A 53-year-old woman comes to the emergency department because of weakness and abdominal pain for 24 hours. She has had three bowel movements with dark stool during this period. She has not had vomiting and has never had such episodes in the past. She underwent a tubal ligation 15 years ago. She has chronic lower extremity lymphedema, osteoarthritis, and type 2 diabetes mellitus. Her father died of colon cancer at the age of 72 years. Current medications include metformin, naproxen, and calcium with vitamin D3. She had a screening colonoscopy at 50 years of age which was normal. She appears pale and diaphoretic. Her temperature is 36°C (96.8°F), pulse is 110/min, respirations are 20/min, and blood pressure is 90/50 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. The abdomen is soft and nondistended with mild epigastric tenderness. Rectal exam shows tarry stool. Two large bore IV lines are placed and fluid resuscitation with normal saline is initiated. Which of the following is the most appropriate next step in management?
Q262
A 36-year-old woman gravida 5, para 4 was admitted at 31 weeks of gestation with worsening fatigue and shortness of breath on exertion for the past month. She also has nausea and loss of appetite. No significant past medical history. The patient denies any smoking history, alcohol or illicit drug use. Her vital signs include: blood pressure 110/60 mm Hg, pulse 120/min, respiratory rate 22/min and temperature 35.1℃ (97.0℉). A complete blood count reveals a macrocytosis with severe pancytopenia, as follows:
Hb 7.2 g/dL
RBC 3.6 million/uL
WBC 4,400/mm3
Neutrophils 40%
Lymphocytes 20%
Platelets 15,000/mm3
MCV 104 fL
Reticulocytes 0.9%
Serum ferritin and vitamin B12 levels were within normal limits. There was an elevated homocysteine level and a normal methylmalonic acid level. Which of the following is the most likely diagnosis in this patient?
Q263
A 55-year-old man with known coronary artery disease presents to the ED with epigastric pain, worsening fatigue, and melena. He takes aspirin and rosuvastatin, but took ibuprofen over the past two weeks for lower back pain. He denies nausea, vomiting, hematemesis, chest pain, fever, and weight loss. Sitting blood pressure is 100/70 mmHg and pulse is 90/min, but standing blood pressure is 85/60 mmHg and pulse is 110/min. Airway is patent. His hands feel cold and clammy. Abdominal exam confirms epigastric pain, but no rebound tenderness or guarding. Despite 2 liters of lactated Ringer's, the blood pressure and pulse have not changed. What hemoglobin (Hb) threshold should be considered if packed red blood cell (pRBC) transfusion is ordered in this patient?
Q264
A 26-year-old primigravida woman comes to her primary care physician for the second prenatal visit. She is 10 weeks pregnant. She has no current complaint except for occasional nausea. She does not have any chronic health problems. She denies smoking or alcohol intake. Her family history is positive for paternal colon cancer at the age of 55. Vital signs include a temperature of 37.1°C (98.8°F), blood pressure of 120/60 mm Hg, and pulse of 90/min. Physical examination discloses no abnormalities. According to the United States Preventive Services Task Force (USPSTF), which of the following screening tests is recommended for this patient?
Q265
A 47-year-old man presents with recurrent epigastric pain and diarrhea. He has had these symptoms for the last year or so and has been to the clinic several times with similar complaints. His current dosage of omeprazole has been steadily increasing to combat his symptoms. The pain seems to be related to food intake. He describes his diarrhea as watery and unrelated to his meals. Blood pressure is 115/80 mm Hg, pulse is 76/min, and respiratory rate is 19/min. He denies tobacco or alcohol use. An upper endoscopy is performed due to his unexplained and recurrent dyspepsia and reveals thickened gastric folds with three ulcers in the first part of the duodenum, all of which are negative for H. pylori. Which of the following is the best next step in this patient's management?
Q266
A 29-year-old man comes to the physician for a routine health maintenance examination. He has no history of serious illness. His mother has hypertension and his father died of testicular cancer at the age of 51 years. He does not smoke or drink. He is sexually active and uses condoms consistently. He takes no medications. His immunization records are unavailable. He works as a financial consultant and will go on a business trip to Mexico City in 2 weeks. His temperature is 36.7°C (98.7° F), pulse is 78/min, and blood pressure is 122/78 mm Hg. Cardiopulmonary examination shows no abnormalities. Laboratory studies show:
Hemoglobin 13.4 g/dL
Leukocyte count 9800/mm3
Platelet count 168,000/mm3
Serum
Glucose 113 mg/dL
Creatinine 1.1 mg/dL
Which of the following recommendations is most appropriate at this time?
