A 70-year-old man is admitted with fever, chills, and rigor which have lasted for 4 days. He also complains of associated recent-onset fatigue. Past medical history is insignificant. He drinks a can of beer every night. His temperature is 39.0°C (102.2°F), pulse is 120/min, blood pressure is 122/80 mm Hg, and respirations are 14/min. Physical examination reveals splinter hemorrhages in the fingernails, and a 2/6 apical pansystolic murmur is heard which was not present during his last visit a month ago. A transoesophageal echocardiogram shows evidence of vegetations over the mitral valve. Blood cultures are taken from 3 different sites, which reveal the growth of Streptococcus gallolyticus. The patient is started on the appropriate antibiotic therapy which results in rapid clinical improvement. Which of the following would be the best next step in management in this patient after he is discharged?
Q52
A 33-year-old man comes to the physician 1 hour after he slipped in the shower and fell on his back. Since the event, he has had severe neck pain. He rates the pain as an 8–9 out of 10. On questioning, he has had lower back pain for the past 2 years that radiates to the buttocks bilaterally. He reports that the pain sometimes awakens him at night and that it is worse in the morning or when he has been resting for a while. His back is very stiff in the morning and he is able to move normally only after taking a hot shower. His temperature is 36.3°C (97.3°F), pulse is 94/min, and blood pressure is 145/98 mm Hg. Range of motion of the neck is limited due to pain; the lumbar spine has a decreased range of motion. There is tenderness over the sacroiliac joints. Neurologic examination shows no abnormalities. An x-ray of the cervical spine shows decreased bone density of the vertebrae. An MRI shows a C2 vertebral fracture as well as erosions and sclerosis of the sacroiliac joints bilaterally. The patient's condition is most likely associated with which of the following findings?
Q53
Two days after undergoing emergent laparotomy with splenectomy for a grade IV splenic laceration sustained in a motor vehicle collision, a 54-year-old man develops decreased urinary output. His urine output is < 350 mL/day despite aggressive fluid resuscitation. During the emergent laparotomy, he required three units of packed RBCs. He has type 2 diabetes mellitus and is on an insulin sliding scale. His vital signs are within normal limits. Physical examination shows a healing surgical incision in the upper abdomen and multiple large ecchymoses of the superior right and left abdominal wall. His hematocrit is 28%, platelet count is 400,000/mm3, serum creatinine is 3.9 mg/dL, and serum urea nitrogen concentration is 29 mg/dL. Urinalysis shows brown granular casts. Which of the following is the most likely underlying cause of these findings?
Q54
A 32-year-old man recently visiting from Thailand presents with diarrhea and fatigue for the past 6 days, which began before leaving Thailand. The patient denies any recent history of laxatives, nausea, or vomiting. His vital signs include: blood pressure 80/50 mm Hg, heart rate 105/min, and temperature 37.7°C (99.8°F). On physical examination, the patient is pale with dry mucous membranes. A stool sample is obtained for culture, which is copious and appears watery. Which of the following is the correct categorization of this diarrheal disease?
Q55
A 72-year-old woman presents to her primary care provider complaining of fatigue for the last 6 months. She can barely complete her morning chores before having to take a long break in her chair. She rarely climbs the stairs to the second floor of her house anymore because it is too tiring. Past medical history is significant for Hashimoto's thyroiditis, hypertension, and hyperlipidemia. She takes levothyroxine, chlorthalidone, and atorvastatin. Her daughter developed systemic lupus erythematosus. She is retired and lives by herself in an old house built in 1945 and does not smoke and only occasionally drinks alcohol. She eats a well-balanced diet with oatmeal in the morning and some protein such as a hardboiled egg in the afternoon and at dinner. Today, her blood pressure is 135/92 mm Hg, heart rate is 110/min, respiratory rate is 22/min, and temperature is 37.0°C (98.6°F). On physical exam, she appears frail and her conjunctiva are pale. Her heart is tachycardic with a regular rhythm and her lungs are clear to auscultation bilaterally. A complete blood count (CBC) shows that she has macrocytic anemia. Peripheral blood smear shows a decreased red blood cell count, anisocytosis, and poikilocytosis with occasional hypersegmented neutrophils. An endoscopy and colonoscopy are performed to rule out an occult GI bleed. Her colonoscopy was normal. Endoscopy shows thin and smooth gastric mucosa without rugae. Which of the following is the most likely cause of this patient's condition?
