Evaluation of occupational exposure to waste anaesthetic gases in the inflammatory and oxidative stress biomarkers in medical residents

Background and Goal of Study: Occupational exposure to anaesthetics is thought to exert adverse effects in operating room personnel. It is known that inflammation and oxidative stress are linked processes; however, it lacks in the literature reports about the effects of occupational exposure to anaesthetics in the inflammation-oxidative stress pathways. Thus, this study aimed to evaluate inflammatory cytokines and oxidative stress in medical residents occupationally exposed to waste anaesthetic gases.

Materials and Methods: The Ethical Committee of the Institution approved the study, which included 30 subjects who were allocated into two groups of 15: the exposed group, consisting of medical residents from anaesthesiology and surgery areas exposed to waste anaesthetic gases (isoflurane, sevoflurane and nitrous oxide) for a three year-period, and a control group composed of medical personnel not exposed to waste anaesthetic gases (internal medicine). Blood samples were collected at the same time for both groups, and plasma aliquots were used. Inflammatory interleukins (IL-6, IL-8 and IL-17) were determined by flow cytometry; oxidative stress was determined by evaluating two markers of lipid peroxidation: malondialdehyde (MDA) by high-performance liquid chromatography (HPLC) and 4-hydroxynonenal (4-HNE) by immunoassay (ELISA), and also by the antioxidative status using the total antioxidant performance (TAP) detected by fluorometry. 

Results and Discussion: There were no significant differences between groups in relation to demographic data. Results showed a significant increase in IL-8 and IL-17A in the exposed group compared with the control group (P<0.05). Interestingly, IL-8 and IL-17A are potent proinflammatory cytokines that have been associated with pathogenesis of a wide range of inflammatory diseases, including the respiratory tract, such as chronic bronchitis. On the other hand, no significant differences between groups were detected regarding oxidative stress markers (P>0.05). Thus, despite the observed changes in the inflammatory cytokines, occupational exposure to anaesthetics does not seem to induce oxidative stress.

Conclusion: The findings suggest an inflammatory response without alterations in the antioxidant status in medical residents exposed for three years to waste anaesthetic gases.

Acknowledgements: This study was supported by FAPESP (grant #2013/21130-0).