The effects of retroperitoneal carbon dioxide insufflation on hemodynamics and arterial carbon dioxide

Abstract

BACKGROUND: Laparoscopic techniques are being increasingly used for retroperitoneal surgery. However, hemodynamic and ventilatory efforts of retroperitoneal carbon dioxide (CO 2) insufflation have not been studied. We hypothesized that differences in absorptive surface, anatomy, and compartment compliance could result in different hemodynamic and ventilatory effects between retroperitoneal and intraperitoneal insufflation. METHODS: Pigs (n = 7) were anesthetized and stabilized. The peritoneal cavity was incrementally insufflated with CO 2 to a maximum pressure of 25 cm H 2O and the gas released. Hemodynamics and arterial blood gas values were recorded initially, at each level of insufflation, and following the pneumoperitoneum release until baseline values were reached. This insufflation protocol was repeated in the retroperitoneum. RESULTS: Mean arterial pressure (111 mm Hg, 95% confidence interval 99 to 156) and cardiac output (3.7 L/min, 2.8 to 5.2) did not change with increasing insufflation pressure of either intraperitoneum or retroperitoneum. PaCO 2 was directly related to insufflation pressure in both spaces, increasing from 41.2 mm Hg (37.3 to 43.4) at baseline to 57.7 mm Hg (47.6 to 82.1) at insufflation pressure of 25 cm H 2O. After release of the insufflation gas, time to return to baseline PaCO 2 was slightly less from the retroperitoneal space (73 minutes, 45 to 105) than the intraperitoneal (107 minutes, 35 to 175). CONCLUSIONS: The effects of CO 2 insufflation on hemodynamics and PaCO 2 are the same in the retroperitoneal and intraperitoneal spaces.