The hepatorenal reflex contributes to the induction of oliguria during pneumoperitoneum in the rat

Nonalcoholic Fatty Liver Disease and Chronic Kidney Disease: Epidemiology, Pathogenesis, and Clinical and Research Implications

Nonalcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease worldwide, affecting up to ~30% of adult populations. NAFLD defines a spectrum of progressive liver conditions ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma, which often occur in close and bidirectional associations with metabolic disorders. Chronic kidney disease (CKD) is characterized by anatomic and/or functional renal damage, ultimately resulting in a reduced glomerular filtration rate. The physiological axis linking the liver and kidneys often passes unnoticed until clinically significant portal hypertension, as a major complication of cirrhosis, becomes apparent in the form of ascites, refractory ascites, or hepatorenal syndrome. However, the extensive evidence accumulated since 2008 indicates that noncirrhotic NAFLD is associated with a higher risk of incident CKD, independent of obesity, type 2 diabetes, and other common renal risk factors. In addition, subclinical portal hypertension has been demonstrated to occur in noncirrhotic NAFLD, with a potential adverse impact on renal vasoregulation. However, the mechanisms underlying this association remain unexplored to a substantial extent. With this background, in this review we discuss the current evidence showing a strong association between NAFLD and the risk of CKD, and the putative biological mechanisms underpinning this association. We also discuss in depth the potential pathogenic role of the hepatorenal reflex, which may be triggered by subclinical portal hypertension and is a poorly investigated but promising research topic. Finally, we address emerging pharmacotherapies for NAFLD that may also beneficially affect the risk of developing CKD in individuals with NAFLD.

[Central venous pressure in liver surgery : A primary therapeutic goal or a hemodynamic tessera?]

Central venous pressure (CVP) is deemed to be an important parameter of anesthesia management in liver surgery. To reduce blood loss during liver resections, a low target value of CVP is often propagated. Although current meta-analyses have shown a connection between low CVP and a reduction in blood loss, the underlying studies show methodological weaknesses and advantages with respect to morbidity and mortality can hardly be proven. The measurement of the CVP itself is associated with numerous limitations and influencing factors and the measures to reduce the CVP have been insufficiently investigated with respect to hepatic hemodynamics. The definition of a generally valid target area for the CVP must be called into question. The primary objective is to maintain adequate oxygen supply and euvolemia. The CVP should be regarded as a mosaic stone of hemodynamic management.