A 33-year-old female presents with recent onset of painful urination, fever, and right flank pain. Urinary sediment analysis is positive for the presence of white blood cell casts and Gram-negative bacteria. She has not recently started any new medications. What is the most likely diagnosis in this patient?
Q212
A 34-year-old woman with no significant prior medical history presents to the clinic with several days of bloody stool. She also complains of constipation and straining, but she has no other symptoms. She has no family history of colorectal cancer or inflammatory bowel disease. She does not smoke or drink alcohol. Her vital signs are as follows: blood pressure is 121/81 mm Hg, heart rate is 77/min, and respiratory rate is 15/min. There is no abdominal discomfort on physical exam, and a digital rectal exam reveals bright red blood. Of the following, which is the most likely diagnosis?
Q213
A 54-year-old man is brought to the emergency department by his wife because of high fever and confusion for the past 10 hours. His wife reports that 1 week ago during a trip to Guatemala he underwent an emergency appendectomy. His temperature is 40.1°C (104.2°F), pulse is 132/min, and blood pressure is 74/46 mm Hg. He is oriented only to person. Physical examination shows a surgical wound in the right lower quadrant with purulent discharge. The skin is warm and dry. Serum studies show a sodium concentration of 138 mEq/L, potassium concentration of 3.7 mEq/L, and lactate concentration of 3.5 mEq/L (N = 0.5–2.2 mEq/L). Arterial blood gas analysis on room air shows:
pH 7.21
pCO2 36
HCO3- 12
O2 saturation 87%
Which of the following is the most likely explanation for these laboratory changes?
Q214
A 50-year-old man visits his primary care practitioner for a general health check-up. He was recently hired as a fitness instructor at a local fitness center. His father died of advanced colorectal cancer, however, his personal medical history is significant for the use of performance-enhancing drugs during his 20’s when he competed in bodybuilding and powerlifting competitions. As part of the paperwork associated with his new position, he received an order for a hemoglobin and hematocrit, occult blood in stool, and serum iron and ferritin level, shown below:
Hemoglobin 11.8 g/dL
Hematocrit 35%
Iron 40 µg/dL
Ferritin 8 ng/mL
His fecal occult blood test was positive. Which of the following is the most recommended follow-up action?
Q215
A 45-year-old man comes to the physician because of a 5-day history of fever, malaise, and right upper abdominal pain. Examination of the abdomen shows tenderness in the right upper quadrant. His leukocyte count is 18,000/mm3 (90% neutrophils) and serum alkaline phosphatase is 130 U/L. Ultrasonography of the abdomen shows a 3-cm hypoechoic lesion in the right lobe of the liver with a hyperemic rim. Which of the following is the most likely underlying cause of this patient's condition?
Q216
A 40-year-old woman presents with a lack of concentration at work for the last 3 months. She says that she has been working as a personal assistant to a manager at a corporate business company for the last 2 years. Upon asking why she is not able to concentrate, she answers that her colleagues are always gossiping about her during work hours and that it disrupts her concentration severely. Her husband works in the same company and denies these allegations. He says the other employees are busy doing their own work and have only formal conversations, yet she is convinced that they are talking about her. He further adds that his wife frequently believes that some advertisements in a newspaper are directed towards her and are published specifically to catch her attention even though they are routine advertisements. The patient denies any mood disturbances, anxiety or hallucinations. Past medical history is significant for a tingling sensation in her legs, 3+ patellar reflexes bilaterally, and absent ankle reflexes bilaterally. She says that she drinks alcohol once to twice a month for social reasons but denies any other substance use or smoking. On physical examination, the patient is conscious, alert, and oriented to time, place and person. A beefy red color of the tongue is noted. No associated cracking, bleeding, or oral lesions. Which of the following laboratory tests would be most helpful to identify this patient’s most likely diagnosis?
