Effects of repetitive sevoflurane anaesthesia on immune response, select biochemical parameters and organ histology in mice.

Animal and technical models often require repeated anaesthetic administrations for surgical procedures. As there is evidence for immunomodulatory effects of anaesthesia, the effects of repeated exposure to sevoflurane anaesthesia on the immune response in mice were studied. Sevoflurane was administered in vivo under conditions that simulate those in clinical procedures. Adult male mice were anaesthetized with 3% sevoflurane in oxygen for 40 min weekly for 3 weeks. Untreated animals served as controls. After sevoflurane anaesthesia, peripheral blood leukocyte counts, the composition and in vitro function of spleen cells (lymphocytes and macrophages) and the in vivo immune response to a conventional T-dependent antigen were assessed. In addition, liver, spleen and kidney histopathology and also hepatic and renal function were studied. Three days after the latest anaesthetic procedure, the absolute number of both leukocyte and lymphocyte counts were reduced in peripheral blood. Splenic cell composition (LB, LTCD3(+), LTCD4(+) and LTCD8(+)), macrophage function and the mitogen-induced lymphoprolipherative response were preserved. Yet, the in vivo humoral response to a conventional antigen was augmented following the antigenic challenge. Assessment at day 9 after the last anaesthetic procedure revealed the persistence of the humoral response alteration. Nevertheless, sevoflurane-treated animals showed no evidence of histological changes or alteration in hepatic or renal function.