Does pneumoperitoneum with different gases, body positions, and intraperitoneal pressures influence renal and hepatic blood flow?

Abstract

Background. Because of the well-known negative effects of carbon dioxide pneumoperitoneum on the hemodynamic and respiratory system, it was questionable how pneumoperitoneum may affect hepatic and renal blood flow. Therefore the influences of different gases, different intraperitoneal pressures, and different body positions on hepatic and renal blood flow were investigated in a porcine model. Methods. Cardiac and hemodynamic function were monitored by means of implanted catheters in the pulmonary artery and the femoral vein and artery. Renal and hepatic blood flow were recorded with a transonic volume flow meter placed at the renal and hepatic arteries and the portal vein. Eighteen animals were randomly assigned to receive one of three insufflation gases (carbon dioxide [CO 2], argon, or helium. After baseline recordings, one of three intraperitoneal pressures (8, 12, or 16 mm Hg) and one of three body positions (supine, head up, or head down) were randomly chosen. After an adaptation time of 15 minutes, all data were recorded for 15 minutes. This was repeated until all nine combinations had been investigated. The end points of the study were blood flow in the hepatic and renal arteries and the portal vein, cardiac output, systemic vascular resistance, and central venous pressure. Results. Total liver blood flow was reduced in relation to intraabdominal pressure, head-up position, and argon insufflation. Arterial hepatic blood flow was reduced by the head-up position and argon insufflation. Portal venous blood flow decreased with the pig in the head-up position, with increased intraabdominal pressure, and argon insufflation. Renal blood flow was reduced by the head-up position and increased pressure. There was no correlation (p < 0.6) between systemic hemodynamic parameters (cardiac output, central venous pressure, and systemic vascular resistance) and hepatic and renal blood flow. Conclusions. Head-up position and intraperitoneal pressure greater than 12 mm Hg should be avoided during laparoscopic surgery because they compromise hepatic and renal blood flow. Argon insufflation impairs liver blood flow. However, helium may be advantageous compared with CO 2 insufflation.