Changes in central venous pressure after moderate hemorrhage and transfusion in man

Changes in central venous pressure were recorded continuously before, during and for 40 to 50 minutes after hemorrhage and transfusion in the amounts of 6.5 cc. per Kg. and 8.1 cc. per Kg. The pressures obtained 15 to 20 minutes after onset of blood volume changes were independent of the rate of hemorrhage or transfusion. In the average subject of 70 Kg., Δ P /ΔV for zero time was 0.7 cm. of water pressure change per 100 cc. volume change. Recovery from hemorrhage was imperceptible during the one hour observation period, but recovery from transfusion was slightly faster.

The continuous recording of central venous pressure changes from an arm vein

With the subject in the right lateral decubitus position, changes of central venous pressure can be recorded accurately and conveniently from a vein in the antecubital fossa of the dependent arm. Theoretically the hydrostatic, pressure transforms the venous bed between the heart and the site of puncture into uninterrupted wide channels with relatively low distensibility. Simultaneous recordings of pressure by the method described and by catheterization of the central veins showed that induced changes of central venous pressure were identically recorded from both sites. The mean pressure gradient between the peripheral and central veins was 35 mm. of water.