CO2 absorption from the pneumoperitoneum increases over time during laparoscopic procedures. Adding 4% of oxygen to the carbon dioxide was shown in rabbits to decrease CO2 resorbtion through prevention of mesothelial hypoxia. We want to prove this concept in human and expand it to the use of full conditioning.

In order to confirm the animal data in the human, a first RCT was performed in which 20 women undergoing a laparoscopy for at least 60 minutes were randomised to a pneumoperitoneum with either 100% carbon dioxide or 96% carbon dioxide plus 4% of oxygen. Insufflation pressure and Trendelenburg were standardised at 15 mm Hg and 30° respectively. In a second trial women were randomized to either 100% carbon dioxide or 86% carbon dioxide plus 4% of oxygen + 10% nitrous oxide + humidification and set temperature of 32°C of the peritoneal cavity.

Inclusion Criteria:

• Women/men planned to undergo a laparoscopic intervention for at least 1 hour and having signed the informed consent

Exclusion Criteria:

• Pregnancy
• Immunodeficiency
• Refuse or unable to sign informed consent
• Chronic disease (i.e. COPD, Crohn, cardiac…)