Warming and humidification have no effect on oxidative stress during pneumoperitoneum in rats

Pneumoperitoneum is reported to induce oxidative stress due to the desiccative effect of cold, dry gas insufflation. The aim of this study is to compare the effect of warmed, humidified insufflation to standard gas, by measuring oxidative stress markers in a physiologically relevant animal model. Twenty male Wistar rats (330?650 g) were alternately assigned to the Warm Humidified group (WH, n = 10) and Control group (n = 10). All rats underwent pneumoperitoneum at 5 mmHg and a controlled flow rate for 110 min. The WH group received warmed (37?C) and humidified (98% Relative Humidity (RH)) gas and the control group received standard gas at room temperature (19?C) and 0% RH. At the end of pneumoperitoneum, samples of liver, kidney, pancreas, jejunum, and lung were excised. Levels of plasma and tissue malondialdehyde (MDA) and protein carbonyls (PC) were measured. Organ light microscopy was performed. There were no differences between groups for MDA or PC concentrations in plasma, liver, kidney, jejunum, or lung tissue. There were no differences in histological score between groups. Warming and humidification of pneumoperitoneum insufflation gas have no effect on measures of oxidative stress compared to non-warmed, non-humidified controls.