Effects of Low Pressure of Laparoscopic Cholecystectomy on Arterial Pressure of Carbon Dioxide and Mean Blood Pressure

Background: The effect of low pressure pneumoperitoneum in laparoscopic cholecystectomy on partial pressure of carbon dioxide in the arterial blood (PaCO2) is an important subject which has not been completely defined.Methods: In a double-blind clinical trial, we randomly studied 202 ASA (The ASA physical status classification system) class 1, 2 patients aged between 20 and 85 years who were candidates for elective laparoscopic cholecystectomy. They were randomly divided into two groups of low pressure pneumoperitoneum (6-8 mm Hg) and standard pressure pneumoperitoneum (12-14 mm Hg). By the same general anesthesia protocol in the two groups, PaCO2 was assessed before CO2 insufflation and desufflation. Mean Arterial blood Pressure (MAP) was measured in the two groups.Results: PaCO2 was not significantly different between the 2 groups before CO2 insufflation. But, PaCO2 was statistically lower in low pressure pneumoperitoneum group before CO2 desufflation (P= 0.001). Mean Arterial Pressure (MAP) in standard pressure pneumoperitoneum group was lower than the low pressure pneumoperitoneum group at 5 and 10 minutes after CO2 insufflation and before the time of CO2 desufflation (P=0.001, P=0.006 and P=0.001, respectively). While, MAP was not statistically different between the two groups before CO2 insufflation (P=0.55).Conclusion: Low pressure pneumoperitoneum during laparoscopic cholecystectomy can be an effective protocol to prevent the rise of PaCO2 by preserving the hemodynamic status in such cases.