Warmed Humidified Carbon Dioxide (CO2) for Open Surgery

Eighty adult patients undergoing open colon surgery will be randomized to either: 1. standard warming measures including heating sheets, warming of fluids, and insulation of limbs and head, or to 2. additional insufflation of humidified carbon dioxide (approx. 36-37ºC, approx. 80-100% relative humidity) via a humidifier with a heated tube (Fisher\&Paykel) connected to a gas diffuser (Cardia Innovation AB) that is able to create a local atmosphere of 100% carbon dioxide (humidified ) in the open wound cavity. PRIMARY AIM The primary aim of this study is to evaluate if humidified carbon dioxide insufflated into an open surgical wound can be used to warm the core, the open wound cavity, and the wound edges during major abdominal surgery. SECONDARY AIMS Secondary aims are to evaluate possible differences between the groups regarding complications and clinical differences including histological signs of desiccation injury of peritoneal samples, time to extubation, core temperature after surgery, ICU stay, bleeding volume, hospital stay, postoperative pain, infections, shivering, postoperative signs of restored bowel function including bowel movements, flatus, and first meal.