Effect of increasing cardiac preload, sympathetic antagonism, or vasodilation on visceral blood flow during pneumoperitoneum

Abstract

An impaired visceral perfusion caused by pneumoperitoneum may contribute to morbidity after laparoscopic surgery. The following three therapeutic concepts: increasing cardiac preload, controlled vasodilation, or selective sympathetic antagonism, were evaluated regarding a possible increase of visceral blood flow during pneumoperitoneum with carbon dioxide. Forty three pigs were assigned to treatment with an increase of preload and vasodilation (group A) or selective sympathetic antagonism with esmolol (group B). In both groups, pigs were assigned to head-up, head-down, or supine position. Perfusion of the vena porta and renal artery was measured by transonic volume flow meters and documented before capnoperitoneum, after induction of a 14-mmHg capnoperitoneum in each body position, after controlled vasodilation with sodium nitroprusside, and after controlled increase of intravascular volume by colloidal infusion. Increasing intravascular volume improved portal blood flow in all body positions (p<0.05), but not renal blood flow. Medication of esmolol did not alter the measured parameters in any body position compared to control. Vasodilation with sodium nitroprusside reduced renal blood flow in supine and in head-up position. An optimal intravascular volume was most effective in improving portal blood flow during capnoperitoneum in this trial. Esmolol had no negative effects on portal and renal blood flow. Patients with renal dysfunction might be treated carefully with sodium nitroprusside during capnoperitoneum.