A 28-year-old woman comes to the emergency department because of increasing weakness and numbness of her legs for 3 days. She noticed that the weakness was more severe after she had a hot shower that morning. A year ago, she had an episode of partial vision loss in her left eye that resolved within 3 weeks. She is sexually active with 3 male partners and uses condoms inconsistently. She appears anxious. Her temperature is 37°C (98.6°F), pulse is 80/min, and blood pressure is 108/77 mm Hg. Examination shows spasticity and decreased muscle strength in bilateral lower extremities. Deep tendon reflexes are 4+ bilaterally. Plantar reflex shows an extensor response bilaterally. The abdominal reflex is absent. Sensation to vibration and position over the lower extremities shows no abnormalities. Tandem gait is impaired. MRI of the brain and spine is inconclusive. Further evaluation is most likely to show which of the following?
Q142
A 39-year-old woman comes to the physician because of a 5-day history of pain and stiffness in her hands and wrists and a nonpruritic generalized rash. The stiffness is worst in the morning and improves after 15–20 minutes of activity. She had fever and a runny nose 10 days ago that resolved without treatment. She is sexually active with a male partner and uses condoms inconsistently. She works as an elementary school teacher. Her temperature is 37.3°C (99.1°F), pulse is 78/min, and blood pressure is 120/70 mm Hg. Examination shows swelling, tenderness, and decreased range of motion of the wrists as well as the metacarpophalangeal and proximal interphalangeal joints. There is a lacy macular rash over the trunk and extremities. Laboratory studies, including erythrocyte sedimentation rate and anti-nuclear antibody and anti-dsDNA serology, show no abnormalities. Which of the following is the most likely cause of this patient's symptoms?
Q143
A 30-year-old woman comes to the physician because of severe headaches and lightheadedness for 2 months. She has also been hearing a 'swoosh' sound in her left ear for the past month. She has allergic rhinitis and acne. Her sister is being treated for thyroid cancer. Current medications include levocetirizine, topical clindamycin, and azelastine-fluticasone nasal spray. She appears anxious. She is 155 cm (5 ft 1 in) tall and weighs 77 kg (170 lb); BMI is 32 kg/m2. Her temperature is 37°C (98.6°F), pulse is 96/min, respirations are 14/min, and blood pressure is 168/96 mm Hg. Examination shows cystic acne over the face and back. The pupils are equal and reactive. There is a bruit on the left side of the neck. The lungs are clear to auscultation. Cardiac examination shows no murmurs, rubs, or gallops. The abdomen is soft and nontender. There is an abdominal bruit on the left side. Neurologic examination shows no focal findings. Further evaluation of this patient is most likely to show which of the following?
Q144
A 27-year-old male with a history of injection drug use has been feeling short of breath and fatigued for the past several weeks. He is having trouble climbing the stairs to his apartment and occasionally feels like his heart is racing out of control. His past medical history is most notable for a previous bout of infective endocarditis after which he was lost to follow-up. On exam, you note that his carotid pulse has rapid rise and fall. Which of the following would you also expect to find?
Q145
A 72-year-old man presents to the emergency department for a change in his behavior. The patient's wife called 911 and he was brought in by emergency medical services. She noticed that he seemed somnolent and not very responsive. The patient has a past medical history of type II diabetes, obesity, osteoarthritis, and migraine headaches. His current medications include naproxen, insulin, atorvastatin, metformin, ibuprofen, omeprazole, and fish oil. His temperature is 99.5°F (37.5°C), blood pressure is 170/115 mmHg, pulse is 80/min, respirations are 19/min, and oxygen saturation is 98% on room air. On physical exam, the patient is somnolent and has a Glasgow Coma Scale of 11. Cardiac and pulmonary exams are notable for bibasilar crackles and a systolic murmur that radiates to the carotids. Neurological exam is deferred due to the patient's condition. Laboratory values are shown below.
Hemoglobin: 12 g/dL
Hematocrit: 36%
Leukocyte count: 9,500 cells/mm^3 with normal differential
Platelet count: 199,000/mm^3
Serum:
Na+: 144 mEq/L
Cl-: 98 mEq/L
K+: 4.0 mEq/L
HCO3-: 16 mEq/L
BUN: 44 mg/dL
Glucose: 202 mg/dL
Creatinine: 2.7 mg/dL
Ca2+: 9.2 mg/dL
AST: 12 U/L
ALT: 22 U/L
The patient is started on IV fluids. Which of the following represents the best next step in management?
Q146
A 49-year-old woman comes to the physician because of a 4-month history of a dry cough and shortness of breath on exertion. She also reports recurrent episodes of pain, stiffness, and swelling in her wrist and her left knee over the past 6 months. She had two miscarriages at age 24 and 28. Physical examination shows pallor, ulcerations on the palate, and annular hyperpigmented plaques on the arms and neck. Fine inspiratory crackles are heard over bilateral lower lung fields on auscultation. Which of the following additional findings is most likely in this patient?
