Gene expression of pulmonary cytokines after sevoflurane or thiopentone anaesthesia in pigs

Background: Volatile anaesthetics have diverse inflammatory effects on the lungs. They increase gene expression of some pro‐inflammatory cytokines in alveolar macrophages whereas in alveolar type II cells they seem to decrease secretion and gene expression of pro‐inflammatory cytokines. We have previously detected increased leukotriene C4, nitrate and nitrite concentrations in bronchoalveolar lavage fluid after sevoflurane anaesthesia. In the current study, we measured gene expression of inflammatory cytokines in the lung tissue and plasma concentrations of cytokines in pigs after thiopentone or sevoflurane anaesthesia. Methods: Sixteen pigs were randomly selected to receive either a continuous thiopentone infusion (control group, n = 8) or sevoflurane (n = 8) at 4.0% inspiratory concentration (1.5 MAC) in air for 6 h. Tissue samples were collected at the end of the study for measurement of gene expression of inflammatory cytokines. Blood samples were collected during anaesthesia for measurement of plasma cytokine concentrations. Results: Compared with thiopentone anaesthesia, lower gene expression of tumour necrosis factor‐α (TNF‐α) and interleukin‐1β (IL‐1β) in lung tissue was observed after sevoflurane anaesthesia. Of measured cytokines IL‐1β, TNF‐α, IL‐6, IL‐8 and IL‐10 only plasma concentrations of IL‐6 could be measured during the study without a difference between the groups. Conclusion: Lower gene expression of TNF‐α and IL‐1β was found in the intact porcine lung tissue after sevoflurane anaesthesia compared with thiopentone anaesthesia. Clinical significance of this finding is unknown.