Q267
A 25-year-old woman is admitted to the intensive care unit (ICU) with hematemesis and shock. Five days ago she had a severe fever 40.0℃ (104.0℉), retro-orbital pain, nausea, and myalgias. The high temperatures decreased over a few days, but she developed severe abdominal pain and bleeding gums. A single episode of hematemesis occurred prior to ICU admission. She travels to Latin America every winter. Two weeks ago, she traveled to Brazil and spent most of her time outdoors. She is restless. The temperature is 38.0℃ (100.4℉), the pulse is 110/min, the respiration rate is 33/min, and the blood pressure is 90/70 mm Hg. Conjunctival suffusion is seen. The extremities are cold. A maculopapular rash covers the trunk and extremities. Ecchymoses are observed on the lower extremities. The lung bases reveal absent sounds with dullness to percussion. The abdomen is distended. The liver edge is palpable and liver span is 15 cm. Shifting dullness is present. The laboratory studies show the following:
Laboratory test
Hemoglobin 16.5 g/dL
Leukocyte count 3500/mm3
Segmented neutrophils 55%
Lymphocytes 30%
Platelet count 90,000/mm3
Serum
Alanine aminotransferase (ALT) 75 U/L
Aspartate aminotransferase (AST) 70 U/L
Total bilirubin 0.8 mg/dL
Direct bilirubin 0.2 mg/dL
Which of the following is the most likely diagnosis?
Q268
A 63-year-old woman comes to the physician because of diarrhea and weakness after her meals for 2 weeks. She has the urge to defecate 15–20 minutes after a meal and has 3–6 bowel movements a day. She also has palpitations, sweating, and needs to lie down soon after eating. One month ago, she underwent a distal gastrectomy for gastric cancer. She had post-operative pneumonia, which was treated with cefotaxime. She returned from a vacation to Brazil 6 weeks ago. Her immunizations are up-to-date. She is 165 cm (5 ft 5 in) tall and weighs 51 kg (112 lb); BMI is 18.6 kg/m2. Vital signs are within normal limits. Examination shows a well-healed abdominal midline surgical scar. The abdomen is soft and nontender. Bowel sounds are hyperactive. Rectal examination is unremarkable. Which of the following is the most appropriate next step in management?
Q269
A 71-year-old woman is brought to the emergency department following a syncopal episode. Earlier in the day, the patient had multiple bowel movements that filled the toilet bowl with copious amounts of bright red blood. Minutes later, she felt dizzy and lightheaded and collapsed into her daughter's arms. The patient has a medical history of diabetes mellitus and hypertension. Her temperature is 99.0°F (37.2°C), blood pressure is 155/94 mmHg, pulse is 82/min, respirations are 15/min, and oxygen saturation is 99% on room air. The patient's exam is notable for fecal occult blood positivity on rectal exam; however, the patient is no longer having bloody bowel movements. The patient's lungs are clear to auscultation and her abdomen is soft and nontender. Labs are ordered as seen below.
Hemoglobin: 7.1 g/dL
Hematocrit: 25%
Leukocyte count: 5,300/mm^3 with normal differential
Platelet count: 182,500/mm^3
Two large bore IV's are placed and the patient is given normal saline. What is the best next step in management?
Q270
A 50-year-old overweight woman presents to her physician with complaints of recurrent episodes of right upper abdominal discomfort and cramping. She says that the pain is mild and occasionally brought on by the ingestion of fatty foods. The pain radiates to the right shoulder and around to the back, and it is accompanied by nausea and occasional vomiting. She admits to having these episodes over the past several years. Her temperature is 37°C (98.6° F), respiratory rate is 15/min, pulse is 67/min, and blood pressure is 122/98 mm Hg. Her physical examination is unremarkable. Lab reports reveal:
Hb% 13 gm/dL
Total count (WBC): 11,000/mm3
Differential count:
Neutrophils: 70%
Lymphocytes: 25%
Monocytes: 5%
ESR: 10 mm/hr
Serum:
Albumin: 4.2 gm/dL
Alkaline phosphatase: 150 U/L
Alanine aminotransferase: 76 U/L
Aspartate aminotransferase: 88 U/L
What is the most likely diagnosis?
Gastroenterology US Medical PG Practice Questions and MCQs
Question 261: A 53-year-old woman comes to the emergency department because of weakness and abdominal pain for 24 hours. She has had three bowel movements with dark stool during this period. She has not had vomiting and has never had such episodes in the past. She underwent a tubal ligation 15 years ago. She has chronic lower extremity lymphedema, osteoarthritis, and type 2 diabetes mellitus. Her father died of colon cancer at the age of 72 years. Current medications include metformin, naproxen, and calcium with vitamin D3. She had a screening colonoscopy at 50 years of age which was normal. She appears pale and diaphoretic. Her temperature is 36°C (96.8°F), pulse is 110/min, respirations are 20/min, and blood pressure is 90/50 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. The abdomen is soft and nondistended with mild epigastric tenderness. Rectal exam shows tarry stool. Two large bore IV lines are placed and fluid resuscitation with normal saline is initiated. Which of the following is the most appropriate next step in management?
