CO₂ insufflation influences the temperature of the open surgical wound

In open surgery, heat is lost due to radiation and evaporation through the wound. Hypothermia causes tissue hypoxia and impairs various cellular immune functions that increases the risk for postoperative wound infections and delayed wound healing. The patient's body is usually well protected with heating arrangements, but the open wound is left unprotected and until now no practical method has been available to protect it thermically. We therefore investigated if insufflation of an open surgical wound with carbon dioxide would affect wound temperature. In 10 patients undergoing cardiac surgery, the sternotomy wound was insufflated with dry, room temperature carbon dioxide via a gas diffuser for 2 minutes. A heat-sensitive camera measured the wound temperature before, during, and after insufflation. Exposure to carbon dioxide increased the median temperature of the whole wound by 0.5 degrees C (p=0.01). The temperature of the area distant to the diffuser increased by 1.2 degrees C (p<0.01) whereas in the area close to the diffuser it decreased by 1.8 degrees C (p<0.01). In conclusion, short-term insufflation of dry room temperature carbon dioxide in an open wound increases the surface temperature significantly. Although a small increase, it may reduce the incidence of postoperative wound infections in the future.