Physiology of a Sick Person (real Example)

Calcium and sodium imbalance

Sarah suffers from cirrhosis of the liver. Cirrhosis of the liver is a disease where healthy liver tissue is slowly replaced with scar tissue. One of the functions of the liver is to extract nutrients from the blood. In Sarah’s case there is scar tissue blocking the flow of blood through the liver; this then inhibits the liver’s ability to process nutrients. As Sarah’s liver cells continue to scar the results are the loss of liver function. If the liver loses its function it is then unable to produce angiotensinogen, which is needed to start the renin-angiotensin-aldosterone-system which leads to an increase of sodium levels in the blood. Without angiotensinogen, the absorption of sodium stops. Sarah’s lab results indicate that she has a decreased level of sodium. The liver’s inability to produce angiotensinogen explains the low levels of sodium in Sarah’s lab results. Sarah’s lab results also show low levels of aldosterone because angiotensin stimulates the release of aldosterone from the adrenal cortex to promote sodium retention by the kidneys.

Healthy kidneys play a huge role in activating vitamin D. The active form of vitamin D is 1,25- dihydroxyvitamin D3 and when it is released it will stimulate the intestines to reabsorb calcium from the diet. Since Sarah suffers from end-stage kidney disease her kidneys are not able to activate vitamin D properly. If Sarah can not activate vitamin D she also can not absorb calcium. This is why Sarah has low levels of calcium.

Anemia and lab tests

Anemia is a deficiency of red blood cells in the body. Red blood cells carry oxygen and remove carbon dioxide from the body. Since Sarah suffers from end-stage kidney disease, her kidneys are not able to produce erythropoietin. Erythropoietin is a hormone produced by the kidneys that helps produce red blood cells. Erythropoiesis is the process of stimulating red blood cell production from bone marrow with the release of the hormone erythropoietin to carry oxygen to the rest of the body. Because Sarah’s kidneys are damaged, the bone marrow produces fewer red blood cells resulting in decreased levels of iron and oxygen in the body. The RBC count or CBC test was the indicator that Sarah has anemia.

Hypotension and homeostasis

Sarah is experiencing abnormally low blood pressure--or hypotension--and decreased blood viscosity because her bone marrow is not producing sufficient red blood cells. Homeostasis is a description of how the human body attempts to keep a relatively stable environment. Sarah’s body will try to correct her hypotension by five different mechanisms that regulate blood pressure. These mechanisms include: heart rate, peripheral resistance, blood viscosity, stroke volume, and blood volume.

Acid-base disorder and compensation

Sarah has metabolic acidosis, which is a condition where too much acid is in the body. Causes of metabolic acidosis can include buildup of toxins or kidney failure. Since Sarah suffers from end-stage kidney disease, metabolic acidosis is a logical diagnosis. To further confirm this diagnosis, one would evaluate Sarah’s lab results and likely discover low pH, low CO2, and low bicarbonate levels, the hallmarks of metabolic acidosis.

Sarah’s respiratory system would attempt to compensate for this state of acidosis by hyperventilating. Hyperventilating would release carbon dioxide and restore normal acid base balance. However, because Sarah has a long history of smoking, she would have difficulties trying to compensate.

ADH and glucose levels

Antidiuretic hormone, also known as ADH, is a hormone that acts on the kidneys to control the amount of water being released in the urine. Sarah is experiencing elevated ADH levels. The elevated ADH levels are in response to Sarah’s low blood pressure. Normally, ADH would cause the kidneys to reabsorb water but in Sarah's case her kidneys are failing and she can not reabsorb water therefore, she can not raise her blood pressure and ADH levels will remain high because the posterior pituitary is functioning normally and releasing ADH while the kidney is not functioning. Sarah also has increased glucose levels. The increase in glucose levels are because Sarah has a history of diabetes. Sarah suffers from diabetes mellitus a disease in which the body cannot produce or respond to the hormone insulin. This results in increased levels of glucose in the blood and urine.

Vitamins, renin and aldosterone levels

Vitamins are very important for maintaining a healthy body. When someone is vitamin deficient they can have serious complications. Fat soluble Vitamins D, K, E, and A are needed for a few important functions. Vitamin D is needed to absorb calcium and stimulate bone growth, vitamin E is an antioxidant, vitamin K is needed to produce prothrombin and factors 10, 9, 7, these are proteins that are vital in blood clotting and bone metabolism, and vitamin A strengthens vision. Sarah suffers from a vitamin deficiency. Her lack of important vitamins are due to her livers inability to absorb and digest lipids. One of the main functions of the liver is to produce bile. The production of bile is needed to help with fat absorption. Since Sarah has cirrhosis of the liver her liver is unable to function properly and fat soluble vitamins cannot be absorbed.