Q217
A 23-year-old man comes to the physician for frequent and painful urination. He has also had progressive painful swelling of his right knee over the past week. He is sexually active with two female partners and uses condoms inconsistently. His mother has an autoimmune disease that involves a malar rash. Examination shows conjunctivitis bilaterally. The right knee is warm, erythematous, and tender to touch; range of motion is limited. Laboratory studies show an erythrocyte sedimentation rate of 62 mm/h. Urinalysis shows WBCs. Further evaluation of this patient is most likely to reveal which of the following?
Q218
A 74-year-old man is brought to the emergency department after he had copious amounts of blood-stained stools. Minutes later, he turned sweaty, felt light-headed, and collapsed into his wife’s arms. Upon admission, he is found to have a blood pressure of 78/40 mm Hg, a pulse of 140/min, and oxygen saturation of 98%. His family history is relevant for both gastric and colorectal cancer. His personal history is relevant for hypertension, for which he takes amlodipine. After an initial successful resuscitation with intravenous fluids, which of the following should be the first step in approaching this case?
Q219
A 27-year-old man presents with a 2-week history of fever, malaise, and occasional diarrhea. On physical examination, the physician notes enlarged inguinal lymph nodes. An HIV screening test is positive. Laboratory studies show a CD4+ count of 650/mm3. This patient is most likely currently in which of the following stages of HIV infection?
Q220
A 40-year-old overweight man presents to the office complaining of heartburn for 6 months. He describes burning in his chest brought on by meals. He has a 20 pack-year smoking history and drinks 2 glasses of red wine with dinner nightly. He denies dysphagia, odynophagia, weight loss, melena, and hematemesis. Over the past month, he has reduced his intake of fatty and spicy foods with some moderate relief of his symptoms; however, his symptoms are still present. He also has stopped smoking. Which of the following is the most appropriate next step in the care of this patient?
Gastroenterology US Medical PG Practice Questions and MCQs
Question 211: A 33-year-old female presents with recent onset of painful urination, fever, and right flank pain. Urinary sediment analysis is positive for the presence of white blood cell casts and Gram-negative bacteria. She has not recently started any new medications. What is the most likely diagnosis in this patient?
A. Appendicitis
B. Cystitis
C. Pyelonephritis (Correct Answer)
D. Acute Interstitial Nephritis
E. Pelvic Inflammatory Disease
Explanation: ***Pyelonephritis***
- The combination of **painful urination**, **fever**, **right flank pain**, and **white blood cell casts** in the urine is highly indicative of pyelonephritis, an infection of the renal parenchyma.
- **White blood cell casts** are pathognomonic for inflammation within the renal tubules and are a key differentiating feature that points to an upper urinary tract infection.
*Appendicitis*
- While appendicitis can cause **right-sided abdominal pain** and **fever**, it typically does not present with painful urination or urinary sediment abnormalities like white blood cell casts.
- The pain is usually localized to the **right lower quadrant** and often migrates, which is not characteristic of flank pain.
*Cystitis*
- Cystitis involves bladder inflammation and causes **painful urination**, **frequency**, and **urgency**, but typically does not cause **fever** or **flank pain**, and **white blood cell casts** are absent.
- It is an infection limited to the **lower urinary tract**, without renal parenchymal involvement.
*Acute Interstitial Nephritis*
- This condition is often associated with a **drug hypersensitivity reaction**, causing inflammation in the renal interstitium, but typically presents with **eosinophilia**, rash, and renal failure, not usually with white blood cell casts directly from infection.
- While it can cause renal dysfunction and sometimes fever, the presence of **Gram-negative bacteria** and **WBC casts** strongly points to an infection rather than an allergic reaction.
*Pelvic Inflammatory Disease*
- PID causes **lower abdominal pain**, **fever**, and sometimes painful urination if there's concurrent urethritis, but it is not associated with **flank pain** or **white blood cell casts** in the urine.
- It is an infection of the **female reproductive organs**, often caused by sexually transmitted organisms, and would typically present with cervical motion tenderness.
