Effects of cardiac preload reduction and dobutamine on hepatosplanchnic blood flow regulation in porcine endotoxemia.

Insufficient cardiac preload and impaired contractility are frequent in early sepsis. We explored the effects of acute cardiac preload reduction and dobutamine on hepatic arterial (Qha) and portal venous (Qpv) blood flows during endotoxin infusion. We hypothesized that the hepatic arterial buffer response (HABR) is absent during preload reduction and reduced by dobutamine.

Increasing abdominal pressure with and without PEEP: effects on intra-peritoneal, intra-organ and intra-vascular pressures.

Background: Intra-organ and intra-vascular pressures can be used to estimate intra-abdominal pressure. The aim of this prospective, interventional study was to assess the effect of PEEP on the accuracy of pressure estimation at different measurement sites in a model of increased abdominal pressure.

Methods: Catheters for pressure measurement were inserted into the stomach, urinary bladder, peritoneal cavity, pulmonary artery and inferior vena cava of 12 pigs.

Membrane microdialysis: Evaluation of a new method to assess splanchnic tissue metabolism.

Objective: Measuring peritoneal lactate concentrations could be useful for detecting splanchnic hypoperfusion. The aims of this study were to evaluate the properties of a new membrane-based microdialyzer in vitro and to assess the ability of the dialyzer to detect a clinically relevant decrease in splanchnic blood flow in vivo.

Design: A membrane-based microdialyzer was first validated in vitro.

Effects of low abdominal blood flow and dobutamine on blood flow distribution and on the hepatic arterial buffer response in anaesthetized pigs.

Low cardiac output impairs the hepatic arterial buffer response (HABR). Whether this is due to low abdominal blood flow per se is not known. Dobutamine is commonly used to increase cardiac output, and it may further modify hepatosplanchnic and renal vasoregulation.

Hepatosplanchnic blood flow control and oxygen extraction are modified by the underlying mechanism of impaired perfusion.

Objective: To assess the effects of low hepatosplanchnic blood flow on regional blood flow control and oxygenation.

Design: Three randomized, controlled animal experiments.

Setting: Two university experimental research laboratories.

Changes in regional blood flow and pCO(2) gradients during isolated abdominal aortic blood flow reduction.

Objective: pCO(2) gradients are used for the assessment of splanchnic regional and local mucosal blood flow changes in experimental and clinical research. pCO(2) gradients may not parallel blood flow changes because of concomitant changes in metabolism, hemoglobin, temperature, and the Haldane effect.

Design And Setting: A randomized, controlled animal experiment in a university experimental research laboratory.

Change in stroke volume in response to fluid challenge: assessment using esophageal Doppler.

Objective: To compare two methods of assessing a change in stroke volume in response to fluid challenge: esophageal Doppler and thermodilution with the pulmonary artery catheter.

Design: Prospective study.

Setting: Department of Intensive Care of a university medical center.