Q56
A 49-year-old man presents to his primary care physician complaining of heartburn and mild epigastric pain after eating for the past 6 months. He reports that his symptoms occur within an hour of eating a meal and persist for approximately an hour. He admits his symptoms have been progressively worsening. He recently began having these symptoms when he lies in the supine position. He has tried eating smaller meals and avoiding spicy food to no avail. He denies vomiting, difficulty swallowing, recent weight loss, or changes in stool color. He does admit to having a "sour" taste in his mouth when symptomatic. His temperature is 99.0°F (37.2°C), blood pressure is 149/82 mmHg, pulse is 86/min, respirations are 18/min, and BMI is 32 kg/m^2. His abdomen is soft, non-tender, and bowel sounds are auscultated in all quadrants. Laboratory results demonstrate the following:
Serum:
Hemoglobin: 13.5 g/dL
Hematocrit: 41%
Leukocyte count: 4,500/mm^3 with normal differential
Platelet count: 257,000/mm^3
Fecal occult blood test (FOBT): Negative
Which of the following is the next best step in management?
Q57
A 61-year-old man with HIV comes to the physician because of a 3-week history of fatigue, nonproductive cough, and worsening shortness of breath. He appears ill. Pulse oximetry on room air shows an oxygen saturation of 89%. Laboratory studies show a CD4+ T-lymphocyte count of 67/mm3 (N ≥ 500/mm3) and an elevated HIV viral load. An x-ray of the chest shows diffuse interstitial infiltrates bilaterally. A bronchoalveolar lavage shows disc-shaped yeast cells. In addition to starting antiretroviral therapy, the appropriate treatment for the patient's current illness is initiated. Maintaining the patient on a medication to prevent recurrence of his current illness will also prevent which of the following conditions?
Q58
A 56-year-old woman comes to the physician because of a 6-month history of difficulty swallowing food. Initially, only solid food was problematic, but liquids have also become more difficult to swallow over the last 2 months. She also reports occasional regurgitation of food when she lies down. The patient is an avid birdwatcher and returned from a 3-week trip to the Amazon rainforest 3 months ago. She has had a 3.5-kg (7.7-lb) weight loss over the past 6 months. She has not had abdominal pain, blood in her stools, or fever. She underwent an abdominal hysterectomy for fibroid uterus 6 years ago. She has smoked a pack of cigarettes daily for 25 years. Current medications include metformin and sitagliptin. The examination shows no abnormalities. Her hemoglobin concentration is 12.2 g/dL. A barium esophagram is shown. Esophageal manometry monitoring shows the lower esophageal sphincter fails to relax during swallowing. Which of the following is the next best step in management?
Q59
A 57-year-old woman presents to her primary care physician with complaints of nausea, vomiting, abdominal pain, and bloating that have increased in severity over the past several months. She reports that she occasionally vomits after eating. She states that the emesis contains undigested food particles. Additionally, the patient states that she often is satiated after only a few bites of food at meals. Her medical history is significant for hypertension and type II diabetes mellitus. Initial laboratory values are notable only for a hemoglobin A1c of 14%. Which of the following is the best initial treatment for this patient?
Q60
A 63-year-old man comes to the physician because of a 2-day history of redness, swelling, and pain of the right leg. He also has fever, chills, and nausea. He has noticed liquid oozing from the affected area on his right leg. He has a history of hypertension and gastroesophageal reflux disease. Three months ago, he was hospitalized for treatment of a hip fracture. His current medications include metoprolol, enalapril, and omeprazole. His temperature is 38.7°C (101.7°F), pulse is 106/min, and blood pressure is 142/94 mm Hg. Examination of the right lower leg shows a large area of erythema with poorly-demarcated borders and purulent drainage. The area is nonfluctuant, warm, and tender to touch. Examination of the right groin shows several enlarged, tender lymph nodes. There is mild edema of the ankles bilaterally. Blood and wound cultures are collected. Which of the following is the best next step in management?
Gastroenterology US Medical PG Practice Questions and MCQs
Question 51: A 70-year-old man is admitted with fever, chills, and rigor which have lasted for 4 days. He also complains of associated recent-onset fatigue. Past medical history is insignificant. He drinks a can of beer every night. His temperature is 39.0°C (102.2°F), pulse is 120/min, blood pressure is 122/80 mm Hg, and respirations are 14/min. Physical examination reveals splinter hemorrhages in the fingernails, and a 2/6 apical pansystolic murmur is heard which was not present during his last visit a month ago. A transoesophageal echocardiogram shows evidence of vegetations over the mitral valve. Blood cultures are taken from 3 different sites, which reveal the growth of Streptococcus gallolyticus. The patient is started on the appropriate antibiotic therapy which results in rapid clinical improvement. Which of the following would be the best next step in management in this patient after he is discharged?