Question 212: A 34-year-old woman with no significant prior medical history presents to the clinic with several days of bloody stool. She also complains of constipation and straining, but she has no other symptoms. She has no family history of colorectal cancer or inflammatory bowel disease. She does not smoke or drink alcohol. Her vital signs are as follows: blood pressure is 121/81 mm Hg, heart rate is 77/min, and respiratory rate is 15/min. There is no abdominal discomfort on physical exam, and a digital rectal exam reveals bright red blood. Of the following, which is the most likely diagnosis?
A. Colorectal cancer
B. Ulcerative colitis
C. Anal fissure
D. External hemorrhoids
E. Internal hemorrhoids (Correct Answer)
Explanation: ***Internal hemorrhoids***
- **Painless bright red blood** per rectum, especially with **constipation and straining**, is highly characteristic of internal hemorrhoids.
- Internal hemorrhoids are located **above the dentate line**, making them typically painless, and they often prolapse during defecation, causing bleeding.
*Colorectal cancer*
- While colorectal cancer can cause bloody stool, it is less likely in a **34-year-old woman with no family history** and no other systemic symptoms like weight loss or abdominal pain.
- The bright red blood associated with straining points away from an upper GI bleed, which is more typical of many colorectal cancers.
*Ulcerative colitis*
- Ulcerative colitis typically presents with bloody diarrhea, abdominal pain, and tenesmus, which are **not mentioned** in this patient's history.
- It is a chronic inflammatory condition, and the isolated symptom of bright red blood with constipation is not classic for UC.
*Anal fissure*
- An anal fissure would cause **severe pain during defecation** due to a tear in the anal canal, which is absent in this patient.
- While an anal fissure can cause bright red blood, the lack of pain makes it less likely than hemorrhoids.
*External hemorrhoids*
- **External hemorrhoids are usually painful or itchy** and located below the dentate line.
- They also can cause bleeding, but the absence of pain and bright red blood suggests internal hemorrhoids which are more likely to bleed painlessly.
Question 213: A 54-year-old man is brought to the emergency department by his wife because of high fever and confusion for the past 10 hours. His wife reports that 1 week ago during a trip to Guatemala he underwent an emergency appendectomy. His temperature is 40.1°C (104.2°F), pulse is 132/min, and blood pressure is 74/46 mm Hg. He is oriented only to person. Physical examination shows a surgical wound in the right lower quadrant with purulent discharge. The skin is warm and dry. Serum studies show a sodium concentration of 138 mEq/L, potassium concentration of 3.7 mEq/L, and lactate concentration of 3.5 mEq/L (N = 0.5–2.2 mEq/L). Arterial blood gas analysis on room air shows:
pH 7.21
pCO2 36
HCO3- 12
O2 saturation 87%
Which of the following is the most likely explanation for these laboratory changes?
A. Diabetic ketoacidosis
B. Primary adrenal insufficiency
C. Hyperventilation
D. Respiratory fatigue
E. Lactic acidosis secondary to sepsis (Correct Answer)
Explanation: ***Lactic acidosis secondary to sepsis***
- The patient presents with classic signs of **sepsis** (fever, hypotension, confusion, tachycardia, surgical site infection with purulent discharge) and an elevated **lactate concentration** (3.5 mEq/L), along with a **metabolic acidosis** (low pH, low HCO3-), all consistent with septic shock causing tissue hypoperfusion and anaerobic metabolism.
- The low O2 saturation (87%) further supports tissue hypoperfusion and impaired oxygen delivery, contributing to the anaerobic metabolism and subsequent lactic acid production.
*Diabetic ketoacidosis*
- While DKA presents with **metabolic acidosis**, it is typically associated with **hyperglycemia** and **ketones** in the urine, which are not mentioned here.
- The patient's presentation with a recent unsterile surgery and purulent wound suggests an underlying **infectious process** as the primary cause, not uncontrolled diabetes.
*Primary adrenal insufficiency*
- Adrenal insufficiency can cause **hypotension** and electrolyte abnormalities like **hyponatremia** and **hyperkalemia**, but the patient's sodium and potassium levels are normal.
