A patient with chronic kidney disease presents with progressively worsening anemia and elevated serum phosphate levels. Which medication is commonly prescribed to reduce serum phosphate levels in patients with chronic kidney disease?

Correct Answer: C

Rationale: Sevelamer is a medication commonly prescribed to reduce serum phosphate levels in patients with chronic kidney disease. Sevelamer is a phosphate binder that works by binding to dietary phosphate in the gut, preventing its absorption into the bloodstream. By reducing serum phosphate levels, sevelamer helps manage complications associated with hyperphosphatemia in chronic kidney disease patients, such as mineral and bone disorders. Other medications like epoetin alfa are used to treat anemia commonly seen in chronic kidney disease patients, while cinacalcet is used to manage secondary hyperparathyroidism. Allopurinol, on the other hand, is used to treat gout by reducing uric acid levels and is not indicated for reducing serum phosphate levels in chronic kidney disease patients.

Correct Answer: D

Rationale: Nephrolithiasis refers to the formation of stones within the kidney or urinary tract. The most common types of kidney stones are either composed of calcium oxalate or calcium phosphate. When these stones form within the renal collecting system, they can lead to symptoms such as flank pain, hematuria, and urinary obstruction. Ureteropelvic junction (UPJ) obstruction and ureterovesical junction (UVJ) obstruction are specific types of blockages within the urinary system that can be caused by kidney stones but are not characteristic of the stone formation itself. Renal colic is the term used to describe the severe pain associated with the passage of a kidney stone through the ureter.

Correct Answer: A

Rationale: The clinical presentation of fever, chills, headache, and myalgia following a trip to sub-Saharan Africa is highly suggestive of malaria, which is caused by the Plasmodium species. Specifically, the presence of intraerythrocytic ring forms and trophozoites on blood smear examination points towards Plasmodium falciparum as the most likely causative agent.

Correct Answer: C

Rationale: The clinical presentation described with fever, headache, maculopapular rash starting on the face and spreading to the trunk and extremities, along with leukopenia and thrombocytopenia suggests a likely diagnosis of Rocky Mountain spotted fever (RMSF), which is caused by the bacterium Rickettsia rickettsii.

Correct Answer: D

Rationale: Incompetent cervix, also known as cervical insufficiency, is the most likely cause of the symptoms described. Incompetent cervix is a condition where the cervix begins to dilate and efface prematurely, typically in the second trimester, without contractions or labor. This can lead to painless cervical dilation and bulging of the amniotic sac into the vagina, which can cause vaginal bleeding and crampy abdominal pain. It is a leading cause of second-trimester pregnancy loss. Treatment may involve a cervical cerclage, a surgical procedure where the cervix is stitched closed to provide additional support.