Immunological and hormonal responses to lung surgery during one-lung ventilation.

The effects of lung surgery performed during one-lung ventilation and the associated endocrine stress response on natural killer (NK) cell activity and the distribution of white blood cells in peripheral blood were studied in 10 patients with malignant lung tumours. Patients were anaesthetized with general anaesthesia combined with thoracic epidural anaesthesia. The endocrine response was measured as changes in serum cortisol, plasma adrenaline and noradrenaline. A significant decrease of NK cell activity was found post-operatively accompanied by leucocytosis, neutrophilia and lymphopenia. Significant increases in serum cortisol were demonstrated at the end of operation and throughout the study period. Plasma adrenaline increased significantly during one-lung ventilation with a gradual normalization post-operatively. Plasma noradrenaline increased significantly during the whole post-operative course. In conclusion, lung surgery was accompanied by similar changes in NK cell activity, leucocyte and differential counts, serum cortisol and plasma adrenaline levels as demonstrated after other types of major surgery. The elevated noradrenaline level post-operatively is a new observation that may be specific for lung surgery.