- Though it can present with fever and confusion, it would not typically cause a significant **lactic acidosis** or be associated with a purulent surgical wound.
*Hyperventilation*
- **Hyperventilation** would lead to a **respiratory alkalosis** (elevated pH, low pCO2) due to increased CO2 elimination, which contradicts the patient's **acidotic pH (7.21)**.
- While the patient has a low pCO2 (36), it is insufficient to compensate for the severe metabolic acidosis, and the primary disturbance is clearly metabolic.
*Respiratory fatigue*
- **Respiratory fatigue** could lead to **respiratory acidosis** (low pH, high pCO2) due to impaired CO2 removal, which is the opposite of the patient's pCO2 of 36.
- The primary derangement is metabolic (low HCO3-, high lactate), and the pCO2 is actually lower than normal, indicating a compensatory response rather than fatigue with CO2 retention.
Question 214: A 50-year-old man visits his primary care practitioner for a general health check-up. He was recently hired as a fitness instructor at a local fitness center. His father died of advanced colorectal cancer, however, his personal medical history is significant for the use of performance-enhancing drugs during his 20’s when he competed in bodybuilding and powerlifting competitions. As part of the paperwork associated with his new position, he received an order for a hemoglobin and hematocrit, occult blood in stool, and serum iron and ferritin level, shown below:
Hemoglobin 11.8 g/dL
Hematocrit 35%
Iron 40 µg/dL
Ferritin 8 ng/mL
His fecal occult blood test was positive. Which of the following is the most recommended follow-up action?
A. Endoscopy only
B. Iron supplementation
C. Colonoscopy only
D. Endoscopy and colonoscopy (Correct Answer)
E. Transfusion
Explanation: ***Endoscopy and colonoscopy***
- The patient has evidence of **iron deficiency anemia** (low hemoglobin, hematocrit, iron, and ferritin) and a **positive fecal occult blood test**, indicating **gastrointestinal blood loss**.
- Given the patient's age, family history of **colorectal cancer**, and positive fecal occult blood, both upper (endoscopy) and lower (colonoscopy) GI tract evaluations are necessary to identify the source of bleeding.
*Endoscopy only*
- While an upper GI source for bleeding is possible, this option would miss any potential **lower GI pathology**, which is a significant concern given the patient's family history and positive occult blood.
- An endoscopy alone would not adequately investigate the cause of **anemia** or the positive stool test if the bleeding source is in the colon.
*Iron supplementation*
- Administering iron supplementation without investigating the cause of **blood loss** would only treat the symptom (anemia) and not the underlying condition, which could be serious (e.g., **colorectal cancer**).
- Delaying diagnostic procedures to initiate iron supplementation could lead to a missed opportunity for early diagnosis and treatment of a potentially life-threatening condition.
*Colonoscopy only*
- While a colonoscopy is crucial due to the **positive fecal occult blood** and family history of colorectal cancer, it will not rule out an **upper GI source of bleeding**.
- Numerous conditions in the upper GI tract, such as **peptic ulcers** or **gastritis**, can cause chronic blood loss and iron deficiency anemia.
*Transfusion*
- A blood transfusion is typically reserved for more severe anemia or acute blood loss causing hemodynamic instability. The patient's hemoglobin and hematocrit values, while low, do not immediately necessitate a **transfusion**.
- A **transfusion** is a supportive measure and does not address the underlying cause of the **blood loss**, which remains the priority for investigation.
Question 215: A 45-year-old man comes to the physician because of a 5-day history of fever, malaise, and right upper abdominal pain. Examination of the abdomen shows tenderness in the right upper quadrant. His leukocyte count is 18,000/mm3 (90% neutrophils) and serum alkaline phosphatase is 130 U/L. Ultrasonography of the abdomen shows a 3-cm hypoechoic lesion in the right lobe of the liver with a hyperemic rim. Which of the following is the most likely underlying cause of this patient's condition?