Q147
A 29-year-old woman, gravida 1, para 0 at 11 weeks' gestation comes to the physician because of a 2-day history of left lower extremity pain and swelling. Her temperature is 37.9°C (100.2°F). Physical examination shows a tender, palpable cord on the lateral aspect of the left lower leg. The overlying skin is erythematous and indurated. Duplex ultrasound shows vascular wall thickening and subcutaneous edema. Which of the following is the most likely diagnosis?
Q148
A 34-year-old woman comes to the emergency department with midsternal chest pain, shortness of breath, and cough with bloody sputum for the past 3 hours. The pain started after moving furniture at home and worsens when taking deep breaths. The patient has a history of hypertension. She has smoked one pack of cigarettes daily for the past 20 years. She drinks 1–2 glasses of wine per day. Current medications include enalapril and an oral contraceptive. Her temperature is 38.2°C (100.8°F), pulse is 110/min, respirations are 20/min, and blood pressure is 110/70 mm Hg. Oxygen saturation is 92% on room air. Physical examination shows decreased breath sounds over the left lung base. There is calf pain on dorsal flexion of the right foot. Examination of the extremities shows warm skin and normal pulses. Further evaluation of this patient is most likely to show which of the following findings?
Q149
A 38-year-old man comes to the physician because of fever, malaise, productive cough, and left-sided chest pain for 2 weeks. During this time, he has woken up to a wet pillow in the morning on multiple occasions and has not been as hungry as usual. He was diagnosed with HIV infection 1 year ago. He currently stays at a homeless shelter. He has smoked one pack of cigarettes daily for 22 years. He has a history of intravenous illicit drug use. He drinks 5–6 beers daily. He is receiving combined antiretroviral therapy but sometimes misses doses. His temperature is 38.6°C (101.5°F), pulse is 106/min, and blood pressure is 125/85 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 94%. Auscultation shows decreased breath sounds over the left base of the lung. There is dullness to percussion on the left lower part of the chest. Laboratory studies show:
Hemoglobin 14 g/dL
Leukocyte count 5,000/mm3
CD4+ T lymphocytes 240/mm3 (N > 500)
Serum
Creatinine 0.9 mg/dL
γ-Glutamyltransferase (GGT) 65 U/L (N = 5–50)
Aspartate aminotransferase (AST) 15 U/L
Alanine aminotransferase (ALT) 19 U/L
Alkaline phosphatase 40 U/L
Lactate dehydrogenase (LDH) 50 U/L
An x-ray of the chest shows a left-sided pleural effusion and hilar lymphadenopathy. Analysis of the pleural fluid shows an effusion with lymphocyte-predominant leukocytosis, high protein, an LDH of 500 U/L, and high adenosine deaminase. Which of the following is the most likely cause of this patient's condition?
Q150
A 44-year-old female is brought to the emergency room after losing consciousness at a shopping mall. Her husband states that they were shopping when the patient appeared sweaty and tremulous, became confused, then collapsed. She was unconscious for 5 minutes until a paramedic arrived. Fingerstick glucose at that time was 31 mg/dL and intramuscular glucagon was administered. The patient regained consciousness as she was being transported to the ambulance. On arrival in the emergency room, she is conscious but sleepy. She is able to report that her last meal prior to the mall was 5 hours ago. Her husband notes that over the last 3 months, she has complained of headaches and a milky discharge from both breasts, as well as nausea if she goes too long without eating. She works as an inpatient nurse and was exposed to tuberculosis 10 years ago but adequately treated. Because she was adopted as an infant, family history is unknown. Temperature is 98.4 deg F (36.9 deg C), blood pressure is 101/59 mmHg, pulse is 88/min, and respiration is 14/min. Preliminary lab values are shown below:
Plasma glucose: 54 mg/dL
Plasma insulin: 29 pmol/L (normal < 19 pmol/L)
Plasma C-peptide: 272 pmol/L (normal < 200 pmol/L)
Plasma proinsulin: 8 pmol/L (normal < 5 pmol/L)
Plasma ß-hydroxybutyrate: 1.2 mmol/L (normal > 2.7 mmol/L after fasting)
Which of the following is the most likely cause of this patient’s hypoglycemic episode?
Cardiology US Medical PG Practice Questions and MCQs
Question 141: A 28-year-old woman comes to the emergency department because of increasing weakness and numbness of her legs for 3 days. She noticed that the weakness was more severe after she had a hot shower that morning. A year ago, she had an episode of partial vision loss in her left eye that resolved within 3 weeks. She is sexually active with 3 male partners and uses condoms inconsistently. She appears anxious. Her temperature is 37°C (98.6°F), pulse is 80/min, and blood pressure is 108/77 mm Hg. Examination shows spasticity and decreased muscle strength in bilateral lower extremities. Deep tendon reflexes are 4+ bilaterally. Plantar reflex shows an extensor response bilaterally. The abdominal reflex is absent. Sensation to vibration and position over the lower extremities shows no abnormalities. Tandem gait is impaired. MRI of the brain and spine is inconclusive. Further evaluation is most likely to show which of the following?
