Evaluation of Oxidative Stress Induced by Occupational Inhalation Exposure to N2O, an Anesthetic Gas

Nitrous oxide (N2O) is the most common anesthetic gas used in operating rooms. The major objective of this investigation is to measure N2O values in two modes: first, when the ventilation system is on, and second, when it is off; and to determine the biomarkers of oxidative stress associated with this exposure among operating room personnel.

A cross-sectional study was conducted on 60 operating room personnel as the N2O exposed group, and on 60 nurses as the referent group. N2O concentrations were determined according to NIOSH method 6600. Total antioxidant capacity (TAC) levels, malondialdehyde (MDA), and superoxide dismutase (SOD) activities were also measured.

The concentrations of N2O in the presence and absence of ventilation systems were significantly higher than the recommended exposure limit (REL) of 25 ppm recommended by NIOSH. The levels of TAC and SOD were significantly lower in participants exposed to N2O in comparison with the referent group. Adjusted for age, work experience, and sex, exposure to N2O was found to be an occupational risk factor for low levels of TAC and SOD, so that exposure to N2O reduced TAC and SOD levels by 0.16 mM and 0.75 U/ml, respectively.

The present study shows that the operating room personnel are exposed to levels of N2O several times more than the REL of this gas and this heavy exposure is associated with a significant increase in oxidative stress.