A. Diverticulitis
B. Echinococcosis
C. Pyogenic liver abscess
D. Cholangitis (Correct Answer)
E. Perinephric infection
Explanation: The patient presents with a **pyogenic liver abscess** (fever, RUQ pain, leukocytosis, hypoechoic liver lesion with hyperemic rim). The question asks for the **underlying cause** of this abscess.
***Cholangitis***
- **Cholangitis** (ascending biliary infection) is the **most common underlying cause** of pyogenic liver abscesses, accounting for 40-60% of cases
- The elevated **alkaline phosphatase** (130 U/L) suggests **biliary tract pathology**, supporting cholangitis as the source
- Bacteria ascend from the biliary tree through the portal venous system to seed the liver parenchyma
- The **leukocytosis with neutrophilia** (18,000/mm³, 90% neutrophils) indicates acute bacterial infection
- **Clinical correlation**: Biliary obstruction from stones, strictures, or malignancy → cholangitis → hematogenous/direct spread → liver abscess
*Diverticulitis*
- **Diverticulitis** typically causes **left lower quadrant pain** and fever, not right upper quadrant symptoms
- While portal pylephlebitis from diverticulitis can rarely cause liver abscesses, the **elevated alkaline phosphatase** points more toward biliary pathology than colonic source
- Absence of GI symptoms (diarrhea, constipation, lower abdominal pain) makes this less likely
*Echinococcosis*
- **Echinococcosis** (hydatid cyst) presents with a **slow-growing, asymptomatic cyst** over months to years, not acute fever
- Imaging shows **multiloculated cysts with daughter cysts** and calcifications ("water lily sign"), not a hyperemic rim suggesting acute inflammation
- Would not cause marked leukocytosis unless the cyst ruptures
*Pyogenic liver abscess*
- This is the **condition the patient HAS**, not the underlying cause
- A pyogenic liver abscess is the result of bacterial seeding, which can occur from biliary sources (cholangitis), hematogenous spread, or direct extension
- The question asks for what **caused** the abscess, not what the abscess is
*Perinephric infection*
- **Perinephric abscess** causes **flank pain** and costovertebral angle tenderness, not RUQ pain
- Imaging would show perirenal or intrarenal findings, not an **isolated liver lesion**
- No urinary symptoms are mentioned
Question 216: A 40-year-old woman presents with a lack of concentration at work for the last 3 months. She says that she has been working as a personal assistant to a manager at a corporate business company for the last 2 years. Upon asking why she is not able to concentrate, she answers that her colleagues are always gossiping about her during work hours and that it disrupts her concentration severely. Her husband works in the same company and denies these allegations. He says the other employees are busy doing their own work and have only formal conversations, yet she is convinced that they are talking about her. He further adds that his wife frequently believes that some advertisements in a newspaper are directed towards her and are published specifically to catch her attention even though they are routine advertisements. The patient denies any mood disturbances, anxiety or hallucinations. Past medical history is significant for a tingling sensation in her legs, 3+ patellar reflexes bilaterally, and absent ankle reflexes bilaterally. She says that she drinks alcohol once to twice a month for social reasons but denies any other substance use or smoking. On physical examination, the patient is conscious, alert, and oriented to time, place and person. A beefy red color of the tongue is noted. No associated cracking, bleeding, or oral lesions. Which of the following laboratory tests would be most helpful to identify this patient’s most likely diagnosis?
A. Serum folate level
B. Serum thyroxine level
C. Serum ethanol level
D. Serum thiamine level
E. Serum cobalamin level (Correct Answer)
Explanation: ***Serum cobalamin level***
- The patient presents with **delusional disorder**, supported by her fixed beliefs about colleagues gossiping and advertisements being directed at her, despite evidence to the contrary.
- Her neurological symptoms (tingling, hyperreflexia, absent ankle reflexes) and characteristic **beefy red tongue** are highly suggestive of **vitamin B12 deficiency**, which can lead to both psychiatric and neurological manifestations.
