Blood distribution during cardiac arrest induced by hypothermia

¹ Departments of Physiology, The Lankenau Hospital and Jefferson Medical College, Philadelphia, Pennsylvania

Blood volumes with simultaneous blood- and red cell-distribution measurements were determined by the Cr⁵¹ technique in four groups of rats. In splenectomized and nonsplenectomized animals, blood volume of the whole body, lung, spleen, liver, kidney, heart, diaphragm, and gastrocnemius muscle was measured in both the control rats (body temperature 37 C) and in rats with hypothermically induced cardiac arrest (body temperature 8–9 C). Splenectomy caused alterations in some visceral blood volumes without concurrent changes in red cell mass. With cardiac arrest increased quantities of blood and red cell mass were observed in the lung, liver, and gastrocnemius in both splenectomized and nonsplenectomized groups. In the nonsplenectomized animals an increase of over 100 % in spleen blood volume was observed. When the two hypothermic groups were compared, differences existed only in blood volume of the lung, heart, and kidney. Hypothermia induced a pattern of blood redistribution toward visceral areas of the body.