Laparoscopic pain, hypothermia cut with warmed, wet [Co.sub.2]. (Abdominal Insufflation).

NEW YORK -- Warm and moist is a whole lot nicer than cold and dry when it comes to laparoscopic peritoneal insufflation.

A simple $125 device that heats and humidifies the [CO.sub.2] before insufflating a patient's abdomen can markedly reduce intraoperative hypothermia as well as shoulder tip pain, the major adverse effect associated with laparoscopy, Dr. Larry Demco said at an international congress sponsored by the Society of Laparoendoscopic Surgeons.

The average insufflator pumps [CO.sub.2] at 21 [degrees] C, with a water vapor content of 0.0002%, into a peritoneal cavity that is normally 37 [degrees] C and extremely moist, said Dr. Demco of the department of obstetrics and gynecology, University of Calgary (Alta.).

These extreme differences result in marked desiccation of peritoneal and mesothelial tissues, cellular destruction, release of cytokines, and exposure of basal lamina to chemical irritation. Dr. Demco and several other speakers at the conference believe these are the major contributors to shoulder tip pain, a referred-pain phenomenon that affects up to 80% of women undergoing [CO.sub.2] insufflation. "If you heat and humidify the [CO.sub.2], you can really reduce pain, need for analgesia, and postoperative recovery time. Many patients will be able to tolerate an awake procedure (local anesthesia only), and you won't need warming blankets."

The Insuflow device, manufactured by Lexion Medical, Sr. Paul, Minn., can be connected to any insufflator. A small electric heater regulated by a controller box warms the gas; by the time it reaches the cannula valve, it is roughly 36 [degrees] C. The gas also passes through a reservoir containing 8 cc of warm sterile water that moistens the gas to 95% relative humidity

Dr. Demco studied the effects of warm, heated gas versus untreated gas in 50 patients undergoing a variety of common laparoscopic procedures. The outcomes weighed clearly in favor of Insuflow. Dr. Demco has received product support from Lexion but has no financial interest in the device.

All patients began their procedures under local anesthesia. With the insufflation of 700 mL of [CO.sub.2] 30% of the controls but only 10% of the Insuflow patients experienced shoulder tip pain. In the latter group, the pain tended to be transient; only 10% of the Insuflow group required general anesthesia to complete their procedures. In contrast, 50% of the control group had pain severe ...