A. Refer for an outpatient upper GI endoscopy
B. Repeat the transesophageal echocardiography
C. Prepare and schedule valve replacement surgery
D. Perform a transthoracic echocardiogram
E. Refer for an outpatient colonoscopy (Correct Answer)
Explanation: ***Refer for an outpatient colonoscopy***
- *Streptococcus gallolyticus* (formerly *Streptococcus bovis* biotype I and II) is strongly associated with **colorectal carcinoma** and other **gastrointestinal pathologies**.
- Given the patient's age and the presence of *S. gallolyticus* endocarditis, a **colonoscopy** is essential to screen for underlying colorectal malignancy.
*Refer for an outpatient upper GI endoscopy*
- While *S. gallolyticus* can be linked to gastrointestinal issues, its association is predominantly with **colonic lesions**, not typically upper GI lesions.
- An upper GI endoscopy would be less targeted and therefore not the *best next step* compared to colonoscopy in this specific scenario.
*Prepare and schedule valve replacement surgery*
- The patient has shown **rapid clinical improvement** with antibiotic therapy, suggesting that the infection is responding well to treatment.
- Valve replacement surgery is typically reserved for cases with **severe heart failure**, large vegetations with embolic risk, or failure of medical therapy, none of which are described here.
*Perform a transthoracic echocardiogram*
- A **transesophageal echocardiogram (TEE)** has already confirmed vegetations on the mitral valve, which is a more sensitive and specific test for endocarditis than a transthoracic echocardiogram (TTE).
- Repeating a less sensitive imaging study would not add significant diagnostic value at this stage, especially given the clinical improvement.
*Repeat the transesophageal echocardiography*
- The initial TEE confirmed the diagnosis and the presence of vegetations; repeating it immediately post-treatment completion is usually performed to ensure clearance, but the **most urgent next step** is to address the underlying cause of the *S. gallolyticus* infection.
- While follow-up imaging is important, evaluating for **colorectal malignancy** takes precedence due to the strong association with this specific organism.
Question 52: A 33-year-old man comes to the physician 1 hour after he slipped in the shower and fell on his back. Since the event, he has had severe neck pain. He rates the pain as an 8–9 out of 10. On questioning, he has had lower back pain for the past 2 years that radiates to the buttocks bilaterally. He reports that the pain sometimes awakens him at night and that it is worse in the morning or when he has been resting for a while. His back is very stiff in the morning and he is able to move normally only after taking a hot shower. His temperature is 36.3°C (97.3°F), pulse is 94/min, and blood pressure is 145/98 mm Hg. Range of motion of the neck is limited due to pain; the lumbar spine has a decreased range of motion. There is tenderness over the sacroiliac joints. Neurologic examination shows no abnormalities. An x-ray of the cervical spine shows decreased bone density of the vertebrae. An MRI shows a C2 vertebral fracture as well as erosions and sclerosis of the sacroiliac joints bilaterally. The patient's condition is most likely associated with which of the following findings?
A. Recurring eye redness and pain (Correct Answer)
B. Urinary and fecal incontinence
C. Recent episode of urethritis
D. Constipation and muscle weakness
E. Foot drop and difficulty heel walking
Explanation: ***Recurring eye redness and pain***
- The patient's presentation with **chronic low back pain** that improves with activity, **morning stiffness**, and **sacroiliac joint involvement** (erosions and sclerosis) is highly suggestive of **ankylosing spondylitis**.
- **Ankylosing spondylitis** is a systemic inflammatory disease often associated with **extra-articular manifestations**, including **acute anterior uveitis** (presenting as recurring eye redness and pain) in up to 40% of patients.
*Urinary and fecal incontinence*
- While **urinary and fecal incontinence** can occur with severe spinal cord compression or cauda equina syndrome, there is **no evidence of neurological deficits** beyond the localized pain and limited range of motion.
- These symptoms are not typical extra-articular manifestations of ankylosing spondylitis and would suggest a more acute and severe neurological emergency.
*Recent episode of urethritis*
- A **recent episode of urethritis** is a common trigger for **reactive arthritis**, another type of spondyloarthritis.
- Although reactive arthritis shares some features with ankylosing spondylitis, the chronic nature of the patient's back pain and specific imaging findings (erosions, sclerosis of SI joints) without mention of other reactive arthritis symptoms (e.g., conjunctivitis, mucocutaneous lesions) make ankylosing spondylitis a more fitting diagnosis.
*Constipation and muscle weakness*
- **Constipation** and **muscle weakness** are non-specific symptoms that can be associated with a wide variety of conditions, including metabolic disturbances or neurological disorders.
- They are not typical or specific extra-articular manifestations of ankylosing spondylitis.
