Determining the influence of biocompatible oxygenators during cardiopulmonary bypass by 99m Tc-DTPA aerosol assessment of pulmonary permeability

Changes in pulmonary permeability provide a partial measure of the clinical impact of biocompatible oxygenator use during cardiopulmonary bypass surgery. Previous research has shown that the clearance rate of 99mTc-labelled diethylene triamine penta-acetic acid (99mTc-DTPA) aerosol from the lungs is increased following cardiopulmonary bypass, resulting from an increase in pulmonary permeability. The aerosol clearance rate has been shown to return to normal after a period of 7 days. A blind trial was set up to assess the clinical impact of a biocompatible, Trillium-coated oxygenator compared with a standard oxygenator. In a group of 25 patients 99mTc-DTPA aerosol studies were carried out prior to cardiopulmonary bypass surgery for mitral valve surgery. Repeat studies were undertaken 3-4 h and 24-28 h after surgery. Analysis of the rates of pulmonary clearance reproduced the trends seen in earlier research. There was however no statistically significant difference in the variation of serial clearance times between the groups of patients undergoing surgery using the Trillium-coated oxygenators and those using the standard oxygenators.