A. Esophagogastroduodenoscopy (Correct Answer)
B. CT scan of the abdomen with contrast
C. Flexible sigmoidoscopy
D. Diagnostic laparoscopy
E. Colonoscopy
Explanation: ***Esophagogastroduodenoscopy***
- The patient presents with symptoms highly suggestive of an **upper GI bleed**, including **melena (dark, tarry stools)**, weakness, abdominal pain, and signs of **hemodynamic instability** (tachycardia, hypotension, pallor, diaphoresis).
- An EGD is the **most appropriate initial diagnostic and therapeutic procedure** for suspected upper GI bleeding, allowing for direct visualization, diagnosis of the source (e.g., peptic ulcer, esophagitis, varices), and immediate intervention (e.g., endoscopic hemostasis).
*CT scan of the abdomen with contrast*
- A CT scan is not the first-line investigation for acute GI bleeding because it is generally less sensitive than endoscopy for active bleeding and does not allow for immediate therapeutic intervention.
- While it can identify some causes of GI bleeding, such as tumors or vascular malformations, it is usually reserved for cases where endoscopy is inconclusive or contraindicated.
*Flexible sigmoidoscopy*
- Flexible sigmoidoscopy visualizes only the **rectum and sigmoid colon**, which is insufficient to evaluate the entire colon for a lower GI bleed, and completely misses the upper GI tract.
- Given the tarry stools (melena), an upper GI bleed is far more likely than a lower GI bleed.
*Diagnostic laparoscopy*
- Diagnostic laparoscopy is an invasive surgical procedure used to explore the abdominal cavity for conditions that cause pain or internal bleeding, but it is not the initial diagnostic choice for **GI bleeding**.
- It would expose the patient to unnecessary surgical risks without first attempting less invasive and highly effective endoscopic methods.
*Colonoscopy*
- While a colonoscopy is the gold standard for evaluating the **lower GI tract**, the patient's symptoms (melena, epigastric tenderness) strongly indicate an **upper GI bleed**.
- Performing a colonoscopy first would delay the diagnosis and treatment of a potentially life-threatening upper GI bleed.
Question 262: A 36-year-old woman gravida 5, para 4 was admitted at 31 weeks of gestation with worsening fatigue and shortness of breath on exertion for the past month. She also has nausea and loss of appetite. No significant past medical history. The patient denies any smoking history, alcohol or illicit drug use. Her vital signs include: blood pressure 110/60 mm Hg, pulse 120/min, respiratory rate 22/min and temperature 35.1℃ (97.0℉). A complete blood count reveals a macrocytosis with severe pancytopenia, as follows:
Hb 7.2 g/dL
RBC 3.6 million/uL
WBC 4,400/mm3
Neutrophils 40%
Lymphocytes 20%
Platelets 15,000/mm3
MCV 104 fL
Reticulocytes 0.9%
Serum ferritin and vitamin B12 levels were within normal limits. There was an elevated homocysteine level and a normal methylmalonic acid level. Which of the following is the most likely diagnosis in this patient?
A. Normal pregnancy
B. Aplastic anemia
C. Vitamin B12 deficiency
D. Iron deficiency anemia
E. Folate deficiency (Correct Answer)
Explanation: ***Folate deficiency***
- The patient presents with **macrocytic anemia** (MCV 104 fL), **pancytopenia**, and symptoms of severe anemia. The elevated **homocysteine** and normal **methylmalonic acid** levels are classic indicators of folate deficiency, as folate is required to convert homocysteine to methionine but not for MMA metabolism.
- Her status as **gravida 5, para 4** in the **third trimester** (31 weeks) significantly increases her risk for folate deficiency due to high fetal demands, even without poor nutritional intake.
*Normal pregnancy*
- While **fatigue and shortness of breath** are common in pregnancy, severe **pancytopenia** and **macrocytosis (MCV 104)** are not normal physiological changes.
- Hemoglobin of 7.2 g/dL indicates severe anemia, far below the expected physiological decrease in Hb during pregnancy due to **hemodilution**.
*Aplastic anemia*
- Aplastic anemia is characterized by **pancytopenia** but typically presents with **normocytic or mildly macrocytic RBCs**, and there would be severe **reticulocytopenia** (which is present here, 0.9%).
- However, the distinct biochemical markers of elevated **homocysteine** and normal **methylmalonic acid** point more specifically towards a nutritional deficiency rather than bone marrow failure.
