A 19-year-old man with a history of type 1 diabetes presents to the emergency department for the evaluation of a blood glucose level of 492 mg/dL. Laboratory examination revealed a serum bicarbonate level of 13 mEq/L, serum sodium level of 122 mEq/L, and ketonuria. Arterial blood gas demonstrated a pH of 6.9. He is admitted to the hospital and given bicarbonate and then started on an insulin drip and intravenous fluid. Seven hours later when his nurse is making rounds, he is confused and complaining of a severe headache. Repeat sodium levels are unchanged, although his glucose level has improved. His vital signs include a temperature of 36.6°C (98.0°F), pulse 50/min, respiratory rate 13/min and irregular, and blood pressure 177/95 mm Hg. What other examination findings would be expected in this patient?
Q772
One day after undergoing a left carotid endarterectomy, a 63-year-old man has a severe headache. He describes it as 9 out of 10 in intensity. He has nausea. He had 80% stenosis in the left carotid artery and received heparin prior to the surgery. He has a history of 2 transient ischemic attacks, 2 and 4 months ago. He has hypertension, type 2 diabetes mellitus, and hypercholesterolemia. He has smoked one pack of cigarettes daily for 40 years. He drinks 1–2 beers on weekends. Current medications include lisinopril, metformin, sitagliptin, and aspirin. His temperature is 37.3°C (99.1°F), pulse is 111/min, and blood pressure is 180/110 mm Hg. He is confused and oriented only to person. Examination shows pupils that react sluggishly to light. There is a right facial droop. Muscle strength is decreased in the right upper and lower extremities. Deep tendon reflexes are 3+ on the right. There is a left cervical surgical incision that shows no erythema or discharge. Cardiac examination shows no abnormalities. A complete blood count and serum concentrations of creatinine, electrolytes, and glucose are within the reference range. A CT scan of the head is shown. Which of the following is the strongest predisposing factor for this patient's condition?
Q773
A 25-year-old mother presents to her primary care physician for wrist pain. The patient recently gave birth to a healthy newborn at 40 weeks gestation. Beginning one week ago, she started having pain over her wrist that has steadily worsened. The patient notes that she also recently fell while walking and broke the fall with her outstretched arm. The patient is an accountant who works from home and spends roughly eight hours a day typing or preparing financial statements. Recreationally, the patient is a competitive cyclist who began a rigorous training routine since the birth of her child. The patient's past medical history is notable for hypothyroidism that is treated with levothyroxine. On physical exam, inspection of the wrist reveals no visible or palpable abnormalities. Pain is reproduced when the thumb is held in flexion, and the wrist is deviated toward the ulna. The rest of the patient's physical exam is within normal limits. Which of the following is the best next step in management?
Q774
A 61-year-old man presents to the urgent care clinic complaining of cough and unintentional weight loss over the past 3 months. He works as a computer engineer, and he informs you that he has been having to meet several deadlines recently and has been under significant stress. His medical history is significant for gout, hypertension, hypercholesterolemia, diabetes mellitus type 2, and pulmonary histoplasmosis 10 years ago. He currently smokes 2 packs of cigarettes/day, drinks a 6-pack of beer/day, and he endorses a past history of cocaine use back in the early 2000s but currently denies any drug use. The vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 87/min, and respiratory rate 18/min. His physical examination shows minimal bibasilar rales, but otherwise clear lungs on auscultation, grade 2/6 holosystolic murmur, and a benign abdominal physical examination. However, on routine lab testing, you notice that his sodium is 127 mEq/L. His chest X-ray is shown in the picture. Which of the following is the most likely underlying diagnosis?
Q775
A 78-year-old man presents to the hospital because of shortness of breath and chest pain that started a few hours ago. 3 weeks ago he had surgery for a total hip replacement with a prosthesis. The patient was treated with prophylactic doses of low-molecular-weight heparin until he was discharged. He did not have a fever, expectoration, or any accompanying symptoms. He has a history of right leg deep vein thrombosis that occurred 5 years ago. His vital signs include: heart rate 110/min, respiratory rate 22/min, and blood pressure 150/90 mm Hg. There were no significant findings on the physical exam. Chest radiography was within normal limits. What is the most likely diagnosis?
