N2O strongly prevents adhesion formation and postoperative pain in open surgery through a drug-like effect

Abstract

Abstract Background Microsurgical tenets and peritoneal conditioning during laparoscopic surgery (LS) decrease postoperative adhesions and pain. For a trial in human, the strong beneficial effects of N2O needed to be confirmed in open surgery (OS). Results In a mouse model for OS, the effect of the gas environment upon adhesions was evaluated. Experiment I evaluated desiccation and the duration of exposure to CO2, N2O or CO2 + 4%O2. Experiment II evaluated the dose-response curve of adding N2O to CO2. Experiment III compared humidified CO2 + 10% N2O during LS and OS. In OS, 30- and 60-min exposure to non-humidified CO2 caused mortality of 33 and 100%, respectively. Mortality was prevented by humidification, by dry N2O or dry CO2 + 4%O2. Adhesions increased with the duration of exposure to CO2 (p < 0.0001) and decreased slightly by humidification or by the addition of 4% O2. N2O strongly decreased adhesions at concentrations of 5% or greater. With humidified CO2 + 10% N2O, adhesion formation was similar in OS and LS. Conclusions The drug-like and strong beneficial effect of low concentrations of N2O is confirmed in OS.