*Vitamin B12 deficiency*
- **Vitamin B12 deficiency** also causes **macrocytic anemia** and **pancytopenia**, with elevated **homocysteine levels**.
- However, a key differentiating factor is that **methylmalonic acid (MMA)** levels would also be **elevated** in B12 deficiency, which is normal in this patient.
*Iron deficiency anemia*
- **Iron deficiency anemia** is typically characterized by **microcytic, hypochromic** red blood cells (low MCV), not macrocytic.
- While it can cause fatigue and shortness of breath, the laboratory findings of a **normal ferritin** (suggesting adequate iron stores), **macrocytosis**, and **pancytopenia** do not fit with iron deficiency.
Question 263: A 55-year-old man with known coronary artery disease presents to the ED with epigastric pain, worsening fatigue, and melena. He takes aspirin and rosuvastatin, but took ibuprofen over the past two weeks for lower back pain. He denies nausea, vomiting, hematemesis, chest pain, fever, and weight loss. Sitting blood pressure is 100/70 mmHg and pulse is 90/min, but standing blood pressure is 85/60 mmHg and pulse is 110/min. Airway is patent. His hands feel cold and clammy. Abdominal exam confirms epigastric pain, but no rebound tenderness or guarding. Despite 2 liters of lactated Ringer's, the blood pressure and pulse have not changed. What hemoglobin (Hb) threshold should be considered if packed red blood cell (pRBC) transfusion is ordered in this patient?
A. < 10
B. threshold does not matter
C. < 9
D. < 7
E. < 8 (Correct Answer)
Explanation: ***< 8***
- This patient presents with signs of **hemodynamic instability** (orthostasis, cold extremities, persistent hypotension despite fluid resuscitation) and active upper gastrointestinal bleeding (melena, epigastric pain, recent NSAID use).
- In patients with **hemodynamic instability** due to acute blood loss, the transfusion threshold is generally higher, at **Hb < 8 g/dL**, to ensure adequate oxygen delivery, especially in the setting of coronary artery disease.
*< 10*
- A transfusion threshold of **Hb < 10 g/dL** is typically reserved for patients with more severe conditions like **unstable angina**, active myocardial ischemia, or when severe symptoms of anemia persist despite an Hb > 8 g/dL.
- While this patient has coronary artery disease, his immediate need for transfusion is driven by acute blood loss and instability, not solely anemic angina.
*threshold does not matter*
- This statement is incorrect as transfusion decisions are based on specific **hemoglobin thresholds** and clinical context to optimize patient outcomes and avoid unnecessary transfusions.
- Ignoring thresholds could lead to either undertransfusion (risking organ damage) or overtransfusion (risking complications like TACO or TRALI).
*< 9*
- An Hb threshold of **< 9 g/dL** might be considered in some scenarios of acute bleeding, but with clear signs of **hemodynamic instability** and severe symptoms, an Hb of 8 g/dL or less is a more commonly accepted trigger.
- The combination of ongoing bleeding, significant orthostasis, and cold extremities points to a more urgent need for correction.
*< 7*
- A transfusion threshold of **Hb < 7 g/dL** is generally applied to hemodynamically stable patients without significant comorbidities, as demonstrated in the TRICC trial.
- This patient is **hemodynamically unstable** and has significant comorbidity (coronary artery disease), warranting a higher transfusion threshold.
Question 264: A 26-year-old primigravida woman comes to her primary care physician for the second prenatal visit. She is 10 weeks pregnant. She has no current complaint except for occasional nausea. She does not have any chronic health problems. She denies smoking or alcohol intake. Her family history is positive for paternal colon cancer at the age of 55. Vital signs include a temperature of 37.1°C (98.8°F), blood pressure of 120/60 mm Hg, and pulse of 90/min. Physical examination discloses no abnormalities. According to the United States Preventive Services Task Force (USPSTF), which of the following screening tests is recommended for this patient?
A. Colonoscopy for colorectal cancer at the age of 40
B. HbA1C for type 2 diabetes mellitus
C. Colonoscopy for colorectal cancer at the age of 50
D. Glucose tolerance test for gestational diabetes mellitus
E. Urine culture for asymptomatic bacteriuria (Correct Answer)
Explanation: ***Urine culture for asymptomatic bacteriuria***
- The **USPSTF** recommends **screening pregnant individuals for asymptomatic bacteriuria** with a urine culture at the first prenatal visit or at 12-16 weeks' gestation to prevent pyelonephritis and other adverse pregnancy outcomes.
- This patient is in her second prenatal visit at 10 weeks, making this a timely and recommended screening.
