Halothane, surgery, immunosuppression and artificial pulmonary metastases.

C57B1/6 mice were given intravenous tumor cells on day O. Mice were then given either a brief exposure to halothane anesthesia or given halothane and then underwent a hind limb amputation. Immune testing was done at varying time intervals and correlated with the development of artificial pulmonary metastases. The effects of a single 15 minute exposure to halothane on the immune system are probably short-lived and no effect on cell-mediated cytotoxicity was seen on day 7, nor was an increase in pulmonary metastases observed. However, when anesthesia was combined with surgery, cell-mediated cytotoxicity was impaired and an increase in pulmonary metastases was seen. The use of thiabendazole (TBZ), an nonspecific immunopotentiator, in the perioperative period restored the cell-mediated cytotoxic response and resulted in a significant decrease in pulmonary metastases.