Laparoscopic surgery with carbon dioxide insufflation causes respiratory acidosis

This study analyzes the changes in cardiopulmonary parameters of patients undergoing laparoscopic cholecystectomy. Six healthy females with normal preoperative cardiopulmonary status were selected for laparoscopic surgery using the same criteria as for traditional cholecystectomy. Respiratory and cardiovascular parameters were collected and compared prior to peritoneal insufflation and just before desufflation. Patients experienced significant elevations of arterial and end-tidal CO2, accompanied by decreased pH. Bicarbonate concentration, blood pressure and pulse rate remained constant. Based on these results, and on our laboratory investigations, we have introduced helium as an alternate agent for insufflation, and present the data from the first two patients so managed. No change was observed in EtCO2, PaCO2 or pH in either of these two patients during the course of surgery. We conclude that hypercarbia occurs in those undergoing laparoscopic cholecystectomy with CO2 insufflation. This acidosis requires compensation by increased minute ventilation to prevent decline in pH. In our initial experience, helium did not produce these changes, and therefore merits further investigation as an alternate agent for abdominal insufflation.