*Colonoscopy for colorectal cancer at the age of 40*
- Although the patient has a **family history of paternal colon cancer at age 55**, the general recommendation for earlier screening due to family history typically starts 10 years before the youngest affected relative's diagnosis, but not earlier than age 40, and is not a routine screening for a 26-year-old.
- This screening is not universally recommended at age 40 for everyone, and current guidelines often suggest individualized approaches based on specific family history details that are not fully met by this patient at this age.
*HbA1C for type 2 diabetes mellitus*
- The patient has **no risk factors for type 2 diabetes**, such as obesity, history of gestational diabetes, or strong family history of diabetes, that would warrant early screening with HbA1c.
- Routine screening for type 2 diabetes for an individual of her age and health status is not typically recommended by the USPSTF.
*Colonoscopy for colorectal cancer at the age of 50*
- The **USPSTF recommends screening for colorectal cancer in average-risk individuals beginning at age 45-50**.
- This patient is only 26 years old and is not in the appropriate age group for this general screening recommendation.
*Glucose tolerance test for gestational diabetes mellitus*
- Screening for **gestational diabetes mellitus (GDM)** typically occurs much later in pregnancy, usually between **24 and 28 weeks of gestation**.
- Performing a glucose tolerance test at 10 weeks pregnant is too early for GDM screening based on standard guidelines.
Question 265: A 47-year-old man presents with recurrent epigastric pain and diarrhea. He has had these symptoms for the last year or so and has been to the clinic several times with similar complaints. His current dosage of omeprazole has been steadily increasing to combat his symptoms. The pain seems to be related to food intake. He describes his diarrhea as watery and unrelated to his meals. Blood pressure is 115/80 mm Hg, pulse is 76/min, and respiratory rate is 19/min. He denies tobacco or alcohol use. An upper endoscopy is performed due to his unexplained and recurrent dyspepsia and reveals thickened gastric folds with three ulcers in the first part of the duodenum, all of which are negative for H. pylori. Which of the following is the best next step in this patient's management?
A. Fasting serum gastrin levels (Correct Answer)
B. Secretin stimulation test
C. CT scan of the abdomen
D. Somatostatin receptor scintigraphy
E. Serum calcium levels
Explanation: ***Fasting serum gastrin levels***
- The patient's presentation with **recurrent epigastric pain**, **multiple duodenal ulcers**, **thickened gastric folds**, and the need for **increasing dosages of omeprazole** strongly suggests **Zollinger-Ellison syndrome (ZES)**, caused by a gastrinoma.
- **Fasting serum gastrin levels** are the initial diagnostic test for ZES; elevated levels confirm excessive gastrin production.
*Secretin stimulation test*
- This test is typically performed when **fasting serum gastrin levels are equivocal** (e.g., mildly elevated) to confirm the diagnosis of ZES.
- It is not the initial best step, as **fasting gastrin levels** are simpler and often sufficient for initial diagnosis.
*CT scan of the abdomen*
- A CT scan is used for **tumor localization** after a diagnosis of ZES has been established.
- It is not the primary diagnostic test for ZES itself, as it won't directly measure gastrin levels.
*Somatostatin receptor scintigraphy*
- This imaging study is highly sensitive for **localizing gastrinomas**, especially in metastatic disease, and is often used after biochemical confirmation of ZES.
- It is not indicated as the initial diagnostic step and is part of the work-up for staging rather than diagnosis.
*Serum calcium levels*
- While **hypercalcemia** can be associated with **Multiple Endocrine Neoplasia type 1 (MEN1)**, which includes gastrinomas, it is not the best initial diagnostic test for Zollinger-Ellison syndrome itself.
- Elevated calcium would be a secondary finding, and direct measurement of gastrin is essential for diagnosing ZES.
Question 266: A 29-year-old man comes to the physician for a routine health maintenance examination. He has no history of serious illness. His mother has hypertension and his father died of testicular cancer at the age of 51 years. He does not smoke or drink. He is sexually active and uses condoms consistently. He takes no medications. His immunization records are unavailable. He works as a financial consultant and will go on a business trip to Mexico City in 2 weeks. His temperature is 36.7°C (98.7° F), pulse is 78/min, and blood pressure is 122/78 mm Hg. Cardiopulmonary examination shows no abnormalities. Laboratory studies show:
Hemoglobin 13.4 g/dL
Leukocyte count 9800/mm3
Platelet count 168,000/mm3
Serum
Glucose 113 mg/dL
Creatinine 1.1 mg/dL
Which of the following recommendations is most appropriate at this time?
