Optimal Gas Flow in the New Shiley Bubble Oxygenator

Abstract

Repeated examinations of the blood gases were made during 170 perfusions with the new efficient Shiley bubble oxygenator. The O₂/blood ratio of 0.3 gave a mean B-PO₂ of 15 kPa and an elevation of the ratio to 0.7 increased the B-PO₂ to 35 kPa. Further increments in the ratio did not raise the B-PO₂. In the Harvey H-200 bubble oxygenator, which was used in 88 patients, a ratio of 1.3 was required to reach the level of 35 kPa. At blood flows of 5–7 litres/min, an O₂/blood ratio of about 0.8 is adequate in the Shiley oxygenator, but when the blood flow is low (2–3 litres/min), a ratio of 1.0 is recommended.