Bleeding Volume in Splenectomized Dogs

Abstract

Acute total bleeding volume was measured several times in succession in the splenectomized dog utilizing an apparatus which records the bleeding within ±1% and facilitates rapid replacement of the collected blood. Blood volume was determined either with T-1824 alone or by simultaneous measurements with T-1824 and P32. In a group of 10 experiments in each of which the acute total bleeding test was carried out six times during 1.5 hours, the maximal variability between two successive bleeding volumes was ±8%. The mean difference between the first and sixth bleeding volumes was only 1.6%. The blood volume after the six successive bleeding tests was on the average 17% lower than before. When the values are corrected for blood lost in samples, etc., there is an unexplained average deficit of 12%. Since the bleeding volume remained fairly constant there was an apparent change in the relation between the bleeding volume and blood volume. The average initial bleeding percentage (first bleeding vol/ initial blood vol. x100) was 56.9, whereas the final bleeding percentage (6th bleeding vol/ final blood vol. x100) was 68. Among the various attempts to alter the bleeding volume, such as change in the bleeding rate, venous bleeding, intravenous injection of adrenaline, etc., only vagotomy and increase in plasma volume changed the bleeding volume beyond the variability observed in the standard bleeding series.