A. Elevated intrinsic factor antibody level
B. Demyelination on nerve biopsy
C. Positive rapid plasma reagin test
D. Slow nerve conduction velocity
E. Oligoclonal bands in cerebrospinal fluid (Correct Answer)
Explanation: ***Oligoclonal bands in cerebrospinal fluid***
- The patient's presentation with **recurrent neurological symptoms** (leg weakness, numbness, previous partial vision loss), worsening with heat (**Uhthoff phenomenon**), **spasticity**, hyperactive reflexes, and absent abdominal reflexes, strongly suggests **multiple sclerosis (MS)**.
- **Oligoclonal bands** in the CSF are highly indicative of MS, reflecting **intrathecal immunoglobulin production** due to CNS inflammation and demyelination.
*Elevated intrinsic factor antibody level*
- This is associated with **pernicious anemia**, which causes **vitamin B12 deficiency** and can lead to subacute combined degeneration of the spinal cord (sensory ataxia, weakness, paresthesias).
- However, MS is a more fitting diagnosis given the patient's relapsing-remitting course and heat sensitivity, and **vibration/position sensation is normal**, which would typically be affected in B12 deficiency.
*Demyelination on nerve biopsy*
- While MS involves **demyelination**, it is primarily a disease of the **central nervous system**, and nerve biopsies are rarely used for diagnosis as they typically assess peripheral nerves.
- The symptoms are more consistent with CNS involvement than a peripheral neuropathy.
*Positive rapid plasma reagin test*
- A positive rapid plasma reagin (RPR) test indicates **syphilis**, which can cause neurological symptoms in its tertiary stage (**neurosyphilis**), affecting the brain and spinal cord (e.g., tabes dorsalis).
- While neurosyphilis can mimic some aspects of MS (e.g., ataxia, neurological deficits), the clinical history of relapsing symptoms and worsening with heat are more classic for MS, and there is no direct evidence of syphilis.
*Slow nerve conduction velocity*
- **Slow nerve conduction velocity** is characteristic of **peripheral nerve demyelination** (e.g., Guillain-Barré syndrome, CIDP).
- Given the patient's signs of **upper motor neuron dysfunction** (spasticity, hyperreflexia, extensor plantar response) and the typical CNS involvement of MS, nerve conduction studies would likely be normal or only mildly affected in MS.
Question 142: A 39-year-old woman comes to the physician because of a 5-day history of pain and stiffness in her hands and wrists and a nonpruritic generalized rash. The stiffness is worst in the morning and improves after 15–20 minutes of activity. She had fever and a runny nose 10 days ago that resolved without treatment. She is sexually active with a male partner and uses condoms inconsistently. She works as an elementary school teacher. Her temperature is 37.3°C (99.1°F), pulse is 78/min, and blood pressure is 120/70 mm Hg. Examination shows swelling, tenderness, and decreased range of motion of the wrists as well as the metacarpophalangeal and proximal interphalangeal joints. There is a lacy macular rash over the trunk and extremities. Laboratory studies, including erythrocyte sedimentation rate and anti-nuclear antibody and anti-dsDNA serology, show no abnormalities. Which of the following is the most likely cause of this patient's symptoms?
A. Disseminated gonococcal disease
B. Rheumatoid arthritis
C. Systemic lupus erythematosus
D. Parvovirus arthritis (Correct Answer)
E. Psoriatic arthritis
Explanation: ***Parvovirus arthritis***
- This patient's symptoms, including **polyarthralgia** and a **lacy macular rash**, following a prodromal illness (fever, runny nose), are highly characteristic of parvovirus B19 infection. The joint involvement often resembles **rheumatoid arthritis** but is typically self-limiting.
- The patient's profession as an **elementary school teacher** increases her risk of exposure to parvovirus B19, which is common in children.
*Disseminated gonococcal disease*
- While it can cause **migratory polyarthralgia** and a rash, the rash is typically **pustular or vesicular** on an erythematous base, often with hemorrhagic lesions, which differs from the described lacy macular rash.
- The rash in DGI also tends to be sparse, unlike the generalized lacy rash described.
*Rheumatoid arthritis*
- Although it causes **symmetrical polyarthritis** with morning stiffness, the rash is not typical for RA, and symptoms usually persist for longer than 6 weeks to meet diagnostic criteria.
- Furthermore, **anti-nuclear antibody** (ANA) and **ESR** would likely be elevated in active RA, but are normal here.
*Systemic lupus erythematosus*
- SLE can present with **arthralgia** and various rashes, but the classic rash associated with SLE is a **malar (butterfly) rash** or **discoid rash**. A lacy macular rash is not typical.
- **ANA** and **anti-dsDNA** serologies are usually positive in SLE, but are normal in this patient.
*Psoriatic arthritis*
- Psoriatic arthritis is associated with **psoriasis skin lesions**, which are typically erythematous, scaly plaques, not a lacy macular rash.
