HESI Registered Nurse EXIT Practice Exam

What pathophysiological mechanism is responsible for ascites related to liver failure?

1. Decreased serum protein affecting fluid shifts

2. Increased hydrostatic pressure in portal circulation

3. Increased circulating aldosterone levels

4. All of the above

The correct answer is: All of the above

Ascites, the accumulation of fluid in the peritoneal cavity, is a common complication of liver failure and results from a combination of several pathophysiological mechanisms. The first mechanism involves decreased serum protein levels, particularly albumin, due to the liver's impaired ability to synthesize proteins. This leads to a reduction in oncotic pressure, which normally helps to retain fluid within the vascular compartments. When serum protein levels drop, fluid shifts from the vascular space into the interstitial tissues and, eventually, into the peritoneal cavity. Another contributing factor is the increased hydrostatic pressure in the portal circulation, a condition known as portal hypertension. When the liver becomes cirrhotic or severely damaged, blood flow through the liver is obstructed, causing pressure to increase in the portal vein. This elevated pressure forces fluid out of the capillaries and contributes further to the formation of ascitic fluid. Circulating aldosterone levels often rise in response to decreased renal perfusion due to low blood volume associated with ascites and other factors related to liver dysfunction. Aldosterone promotes sodium and water retention by the kidneys, which can exacerbate fluid retention and ascites. Each of these mechanisms contributes to the development of ascites in liver failure, making