A 50-year-old man with a long history of chronic obstructive pulmonary disease has noticed increasingly swollen ankles. He does not have any features of pulmonary oedema but has a raised jugular venous pressure. Which of the following is the most likely diagnosis?

Correct Answer: D

Rationale: The most likely diagnosis for the 50-year-old man with swollen ankles, raised jugular venous pressure, and a history of chronic obstructive pulmonary disease is right heart failure (Choice D). In this case, the patient's symptoms suggest signs of right-sided heart failure, such as peripheral edema and jugular venous distention. Chronic obstructive pulmonary disease can lead to pulmonary hypertension, causing right heart failure. Asthma (Choice A) is primarily a respiratory condition, not typically associated with jugular venous distention or peripheral edema. Congestive heart failure (Choice B) usually presents with features of pulmonary edema and bilateral lower extremity edema, rather than isolated right-sided heart failure. Constrictive pericarditis (Choice C) may present with jugular venous distention, but it is less common compared to right heart failure in a patient with a history of chronic obstructive pulmonary disease.

Correct Answer: D

Rationale: The correct answer is D: Idiopathic. Idiopathic pulmonary fibrosis is the most common cause of pulmonary fibrosis, accounting for about 20-30% of cases. It is a chronic and progressive lung disease of unknown cause. Other choices are less common causes: A) Iatrogenic refers to fibrosis caused by medical interventions, B) Occupational chemical exposure can lead to fibrosis but is not the most common cause, and C) Sarcoidosis causes granulomatous inflammation, not fibrosis.

Correct Answer: B

Rationale: The correct answer is B: Misoprostol is superior to an H2-blocker in prophylaxis against NSAID-related GI toxicity. Misoprostol is a prostaglandin analog that helps protect the stomach lining, reducing the risk of NSAID-induced ulcers. H2 blockers only reduce acid production and do not address the underlying mechanism of NSAID-induced injury. Sucralfate does not provide as effective prophylaxis as misoprostol. H. pylori infection can increase the risk of NSAID-induced ulcers; eradication of H. pylori can reduce this risk.

Correct Answer: B

Rationale: The correct answer is B: Proton-pump inhibitor. The patient's symptoms of chest pain and dysphagia suggest possible gastroesophageal reflux disease (GERD). Proton-pump inhibitors reduce gastric acid production, providing relief for symptoms of GERD. This is the most appropriate initial therapy given the symptoms. Choice A: Sucralfate is a cytoprotective agent that forms a protective barrier over ulcers but does not address the underlying issue of acid reflux. Choice C: Prokinetic agents help with motility disorders but are not the first-line treatment for GERD. Choice D: Benzodiazepines are not indicated for the treatment of GERD and would not address the underlying cause of the patient's symptoms.

Correct Answer: D

Rationale: The correct answer is D: Obtain serologic studies for antibodies to Trypanosoma cruzi. This patient's presentation is consistent with Chagas disease, caused by Trypanosoma cruzi. The patient is from Brazil, where Chagas disease is endemic. The dilated esophagus and lower esophageal sphincter tapering are classic findings of megaesophagus, a complication of Chagas disease. Serologic studies for antibodies to Trypanosoma cruzi are necessary for definitive diagnosis. Choice A: Refer for partial esophagectomy - Not appropriate as surgery is not indicated without confirming the diagnosis. Choice B: Thick and thin smears of peripheral blood looking for parasites - Not appropriate as Chagas disease is diagnosed through serologic testing, not blood smears. Choice C: Therapeutic trial of a proton pump inhibitor - Not appropriate as the patient's symptoms are likely due to Chagas disease, not gastroesophageal reflux disease.