Abstract
Prolonged interruption of blood flow to the heart and lungs followed by survival of the animals has been accomplished(l). The blood was oxygenated extracorporeally by blowing oxygen over a blood film upon the inner surface of a revolving vertical metal cylinder of 0.23 sq. meter surface area. A larger oxygenator of this type was described in detail(2). Recently, a still larger vertical cylinder, 79 cm in height, and 30 cm in internal diameter, has been constructed which differs from those previously described only in having a larger surface area, 0.71 sq. meter. It was thought that if the blood flow on the smooth inner surface of the cylinder could be made turbulent, the capacity of the apparatus to introduce oxygen could be increased. The basic apparatus was therefore modified by closely adapting a 16-mesh, 26-gauge wire screen to the cylinder's entire inner surface.
Data showing the relative oxygenating efficiency with and without the screen are shown in Table I. These values for oxygen introduced by a single passage of blood over the oxygenating surface were chosen from a number of determinations for the similarity of their initial venous oxygen saturations.
The maximum amount of oxygen which could be added to the blood with the original apparatus was 71.3 cc per minute, with a change in oxygen saturation from 40.6% to 70.8% (Observation No. 3, Table I), at a blood flow rate of 1080 ml per minute. Since the addition of a screen, a maximum of 543 cc of oxygen per minute has been added to the blood with an increase in saturation from 47.4% to 86.2% at a blood flow rate of 8,200 ml per minute. With nearly identical venous oxygen saturations, 48.2 and 47.7%, the attainment of closely similar arterial saturations, 87.0 and 86.2% respectively, occurred at a flow rate of 510 ml per minute without the screen and at 8,200 ml per minute with the screen (Observations No. 5 and 6, Table I).
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