A. Malaria chemoprophylaxis
B. Rabies vaccine
C. Cholera vaccine
D. Hepatitis A vaccine (Correct Answer)
E. Yellow fever vaccine
Explanation: **Hepatitis A vaccine**
- Travel to Mexico City, even for business, carries a risk of exposure to **Hepatitis A**, especially with potential for consuming local food or water.
- The **Hepatitis A vaccine** is recommended for unvaccinated individuals traveling to areas with intermediate or high endemicity, which includes Mexico.
*Malaria chemoprophylaxis*
- **Mexico City** is at a high altitude and is not considered a **malaria-endemic area**, so chemoprophylaxis is not typically recommended for this destination.
- Prophylaxis is generally reserved for travel to regions with a higher risk of **mosquito-borne malaria infection**.
*Rabies vaccine*
- Routine **pre-exposure rabies vaccination** is not typically recommended for general travel to Mexico City unless there is a specific risk, such as prolonged outdoor activities, animal handling, or substantial interaction with wildlife.
- The presented scenario does not indicate such high-risk exposure for a financial consultant on a business trip.
*Cholera vaccine*
- **Cholera** is rare in travelers, and the vaccine is generally only recommended for individuals traveling to areas with active cholera transmission and who are at high risk due to poor hygiene or unstable living conditions.
- Mexico City is not considered a high-risk area for **cholera for a typical tourist or business traveler**.
*Yellow fever vaccine*
- **Yellow fever** is not endemic in Mexico, and a **yellow fever vaccine** is not required or recommended for travel to Mexico City.
- This vaccine is primarily for travel to parts of Africa and South America where the disease is prevalent.
Question 267: A 25-year-old woman is admitted to the intensive care unit (ICU) with hematemesis and shock. Five days ago she had a severe fever 40.0℃ (104.0℉), retro-orbital pain, nausea, and myalgias. The high temperatures decreased over a few days, but she developed severe abdominal pain and bleeding gums. A single episode of hematemesis occurred prior to ICU admission. She travels to Latin America every winter. Two weeks ago, she traveled to Brazil and spent most of her time outdoors. She is restless. The temperature is 38.0℃ (100.4℉), the pulse is 110/min, the respiration rate is 33/min, and the blood pressure is 90/70 mm Hg. Conjunctival suffusion is seen. The extremities are cold. A maculopapular rash covers the trunk and extremities. Ecchymoses are observed on the lower extremities. The lung bases reveal absent sounds with dullness to percussion. The abdomen is distended. The liver edge is palpable and liver span is 15 cm. Shifting dullness is present. The laboratory studies show the following:
Laboratory test
Hemoglobin 16.5 g/dL
Leukocyte count 3500/mm3
Segmented neutrophils 55%
Lymphocytes 30%
Platelet count 90,000/mm3
Serum
Alanine aminotransferase (ALT) 75 U/L
Aspartate aminotransferase (AST) 70 U/L
Total bilirubin 0.8 mg/dL
Direct bilirubin 0.2 mg/dL
Which of the following is the most likely diagnosis?
A. Yellow fever
B. Dengue fever (Correct Answer)
C. Chikungunya virus infection
D. Zika virus infection
E. Chagas disease
Explanation: ***Correct: Dengue fever***
- The patient's presentation with **biphasic fever**, retro-orbital pain, severe abdominal pain, bleeding gums, **hematemesis**, maculopapular rash, **thrombocytopenia** (platelet count 90,000/mm3), hemoconcentration (hemoglobin 16.5 g/dL), leukopenia, and travel history to **Latin America** (Brazil) highly correlates with severe dengue fever.
- The **signs of plasma leakage** (absent lung sounds with dullness at bases, distended abdomen with shifting dullness indicating ascites, cold extremities, and hypotension) and shock are characteristic of **dengue hemorrhagic fever/dengue shock syndrome**.
*Incorrect: Yellow fever*
- While yellow fever can present with fever, myalgia, and hemorrhage, **jaundice (yellow skin)** is a prominent feature, often leading to the name "yellow fever," which is absent here (total bilirubin 0.8 mg/dL).
- Liver enzyme elevations in yellow fever are typically much higher, often in the thousands, compared to the modest elevations seen in this patient.
*Incorrect: Chikungunya virus infection*
- Characterized primarily by **severe arthralgia** (joint pain) that is often debilitating and can be prolonged, which is not the main presenting complaint in this case.
- While fever and rash can occur, severe hemorrhagic manifestations and shock leading to ICU admission are **less common** compared to dengue.
*Incorrect: Zika virus infection*
- Often presents with a **milder illness** involving maculopapular rash, fever, arthralgia, and **conjunctivitis**, but severe manifestations like hemorrhage, shock, and significant organ involvement are rare.
- The severe constitutional symptoms, profound thrombocytopenia, and signs of plasma leakage seen in this patient are **not typical** for Zika.