Q776
A 74-year-old man is rushed to the emergency department with left-sided weakness, facial deviation, and slurred speech. His wife first noticed these changes about an hour ago. The patient is having difficulty communicating. He can answer questions by nodding his head, and his wife is providing detailed information. He denies fever, loss of consciousness, head injury, bleeding, or seizures. Past medical history is significant for diabetes mellitus, hypertension, hyperlipidemia, ischemic heart disease, chronic kidney disease, and osteoarthritis. He had a heart attack 6 weeks ago. Baseline creatinine is 2.5 mg/dL, and he is not on hemodialysis. Medications include aspirin, clopidogrel, metoprolol, ramipril, rosuvastatin, and insulin detemir. Blood pressure is 175/95 mm Hg and the heart rate is 121/min. Muscle strength is decreased in both the upper and lower extremities on the left-side. A forehead sparing left sided facial weakness is also appreciated. An ECG reveals atrial fibrillation. An urgent head CT shows a hypodense area in the right parietal cortex with no indication of hemorrhage. Treatment with tissue plasminogen activator (tPA) is deferred due to which condition?
Q777
A 45-year-old woman presents to her primary care provider complaining of daytime drowsiness and fatigue. She reports that she can manage at most a couple of hours of work before needing a nap. She has also noted impaired memory and a 6.8 kg (15 lb) weight gain. She denies shortness of breath, chest pain, lightheadedness, or blood in her stool. At the doctor’s office, the vital signs include: pulse 58/min, blood pressure 104/68 mm Hg, and oxygen saturation 99% on room air. The physical exam is notable only for slightly dry skin. The complete blood count (CBC) is within normal limits. Which of the following is a likely additional finding in this patient?
Q778
A 48-year-old woman is transferred from her primary care physician's office to the emergency department for further evaluation of hypokalemia to 2.5 mEq/L. She was recently diagnosed with hypertension 2 weeks ago and started on medical therapy. The patient said that she enjoys all kinds of food and exercises regularly, but has not been able to complete her workouts as she usually does. Her temperature is 97.7°F (36.5°C), blood pressure is 107/74 mmHg, pulse is 80/min, respirations are 15/min, and SpO2 is 94% on room air. Her physical exam is unremarkable. Peripheral intravenous (IV) access is obtained. Her basic metabolic panel is obtained below.
Serum:
Na+: 135 mEq/L
Cl-: 89 mEq/L
K+: 2.2 mEq/L
HCO3-: 33 mEq/L
BUN: 44 mg/dL
Glucose: 147 mg/dL
Creatinine: 2.3 mg/dL
Magnesium: 2.0 mEq/L
What is the next best step in management?
Q779
A 22-year-old woman presents to the emergency department with a chief concern of shortness of breath. She was hiking when she suddenly felt unable to breathe and had to take slow deep breaths to improve her symptoms. The patient is a Swedish foreign exchange student and does not speak any English. Her past medical history and current medications are unknown. Her temperature is 99.5°F (37.5°C), blood pressure is 127/68 mmHg, pulse is 120/min, respirations are 22/min, and oxygen saturation is 90% on room air. Physical exam is notable for poor air movement bilaterally and tachycardia. The patient is started on treatment. Which of the following best describes this patient's underlying pathology?
FEV1 = Forced expiratory volume in 1 second
FVC = Forced vital capacity
DLCO = Diffusing capacity of carbon monoxide
Q780
A 29-year-old woman presents with progressive vision loss in her right eye and periorbital pain for 5 days. She says that she has also noticed weakness, numbness, and tingling in her left leg. Her vital signs are within normal limits. Neurological examination shows gait imbalance, positive Babinski reflexes, bilateral spasticity, and exaggerated deep tendon reflexes in the lower extremities bilaterally. FLAIR MRI is obtained and is shown in the image. Which of the following is the most likely cause of this patient’s condition?
Cardiology US Medical PG Practice Questions and MCQs
Question 771: A 19-year-old man with a history of type 1 diabetes presents to the emergency department for the evaluation of a blood glucose level of 492 mg/dL. Laboratory examination revealed a serum bicarbonate level of 13 mEq/L, serum sodium level of 122 mEq/L, and ketonuria. Arterial blood gas demonstrated a pH of 6.9. He is admitted to the hospital and given bicarbonate and then started on an insulin drip and intravenous fluid. Seven hours later when his nurse is making rounds, he is confused and complaining of a severe headache. Repeat sodium levels are unchanged, although his glucose level has improved. His vital signs include a temperature of 36.6°C (98.0°F), pulse 50/min, respiratory rate 13/min and irregular, and blood pressure 177/95 mm Hg. What other examination findings would be expected in this patient?
