Laparoscopy: Searching for the proper insufflation gas

Background: Although many aspects of laparoscopic surgery have been determined, the question of which insufflation gas is the best arises repeatedly. The aim of this study was to review the findings on the major gases used today in order to provide information and guidelines for the laparoscopic surgeon. Methods: We reviewed the literature for clinical and laboratory studies on the currently used laparoscopic insufflation gases: carbon dioxide (CO₂), nitrous oxide (N₂O), helium (He), air, nitrogen (N₂), and argon (Ar). The following parameters were evaluated: acid-base changes, hemodynamic and respiratory sequelae, hepatic and renal blood flow changes, increase in intracranial pressure, outcome of venous emboli, and port-site tumor growth. Results: The major advantage of CO₂ is its rapid dissolution in the event of venous emboli. Hemodynamic and acid-base changes with CO₂ insufflation usually are mild and clinically negligible for most patients. Although N₂O is advantageous for procedures requiring local/regional anesthesia, it does not suppress combustion. Findings show that Ar may have unwanted hemodynamic effects, especially on hepatic blood flow. There are almost no hemodynamic or acid-base sequelae with the use of He, air, and N₂, but they dissolve slowly and carry a potential risk of lethal venous emboli. Conclusions: Clearly, CO₂ maintains its role as the primary insufflation gas in laparoscopy, but N₂O has a role in some cases of depressed pulmonary function or in local/regional anesthesia cases. Other gases have no significant advantage over CO₂ or N₂O and should be used only in protocol studies. The relation of port-site metastasis to a specific type of gas requires further research.