*Foot drop and difficulty heel walking*
- **Foot drop** and **difficulty heel walking** indicate **L5 radiculopathy** or peroneal nerve palsy, which can result from disc herniation or nerve compression.
- While spinal issues can cause these, they are more associated with compressive neuropathies originating from a specific spinal level rather than a systemic inflammatory condition like ankylosing spondylitis.
Question 53: Two days after undergoing emergent laparotomy with splenectomy for a grade IV splenic laceration sustained in a motor vehicle collision, a 54-year-old man develops decreased urinary output. His urine output is < 350 mL/day despite aggressive fluid resuscitation. During the emergent laparotomy, he required three units of packed RBCs. He has type 2 diabetes mellitus and is on an insulin sliding scale. His vital signs are within normal limits. Physical examination shows a healing surgical incision in the upper abdomen and multiple large ecchymoses of the superior right and left abdominal wall. His hematocrit is 28%, platelet count is 400,000/mm3, serum creatinine is 3.9 mg/dL, and serum urea nitrogen concentration is 29 mg/dL. Urinalysis shows brown granular casts. Which of the following is the most likely underlying cause of these findings?
A. Focal segmental glomerulosclerosis
B. Rhabdomyolysis
C. Acute renal infarction
D. Rapidly progressive glomerulonephritis
E. Acute tubular necrosis (Correct Answer)
Explanation: ***Acute tubular necrosis***
- The combination of **decreased urinary output** despite fluid resuscitation, elevated **creatinine (3.9 mg/dL)**, and **brown granular casts** on urinalysis strongly suggests acute tubular necrosis (ATN).
- Risk factors for ATN are present, including **hypoperfusion during splenectomy**, likely contributing to **ischemic injury** to the renal tubules, and the patient's underlying **diabetes mellitus**.
*Focal segmental glomerulosclerosis*
- This is a form of **chronic kidney disease** typically presenting with **proteinuria** and **nephrotic syndrome**, not acute kidney injury with brown granular casts.
- It would not explain the rapid onset of renal failure two days post-surgery with signs of tubular damage.
*Rhabdomyolysis*
- Rhabdomyolysis is characterized by **muscle breakdown with myoglobin release**, causing acute kidney injury that can present with elevated creatinine kinase, myoglobinuria (tea-colored urine), and hyperkalemia.
- While trauma occurred, there is no evidence of **significant muscle injury**, markedly elevated CK, or myoglobinuria; the primary cause here is **ischemic ATN** from perioperative hypoperfusion.
*Acute renal infarction*
- An acute renal infarction typically presents with **sudden flank pain**, hematuria, and a rise in creatinine.
- Urinalysis in renal infarction usually shows **red blood cells** and protein, but less commonly brown granular casts, which are characteristic of ATN.
*Rapidly progressive glomerulonephritis*
- This condition is characterized by **rapid decline in glomerular function**, often with features like hematuria, red blood cell casts, and severe proteinuria due to inflammation of the glomeruli.
- While it causes acute kidney injury, the presence of **brown granular casts** points more specifically to tubular damage as seen in ATN, rather than primary glomerular inflammation.
Question 54: A 32-year-old man recently visiting from Thailand presents with diarrhea and fatigue for the past 6 days, which began before leaving Thailand. The patient denies any recent history of laxatives, nausea, or vomiting. His vital signs include: blood pressure 80/50 mm Hg, heart rate 105/min, and temperature 37.7°C (99.8°F). On physical examination, the patient is pale with dry mucous membranes. A stool sample is obtained for culture, which is copious and appears watery. Which of the following is the correct categorization of this diarrheal disease?
A. Secretory diarrhea (Correct Answer)
B. Osmotic diarrhea
C. Steatorrhea
D. Invasive diarrhea
E. Motility diarrhea
Explanation: ***Secretory diarrhea***
- The patient exhibits symptoms of severe dehydration (low blood pressure 80/50 mm Hg, heart rate 105/min, dry mucous membranes) and copious, watery diarrhea, characteristic of **secretory diarrhea**.
- This results from active secretion of water and electrolytes into the bowel lumen, often caused by bacterial toxins like those from **Vibrio cholerae** (common in endemic areas like Thailand).
- Key feature: **Persists with fasting** and produces large-volume (>1 L/day), watery stools without blood or mucus.
- The severe dehydration and hemodynamic compromise (hypotension, tachycardia) are classic for cholera-like illness.
*Osmotic diarrhea*
- This type is caused by the presence of **non-absorbable solutes** in the GI tract (e.g., lactose intolerance, laxatives, malabsorption), drawing water into the lumen.
- Key differentiating feature: **Stops with fasting** as the osmotic agent is removed.