*Serum folate level*
- Folate deficiency can also cause **neurological symptoms** and **megaloblastic anemia**, similar to B12 deficiency.
- However, the classic "beefy red tongue" is more frequently associated with **cobalamin (B12) deficiency**, and folate deficiency alone does not typically present with the specific combination of psychiatric and neurological signs seen here without other B12 deficiency indicators.
*Serum thyroxine level*
- **Hypothyroidism** can cause cognitive impairments like lack of concentration, and depression, but it does not typically cause the specific delusional symptoms described or the specific neurological signs like hyperreflexia and absent ankle reflexes, or a beefy red tongue.
- While fatigue and concentration issues might be present, the symptom complex aligns less with thyroid dysfunction.
*Serum ethanol level*
- The patient reports only **occasional social alcohol use**, unlikely to cause chronic ethanol toxicity leading to such a presentation.
- Chronic alcohol abuse can cause neurological issues (e.g., Wernicke-Korsakoff syndrome) and some psychiatric symptoms, but the **beefy red tongue** and the specific pattern of neurological signs, combined with the nature of her delusions, point away from ethanol as the primary cause.
*Serum thiamine level*
- **Thiamine deficiency** is primarily associated with **Wernicke-Korsakoff syndrome** in the context of chronic alcohol abuse, characterized by ataxia, ophthalmoplegia, and confusion, as well as memory impairment.
- Although it can cause neurological symptoms, the patient's low alcohol intake, the **delusional disorder**, and the presence of a **beefy red tongue** make thiamine deficiency less likely than cobalamin deficiency.
Question 217: A 23-year-old man comes to the physician for frequent and painful urination. He has also had progressive painful swelling of his right knee over the past week. He is sexually active with two female partners and uses condoms inconsistently. His mother has an autoimmune disease that involves a malar rash. Examination shows conjunctivitis bilaterally. The right knee is warm, erythematous, and tender to touch; range of motion is limited. Laboratory studies show an erythrocyte sedimentation rate of 62 mm/h. Urinalysis shows WBCs. Further evaluation of this patient is most likely to reveal which of the following?
A. Hiking trip two months ago
B. Recent norovirus gastroenteritis
C. Chondrocalcinosis of the left knee
D. Positive anti-dsDNA antibodies
E. HLA-B27 positive genotype (Correct Answer)
Explanation: ***HLA-B27 positive genotype***
- The patient's symptoms (urethritis, conjunctivitis, and arthritis) constitute the classic triad of **Reiter's syndrome**, a form of **reactive arthritis**.
- **Reactive arthritis** is strongly associated with the **HLA-B27 genotype**, which is found in a significant majority of affected individuals.
*Hiking trip two months ago*
- This information is vague and does not directly link to a specific pathogen or trigger for reactive arthritis.
- While some bacterial infections can be acquired through environmental exposure, there is no direct evidence provided in the stem to support a connection.
*Recent norovirus gastroenteritis*
- **Norovirus** typically causes acute, self-limiting gastroenteritis and is not commonly associated with the development of **reactive arthritis**.
- Reactive arthritis is primarily triggered by certain **genitourinary** or **gastrointestinal bacterial infections** (e.g., Chlamydia, Shigella, Salmonella, Campylobacter).
*Chondrocalcinosis of the left knee*
- **Chondrocalcinosis** (calcium pyrophosphate deposition disease or pseudogout) primarily affects older individuals and typically presents with acute, severe arthritis.
- While it can affect the knee, it is not consistently associated with the extra-articular manifestations (urethritis, conjunctivitis) seen in this patient, and its etiology is distinct from reactive arthritis.
*Positive anti-dsDNA antibodies*
- **Positive anti-dsDNA antibodies** are a hallmark of **systemic lupus erythematosus (SLE)**, an autoimmune disease.
- While SLE can cause arthritis and sometimes conjunctivitis, it does not typically cause urethritis in the manner described, nor does it fit the overall clinical picture as well as reactive arthritis.
