Effect of extraperitoneal carbon dioxide insufflation on intraoperative blood gas and hemodynamic changes

Carbon dioxide pneumoperitoneum has been shown to produce respiratory and hemodynamic changes due to both CO2 absorption and the effects of increased intraperitoneal pressure. We have measured the blood gas, end-tidal CO2, and hemodynamic changes produced during extraperitoneal CO2 insufflation (n = 22). These have been compared with the changes occurring during CO2 pneumoperitoneum (n = 11) under standardized anesthetic conditions. The changes observed during pneumoperitoneum were consistent with previous descriptions. There was a median rise in arterial pCO2 of 1 kPa over the first 15-20 min, followed by a second phase of only gradual change. There was also an increase in mean arterial pressure of 18 mmHg during the insufflation period. We have found a similar magnitude of rise in arterial pCO2 during extraperitoneal insufflation (median 0.83 kPa), but the rate of rise was significantly slower (P < 0.05). In addition, there was no change in the mean arterial pressure during extraperitoneal insufflation. Our results suggest that extraperitoneal CO2 insufflation may be safer than CO2 pneumoperitoneum in patients with preexisting cardiorespiratory disease.