A. Hypoglycemia
B. Pupillary constriction
C. Papilledema (Correct Answer)
D. Pancreatitis
E. Peripheral edema
Explanation: ***Papilledema***
- This patient's symptoms (confusion, severe headache, bradycardia, irregular respiration, hypertension) following treatment for **diabetic ketoacidosis (DKA)** are highly suggestive of **cerebral edema**.
- **Papilledema** is a retinal finding resulting from increased intracranial pressure (ICP), which is a characteristic sign of cerebral edema.
*Hypoglycemia*
- While the patient's glucose level has improved, it is not described as being low enough to cause hypoglycemia, and the symptoms are more consistent with **increased ICP**.
- Symptoms of hypoglycemia (e.g., tremors, sweating, hunger, anxiety) are different from the patient's current presentation of confusion and severe headache.
*Pupillary constriction*
- **Pupillary constriction** (miosis) is typically not associated with cerebral edema; instead, **pupillary dilation** (mydriasis) can occur with severe increase in ICP due to uncal herniation.
- The combination of bradycardia, irregular respiration, and hypertension (Cushing's triad) is indicative of increased ICP, which would likely cause pupillary changes related to brainstem compression.
*Pancreatitis*
- Pancreatitis is a known complication of DKA, but it typically presents with **severe abdominal pain**, nausea, and vomiting, rather than cerebral symptoms.
- Although the patient had DKA, the current neurological symptoms point directly to an intracranial process rather than an abdominal issue.
*Peripheral edema*
- **Peripheral edema** results from fluid accumulation in peripheral tissues and is not a direct consequence or expected finding in cerebral edema.
- While fluid administration can cause some peripheral fluid retention, it typically does not lead to the acute neurological deterioration seen in this patient.
Question 772: One day after undergoing a left carotid endarterectomy, a 63-year-old man has a severe headache. He describes it as 9 out of 10 in intensity. He has nausea. He had 80% stenosis in the left carotid artery and received heparin prior to the surgery. He has a history of 2 transient ischemic attacks, 2 and 4 months ago. He has hypertension, type 2 diabetes mellitus, and hypercholesterolemia. He has smoked one pack of cigarettes daily for 40 years. He drinks 1–2 beers on weekends. Current medications include lisinopril, metformin, sitagliptin, and aspirin. His temperature is 37.3°C (99.1°F), pulse is 111/min, and blood pressure is 180/110 mm Hg. He is confused and oriented only to person. Examination shows pupils that react sluggishly to light. There is a right facial droop. Muscle strength is decreased in the right upper and lower extremities. Deep tendon reflexes are 3+ on the right. There is a left cervical surgical incision that shows no erythema or discharge. Cardiac examination shows no abnormalities. A complete blood count and serum concentrations of creatinine, electrolytes, and glucose are within the reference range. A CT scan of the head is shown. Which of the following is the strongest predisposing factor for this patient's condition?
A. Smoking
B. Hypertension (Correct Answer)
C. Perioperative heparin
D. Degree of carotid stenosis
E. Aspirin therapy
Explanation: ***Hypertension***
- Uncontrolled **hypertension** is the strongest predisposing factor for **cerebral hyperperfusion syndrome (CHS)**, especially in patients undergoing carotid endarterectomy.
- The patient's blood pressure of **180/110 mm Hg** post-surgery, combined with symptoms like severe headache, confusion, and focal neurological deficits, is highly indicative of CHS, which is exacerbated by poor blood pressure control.
*Smoking*
- While **smoking** is a significant risk factor for **atherosclerosis** and stroke, it is not the primary predisposing factor for **cerebral hyperperfusion syndrome (CHS)** specifically.
- The immediate postoperative presentation of headache, confusion, and focal deficits points more directly to issues related to cerebral blood flow regulation rather than generalized atherosclerotic disease.
*Perioperative heparin*
- **Heparin** administration increases the risk of **hemorrhage**, which could manifest as an intracranial bleed.