- The patient's severe dehydration, large volume, and the fact that diarrhea persists despite likely reduced oral intake point away from osmotic causes.
*Steatorrhea*
- **Steatorrhea** is characterized by bulky, greasy, foul-smelling, fatty stools that float, indicating **fat malabsorption** (pancreatic insufficiency, celiac disease).
- The description of "copious and watery" stools does not align with the typical oily, sticky appearance of steatorrhea.
*Invasive diarrhea*
- **Invasive (inflammatory) diarrhea** is caused by pathogens that invade the intestinal mucosa (Shigella, Salmonella, Campylobacter, EHEC), causing mucosal damage.
- Typically presents with **bloody or mucoid stools**, high fever, severe abdominal pain, and tenesmus.
- The patient's watery (non-bloody) diarrhea and minimal fever (37.7°C) make invasive diarrhea unlikely.
*Motility diarrhea*
- **Motility diarrhea** results from disorders of gut motility (IBS, hyperthyroidism, post-vagotomy), leading to rapid transit of intestinal contents.
- While it can produce watery stools, the **massive volume** and **severe dehydrating nature** of this presentation are more consistent with active toxin-mediated secretion rather than simply altered transit time.
Question 55: A 72-year-old woman presents to her primary care provider complaining of fatigue for the last 6 months. She can barely complete her morning chores before having to take a long break in her chair. She rarely climbs the stairs to the second floor of her house anymore because it is too tiring. Past medical history is significant for Hashimoto's thyroiditis, hypertension, and hyperlipidemia. She takes levothyroxine, chlorthalidone, and atorvastatin. Her daughter developed systemic lupus erythematosus. She is retired and lives by herself in an old house built in 1945 and does not smoke and only occasionally drinks alcohol. She eats a well-balanced diet with oatmeal in the morning and some protein such as a hardboiled egg in the afternoon and at dinner. Today, her blood pressure is 135/92 mm Hg, heart rate is 110/min, respiratory rate is 22/min, and temperature is 37.0°C (98.6°F). On physical exam, she appears frail and her conjunctiva are pale. Her heart is tachycardic with a regular rhythm and her lungs are clear to auscultation bilaterally. A complete blood count (CBC) shows that she has macrocytic anemia. Peripheral blood smear shows a decreased red blood cell count, anisocytosis, and poikilocytosis with occasional hypersegmented neutrophils. An endoscopy and colonoscopy are performed to rule out an occult GI bleed. Her colonoscopy was normal. Endoscopy shows thin and smooth gastric mucosa without rugae. Which of the following is the most likely cause of this patient's condition?
A. Lead poisoning
B. Pernicious anemia (Correct Answer)
C. Glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency)
D. Anemia due to chronic alcoholism
E. Helicobacter pylori gastritis
Explanation: **Pernicious anemia**
* The patient's presentation with **macrocytic anemia**, **hypersegmented neutrophils**, and **fatigue** is highly suggestive of **pernicious anemia**, caused by **vitamin B12 deficiency**. The history of **Hashimoto's thyroiditis** and a family history of **systemic lupus erythematosus** point towards an **autoimmune predisposition**.
* **Thin and smooth gastric mucosa without rugae** observed on endoscopy is characteristic of **atrophic gastritis**, which often accompanies pernicious anemia due to the autoimmune destruction of **parietal cells** that produce **intrinsic factor**.
* *Lead poisoning*
* **Lead poisoning** typically causes **microcytic hypochromic anemia** with **basophilic stippling**, not macrocytic anemia and hypersegmented neutrophils.
* While the patient lives in an old house (built in 1945), suggesting potential for lead exposure, her hematological findings do not align with lead toxicity.
* *Glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency)*
* **G6PD deficiency** leads to **hemolytic anemia** (often acutely triggered by certain medications or foods) and typically presents with **normocytic or microcytic anemia**, not macrocytic anemia.
* The absence of acute hemolytic symptoms and the presence of hypersegmented neutrophils rule out G6PD deficiency.
* *Anemia due to chronic alcoholism*
* **Chronic alcoholism** can cause **macrocytic anemia** due to **folate deficiency** or direct toxic effects on bone marrow, but it's typically associated with a history of significant alcohol consumption.
* This patient "occasionally drinks alcohol," making chronic alcoholism an unlikely primary cause for her severe symptoms and specific endoscopic findings.
* *Helicobacter pylori gastritis*
* **_Helicobacter pylori_ gastritis** can cause **iron deficiency anemia** (microcytic) due to chronic blood loss or decreased iron absorption, and sometimes **B12 deficiency** through malabsorption.
* However, it does not directly lead to the characteristic **atrophic gastritis without rugae** described, nor is it the most direct cause of pernicious anemia.