*Incorrect: Chagas disease*
- Chagas disease (caused by *Trypanosoma cruzi*) is typically a chronic infection that can lead to **cardiomyopathy** or **gastrointestinal mega-syndromes** years after the initial infection.
- The acute phase may involve fever and local swelling (chagoma or Romaña's sign), but it does not typically present with the acute, severe hemorrhagic and shock syndrome observed here.
Question 268: A 63-year-old woman comes to the physician because of diarrhea and weakness after her meals for 2 weeks. She has the urge to defecate 15–20 minutes after a meal and has 3–6 bowel movements a day. She also has palpitations, sweating, and needs to lie down soon after eating. One month ago, she underwent a distal gastrectomy for gastric cancer. She had post-operative pneumonia, which was treated with cefotaxime. She returned from a vacation to Brazil 6 weeks ago. Her immunizations are up-to-date. She is 165 cm (5 ft 5 in) tall and weighs 51 kg (112 lb); BMI is 18.6 kg/m2. Vital signs are within normal limits. Examination shows a well-healed abdominal midline surgical scar. The abdomen is soft and nontender. Bowel sounds are hyperactive. Rectal examination is unremarkable. Which of the following is the most appropriate next step in management?
A. Dietary modifications (Correct Answer)
B. Stool PCR test
C. Octreotide therapy
D. Metronidazole therapy
E. Stool microscopy
Explanation: ***Dietary modifications***
- This patient's symptoms (diarrhea, weakness, palpitations, sweating, and urge to defecate soon after meals) following a **distal gastrectomy** are classic for **dumping syndrome**. **Dietary modification** is the first-line treatment.
- Recommended modifications include **smaller, more frequent meals**, avoiding high-sugar foods, increasing protein and fiber, and separating solids from liquids during meals.
*Stool PCR test*
- While diarrhea is present, the patient's symptoms are strongly linked to her recent gastrectomy and meal ingestion rather than an infectious cause.
- A stool PCR test would be appropriate if there were other signs of infection, such as fever or severe abdominal pain, or if dietary modifications failed to resolve symptoms.
*Octreotide therapy*
- **Octreotide**, a somatostatin analog, is reserved for **severe cases of dumping syndrome** that do not respond to dietary modifications.
- It works by inhibiting the release of gastrointestinal hormones and slowing gastric emptying, but it is not the initial management step.
*Metronidazole therapy*
- **Metronidazole** is an antibiotic used to treat bacterial and parasitic infections. There is no evidence suggesting an infection in this patient.
- The timing of symptoms immediately post-meal points away from an infection and towards post-gastrectomy complications.
*Stool microscopy*
- Similar to a stool PCR, **stool microscopy** is used to identify parasites or other pathogens.
- Given the classic presentation of dumping syndrome following gastrectomy, an infectious cause is less likely, and other diagnostic tests should be pursued if dietary measures fail.
Question 269: A 71-year-old woman is brought to the emergency department following a syncopal episode. Earlier in the day, the patient had multiple bowel movements that filled the toilet bowl with copious amounts of bright red blood. Minutes later, she felt dizzy and lightheaded and collapsed into her daughter's arms. The patient has a medical history of diabetes mellitus and hypertension. Her temperature is 99.0°F (37.2°C), blood pressure is 155/94 mmHg, pulse is 82/min, respirations are 15/min, and oxygen saturation is 99% on room air. The patient's exam is notable for fecal occult blood positivity on rectal exam; however, the patient is no longer having bloody bowel movements. The patient's lungs are clear to auscultation and her abdomen is soft and nontender. Labs are ordered as seen below.
Hemoglobin: 7.1 g/dL
Hematocrit: 25%
Leukocyte count: 5,300/mm^3 with normal differential
Platelet count: 182,500/mm^3
Two large bore IV's are placed and the patient is given normal saline. What is the best next step in management?
A. Packed red blood cells
B. Type and screen (Correct Answer)
C. Fresh frozen plasma
D. CT abdomen
E. Colonoscopy
Explanation: ***Type and screen***
- The patient has experienced a **significant colonic bleed** with associated **syncopal episode** and a **hemoglobin drop** to 7.1 g/dL. Before administering blood products, **blood typing and cross-matching** must be performed to ensure compatibility.
- This step is critical for **patient safety** to prevent transfusion reactions, especially given the likelihood of needing a transfusion soon.
- In the **sequence of acute blood loss management**, type and screen must be completed **before** packed red blood cells can be safely administered, making it the immediate next step after initial resuscitation with IV fluids.
