Growth of Allogeneic Sarcoma in Mice Subjected to Halothane Anesthesia and/or Surgical Stress

Abstract

The present study was designed to clarify mechanisms involved in suppression of cell-mediated immunity reported in patients undergoing major surgery with general anesthesia by determining the effects of halothane anesthesia with and without surgery on the growth of Sarcoma I (Sa I), a tumor allogeneic to BALB/c mice. Mice were given subcutaneous injections of 5 × 10⁶ tumor cells from A/Jax mice and then immediately exposed to 0.5%-1.0% halothane for 1 hr without surgery (n = 7) or with surgery (midline laparotomy; n = 12). In control groups mice were also injected with tumor cells but were not exposed to prolonged halothane anesthesia. Some of them received only Sa 1 (n = 6), while the rest (n = 7) were also laparotomized. The rejection time of Sa I in mice exposed to halothane anesthesia was significantly longer (15.4 ± 1.25 days) than in untreated controls (12.10 ± 0.68 days) (P < 0.05). In the mice exposed to halothane tumor growth was also greater. Surgical stress per se did not significantly affect growth or rejection time of Sa I(11.0 ± 0.66 vs 12.0 ± 0.68 days). Similarly, the combination of surgical stress with halothane anesthesia did not affect the immunosuppression associated with halothane alone (12.9 ± 1.3 vs 15.4 ± 1.25; P < 0.05). The results indicate that halothane anesthesia per se may be associated with impairment of cell-mediated immunity under experimental conditions.