Question 56: A 49-year-old man presents to his primary care physician complaining of heartburn and mild epigastric pain after eating for the past 6 months. He reports that his symptoms occur within an hour of eating a meal and persist for approximately an hour. He admits his symptoms have been progressively worsening. He recently began having these symptoms when he lies in the supine position. He has tried eating smaller meals and avoiding spicy food to no avail. He denies vomiting, difficulty swallowing, recent weight loss, or changes in stool color. He does admit to having a "sour" taste in his mouth when symptomatic. His temperature is 99.0°F (37.2°C), blood pressure is 149/82 mmHg, pulse is 86/min, respirations are 18/min, and BMI is 32 kg/m^2. His abdomen is soft, non-tender, and bowel sounds are auscultated in all quadrants. Laboratory results demonstrate the following:
Serum:
Hemoglobin: 13.5 g/dL
Hematocrit: 41%
Leukocyte count: 4,500/mm^3 with normal differential
Platelet count: 257,000/mm^3
Fecal occult blood test (FOBT): Negative
Which of the following is the next best step in management?
A. Famotidine
B. 24-hour pH monitoring
C. Endoscopy
D. Omeprazole (Correct Answer)
E. Metoclopramide
Explanation: ***Omeprazole***
- The patient's symptoms of **heartburn** and **epigastric pain**, worsening after meals and when supine, are classic for **Gastroesophageal Reflux Disease (GERD)**. A trial of a **proton pump inhibitor (PPI)** like omeprazole is the initial treatment of choice for typical GERD symptoms.
- The absence of **alarm symptoms** such as dysphagia, odynophagia, weight loss, or gastrointestinal bleeding allows for empirical PPI therapy without immediate endoscopy.
*Famotidine*
- Famotidine is a **histamine-2 receptor antagonist (H2RA)**, which is generally less potent than a PPI in suppressing acid production.
- While it can be used for GERD, **PPIs are more effective** for moderate to severe symptoms and in patients who fail to respond to lifestyle modifications.
*24-hour pH monitoring*
- **24-hour pH monitoring** is a diagnostic test typically reserved for patients with persistent, atypical, or refractory GERD symptoms who have failed empirical PPI therapy or when the diagnosis is unclear.
- It is not indicated as a first-line diagnostic or management step in a patient with classic GERD symptoms and no alarm features.
*Endoscopy*
- **Upper endoscopy** is indicated when alarm symptoms (e.g., dysphagia, unexplained weight loss, GI bleeding) are present or if symptoms persist despite a trial of PPIs.
- Given the absence of alarm symptoms and the typical presentation of GERD, an empirical trial of PPI is the appropriate initial step.
*Metoclopramide*
- **Metoclopramide** is a **prokinetic agent** that increases gastric motility and lowers esophageal sphincter pressure.
- It is typically used for specific indications like **gastroparesis** or refractory GERD, and its use is limited by potential side effects such as **tardive dyskinesia**. It is not a first-line treatment for uncomplicated GERD.
Question 57: A 61-year-old man with HIV comes to the physician because of a 3-week history of fatigue, nonproductive cough, and worsening shortness of breath. He appears ill. Pulse oximetry on room air shows an oxygen saturation of 89%. Laboratory studies show a CD4+ T-lymphocyte count of 67/mm3 (N ≥ 500/mm3) and an elevated HIV viral load. An x-ray of the chest shows diffuse interstitial infiltrates bilaterally. A bronchoalveolar lavage shows disc-shaped yeast cells. In addition to starting antiretroviral therapy, the appropriate treatment for the patient's current illness is initiated. Maintaining the patient on a medication to prevent recurrence of his current illness will also prevent which of the following conditions?
A. Toxoplasmosis (Correct Answer)
B. Candidiasis
C. Cytomegalovirus end-organ disease
D. Mycobacterium avium complex infection
E. Cryptosporidiosis
Explanation: ***Toxoplasmosis***
- The current illness is **Pneumocystis pneumonia (PJP)**, characterized by **fatigue, nonproductive cough, worsening shortness of breath, hypoxemia, diffuse interstitial infiltrates**, and **disc-shaped cysts in bronchoalveolar lavage** in an HIV-positive patient with a **CD4+ count of 67/mm³** (severely immunocompromised).
- The standard treatment and prophylaxis for PJP is **trimethoprim-sulfamethoxazole (TMP-SMX)**, which is initiated when CD4+ counts fall below **200 cells/mm³**.
- **TMP-SMX prophylaxis also prevents toxoplasmosis** (Toxoplasma gondii encephalitis), which is indicated when CD4+ counts are **<100 cells/mm³** and the patient has **positive Toxoplasma serology**. This represents a **dual prophylaxis benefit** of TMP-SMX in HIV patients.