The renin-angiotensin-aldosterone-system is a hormone system that regulates blood pressure. When a drop in blood pressure occurs renin is secreted from the juxtaglomerular granular cells. Renin then converts angiotensinogen into angiotensin I. Angiotensin I is converted into angiotensin II by the angiotensin-converting enzyme or (ACE) in the lungs. Angiotensin II is also a vasoconstrictor. Vasoconstriction is another way the body increases blood pressure. When angiotensin II gets to the adrenal gland it causes a release of aldosterone. The aldosterone causes a reabsorption of sodium. Sodium alone does not raise blood pressure, but an increase in sodium increases osmolarity and results in someone becoming thirsty. When this person drinks more water their extracellular fluid volume increases. As said above, when blood volume increases so does blood pressure. Since Sarah suffers from end stage kidney disease, therefore her kidneys are not able to produce renin. This explains her low levels of renin. Without renin the renin-angiotensin-aldosterone-system will not occur and Sarah’s blood pressure would not improve. The reason Sarah has low levels of aldosterone is because without the release of renin, aldosterone would not be released from the adrenal cortex.

Calcium homeostasis

Sarah’s lab results reveal low calcium levels. This is another complication of end stage kidney disease. Sarah’s kidneys are unable to absorb calcium from urine and fails to activate Vitamin D. Sarah’s body will attempt to bring her calcium levels back to normal by secreting the Parathyroid hormone. The Parathyroid hormone will break down bone in order to reabsorb calcium into the blood. The parathyroid hormone will reabsorb calcium from the kidneys. Lastly, parathyroid hormone will also activate vitamin D to reabsorb calcium from the intestines. All these mechanisms combined will attempt to raise Sarah’s calcium levels.

Physical findings

After a physical examination it appears that Sarah has a yellowish discoloration to the skin and sclera. The yellowish discoloration of Sarah’s skin and eyes is called jaundice. Jaundice is caused by an excessive amount of pigment called bilirubin and can be caused by obstruction of the bile duct, by liver disease, or by excessive breakdown of red blood cells.

Sarah also presents with multiple bruises. These bruises are because Sarah has cirrhosis of the liver and cirrhosis of the liver inhibits the absorption of vitamins. This results in Sarah having a vitamin K deficiency. Since Sarah has a vitamin K deficiency, vitamin K-dependent clotting factors 2, 7, 9, and 10 cannot be produced. If these factors can not be produced then blood clotting cannot occur. This explains Sarah’s multiple bruises.

Sarah has also been suffering from muscle weakness that has lasted longer than three weeks. The reason Sarah has been experiencing muscle weakness is because she has decreased levels of calcium in her body. Calcium plays an important role in muscle contraction. When calcium bind to troponin, it causes tropomyosin to move causing a contraction. When the muscle relaxes it is due to the absence of calcium. Once calcium is removed from troponin the muscle will return to its original position.

Edema is swelling, usually in the feet, legs, or hands due to excess amounts of fluid within the surrounding tissues. Sarah has 2+ bilateral edema as a result of the failure of her kidney and liver. The edema Sarah is experiencing is due to excess salt retention.

Abnormal stool and urine sample

Sarah’s abnormal stool and urine shows that she is unable to metabolize bilirubin to create bile, urobilin, and stercobilin. Sarah’s liver is not functioning properly and therefore, bilirubin is not converted into bile. Since Sarah cannot produce the right amount of bile, she will not be able to digest fats. This is why Sarah’s stool appears grey in color because she has an elevated fat content in her stool. Stercobilin is what gives bile the brown color and urobilin gives urine its yellow color. Since Sarah’s liver is not functioning correctly urine and bile will have an abnormal color.

Glisten and insulin secretion

Sarah has a history of diabetes mellitus. The reason diabetes is a problem is because the person who has diabetes either doesn’t produce enough insulin, the insulin they do produce doesn’t work, or their cells no longer respond to insulin. All three of these reasons have the same problem. That is that glucose can not be cleared from their blood and it results in high blood glucose levels. Since Sarah has diabetes she has been prescribed a drug called Glisten. Glisten is a new drug for diabetes that causes ATP sensitive potassium channels to close, thereby releasing Insulin. Glisten works on the beta cells of the pancreas in order to stimulate insulin secretion.

Conclusion

The human body has many mechanisms to maintain homeostasis. In Sarah’s case her body could not overcome her complications. Sarah presented to the emergency room in poor health. Sarah’s liver and kidney failure have caused a number of complications. Since Sarah has cirrhosis of the liver she has a calcium and sodium imbalance, vitamin deficiency, jaundice, multiple bruises, and edema. Also Sarah suffers from end stage kidney disease which results in anemia, metabolic acidosis, and hypotension. In order to improve Sarah’s health, she will need kidney and liver transplants. Sarah also has a history of diabetes mellitus and a 30 pack a year smoking history. Sarah’s poor health added increased difficulty for her body to attempt to bring her abnormal levels back to normal. 

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