RESUMO
Lung injury after cardiac surgery is believed to result from cardiopulmonary bypass and its pro-inflammatory effects. To test this hypothesis, we compared the oxygenation ratios, extravascular lung water indices and systemic and pulmonary tumour necrosis factor alpha (TNF-alpha) and interleukin (IL)-8 at predetermined intervals in coronary artery surgery patients with or without cardiopulmonary bypass. No differences in oxygenation ratios or extravascular lung water indices were found. Serum values of TNF-alpha and IL-8 increased in both groups but were higher in the cardiopulmonary bypass group (end of surgery: mean (SD) TNF-alpha 3.68 (2.5) vs 2.20 (1.2) pg.ml(-1) (p = 0.043 (CI 0.05-2.9)) and mean (SD) IL-8 19.45 (10.8) vs 6.31 (5.3) pg.ml(-1) (p = 0.001 (CI 6.9-19.3)). In broncho-alveolar lavage fluid, TNF-alpha and IL-8 increased in both groups with no differences between the groups.