the compliances of the “effective” interstitial fluid space.
