The effect of repeated sevoflurane and nitrous oxide exposure on immunity in rabbits

The aim of this study was to investigate the effect of repeated/prolonged exposure to sevoflurane and nitrous oxide on the immune response in rabbits. Venous blood samples were obtained from twenty New Zealand rabbits, randomly allocated to four groups of five rabbits each. Group A rabbits served as controls, breathing 100% oxygen, group B rabbits inhaled a mixture of oxygen and nitrous oxide, group C inhaled a combination of oxygen and sevoflurane, and group D inhaled a combination of oxygen, nitrous oxide and sevoflurane. Flow cytometry was used to determine the proportions of CD45(+), CD4(+), CD8(+) and CD21(+) leukocytes subpopulations. Peripheral lymph nodes, lungs and spleen were sampled and subjected to histologic examination. The greatest changes in the proportion of CD21(+), CD4(+), CD8(+) and CD45(+) cells were recorded in groups C and D on days 7, 14 and 21. Comparison of the CD21(+), CD4(+), CD8(+) and CD45(+) cell counts on day 0 and day 21 showed a 30% decrease. This study demonstrated that sevoflurane alone and in combination with nitrous oxide exerts a strong immunosuppressive effect, modifying the physiological values of the hematologic parameters, and inducing histopathological alterations in peripheral lymph node, lung and spleen tissues.