- While it can affect the hands and wrists, the rash and preceding viral-like illness do not fit the typical presentation of psoriatic arthritis.
Question 143: A 30-year-old woman comes to the physician because of severe headaches and lightheadedness for 2 months. She has also been hearing a 'swoosh' sound in her left ear for the past month. She has allergic rhinitis and acne. Her sister is being treated for thyroid cancer. Current medications include levocetirizine, topical clindamycin, and azelastine-fluticasone nasal spray. She appears anxious. She is 155 cm (5 ft 1 in) tall and weighs 77 kg (170 lb); BMI is 32 kg/m2. Her temperature is 37°C (98.6°F), pulse is 96/min, respirations are 14/min, and blood pressure is 168/96 mm Hg. Examination shows cystic acne over the face and back. The pupils are equal and reactive. There is a bruit on the left side of the neck. The lungs are clear to auscultation. Cardiac examination shows no murmurs, rubs, or gallops. The abdomen is soft and nontender. There is an abdominal bruit on the left side. Neurologic examination shows no focal findings. Further evaluation of this patient is most likely to show which of the following?
A. Adrenal adenoma
B. Abnormal breathing pattern at night
C. Parathyroid adenoma
D. Elevated renin level (Correct Answer)
E. Increased 24-hour urine cortisol
Explanation: ***Elevated renin level***
- The patient presents with **severe headaches, lightheadedness, pulsatile tinnitus ('swoosh' sound), hypertension**, and **abdominal and neck bruits**, which are classic signs of **renovascular hypertension**.
- The clinical picture is highly suggestive of **fibromuscular dysplasia (FMD)**, the most common cause of renovascular hypertension in **young women**, which can affect both renal and carotid arteries.
- **Renal artery stenosis** leads to decreased renal blood flow, which activates the **renin-angiotensin-aldosterone system (RAAS)** and results in **elevated renin levels**.
- The neck bruit and pulsatile tinnitus suggest concurrent carotid artery involvement, which is common in FMD.
*Adrenal adenoma*
- This would lead to **primary hyperaldosteronism (Conn's syndrome)**, characterized by hypertension, but typically with **low renin levels** due to negative feedback from aldosterone excess.
- While hypertension is present, the presence of **vascular bruits** and the absence of **hypokalemia** make this less likely.
*Abnormal breathing pattern at night*
- This suggests **obstructive sleep apnea (OSA)**, which can cause **secondary hypertension** and headaches, especially in obese patients.
- However, OSA does not explain the presence of **vascular bruits** (neck and abdominal) or pulsatile tinnitus, which point to a primary vascular etiology.
*Parathyroid adenoma*
- A parathyroid adenoma causes **primary hyperparathyroidism**, characterized by **hypercalcemia** and potential bone, kidney stone, and psychiatric symptoms.
- While it can be associated with hypertension, it does not explain the **bruits** or pulsatile tinnitus, and there is no mention of hypercalcemia or related symptoms.
*Increased 24-hour urine cortisol*
- This is indicative of **Cushing's syndrome**, which presents with hypertension, weight gain, central obesity, moon facies, striae, and possibly acne.
- While the patient has hypertension, obesity, and acne, the presence of **vascular bruits** and **pulsatile tinnitus** are not typical features of Cushing's syndrome, and other classic signs like central obesity, moon facies, or striae are not mentioned.
Question 144: A 27-year-old male with a history of injection drug use has been feeling short of breath and fatigued for the past several weeks. He is having trouble climbing the stairs to his apartment and occasionally feels like his heart is racing out of control. His past medical history is most notable for a previous bout of infective endocarditis after which he was lost to follow-up. On exam, you note that his carotid pulse has rapid rise and fall. Which of the following would you also expect to find?
A. Mid-systolic click
B. Venous hum
C. Systolic murmur that increases with valsalva
D. Fixed, split S2
E. Widened pulse pressure (Correct Answer)
Explanation: ***Widened pulse pressure***
- The patient's history of **injection drug use** and prior **infective endocarditis** suggests a likely etiology of **aortic regurgitation**, which is commonly complicated by **widened pulse pressure**.
- **Aortic regurgitation** leads to a large stroke volume and rapid fall in diastolic pressure, directly causing a **widened pulse pressure** and the described **rapid rise and fall (water-hammer) pulse**.
*Mid-systolic click*
- A **mid-systolic click** is characteristic of **mitral valve prolapse**, a condition not directly suggested by the patient's symptoms or risk factors for **infective endocarditis** affecting the aortic valve.
- While it can be associated with valvular issues, it does not explain the **rapid rise and fall carotid pulse** or the clinical picture of **aortic regurgitation**.
*Venous hum*
- A **venous hum** is a continuous murmur heard over the **internal jugular vein** in children and young adults, often benign, and not specifically associated with the cardiac pathology indicated here.
- It is unrelated to **aortic valve dysfunction** or the signs of heart failure and valvular regurgitation presented in the scenario.
