Humidification during surgery: Benefits of using humidified gas during laparoscopic and open surgery

During laparoscopic surgery, the abdominopelvic cavity is inflated with carbon dioxide (CO₂). Currently, dry CO₂ gas at room temperature is used for insufflation. However, the peritoneum is not designed to cope with variable conditions such as the introduction of dry and cold gas. Significant evidence suggests that the use of humidified and warmed gas may reduce at least two of the major morbidities associated with laparoscopic surgery: postoperative pain and hypothermia. During open surgery, the peritoneum is exposed to dry and cold ambient air in the operating room. Taking into account the composition of air (20.9% oxygen, 78% nitrogen, 0.03% CO₂ and other gases) and that the physiologic intracellular partial pressure of oxygen and at the intercellular space is around 3% to 4% (540 mmHg), this dry and hyperoxic environment will also be traumatic for the peritoneum. The effect of desiccation upon the peritoneum during open surgery will be of equal importance to that observed during laparoscopic surgery.