Objective: Anaesthetic agents are believed to have an adverse effect on human immune defense mechanisms. We investigated changes in peripheral immune cell numbers such as natural killer (NK) cells, B cells and T lymphocyte subpopulations (CD4+ and CD8+ cells) and differences in cytokine production after stimulation with different mitogens before and during narcosis.
Methods: We studied 30 patients undergoing elective orthopedic surgery. Stimulatory experiments were performed with the mitogens lipopolysaccharide (LPS), phytohemagglutinin (PHA) and inactivated Newcastle Disease Virus (NDV).
Results: During general anaesthesia with fentanyl, thiopental, isoflurane and nitrous oxide there was a significant decrease of circulating NK cells in the peripheral blood accompanied by a significant increase of B cells and CD8+ T lymphocytes. We detected a significant anesthesia-associated increase of interferon (IFN)-gamma, INF-alpha, tumor necrosis factor (TNF)-alpha and soluble interleukin-2 receptor (sIL-2R) synthesis after stimulation with different mitogens while interleukin (IL)-1 beta and IL-6 protein did not change significantly. After the beginning of surgery CD8-positive cells showed a return to control values and NK cell number increased slightly.
Conclusion: These findings suggest that general anaesthesia interferes with immune cell number and immune cell response. This may explain the clinically well-recognized disturbance of human immunity after surgery and general anaesthesia.