*Systolic murmur that increases with valsalva*
- A **systolic murmur that increases with Valsalva maneuver** is characteristic of **hypertrophic obstructive cardiomyopathy**, which is not supported by the patient's history of **injection drug use** and prior **infective endocarditis**.
- The presentation strongly points to a valvular issue, specifically **aortic regurgitation**, rather than an outflow tract obstruction.
*Fixed, split S2*
- A **fixed, split S2** is a classic finding in an **atrial septal defect (ASD)**, which is an acyanotic congenital heart defect.
- This finding is unrelated to the patient's signs and symptoms, which are suggestive of acquired valvular heart disease resulting from **infective endocarditis**.
Question 145: A 72-year-old man presents to the emergency department for a change in his behavior. The patient's wife called 911 and he was brought in by emergency medical services. She noticed that he seemed somnolent and not very responsive. The patient has a past medical history of type II diabetes, obesity, osteoarthritis, and migraine headaches. His current medications include naproxen, insulin, atorvastatin, metformin, ibuprofen, omeprazole, and fish oil. His temperature is 99.5°F (37.5°C), blood pressure is 170/115 mmHg, pulse is 80/min, respirations are 19/min, and oxygen saturation is 98% on room air. On physical exam, the patient is somnolent and has a Glasgow Coma Scale of 11. Cardiac and pulmonary exams are notable for bibasilar crackles and a systolic murmur that radiates to the carotids. Neurological exam is deferred due to the patient's condition. Laboratory values are shown below.
Hemoglobin: 12 g/dL
Hematocrit: 36%
Leukocyte count: 9,500 cells/mm^3 with normal differential
Platelet count: 199,000/mm^3
Serum:
Na+: 144 mEq/L
Cl-: 98 mEq/L
K+: 4.0 mEq/L
HCO3-: 16 mEq/L
BUN: 44 mg/dL
Glucose: 202 mg/dL
Creatinine: 2.7 mg/dL
Ca2+: 9.2 mg/dL
AST: 12 U/L
ALT: 22 U/L
The patient is started on IV fluids. Which of the following represents the best next step in management?
A. Bicarbonate
B. Potassium
C. Insulin and potassium (Correct Answer)
D. Insulin
E. Discontinue the patient's home medications
Explanation: ***Insulin and potassium***
- The patient presents with **hyperglycemia** (glucose 202 mg/dL), a **high anion gap metabolic acidosis** (anion gap = 144 - (98 + 16) = 30), and altered mental status, consistent with **diabetic ketoacidosis (DKA)** in a patient with type 2 diabetes.
- **Insulin therapy** is essential to halt ketogenesis, correct hyperglycemia, and reverse metabolic acidosis.
- **Potassium replacement** must be initiated simultaneously when serum K+ is between 3.3-5.2 mEq/L (patient's K+ is 4.0 mEq/L). Insulin drives potassium intracellularly, and without replacement, **life-threatening hypokalemia** can develop rapidly.
- Current **DKA management guidelines** recommend starting both insulin and potassium together when potassium is in the normal range to prevent cardiac arrhythmias from hypokalemia.
*Insulin*
- While insulin is critical for DKA management, giving insulin **without potassium replacement** when K+ is normal risks precipitating **severe hypokalemia** as insulin shifts potassium into cells.
- Hypokalemia can lead to cardiac arrhythmias, muscle weakness, and respiratory failure.
- Modern protocols emphasize **concurrent potassium administration** with insulin therapy.
*Bicarbonate*
- Bicarbonate therapy is **not routinely recommended** in DKA management and is reserved only for severe acidosis with pH <6.9 to prevent cardiovascular collapse.
- The patient's acidosis (HCO3- 16 mEq/L) will correct with insulin therapy as ketone production ceases.
- Bicarbonate can cause complications including **cerebral edema, paradoxical CNS acidosis, hypokalemia**, and rebound alkalosis.
*Potassium*
- While potassium replacement is necessary, it must be given **with insulin**, not alone.
- Potassium monotherapy would not address the underlying hyperglycemia and ongoing ketoacidosis.
- The patient's current potassium is normal (4.0 mEq/L), making isolated potassium therapy unnecessary without insulin.
*Discontinue the patient's home medications*
- The patient is taking multiple **NSAIDs** (naproxen and ibuprofen) that likely contributed to his **acute kidney injury** (Cr 2.7 mg/dL).
- While discontinuing nephrotoxic medications is important, this does not address the **immediate life-threatening metabolic crisis** of DKA.
- The priority is correcting the acidosis and hyperglycemia; medication reconciliation can occur after stabilization.
Question 146: A 49-year-old woman comes to the physician because of a 4-month history of a dry cough and shortness of breath on exertion. She also reports recurrent episodes of pain, stiffness, and swelling in her wrist and her left knee over the past 6 months. She had two miscarriages at age 24 and 28. Physical examination shows pallor, ulcerations on the palate, and annular hyperpigmented plaques on the arms and neck. Fine inspiratory crackles are heard over bilateral lower lung fields on auscultation. Which of the following additional findings is most likely in this patient?