Question 218: A 74-year-old man is brought to the emergency department after he had copious amounts of blood-stained stools. Minutes later, he turned sweaty, felt light-headed, and collapsed into his wife’s arms. Upon admission, he is found to have a blood pressure of 78/40 mm Hg, a pulse of 140/min, and oxygen saturation of 98%. His family history is relevant for both gastric and colorectal cancer. His personal history is relevant for hypertension, for which he takes amlodipine. After an initial successful resuscitation with intravenous fluids, which of the following should be the first step in approaching this case?
A. Radionuclide imaging
B. Mesenteric angiography
C. Upper endoscopy (Correct Answer)
D. Colonoscopy
E. Nasogastric lavage
Explanation: ***Upper endoscopy***
- After **initial hemodynamic stabilization** (as stated in the question), **early upper endoscopy** is the recommended first-line approach for patients with acute GI bleeding.
- **Upper GI sources** must be ruled out first, even in patients presenting with hematochezia (blood-stained stools), as **10-15% of cases** with bright red blood per rectum originate from an upper GI source.
- Upper endoscopy is both **diagnostic and therapeutic**, allowing for immediate intervention (banding, sclerotherapy, thermal coagulation, clipping) if a bleeding source is identified.
- **Current ACG/ASGE guidelines** recommend endoscopy **within 24 hours** (ideally within 12 hours) after resuscitation in patients with acute upper GI bleeding.
- The degree of **hemodynamic instability** in this patient (BP 78/40, HR 140) suggests a brisk bleed more consistent with an upper GI source.
*Nasogastric lavage*
- NG lavage has **low sensitivity (42-84%)** for upper GI bleeding and can miss up to 15% of cases.
- It is **no longer routinely recommended** by current guidelines as it delays definitive diagnosis and treatment without providing therapeutic benefit.
- Modern practice favors proceeding directly to endoscopy after stabilization rather than performing NG lavage first.
*Radionuclide imaging*
- **Tagged RBC scan** is useful for **intermittent or slow bleeding** (0.1-0.5 mL/min) when endoscopy is non-diagnostic.
- Not appropriate as the **first step** in an acute, massive bleed requiring immediate source localization and potential intervention.
- Provides localization but no therapeutic capability.
*Mesenteric angiography*
- Indicated for **active, brisk bleeding** (>0.5-1 mL/min) when endoscopy fails to identify the source or when immediate therapeutic embolization is needed.
- Can be both diagnostic and therapeutic but is typically a **second-line intervention** after endoscopy.
- Requires active bleeding at the time of the procedure to visualize the source.
*Colonoscopy*
- **Colonoscopy** is the appropriate diagnostic tool for **lower GI bleeding** after upper GI sources have been excluded.
- Should be performed **after upper endoscopy** rules out an upper source, particularly in patients with this degree of hemodynamic compromise.
- Requires adequate bowel preparation for optimal visualization, which may delay diagnosis.
Question 219: A 27-year-old man presents with a 2-week history of fever, malaise, and occasional diarrhea. On physical examination, the physician notes enlarged inguinal lymph nodes. An HIV screening test is positive. Laboratory studies show a CD4+ count of 650/mm3. This patient is most likely currently in which of the following stages of HIV infection?
A. Chronic HIV infection
B. Asymptomatic HIV infection
C. AIDS
D. Acute HIV infection (Correct Answer)
E. Clinical latency stage
Explanation: ***Acute HIV infection***
- The symptoms (fever, malaise, diarrhea, enlarged lymph nodes) and the timeframe (2 weeks) are classic for **acute retroviral syndrome**, which occurs 2-4 weeks after initial HIV infection.
- A positive HIV screening test with a relatively high **CD4+ count** (650/mm³) is typical during this initial phase before significant immune deterioration.
- Also known as **primary HIV infection**, this stage represents the body's initial immune response to the virus.