- TMP-SMX is the **preferred agent for preventing both PJP and cerebral toxoplasmosis**, making it highly cost-effective in HIV management.
*Mycobacterium avium complex infection*
- **Macrolide antibiotics (azithromycin or clarithromycin)** are used for prophylaxis against **Mycobacterium avium complex (MAC) infection** in HIV patients with CD4+ counts **<50 cells/mm³**.
- **TMP-SMX has no activity against MAC** and does not provide prophylaxis for this infection.
- MAC typically presents as disseminated disease with fever, night sweats, weight loss, and anemia.
*Cryptosporidiosis*
- **Cryptosporidium parvum** causes severe watery diarrhea in immunocompromised patients.
- There is **no effective chemoprophylaxis** for cryptosporidiosis; treatment options include **nitazoxanide** or **paromomycin**, but these are not used for prevention.
- **TMP-SMX does not prevent cryptosporidiosis**.
*Candidiasis*
- **Fluconazole** is the agent used for prophylaxis against oropharyngeal and esophageal **candidiasis** in severely immunocompromised HIV patients.
- **TMP-SMX is an antibacterial/antiprotozoal agent** and has **no antifungal activity** against Candida species.
- TMP-SMX does not prevent candidiasis.
*Cytomegalovirus end-organ disease*
- Prophylaxis for **cytomegalovirus (CMV) end-organ disease** (retinitis, colitis, esophagitis) requires **ganciclovir, valganciclovir, or foscarnet** in high-risk HIV patients.
- **TMP-SMX provides no protection against CMV infection**.
- CMV prophylaxis is typically considered when CD4+ counts are **<50 cells/mm³**.
Question 58: A 56-year-old woman comes to the physician because of a 6-month history of difficulty swallowing food. Initially, only solid food was problematic, but liquids have also become more difficult to swallow over the last 2 months. She also reports occasional regurgitation of food when she lies down. The patient is an avid birdwatcher and returned from a 3-week trip to the Amazon rainforest 3 months ago. She has had a 3.5-kg (7.7-lb) weight loss over the past 6 months. She has not had abdominal pain, blood in her stools, or fever. She underwent an abdominal hysterectomy for fibroid uterus 6 years ago. She has smoked a pack of cigarettes daily for 25 years. Current medications include metformin and sitagliptin. The examination shows no abnormalities. Her hemoglobin concentration is 12.2 g/dL. A barium esophagram is shown. Esophageal manometry monitoring shows the lower esophageal sphincter fails to relax during swallowing. Which of the following is the next best step in management?
A. Myotomy with fundoplication
B. CT scan of the chest and abdomen
C. Gastroesophageal endoscopy (Correct Answer)
D. Nifedipine
E. Giemsa stain of blood smear
Explanation: ***Gastroesophageal endoscopy***
- Endoscopy is crucial to **rule out malignancy** in patients with new-onset dysphagia, especially given her age, significant **weight loss**, and **smoking history**.
- It allows for direct visualization of the esophagus and stomach, and **biopsies** can be taken if any suspicious lesions are found.
*Myotomy with fundoplication*
- This is a **surgical treatment** for achalasia, typically reserved after a diagnosis has been confirmed and other causes of dysphagia have been ruled out.
- While achalasia is suggested by the manometry findings, further investigation to exclude malignancy is necessary before proceeding with definitive surgical treatment.
*CT scan of the chest and abdomen*
- A CT scan can assess for extraluminal compression or metastatic disease, but it is **less sensitive for detecting primary esophageal lesions** compared to endoscopy.
- Endoscopy provides direct mucosal visualization and biopsy capabilities, making it a more appropriate initial diagnostic step for esophageal pathology.
*Nifedipine*
- **Nifedipine** is a calcium channel blocker used to relax the lower esophageal sphincter in some cases of achalasia, but it is a **medical treatment**, not a diagnostic step.
- Drug therapy would only be considered after a definitive diagnosis of achalasia has been made and malignancy has been excluded.
*Giemsa stain of blood smear*
- A Giemsa stain of a blood smear is used to identify **Trypanosoma cruzi**, the causative agent of **Chagas disease**, which can lead to secondary achalasia.
- While her travel history to the Amazon rainforest raises suspicion for Chagas disease, other more common and potentially life-threatening causes of dysphagia (like malignancy) must be excluded first before pursuing this specific etiologic diagnosis.