A. Increased airway resistance
B. Decreased A-a gradient
C. Decreased right atrial pressure
D. Decreased diffusing capacity (Correct Answer)
E. Increased lung compliance
Explanation: ***Decreased diffusing capacity***
- This patient presents with symptoms highly suggestive of **systemic lupus erythematosus (SLE)**, including recurrent miscarriages, joint pain, oral ulcers, skin lesions (annular hyperpigmented plaques), and pulmonary involvement (dry cough, dyspnea, crackles).
- **Interstitial lung disease (ILD)**, a common pulmonary manifestation of SLE, leads to **fibrosis** of the alveolar-capillary membrane, thereby **decreasing the diffusing capacity of the lung for carbon monoxide (DLCO)**.
*Increased airway resistance*
- Increased airway resistance is characteristic of **obstructive lung diseases** like asthma or COPD, which primarily involve narrowing of the airways.
- The patient's presentation with **inspiratory crackles** and symptoms of restrictive disease (shortness of breath on exertion, dry cough) is not consistent with increased airway resistance.
*Decreased A-a gradient*
- A **decreased alveolar-arterial (A-a) gradient** indicates efficient gas exchange and is typically seen in healthy individuals or in conditions causing hypoventilation without intrinsic lung disease.
- In conditions like pulmonary fibrosis or ILD, there is impaired gas exchange leading to an **increased A-a gradient**.
*Decreased right atrial pressure*
- **Decreased right atrial pressure** would typically signify reduced venous return or normal cardiac function.
- Given the patient's respiratory symptoms and potential for pulmonary hypertension secondary to ILD, an **increased right atrial pressure** would be more likely due to increased pulmonary vascular resistance.
*Increased lung compliance*
- **Increased lung compliance** is seen in conditions where the lung tissue becomes more distensible, such as **emphysema**, due to destruction of elastic fibers.
- **Interstitial lung disease** and pulmonary fibrosis, as suggested by the patient's symptoms and signs, lead to **decreased lung compliance** due to stiffening of the lung tissue.
Question 147: A 29-year-old woman, gravida 1, para 0 at 11 weeks' gestation comes to the physician because of a 2-day history of left lower extremity pain and swelling. Her temperature is 37.9°C (100.2°F). Physical examination shows a tender, palpable cord on the lateral aspect of the left lower leg. The overlying skin is erythematous and indurated. Duplex ultrasound shows vascular wall thickening and subcutaneous edema. Which of the following is the most likely diagnosis?
A. Erysipelas
B. Deep vein thrombosis
C. Erythema nodosum
D. Varicose vein
E. Superficial thrombophlebitis (Correct Answer)
Explanation: ***Superficial thrombophlebitis***
- The presence of a **tender, palpable cord** with overlying **erythema** and **induration** along a superficial vein is classic for superficial thrombophlebitis.
- **Duplex ultrasound** findings of vascular wall thickening and subcutaneous edema further support this diagnosis by indicating inflammation and thrombosis of a superficial vessel rather than a deep one.
*Erysipelas*
- This is a **superficial cellulitis** characterized by a well-demarcated, rapidly spreading erythematous lesion, often with a "raised edge."
- While it causes erythema and induration, it typically does not present with a **palpable cord** indicative of a thrombosed vessel.
*Deep vein thrombosis*
- While presenting with **leg pain and swelling**, a DVT typically causes symptoms in the **proximal veins** and would not present with a palpable cord on the *lateral* aspect of the lower leg.
- Duplex ultrasound for DVT would show **non-compressibility** of a deep vein, which is different from "vascular wall thickening" and "subcutaneous edema" seen in superficial thrombophlebitis.
*Erythema nodosum*
- Presents as **tender, red nodules** typically on the shins, reflecting inflammation of subcutaneous fat (panniculitis), not superficial veins.
- It does not involve a **palpable cord** or symptoms related to vascular thrombosis.
*Varicose vein*
- Varicose veins are **dilated, tortuous superficial veins** that can be palpable, but they typically are not acutely tender, erythematous, or associated with a palpable cord indicating thrombosis unless a complication like phlebitis occurs.
- The ultrasound findings of **vascular wall thickening** and **subcutaneous edema** point to an active inflammatory and thrombotic process, beyond simple varicosity.
Question 148: A 34-year-old woman comes to the emergency department with midsternal chest pain, shortness of breath, and cough with bloody sputum for the past 3 hours. The pain started after moving furniture at home and worsens when taking deep breaths. The patient has a history of hypertension. She has smoked one pack of cigarettes daily for the past 20 years. She drinks 1–2 glasses of wine per day. Current medications include enalapril and an oral contraceptive. Her temperature is 38.2°C (100.8°F), pulse is 110/min, respirations are 20/min, and blood pressure is 110/70 mm Hg. Oxygen saturation is 92% on room air. Physical examination shows decreased breath sounds over the left lung base. There is calf pain on dorsal flexion of the right foot. Examination of the extremities shows warm skin and normal pulses. Further evaluation of this patient is most likely to show which of the following findings?