- However, the clinical presentation and the typical CT findings of CHS (edema, hemorrhage in severe cases) are more strongly associated with the sudden increase in cerebral blood flow rather than just anticoagulation.
*Degree of carotid stenosis*
- A high degree of **carotid stenosis** (e.g., 80% in this case) is an indication for endarterectomy to reduce stroke risk.
- While it sets the stage for potential **cerebral hyperperfusion syndrome (CHS)** by suddenly restoring flow to a chronically ischemic brain, the degree of stenosis itself is not the predisposing factor; rather, the subsequent deregulation of cerebral autoregulation in the context of other risk factors (like hypertension) is key.
*Aspirin therapy*
- **Aspirin** is an antiplatelet agent used for secondary stroke prevention and could increase the risk of minor bleeding.
- However, it is not a direct predisposing factor for **cerebral hyperperfusion syndrome (CHS)**, nor does it typically cause the acute neurological deterioration seen in this patient in the absence of a major hemorrhagic event.
Question 773: A 25-year-old mother presents to her primary care physician for wrist pain. The patient recently gave birth to a healthy newborn at 40 weeks gestation. Beginning one week ago, she started having pain over her wrist that has steadily worsened. The patient notes that she also recently fell while walking and broke the fall with her outstretched arm. The patient is an accountant who works from home and spends roughly eight hours a day typing or preparing financial statements. Recreationally, the patient is a competitive cyclist who began a rigorous training routine since the birth of her child. The patient's past medical history is notable for hypothyroidism that is treated with levothyroxine. On physical exam, inspection of the wrist reveals no visible or palpable abnormalities. Pain is reproduced when the thumb is held in flexion, and the wrist is deviated toward the ulna. The rest of the patient's physical exam is within normal limits. Which of the following is the best next step in management?
A. Thumb spica cast
B. Rest and ibuprofen (Correct Answer)
C. Repositioning of the wrist while cycling
D. Wrist guard to be worn during work and at night
E. Radiography of the wrist
Explanation: ***Rest and ibuprofen***
- This patient presents with symptoms consistent with **De Quervain tenosynovitis**, characterized by pain over the radial side of the wrist, especially with activities involving thumb movement, and a positive **Finkelstein test** (pain with ulnar deviation of the wrist while the thumb is flexed).
- Initial management for **De Quervain tenosynovitis** typically involves conservative measures like **rest**, **NSAIDs** (e.g., ibuprofen), and **splinting** to immobilize the thumb and wrist.
*Thumb spica cast*
- A **thumb spica cast** provides more rigid immobilization than typically needed for initial management of uncomplicated De Quervain tenosynovitis.
- While immobilization is important, a full cast is usually reserved for cases that fail to improve with less restrictive measures, or for specific conditions like **scaphoid fractures**.
*Repositioning of the wrist while cycling*
- While proper ergonomics can help prevent occupational injuries, simply repositioning the wrist while cycling does not address the underlying **inflammation** of the **extensor pollicis brevis** and **abductor pollicis longus tendons**.
- This measure alone is insufficient for treating an actively inflamed and painful tenosynovitis.
*Wrist guard to be worn during work and at night*
- A wrist guard or splint can be helpful for immobilization in De Quervain tenosynovitis, but the question asks for the **best next step** in management, which includes addressing the **inflammation** and **pain** in acute cases.
- A wrist guard alone without **rest** or **anti-inflammatory medication** may not provide adequate relief or promote healing effectively.
*Radiography of the wrist*
- Radiography is useful for ruling out **bony injuries** (e.g., fractures), but the patient's presentation, particularly the positive Finkelstein test, strongly points to a **soft tissue inflammation** (tenosynovitis).
- Given no reported acute trauma to the wrist itself (only falling on an outstretched hand, which would often localize pain differently for a fracture) and no visible deformity, X-rays are not typically the immediate next step for presumed **De Quervain tenosynovitis**.
