Physiologic changes during CO2 and N2O pneumoperitoneum in diagnostic laparoscopy. A comparative study.

The aim of this work was to study the cardiovascular effects, the acid-base balance in serum electrolytes and chlorides in 50 patients during diagnostic laparoscopy, comparing the use of CO2 and N2O for pneumoperitoneum. The CO2 group showed a significant decrease in pH, a significant increase in pCO2 and a significant decrease in pO2, while the changes in HCO3 and base change were insignificant. In the N2O group, the changes in pH, pCO2, pO2, HCO 3 and base excess were statistically insignificant. The heart rate during CO2 and N2O pneumoperitoneum revealed that both groups showed a significant increase, but in the recovery stage there was a significant increase in the CO2 group (p less than 0.025) and insignificant increase in the N2O group (p greater than 0.05). The other circulatory and electrocardiographic changes are described. CO2 pneumoperitoneum induced a significant decrease in serum chlorides but an insignificant increase in Na and an insignificant decrease in potassium, while the N2O pneumoperitoneum group did not show any significant change in serum electrolytes.