Intracardiac Pressure Changes with Overtransfusion of Normal Dogs

Abstract

The sensitivity of 4 different blood pressures (arterial, venous, pulmonary arterial, and left atrial) to overtranfusion was studied in 11 dogs. Transfusion of 100 to 130 ml/Kg of fresh heparinized blood was serially performed over a period of 50 to 190 min. Before transfusion, the systolic blood pressures were as follows arterial: 115-175 mm. Hg, venous 3-7 mm., pulmonary arterial 14-22 mm, left atrial 2-11 mm. During transfusion the animals became dyspneic as all pressures gradually rose. The average increase in systolic blood pressures were: arterial 33 mm., venous 7 mm, pulmonary arterial 14 mm, left atrial 6 mm. Within 30 to 60 min following completion of the transfusions, the venous and left atrial pressures returned to normal or nearly normal levels, while the pulmonary arterial pressure remained elevated. Two dogs died from pulmonary congestion within a few hours although the left atrial pressure was not elevated. At autopsy, 24 hours later, the other animals showed moderate to severe pulmonary congestion. These studies indicate severe limitations of venous and left atrial pressure as guides to overtransfusion. Increase in pulmonary arterial pressure was the most consistent abnormality found with overtransfusion.