Question 774: A 61-year-old man presents to the urgent care clinic complaining of cough and unintentional weight loss over the past 3 months. He works as a computer engineer, and he informs you that he has been having to meet several deadlines recently and has been under significant stress. His medical history is significant for gout, hypertension, hypercholesterolemia, diabetes mellitus type 2, and pulmonary histoplasmosis 10 years ago. He currently smokes 2 packs of cigarettes/day, drinks a 6-pack of beer/day, and he endorses a past history of cocaine use back in the early 2000s but currently denies any drug use. The vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 87/min, and respiratory rate 18/min. His physical examination shows minimal bibasilar rales, but otherwise clear lungs on auscultation, grade 2/6 holosystolic murmur, and a benign abdominal physical examination. However, on routine lab testing, you notice that his sodium is 127 mEq/L. His chest X-ray is shown in the picture. Which of the following is the most likely underlying diagnosis?
A. Large cell lung cancer
B. Squamous cell carcinoma
C. Non-small cell lung cancer
D. Adenocarcinoma
E. Small cell lung cancer (Correct Answer)
Explanation: ***Small cell lung cancer***
- The patient's presentation with **cough**, **unintentional weight loss**, **hyponatremia (Na 127 mEq/L)**, and a significant smoking history (2 packs/day) are highly suggestive of **small cell lung cancer (SCLC)**.
- SCLC is **strongly associated with paraneoplastic syndromes**, particularly **syndrome of inappropriate antidiuretic hormone secretion (SIADH)**, which causes **euvolemic hyponatremia** - the key diagnostic clue in this case.
- The chest x-ray findings would typically show a **central mass** with **mediastinal widening**, characteristic of SCLC.
- SCLC accounts for approximately 15% of lung cancers but has the strongest association with paraneoplastic SIADH.
*Large cell lung cancer*
- While strongly associated with smoking, **large cell carcinoma** more commonly presents as a **peripheral mass** and is **less frequently associated with paraneoplastic syndromes like SIADH**.
- It's a diagnosis of exclusion and less likely to cause prominent hyponatremia compared to SCLC.
*Squamous cell carcinoma*
- **Squamous cell carcinoma** often presents with **hemoptysis** and can cause **hypercalcemia** (not hyponatremia) due to paraneoplastic **PTHrP secretion**.
- While it's centrally located and linked to smoking, **hyponatremia from SIADH is much less common** than in SCLC.
*Non-small cell lung cancer*
- This is a broad category that includes adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. While specific types within NSCLC can cause various symptoms, the highly characteristic presentation of **cough, weight loss, and hyponatremia (suggesting SIADH)** in a heavy smoker points more specifically to SCLC.
- This option is too general; the clinical picture allows for a more specific diagnosis.
*Adenocarcinoma*
- **Adenocarcinoma** is typically a **peripheral lung cancer** and is the most common type in non-smokers, though it can occur in smokers.
- It is **less commonly associated with paraneoplastic hyponatremia (SIADH)** compared to small cell lung cancer.
- Would not typically present with the prominent hyponatremia seen in this patient.
Question 775: A 78-year-old man presents to the hospital because of shortness of breath and chest pain that started a few hours ago. 3 weeks ago he had surgery for a total hip replacement with a prosthesis. The patient was treated with prophylactic doses of low-molecular-weight heparin until he was discharged. He did not have a fever, expectoration, or any accompanying symptoms. He has a history of right leg deep vein thrombosis that occurred 5 years ago. His vital signs include: heart rate 110/min, respiratory rate 22/min, and blood pressure 150/90 mm Hg. There were no significant findings on the physical exam. Chest radiography was within normal limits. What is the most likely diagnosis?
A. Myocardial infarction
B. Pneumonia
C. Pneumothorax
D. Exacerbation of chronic lung disease
E. Pulmonary thromboembolism (Correct Answer)
Explanation: ***Pulmonary thromboembolism***
- The patient's recent **hip replacement surgery**, a history of **DVT**, and the acute onset of **shortness of breath** and **chest pain** strongly suggest a pulmonary embolism.
- The elevated heart rate and respiratory rate, despite a normal chest X-ray and absence of fever/expectoration, align with the presentation of a **pulmonary embolism**.
- **Normal chest X-ray** is common in PE, as radiography is often non-specific.
- The **3-week post-operative period** represents peak risk for venous thromboembolism following orthopedic surgery.
*Myocardial infarction*
- While chest pain is present, the clinical context of **recent orthopedic surgery** and **prior DVT** makes PE more likely than MI.
- MI would typically present with ECG changes and elevated cardiac biomarkers.
