White blood cell populations in patients undergoing major vascular surgery.

In 16 patients undergoing major vascular surgery, study was made of variations in white blood cell populations, cortisol concentration, pulmonary vascular resistance and intrapulmonary shunting. Six hours post-operatively the number of circulating lymphocytes and the relative proportion of T-lymphocytes were significantly reduced. During and after operation the relative proportion of T-suppressor cells rose from 20.5 to 44.8% of all lymphocytes. There was corresponding fall in T-helper cells. The proportion of lymphocytes with surface-bound Ig (B-lymphocytes) did not alter during surgery. No correlation was found between the number of circulating white blood cells and the haemodynamic parameters. Intrapulmonary shunting, which was increased already before operation, remained unchanged during and after surgery. Cortisol levels increased significantly and peaked 6 hours postoperatively. Significant correlations were found between cortisol levels and reduction in total number of lymphocytes and in percentage of T-lymphocytes. The study thus demonstrated significant changes in white blood cell populations following major vascular surgery and indicated a correlation between lymphocyte concentration and cortisol level.