A. Thrombus in the left atrium on TEE
B. Elevated serum CK-MB
C. Wedge-shaped filling defect on chest CT (Correct Answer)
D. Tracheal deviation on CXR
E. Diffuse fluffy bilateral lung infiltrates on CXR
Explanation: ***Wedge-shaped filling defect on chest CT***
- This finding, specifically a **wedge-shaped perfusion defect**, points to a **pulmonary embolism (PE)**, which is strongly suggested by the patient's acute onset of dyspnea, pleuritic chest pain, hemoptysis, tachycardia, hypoxia, and risk factors (oral contraceptive use, smoking, calf pain indicating DVT).
- A definitive diagnostic test for PE is a **CT pulmonary angiography (CTPA)**, which would show such a filling defect in the pulmonary arterial tree.
*Thrombus in the left atrium on TEE*
- A left atrial thrombus is typically associated with **atrial fibrillation** or other conditions causing stasis in the left atrium, which are not suggested by the patient's presentation.
- While a **TEE** can visualize left atrial thrombi, it's not the primary diagnostic test for the described symptoms of acute chest pain, dyspnea, and hemoptysis, which are more consistent with PE.
*Elevated serum CK-MB*
- **Elevated CK-MB** is a marker for **myocardial injury** or infarction. Although the patient has chest pain, the pain is pleuritic (worsens with deep breaths) and is associated with hemoptysis and dyspnea, making **acute coronary syndrome** less likely.
- The other symptoms and risk factors point more strongly to **pulmonary embolism** rather than cardiac ischemia.
*Tracheal deviation on CXR*
- **Tracheal deviation** on a chest X-ray typically indicates a medical emergency such as tension pneumothorax or a very large pleural effusion/mass.
- While a **tension pneumothorax** can cause acute chest pain and dyspnea, her symptoms of hemoptysis and calf pain are not consistent, and a tension pneumothorax would present with more profound hemodynamic instability.
*Diffuse fluffy bilateral lung infiltrates on CXR*
- **Diffuse fluffy bilateral lung infiltrates** are characteristic of conditions like **pulmonary edema** or **acute respiratory distress syndrome (ARDS)**.
- While PE can cause some lung changes, diffuse infiltrates are not the classic presentation, and the patient's symptoms are more consistent with a focal process in the pulmonary vasculature.
Question 149: A 38-year-old man comes to the physician because of fever, malaise, productive cough, and left-sided chest pain for 2 weeks. During this time, he has woken up to a wet pillow in the morning on multiple occasions and has not been as hungry as usual. He was diagnosed with HIV infection 1 year ago. He currently stays at a homeless shelter. He has smoked one pack of cigarettes daily for 22 years. He has a history of intravenous illicit drug use. He drinks 5–6 beers daily. He is receiving combined antiretroviral therapy but sometimes misses doses. His temperature is 38.6°C (101.5°F), pulse is 106/min, and blood pressure is 125/85 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 94%. Auscultation shows decreased breath sounds over the left base of the lung. There is dullness to percussion on the left lower part of the chest. Laboratory studies show:
Hemoglobin 14 g/dL
Leukocyte count 5,000/mm3
CD4+ T lymphocytes 240/mm3 (N > 500)
Serum
Creatinine 0.9 mg/dL
γ-Glutamyltransferase (GGT) 65 U/L (N = 5–50)
Aspartate aminotransferase (AST) 15 U/L
Alanine aminotransferase (ALT) 19 U/L
Alkaline phosphatase 40 U/L
Lactate dehydrogenase (LDH) 50 U/L
An x-ray of the chest shows a left-sided pleural effusion and hilar lymphadenopathy. Analysis of the pleural fluid shows an effusion with lymphocyte-predominant leukocytosis, high protein, an LDH of 500 U/L, and high adenosine deaminase. Which of the following is the most likely cause of this patient's condition?
A. Rheumatoid arthritis
B. Pulmonary tuberculosis (Correct Answer)
C. Pneumocystis jirovecii pneumonia
D. Cirrhosis
E. Lung cancer
Explanation: ***Pulmonary tuberculosis***
- The patient's presentation with **fever, night sweats (wet pillow), weight loss (not as hungry), productive cough, and chest pain** is highly suggestive of pulmonary tuberculosis, especially given his **HIV infection with a low CD4+ count (240/mm3)**, **homelessness**, and **intravenous drug use**, which are all significant risk factors.
- Pleural fluid analysis showing **lymphocyte-predominant leukocytosis, high protein, very high LDH (500 U/L), and high adenosine deaminase** is characteristic of tuberculous pleural effusion. The chest X-ray findings of **pleural effusion and hilar lymphadenopathy** further support this diagnosis.
*Rheumatoid arthritis*
- While rheumatoid arthritis can cause pleural effusions, the patient's acute symptoms, particularly **persistent fever, night sweats, and productive cough**, are not typical presentations of rheumatoid pleuritis.