- The absence of typical cardiovascular risk factors in the stem and the **tachypnea** more strongly suggest pulmonary rather than cardiac pathology.
*Pneumonia*
- **Absence of fever**, expectoration, and a **normal chest X-ray** effectively rule out pneumonia.
- Pneumonia typically presents with cough, fever, productive sputum, and infiltrates on chest imaging.
*Pneumothorax*
- A pneumothorax would present with **sudden, sharp chest pain** and shortness of breath, often with diminished breath sounds and hyperresonance on the affected side.
- However, the **normal chest X-ray** makes pneumothorax highly unlikely, as it would show visceral pleural line and absence of lung markings peripherally.
*Exacerbation of chronic lung disease*
- There is **no mention of a prior diagnosis of chronic lung disease** (e.g., COPD, asthma) in the patient's history.
- The **acute, sudden onset** of symptoms in the context of recent surgery with known VTE risk factors is more indicative of an acute thrombotic event rather than an exacerbation of chronic disease.
Question 776: A 74-year-old man is rushed to the emergency department with left-sided weakness, facial deviation, and slurred speech. His wife first noticed these changes about an hour ago. The patient is having difficulty communicating. He can answer questions by nodding his head, and his wife is providing detailed information. He denies fever, loss of consciousness, head injury, bleeding, or seizures. Past medical history is significant for diabetes mellitus, hypertension, hyperlipidemia, ischemic heart disease, chronic kidney disease, and osteoarthritis. He had a heart attack 6 weeks ago. Baseline creatinine is 2.5 mg/dL, and he is not on hemodialysis. Medications include aspirin, clopidogrel, metoprolol, ramipril, rosuvastatin, and insulin detemir. Blood pressure is 175/95 mm Hg and the heart rate is 121/min. Muscle strength is decreased in both the upper and lower extremities on the left-side. A forehead sparing left sided facial weakness is also appreciated. An ECG reveals atrial fibrillation. An urgent head CT shows a hypodense area in the right parietal cortex with no indication of hemorrhage. Treatment with tissue plasminogen activator (tPA) is deferred due to which condition?
A. History of myocardial infarction 6 weeks ago (Correct Answer)
B. Chronic kidney disease
C. Atrial fibrillation on electrocardiogram
D. Raised blood pressures
E. Aspirin and clopidogrel use
Explanation: ***History of myocardial infarction 6 weeks ago***
- Recent **myocardial infarction (MI)**, especially within the last 3 months, is a relative contraindication for tPA due to the increased risk of hemorrhage. The patient's MI 6 weeks ago falls within this critical window.
- While not an absolute contraindication, the increased risk of hemorrhagic complications from tPA outweighs potential benefits in this specific scenario.
*Chronic kidney disease*
- **Chronic kidney disease (CKD)** itself is not a contraindication to tPA administration.
- The elevated creatinine and CKD stage do not directly increase the risk of hemorrhage from tPA in the absence of other bleeding diatheses.
*Atrial fibrillation on electrocardiogram*
- **Atrial fibrillation (AFib)** is a common cause of embolic stroke and does not contraindicate tPA.
- In fact, identifying AFib helps confirm the likely cardioembolic etiology of the stroke, making tPA a potentially beneficial treatment if other contraindications are absent.
*Raised blood pressures*
- While BP above 185/110 mm Hg is an absolute contraindication for tPA, the patient's current BP of **175/95 mm Hg** can typically be managed pharmacologically to below the threshold before tPA administration.
- **Hypertension** itself can be treated to enable tPA, it is not an intrinsic contraindication provided it can be lowered.
*Aspirin and clopidogrel use*
- Concurrent use of **antiplatelet agents** like aspirin and clopidogrel is not an absolute or relative contraindication for tPA.
- The combination of antiplatelets does not significantly increase the risk of hemorrhage with tPA to the extent that it would prompt deferral.
Question 777: A 45-year-old woman presents to her primary care provider complaining of daytime drowsiness and fatigue. She reports that she can manage at most a couple of hours of work before needing a nap. She has also noted impaired memory and a 6.8 kg (15 lb) weight gain. She denies shortness of breath, chest pain, lightheadedness, or blood in her stool. At the doctor’s office, the vital signs include: pulse 58/min, blood pressure 104/68 mm Hg, and oxygen saturation 99% on room air. The physical exam is notable only for slightly dry skin. The complete blood count (CBC) is within normal limits. Which of the following is a likely additional finding in this patient?
