A patient with chronic kidney disease presents with fatigue, dyspnea on exertion, peripheral edema, and hypertension. Laboratory findings reveal elevated serum creatinine and urea levels, metabolic acidosis, and hyperkalemia. What is the most appropriate initial management for this patient?

Correct Answer: B

Rationale: The most appropriate initial management for the patient described is hemodialysis. Hemodialysis is essential for managing chronic kidney disease with severe symptoms and electrolyte imbalances like hyperkalemia and metabolic acidosis. Hemodialysis helps to remove urea and creatinine from the blood, correct electrolyte abnormalities, and improve symptoms such as fatigue, dyspnea, and peripheral edema. Initiation of ACE inhibitor therapy (Choice A) is contraindicated in severe kidney disease due to the risk of worsening renal function. Intravenous administration of calcium gluconate (Choice C) is used for acute hyperkalemia with cardiac toxicity, not for initial management. Sodium bicarbonate administration (Choice D) may help correct metabolic acidosis, but it does not address the underlying cause or the need for urgent renal replacement therapy.

Correct Answer: C

Rationale: The correct answer is C: Cryptosporidium parvum. This parasite is the most likely cause of the infection due to its presentation with watery diarrhea, abdominal cramps, and nausea after consuming contaminated water. Laboratory tests revealing oocysts in the stool sample further support this diagnosis as Cryptosporidium parvum is known to produce oocysts in the stool. Giardia lamblia (choice A) presents with similar symptoms but does not typically produce oocysts. Entamoeba histolytica (choice B) is more associated with bloody diarrhea and liver abscesses. Cyclospora cayetanensis (choice D) is also associated with watery diarrhea but is less common in this scenario. Thus, based on the symptoms and laboratory findings, Cryptosporidium parvum is the most likely culprit.

Correct Answer: A

Rationale: The correct answer is A: Plasmodium falciparum. Plasmodium falciparum is the most likely causative agent because the patient's symptoms of fever, chills, headache, and myalgia, along with the presence of intraerythrocytic ring forms and trophozoites on blood smear, are characteristic of malaria, particularly caused by P. falciparum in sub-Saharan Africa. Summary of other choices: B: Trypanosoma cruzi causes Chagas disease, which presents with symptoms like fever, rash, and swelling at the site of entry, not consistent with the patient's presentation. C: Borrelia burgdorferi causes Lyme disease, which typically presents with a characteristic rash (erythema migrans) and arthritis, not matching the patient's symptoms. D: Leishmania donovani causes visceral leishmaniasis, which presents with symptoms like weight loss, hepatosplen

Correct Answer: B

Rationale: In this scenario, the pregnant woman is presenting with severe abdominal pain, passage of tissue, and cervical dilation with products of conception protruding through the cervical os at 12 weeks gestation. These are classic signs and symptoms of an incomplete abortion. Incomplete abortion occurs when not all of the products of conception are expelled from the uterus. It can present with vaginal bleeding, abdominal pain, cervical dilation, and passage of tissue. The management of incomplete abortion may involve expectant, medical, or surgical options depending on the clinical context and the patient's condition.

Correct Answer: C

Rationale: The scenario described in the question is consistent with acute cholecystitis, which is inflammation of the gallbladder usually caused by an impacted gallstone in the cystic duct. The key clinical features of acute cholecystitis include fever, chills, right upper quadrant abdominal pain (which can be localized to the right upper quadrant), tenderness in the right upper abdomen, and a positive Murphy's sign (pain and inspiratory arrest upon palpation of the right upper quadrant). This condition is more common in pregnant women due to hormonal changes that can lead to gallstone formation and subsequent inflammation of the gallbladder. Ectopic pregnancy, pelvic inflammatory disease, and ovarian torsion typically present with different clinical features compared to those described in acute cholecystitis.