Effects of Insufflated Gas on Core Temperature and Post-operative Pain During Laparoscopic Surgery

During laparoscopy, administration of cold and dry carbon dioxide (CO2) leads to hypothermia. Different types of gas conditioning have been studied in order to prevent this specific hypothermia. Intra-abdominal administration of local anesthetics has also been studied in order to prevent post-operative pain. In both cases, some results have been described. The investigators propose to evaluate in a prospective, randomized, double blind trial, the impact of 4 different types of conditioning of insufflated gas during laparoscopy for womb surgery on hypothermia prevention and post-operative pain. These 4 types of gas conditioning are: * CO2 wet and cold with nebulized Nacl and direct intra-abdominal administration of Nacl * CO2 wet and cold with nebulized ropivacaïne 0.75% and direct intra-abdominal administration of Nacl * CO2 dry and cold with direct intra-abdominal administration of ropivacaïne 0.2% * CO2 dry and cold with direct intra-abdominal administration of Nacl The investigators use a new device (Aeroneb® Pro \[Aerogen® Company\]) which can wet (by nebulization) the insufflated gas and therefore permits intraperitoneal medicament administration (local anesthetics).