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case study for Alcoholism in med surg 2 clinicals...

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Nestor Gardon Jr. Booze Blues: A Case on the Liver

1. Besides the nurse’s “bender” comment, and Mrs. Fender’s social history, Tim suspects alcohol abuse based on many of his physical exam findings. Name at least three signs and/or symptoms that point to alcoholism, and briefly explain why each sign/symptom may occur.   

Bruising of arms and legs because slow clotting times (prothrombin times – clotting factors produced in the liver). Elevated blood transaminases because of destruction of hepatocytes Jaundice – elevated bilirubin because of liver dysfunction

2. The liver is known for its ability to remove certain toxins from the blood. It can perform this function because its cells, or hepatocytes, contain large quantities of lysosomes and peroxisomes, and also have an extensive smooth endoplasmic reticulum. Briefly describe how these three organelles contribute to this major function of the liver.   

Lysosomes and peroxisomes are membranous organelles that engulf toxins by endocytosis. Lysosomes contain acid hydrolases that digest the toxins so they can be safely eliminated by the cell. Peroxisomes contain oxidases and catalases that detoxify substances like alcohol and neutralize free radicals. The oxidases convert free radicals to hydrogen peroxide, while the catalases complete the process by converting the hydrogen peroxide to water. The smooth endoplasmic reticulum (ER) is part of a network of interconnecting, fluid-filled tubules. The smooth ER contains enzymes (such as the cytochrome P450 enzymatic system) that detoxify certain drugs (such as alcohol).

3. Mrs. Fender’s jaundice is caused by the accumulation of bilirubin in her blood and tissues. What is the normal fate of bilirubin, and what role does the liver play? Explain how Mrs. Fender’s cirrhosis is related to her jaundice. 

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Hemoglobin from worn-out erythrocytes is broken down into heme and iron. The iron is recycled, and the heme is further degraded into bilirubin, bound to albumin, and carried to the liver. The liver removes it from the blood and excretes it into the intestines as bile. When the liver is damaged (as in cirrhosis or hepatitis), bilirubin, which is a yellow pigment, spills over into tissues and the blood, thus giving tissues, blood, and the overlying skin a yellowish appearance, especially the lighter skin of the palms of the hands. Jaundice is also more apparent in the white sclera of the eyes.

4. Mrs. Fender’s prolonged clotting times and excessive bruising are related. Again, referring to normal physiological functioning of the liver, why do these two things happen when alcohol damages hepatocytes? 

The liver produces clotting proteins. When it is damaged (as in cirrhosis), clotting proteins are underproduced and it takes longer for blood to clot (prolonged prothrombin time). This can be evidenced by excessive bruising as well.

5. The liver has a portal vein as well as a hepatic vein. It also has unique exchange blood vessels similar to capillaries, called “sinusoids.” How do these unique structures determine the function of the organ? 

A liver sinusoid is a type of sinusoidal blood vessel (with fenestrated, discontinuous endothelium) that serves as a location for mixing of the oxygen-rich blood from the hepatic artery and the nutrient-rich blood from the portal vein. The walls of the sinusoids allow plasma and solute to 1

Nestor Gardon Jr. Booze Blues: A Case on the Liver

leak into the interstitial space between surrounding hepatocytes. In essence, the blood "percolates" in the sinusoids on its way to the hepatic veins, and then to the vena cava. This percolation is ideal for hepatocytes to filter the blood, process and store nutrients, detoxify (e.g., remove ammonia), and remove debris (e.g., worn-out RBCs, bacteria). 6. Cirrhosis leads to scarring and increased hydrostatic pressure in the hepatic portal vein. Explain why this increased venous pressure causes net filtration to increase in the hepatic capillaries, leading to ascites (swollen and fluid-filled interstitial space of the abdomen). 

In alcoholic cirrhosis, the portal vein becomes scarred and blocked, causing an increase in hydrostatic pressure (portal hypertension). This leads to an increase in capillary hydrostatic pressure. Alcoholic cirrhosis also causes the liver to underproduce albumin. This lowers osmotic pressure in the vasculature, enhancing filtration out of the capillaries.

7. Explain why the underproduction of albumin by a cirrhotic liver contributes to excessive filtration, which leads to ascites. Refer again to the forces that determine net filtration pressure in the hepatic capillaries, and to the function of albumins. 

The liver is the major production site of albumins. Albumin (the main protein) is typically too large to diffuse across the capillary wall, so it remains in the blood vessels where they create an osmotic force that maintains water volume in the vasculature. In fact, albumins are the primary source of osmotic pressure, contributing to the reabsorption of water.

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