S. Deavers

Effects of certain anesthetics on distribution of red cells in the dog.

The animals were anesthetized with either sodium pentobarbital or morphine alone or in combination and the effects of these drugs were determined on the cell and plasma volumes and hematocrits on unsplenectomized and splenectomized groups. ‘Circulatory’ hematocrit is used to designate the distribution of cells and plasma throughout the circulatory system rather than ‘body’ hematocrit or over-all cell percentage; and BVR cells is used in place of the term F cells . In unsplenectomized dogs with pentobarbital alone the venous hematocrit is significantly lower than the morphinized or morphine-pentobarbitalized dogs, and the BVR cells (circ. hemat/venous hemat.) is 1.02. The latter figure is significantly different from 0.89 with morphine alone or 0.90 with the combined drugs. Removal of the spleen affected neither the variability of individual dogs nor significantly changed the BVR cells . The action of morphine when given alone, markedly increased the plasma volume and when combined with pentobarbital resulted in a redistribution of red cells; thus the BVR cells was decreased for these groups compared to pentobarbital alone. These data imply that cell and plasma volume should be measured simultaneously and independently for determining the blood volume with the utmost accuracy.

Determination of Cell Volume in Massive Transfusions Using Fe59 and Cr51

When dogs are injected with either or both Fe59 and Cr51-labeled cells (initial tag) prior to a series of transfusions (up to 20.0–25.0 cc % body weight) the measured blood and cell volume closely approach and may exceed the expected. After the series of transfusions are completed, if an additional isotope (final tag) is injected the blood and cell volumes are much less than the expected. The difference between the blood and cell volumes determined by the initial and final tag can be explained by the ‘trapping’ of red blood cells. The volume of red blood cells ‘trapped’ after multiple transfusion (up to 10.0–14.9% body weight) can equal or exceed the added cell volume.