- The **high adenosine deaminase level in the pleural fluid** is a strong indicator of mycobacterial infection and is not associated with rheumatoid pleural effusions.
*Pneumocystis jirovecii pneumonia*
- *Pneumocystis jirovecii* pneumonia (PJP) usually presents with **dry cough, dyspnea, and hypoxemia**, and is less commonly associated with a **large pleural effusion or hilar lymphadenopathy**.
- PJP is also typically seen in patients with **CD4+ counts below 200/mm3**, while this patient's CD4 is 240/mm3, although he is at risk. Pleural fluid in PJP would typically not show elevated adenosine deaminase.
*Cirrhosis*
- Cirrhosis can lead to **hepatic hydrothorax**, which is typically a **transudative pleural effusion** (low protein, low LDH), not an exudative effusion with high protein and very high LDH as seen in this patient.
- The patient's **liver enzymes (AST, ALT, ALP) are largely normal**, although GGT is mildly elevated, suggesting that cirrhosis is not the primary cause of his respiratory symptoms or effusion.
*Lung cancer*
- While lung cancer can cause pleural effusions and hilar lymphadenopathy, the patient's acute systemic symptoms of **fever, night sweats, and productive cough for 2 weeks** are more consistent with an acute infectious process.
- The **lymphocyte-predominant exudative effusion with high adenosine deaminase** is more indicative of tuberculosis than a typical malignant effusion.
Question 150: A 44-year-old female is brought to the emergency room after losing consciousness at a shopping mall. Her husband states that they were shopping when the patient appeared sweaty and tremulous, became confused, then collapsed. She was unconscious for 5 minutes until a paramedic arrived. Fingerstick glucose at that time was 31 mg/dL and intramuscular glucagon was administered. The patient regained consciousness as she was being transported to the ambulance. On arrival in the emergency room, she is conscious but sleepy. She is able to report that her last meal prior to the mall was 5 hours ago. Her husband notes that over the last 3 months, she has complained of headaches and a milky discharge from both breasts, as well as nausea if she goes too long without eating. She works as an inpatient nurse and was exposed to tuberculosis 10 years ago but adequately treated. Because she was adopted as an infant, family history is unknown. Temperature is 98.4 deg F (36.9 deg C), blood pressure is 101/59 mmHg, pulse is 88/min, and respiration is 14/min. Preliminary lab values are shown below:
Plasma glucose: 54 mg/dL
Plasma insulin: 29 pmol/L (normal < 19 pmol/L)
Plasma C-peptide: 272 pmol/L (normal < 200 pmol/L)
Plasma proinsulin: 8 pmol/L (normal < 5 pmol/L)
Plasma ß-hydroxybutyrate: 1.2 mmol/L (normal > 2.7 mmol/L after fasting)
Which of the following is the most likely cause of this patient’s hypoglycemic episode?
A. Noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS)
B. Primary adrenal insufficiency
C. Insulinoma (Correct Answer)
D. Sulfonylurea use
E. Exogenous insulin use
Explanation: ***Insulinoma***
- The patient's presentation with **recurrent hypoglycemic episodes** (sweaty, tremulous, confused, collapsed) that resolve with glucose administration (intramuscular glucagon) is highly suggestive of an insulinoma.
- The laboratory findings of **elevated insulin, C-peptide, and proinsulin levels** during hypoglycemia, coupled with suppressed beta-hydroxybutyrate, confirm endogenous hyperinsulinism, characteristic of an insulin-producing tumor. The **galactorrhea** and **headaches** suggest a possible co-occurring **pituitary adenoma** as part of **MEN1**, which is often associated with insulinomas.
*Noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS)*
- NIPHS typically presents with **postprandial hypoglycemia** and is more common after gastric bypass surgery, which is not mentioned in this patient's history.
- While it also involves endogenous hyperinsulinism, the patient's symptoms are more consistent with **fasting hypoglycemia**, a hallmark of insulinoma.
*Primary adrenal insufficiency*
- Adrenal insufficiency can cause hypoglycemia due to **cortisol deficiency**, which impairs gluconeogenesis.
- However, the lab results show **elevated insulin and C-peptide**, indicating hyperinsulinism, which is not characteristic of primary adrenal insufficiency.
*Sulfonylurea use*
- Sulfonylureas stimulate insulin release from pancreatic beta cells, leading to **elevated insulin and C-peptide** levels during hypoglycemia.
- However, the patient's history does not mention diabetes or sulfonylurea use, and her persistent symptoms over months without a diagnosis of diabetes make this less likely. A **sulfonylurea screen** would distinguish this.
*Exogenous insulin use*
- Exogenous insulin administration would result in **high insulin levels** but **suppressed C-peptide levels**, as C-peptide is co-secreted with endogenous insulin.
- The patient's lab results show **elevated C-peptide**, ruling out exogenous insulin as the sole cause of hyperinsulinism.