The Cardiac Output and Blood Volume of the Anaesthetized Cat

Abstract

1. The cardiac output and blood volume have been measured in thirty-two cats by an indicator dilution 2. In six experiments both 32P-labelled red cells and 131I-labelled human serum albumin were used as indicators. In the rest one or other indicator was used. 3. Cardiac output of the cat anaesthetized with chloralose is 113±30 ml/min/kg (32 animals). 4. Repeated determinations show random variations of cardiac output to be about 5%. 5. The blood volume of the cat anaesthetized with chloralose is 49·0±10 ml/kg (25 animals) and the ` central ' blood volume, as defined, 16·9±1·2 ml/kg. 6. The ratio of the value of the whole body haematocrit to that of the arterial haematocrit is 0·93±0·09. The causes of the large variation are considered. 7. The accuracy of the technique and its advantages are discussed.