Question 59: A 57-year-old woman presents to her primary care physician with complaints of nausea, vomiting, abdominal pain, and bloating that have increased in severity over the past several months. She reports that she occasionally vomits after eating. She states that the emesis contains undigested food particles. Additionally, the patient states that she often is satiated after only a few bites of food at meals. Her medical history is significant for hypertension and type II diabetes mellitus. Initial laboratory values are notable only for a hemoglobin A1c of 14%. Which of the following is the best initial treatment for this patient?
A. Metoclopramide
B. Erythromycin
C. Surgical resection
D. Dietary modification (Correct Answer)
E. Myotomy
Explanation: ***Dietary modification***
- Initial management for **gastroparesis**, especially in patients with **diabetic gastroparesis**, typically involves **dietary adjustments** to alleviate symptoms.
- Recommended changes include **frequent small meals**, consuming **low-fat and low-fiber foods**, and **liquid or blended foods** which are easier to digest.
*Metoclopramide*
- This **prokinetic agent** can be used to stimulate gastric emptying but is generally considered after dietary modifications.
- It carries a risk of side effects, including **tardive dyskinesia**, particularly with long-term use.
*Erythromycin*
- This **macrolide antibiotic** has prokinetic effects due to its action on motilin receptors, but it is typically used for **acute exacerbations** of gastroparesis or in cases resistant to other treatments.
- Its long-term use is limited by the development of **tachyphylaxis** and potential for cardiac side effects.
*Surgical resection*
- **Surgical intervention** is not indicated for the initial management of gastroparesis and is reserved for **rare cases of refractory symptoms** or when there is evidence of mechanical obstruction.
- The patient's symptoms are consistent with gastroparesis, not a surgical emergency.
*Myotomy*
- **Myotomy**, such as pyloromyotomy or gastric electrical stimulation, are **invasive procedures** considered only for severe, **refractory cases** of gastroparesis after medical and dietary interventions have failed.
- It is not the initial treatment choice given the patient's presentation.
Question 60: A 63-year-old man comes to the physician because of a 2-day history of redness, swelling, and pain of the right leg. He also has fever, chills, and nausea. He has noticed liquid oozing from the affected area on his right leg. He has a history of hypertension and gastroesophageal reflux disease. Three months ago, he was hospitalized for treatment of a hip fracture. His current medications include metoprolol, enalapril, and omeprazole. His temperature is 38.7°C (101.7°F), pulse is 106/min, and blood pressure is 142/94 mm Hg. Examination of the right lower leg shows a large area of erythema with poorly-demarcated borders and purulent drainage. The area is nonfluctuant, warm, and tender to touch. Examination of the right groin shows several enlarged, tender lymph nodes. There is mild edema of the ankles bilaterally. Blood and wound cultures are collected. Which of the following is the best next step in management?
A. Vancomycin therapy (Correct Answer)
B. Prednisone therapy
C. Dicloxacillin therapy
D. Surgical debridement
E. Incision and drainage
Explanation: ***Vancomycin therapy***
- The patient presents with **cellulitis with purulent drainage**, suggesting a *Staphylococcus aureus* infection, potentially **methicillin-resistant *S. aureus* (MRSA)**.
- Given the systemic symptoms (**fever, chills, nausea**) and risk factors (recent hospitalization, purulent drainage), empiric broad-spectrum antibiotic coverage targeting MRSA with **vancomycin** is the most appropriate initial therapy.
*Prednisone therapy*
- **Corticosteroids like prednisone** are anti-inflammatory but are not indicated for acute bacterial infections like cellulitis and can worsen outcomes by **suppressing the immune response**.
- There is no evidence of an allergic reaction or autoimmune condition that would warrant corticosteroid use in this context.
*Dicloxacillin therapy*
- **Dicloxacillin** is a penicillinase-resistant penicillin typically used for **methicillin-sensitive *S. aureus* (MSSA)** infections.
- Given the purulent nature of the infection and recent hospitalization, there's a higher clinical suspicion for **MRSA**, making dicloxacillin inadequate as initial empiric therapy.
*Surgical debridement*
- **Surgical debridement** is indicated for severe infections involving **necrotic tissue** (e.g., necrotizing fasciitis) or abscesses that require removal of dead tissue to facilitate healing.
- While there is purulent drainage, the lesion is described as "nonfluctuant," suggesting that extensive necrosis or a deep, drainable abscess requiring debridement is not the primary issue at this stage. Immediate antibiotics are the priority.
*Incision and drainage*
- **Incision and drainage (I&D)** is the primary treatment for **fluctuant abscesses** or boils to relieve pressure and remove infected material.
- The patient's lesion is described as "nonfluctuant," indicating that a collection of pus requiring immediate I&D is unlikely, and the infection is more diffuse, consistent with cellulitis.