The amounts of O2 consumed and CO2 produced reflect the rate of body metabolism and the types of nutrients metabolized. The tasks of the respiratory and cardiovascular systems are to ensure that the cells of the body receive sufficient O2 and adequate amounts of CO2 are removed. Human lungs excrete almost all the CO2 produced, with only a miniscule amount excreted through the skin. When measuring CO2 production, gas leaks around endotracheal tubes render measurements inaccurate due to loss of expiratory minute ventilation. Anesthesia and surgery greatly affect body homeostasis and, consequently, alter the performance of the respiratory, cardiovascular, and metabolic systems, which influences the elimination of CO2 from the human body. The CO2 insufflated into the peritoneal cavity diffuses into the abdominal organs and abdominal wall. The use of hypothermic cardiopulmonary bypass (CPB) during open-heart surgery causes many changes in body homeostasis.