Tumor necrosis factor-α has been implicated in complications seen after cardiac operations with cardiopulmonary bypass. The release of tumor necrosis factor-α and its possible effects were studied in patients undergoing coronary artery bypass grafting with and without cardiopulmonary bypass.

Twenty patients were studied, 10 with (group 1) and 10 without cardiopulmonary bypass (group 2). Serial blood samples were obtained before, during, and up to 48 hours after operation. Circulating tumor necrosis factor-α levels, leukocyte counts, and erythrocyte sedimentation rates were measured. Hemodynamic variables (blood pressure and heart rate), temperature, orotracheal intubation time, postoperative bleeding, and inotropic drug requirements were compared.

Serum levels of tumor necrosis factor-α were detected in 6 patients (60%) in group 1 and none in group 2. The patients in group 1 had more hypotension than those in group 2 (7.4 ± 1.0 mm Hg versus 8.5 ± 0.7 mm Hg), required more inotropic drugs (8 patients versus 1 patient), and had a higher heart rate (114 ± 8 beats per minute versus 98 ± 10 beats per minute), a higher temperature (37.1° ± 0.5°C versus 36.6° ± 0.3°C), increased postoperative bleeding (820 ± 120 mL versus 360 ± 84 mL), a longer orotracheal intubation time (13.6 ± 2.2 hours versus 9.3 ± 1.4 hours), and a more pronounced leukocytosis.

Cardiopulmonary bypass induces the whole-body inflammatory response through the release of tumor necrosis factor α, resulting in adverse systemic effects.