When determining the focus group for a community screening program, the nurse recognizes which ethnic group as having the highest incidence of colorectal cancer?

Choice A rationale

High-dose corticosteroid therapy, such as with prednisone, can cause hypokalemia by increasing potassium excretion in the kidneys. These steroids mimic the action of aldosterone, which promotes sodium reabsorption and potassium excretion in the distal convoluted tubules and collecting ducts. This process leads to increased urinary loss of potassium, potentially causing a serum potassium level below the normal range of 3.5 to 5.0 mEq/L.

Choice B rationale

Hypermagnesemia is not a typical side effect of corticosteroid therapy. Corticosteroids primarily affect sodium and potassium balance. Hypermagnesemia is more commonly associated with kidney failure or excessive intake of magnesium-containing medications. The kidneys are highly efficient at excreting magnesium, so elevated levels (normal range 1.5 to 2.5 mEq/L) are rare unless renal function is compromised.

Choice C rationale

Corticosteroid therapy actually increases the excretion of potassium from the body, leading to a decrease in serum potassium levels, not an increase. The mineralocorticoid effects of these drugs cause increased activity of the sodium-potassium pump in renal tubules, leading to the exchange of potassium for sodium, resulting in increased urinary potassium loss and a risk for hypokalemia.

Choice D rationale

While some electrolyte imbalances can occur, hypomagnesemia is not a primary concern directly linked to high-dose corticosteroid therapy. Corticosteroids' main effect on electrolytes is their mineralocorticoid activity, which primarily targets sodium and potassium regulation. Hypomagnesemia is more commonly associated with conditions like chronic alcoholism, malnutrition, or gastrointestinal losses.

Choice A rationale

Red blood cells are produced in the bone marrow, not the kidneys, and they do not produce erythropoietin. Erythropoietin is a hormone primarily produced by the kidneys in response to tissue hypoxia, which stimulates the bone marrow to produce red blood cells, thus increasing the oxygen-carrying capacity of the blood.

Choice B rationale

Anemia in renal insufficiency is not primarily related to vitamin D deficiency or bone density loss. While kidney disease can affect vitamin D activation and calcium-phosphate balance, the main cause of anemia in this context is the decreased production of erythropoietin by the failing kidneys.

Choice C rationale

The kidneys are the primary producers of erythropoietin in the body. When kidney function is compromised, this production is significantly reduced, leading to inadequate stimulation of the bone marrow. This results in decreased red blood cell production, causing the anemia commonly seen in patients with chronic renal insufficiency.