New additional risks factors that may act to increase the risk of subcutaneous emphysema include total gas volume, gas flow rate, valveless trocar systems, and robotic fulcrum forces.

No abstract

Operative laparoscopy is experiencing an increase in its use and indications. This expansion exposes patients to increased operating time, larger volumes of carbon dioxide for maintenance of a pneumoperitoneum, and higher gas flow rates for intraperitoneal delivery. Patients with medical complications, advancing age, and potentially contaminated procedures are now considered acceptable candidates for operative endoscopic techniques via laparoscopy. A previously observed but unquantified amount of hypothermia was measured and evaluated by changes in core temperature after known quantities of carbon dioxide were delivered intra-abdominally over measured periods of time and with controlled flow rates. A decrease of 0.3 degrees C in the core temperature was observed for each 50 L of carbon dioxide delivered.

Laparoscopic peritoneal adhesion formation follows a pathway similar to laparotomy, both of which are only partially understood. Laparoscopic adhesion formation is complicated and influenced by pressure, dry gas desiccation, and hypoxia caused and superimposed by the pneumoperitoneum. It may further be affected by products of tissue combustion and inappropriate irrigation. Adjuvants are a poor substitute for attention to surgical detail and offer little help for the problem. The best defenses to reduce adhesion formation are maintenance of a normal physiologic peritoneal state that is wet and warm, gentle tissue handling, low intra-abdominal pressure, appropriate irrigation, and evacuation of smoke. Continued research into peritoneal cell response to the provocative circumstances of laparoscopic surgery will hopefully offer assistance to diminish the potential for laparoscopic adhesion formation.

Because of the iatrogenic hypothermic stress of a 0.3 degrees C loss created by carbon dioxide pneumoperitoneum insufflation at laparoscopy, it is important to reduce this danger to a minimum. The risk is diminished by increasing the temperature of the delivered carbon dioxide gas to 30.0-30.5 degrees C. This was demonstrated by evaluating 20 patients undergoing laparoscopies with unheated carbon dioxide pneumoperitoneum and 20 with heated carbon dioxide pneumoperitoneum. All procedures were performed without the use of laser or cautery. The group receiving the heated gas had lower and more stable thermal losses. Warming of the carbon dioxide prior to abdominal delivery is recommended to counteract hypothermia.