Per- and postoperative monocyte and lymphocyte functions: effects of combined epidural and general anaesthesia.

Monocyte-mediated cytolysis and thymidine uptake in phytohaemagglutinin-stimulated lymphocytes during and after hip replacement performed under combined epidural- and general anaesthesia were studied using in vitro culture techniques. Monocyte-mediated cytolysis was unchanged during operation but was significantly reduced on the first postoperative day, coinciding with an increasing serum cortisol which indicates an incomplete epidural analgesia. However, there was no significant correlation between the increased cortisol concentration and the reduction of cytolysis. Lymphocyte proliferation was unchanged both during and after operation. These findings indicate that the presence of anaesthetic agents during surgery does not influence the studied functions of monocytes and lymphocytes. This supports the hypothesis that monocyte and lymphocyte depression during surgery under general anaesthesia alone is due to the trauma-induced stress reaction. The difference between postoperative suppression of monocytes and lymphocytes in this study indicates that monocytes are more vulnerable to surgical stress than lymphocytes.