Abstract
The bubble formation inside the membrane oxygenator on the routine cardiopulmonary bypass technique was studied. When the heat-exchanger was turned off after recirculation was stopped, air bubble, which was 6.0ml and 5.2ml respectively, was observed inside the hollow fiber chamber of Compactflo D-703 and Monolyth. In case of Compactflo, the bubble was completely infused into the arterial side under the pump flow of 4l/min. However, in Monolyth, no bubble was infused into the arterial side, because of the lower location of the outlet-port. The mechanism was suspected that the air bubble was moved into the priming solution due to the negative pressure, which was induced inside the hollow fiber chamber as the heat-exchanger was tuned off. In spite of the efforts for better heat-exchanger efficiency and lesser priming volume, the safety of the oxygenator was spoiled. The design of the membrane oxygenator would have to be modified with this notion in mind.
