Pulmonary structure and extravascular lung water after cardiopulmonary bypass

1. This paper describes the pulmonary alterations that occur after cardiopulmonary bypass (CPB) when a bubble oxygenator is used. 2. Two groups of patients who underwent myocardial revascularization were studied before and after CPB. The first group (7 patients with a bypass time of 130 +/- 17 min), when examined by light and electron microscopy showed platelet/neutrophil accumulation in the pulmonary parenchyma, endothelial lesions and interstitial edema. In the second group (10 patients with a bypass time of 123 +/- 37 min), extravascular lung water (EVLW) was measured by the thermal and green-dye dilution technique, and showed a significant increase immediately after CPB which lasted through the 1st and 2nd post-operative days. 3. No statistical correlation was found between the increase in EVLW and the plasma colloid oncotic pressure/pulmonary artery wedge pressure gradient, CPB time or intra-operative fluid balance. 4. Our results indicate an increase in pulmonary endothelium permeability after CPB when a bubble oxygenator is used.