*Chronic HIV infection*
- This stage is typically characterized by a **longer duration** (years) with often **asymptomatic periods** or mild, non-specific symptoms, and a gradually declining CD4+ count.
- While enlarged lymph nodes can persist, the acute onset of fever and malaise with only 2 weeks of symptoms points away from this more stable, quiescent phase.
*Asymptomatic HIV infection*
- This phrase is often used interchangeably with the **clinical latency stage** of chronic HIV infection, where the patient has no symptoms related to HIV despite ongoing viral replication.
- The presence of fever, malaise, diarrhea, and lymphadenopathy described in the case clearly indicates a **symptomatic phase**, not an asymptomatic one.
*AIDS*
- **AIDS (Acquired Immunodeficiency Syndrome)** is defined by a CD4+ T cell count below 200 cells/mm³ or the presence of an AIDS-defining opportunistic infection or malignancy.
- The patient's CD4+ count of 650/mm³ is well above the threshold for AIDS diagnosis.
*Clinical latency stage*
- This stage, also called **chronic asymptomatic HIV infection**, typically lasts 8-10 years without treatment and is characterized by minimal or no symptoms.
- Patients in clinical latency have **declining but not yet critically low CD4+ counts** and generally feel well.
- The acute presentation with fever, malaise, and the **2-week timeframe** clearly indicates a much earlier stage of infection.
Question 220: A 40-year-old overweight man presents to the office complaining of heartburn for 6 months. He describes burning in his chest brought on by meals. He has a 20 pack-year smoking history and drinks 2 glasses of red wine with dinner nightly. He denies dysphagia, odynophagia, weight loss, melena, and hematemesis. Over the past month, he has reduced his intake of fatty and spicy foods with some moderate relief of his symptoms; however, his symptoms are still present. He also has stopped smoking. Which of the following is the most appropriate next step in the care of this patient?
A. Nissen fundoplication
B. Pantoprazole, sucralfate, and amoxicillin
C. Ranitidine
D. Esophagogastroduodenoscopy
E. Omeprazole (Correct Answer)
Explanation: ***Omeprazole***
- This patient presents with classic symptoms of **gastroesophageal reflux disease (GERD)**, including heartburn exacerbated by meals, along with risk factors like being overweight, smoking history, and alcohol consumption.
- A trial of an **empiric proton pump inhibitor (PPI)** like omeprazole is the most appropriate initial medical therapy for presumed GERD given the absence of alarm symptoms (dysphagia, odynophagia, weight loss, GI bleeding).
*Nissen fundoplication*
- This is a **surgical procedure** typically reserved for patients with severe GERD that is refractory to maximal medical therapy or for those who cannot tolerate long-term PPIs.
- It would be **premature** to consider surgery at this stage, as the patient has not yet received an adequate trial of guideline-recommended medical treatment.
*Pantoprazole, sucralfate, and amoxicillin*
- This combination is **inappropriate** for initial management of GERD. Pantoprazole is a PPI, but sucralfate is typically used for *ulcers* or *stress gastritis*, and amoxicillin is an *antibiotic* for *Helicobacter pylori* or other bacterial infections.
- There is no indication for **antibiotic therapy** or sucralfate based on the patient's symptoms; *H. pylori* eradication would only be considered if an ulcer was suspected or confirmed.
*Ranitidine*
- Ranitidine is an **H2 receptor antagonist (H2RA)**, which is generally less potent and effective than PPIs like omeprazole for managing moderate to severe GERD symptoms.
- While H2RAs can be used for mild, intermittent heartburn, **PPIs are superior** for persistent symptoms and are the recommended first-line treatment in this scenario.
*Esophagogastroduodenoscopy*
- An EGD is an **invasive diagnostic procedure** indicated when there are alarm symptoms (e.g., dysphagia, odynophagia, weight loss, GI bleeding) or when GERD symptoms are **refractory** to an adequate trial of empiric PPI therapy.
- Since this patient has no alarm symptoms and has not yet received a trial of maximal medical therapy, an EGD is **not the initial step**.