*Packed red blood cells*
- While the patient will likely need **packed red blood cells (PRBCs)** due to severe anemia (Hb 7.1 g/dL) and hemodynamic instability (syncopal episode), PRBCs cannot be administered safely without first performing a **type and screen** to ensure compatibility.
- Administering PRBCs before compatibility testing is generally reserved for **life-threatening emergencies** with ongoing massive hemorrhage where there is no time for even an immediate cross-match (in which case O-negative blood would be used).
- This patient, while anemic, is currently **hemodynamically stable** (normal BP and pulse), allowing time for proper type and screen.
*Fresh frozen plasma*
- **Fresh frozen plasma (FFP)** is used to replace clotting factors in patients with **coagulopathies** or significant bleeding, often observed in massive transfusions or liver disease.
- This patient's **platelet count is normal** and there is no information to suggest a coagulopathy, thus FFP is not indicated as the immediate next step.
*CT abdomen*
- A **CT scan of the abdomen** may be useful later to identify the cause of the lower GI bleed, such as diverticulosis or angiodysplasia.
- However, the immediate priority is to **stabilize the patient hemodynamically** and address the acute blood loss before pursuing diagnostic imaging.
*Colonoscopy*
- A **colonoscopy** is the definitive diagnostic and potentially therapeutic procedure for a lower GI bleed.
- However, before performing a colonoscopy, the patient must be **hemodynamically stable**, which includes addressing their **anemia** and ensuring adequate blood product availability.
Question 270: A 50-year-old overweight woman presents to her physician with complaints of recurrent episodes of right upper abdominal discomfort and cramping. She says that the pain is mild and occasionally brought on by the ingestion of fatty foods. The pain radiates to the right shoulder and around to the back, and it is accompanied by nausea and occasional vomiting. She admits to having these episodes over the past several years. Her temperature is 37°C (98.6° F), respiratory rate is 15/min, pulse is 67/min, and blood pressure is 122/98 mm Hg. Her physical examination is unremarkable. Lab reports reveal:
Hb% 13 gm/dL
Total count (WBC): 11,000/mm3
Differential count:
Neutrophils: 70%
Lymphocytes: 25%
Monocytes: 5%
ESR: 10 mm/hr
Serum:
Albumin: 4.2 gm/dL
Alkaline phosphatase: 150 U/L
Alanine aminotransferase: 76 U/L
Aspartate aminotransferase: 88 U/L
What is the most likely diagnosis?
A. Choledocholithiasis (Correct Answer)
B. Pancreatitis
C. Gallbladder cancer
D. Duodenal peptic ulcer
E. Acute cholecystitis
Explanation: ***Choledocholithiasis***
- The patient's presentation with **recurrent right upper quadrant pain** radiating to the **right shoulder** and back, especially after **fatty meals**, is consistent with **biliary colic**. The elevated **alkaline phosphatase (150 U/L)**, **ALT (76 U/L)**, and **AST (88 U/L)** suggest **early biliary obstruction** from a **common bile duct stone**.
- The **absence of jaundice** and **normal temperature** indicate this is likely **intermittent or partial obstruction** rather than complete CBD blockage. The **mild leukocytosis (11,000)** without fever suggests irritation without acute infection.
- The **chronic, recurrent nature over years** suggests **intermittent passage of stones** into the CBD, causing transient obstruction and enzyme elevations.
*Pancreatitis*
- Pancreatitis typically presents with **severe, constant epigastric pain** radiating to the back, associated with markedly elevated **amylase and lipase** (not provided here).
- While gallstones can cause pancreatitis, the **pattern of pain triggered by fatty meals** with elevated alkaline phosphatase is more consistent with **biliary obstruction** rather than pancreatic inflammation.
*Gallbladder cancer*
- Gallbladder cancer typically presents in elderly patients with **persistent RUQ pain**, **jaundice**, **weight loss**, and often a **palpable mass**.
- The **recurrent, mild pain over years triggered by fatty meals** is characteristic of **benign gallstone disease**, not malignancy. The patient has no constitutional symptoms or mass.
*Duodenal peptic ulcer*
- Duodenal ulcers cause **epigastric pain** that typically **improves with food** or antacids and has a **burning quality**, not colicky pain radiating to the shoulder and back.
- The **elevated alkaline phosphatase and transaminases** are not features of uncomplicated peptic ulcer disease, and the **relationship to fatty foods** points to biliary pathology.
*Acute cholecystitis*
- Acute cholecystitis presents with **severe, persistent RUQ pain**, **fever**, **marked leukocytosis**, and a positive **Murphy's sign** on examination.
- This patient has **mild, recurrent pain over years** with **normal temperature**, normal examination, and only mild leukocytosis, making acute cholecystitis unlikely. The chronic pattern suggests **chronic cholecystitis with CBD stone involvement**.