A. Tremor
B. Anxiety
C. Hypercholesterolemia (Correct Answer)
D. Lid lag
E. Palpitations
Explanation: ***Hypercholesterolemia***
- The patient's symptoms of **fatigue, weight gain, impaired memory, daytime drowsiness, dry skin, and bradycardia** are classic for **hypothyroidism**.
- **Hypothyroidism** leads to a decrease in the breakdown of **lipids**, resulting in elevated **LDL cholesterol and triglycerides**.
*Tremor*
- A **fine tremor** is commonly associated with **hyperthyroidism**, not hypothyroidism, due to sympathetic overactivity.
- It is a sign of an **overactive metabolic state**, which is the opposite of the patient's presentation.
*Anxiety*
- While anxiety can be a symptom of many conditions, it is more typically associated with **hyperthyroidism** due to increased metabolic activity and sympathetic tone.
- Patients with **hypothyroidism** tend to experience **depression, lethargy, and slowed mentation** rather than anxiety.
*Lid lag*
- **Lid lag** (Graefe's sign) is a classic ophthalmic sign of **hyperthyroidism**, often seen in **Graves' ophthalmopathy**.
- It is caused by increased sympathetic stimulation of the **levator palpebrae superioris muscle**, not a feature of hypothyroidism.
*Palpitations*
- **Palpitations** are a common symptom of **hyperthyroidism** due to increased heart rate and contractility.
- In contrast, **hypothyroidism** is usually associated with **bradycardia** and a *slowed heart rate*, as seen in this patient.
Question 778: A 48-year-old woman is transferred from her primary care physician's office to the emergency department for further evaluation of hypokalemia to 2.5 mEq/L. She was recently diagnosed with hypertension 2 weeks ago and started on medical therapy. The patient said that she enjoys all kinds of food and exercises regularly, but has not been able to complete her workouts as she usually does. Her temperature is 97.7°F (36.5°C), blood pressure is 107/74 mmHg, pulse is 80/min, respirations are 15/min, and SpO2 is 94% on room air. Her physical exam is unremarkable. Peripheral intravenous (IV) access is obtained. Her basic metabolic panel is obtained below.
Serum:
Na+: 135 mEq/L
Cl-: 89 mEq/L
K+: 2.2 mEq/L
HCO3-: 33 mEq/L
BUN: 44 mg/dL
Glucose: 147 mg/dL
Creatinine: 2.3 mg/dL
Magnesium: 2.0 mEq/L
What is the next best step in management?
A. Obtain an electrocardiogram (Correct Answer)
B. Obtain urine sodium and creatinine
C. Administer isotonic saline 1 liter via peripheral IV
D. Administer potassium chloride 40mEq via peripheral IV
E. Administer potassium bicarbonate 50mEq per oral
Explanation: ***Obtain an electrocardiogram***
- The patient has severe **hypokalemia** (K+ 2.2 mEq/L), which requires urgent assessment for cardiac complications before initiating treatment.
- An **ECG is the mandatory first step** in severe hypokalemia (K+ <2.5 mEq/L) to evaluate for life-threatening arrhythmias and ECG changes including U waves, T wave flattening, ST depression, and QT prolongation.
- The patient is **hemodynamically stable** with only mild symptoms (exercise intolerance), so immediate potassium administration is not required before obtaining an ECG.
- ECG findings will guide the urgency and route of potassium repletion and determine the need for cardiac monitoring during treatment.
*Administer potassium chloride 40mEq via peripheral IV*
- While **IV potassium chloride** will be needed for repletion, it should be administered after ECG assessment in a stable patient.
- IV potassium administration carries risks including phlebitis, infiltration, and potential cardiac complications if given too rapidly without monitoring.
- In severe hypokalemia without cardiac arrest or documented life-threatening arrhythmias, obtaining an ECG first is standard practice.
*Obtain urine sodium and creatinine*
- Measuring **urine electrolytes** helps identify the cause of hypokalemia (likely diuretic-induced given recent hypertension treatment with metabolic alkalosis and hypochloremia).
- However, this diagnostic workup should follow the immediate assessment and treatment of severe hypokalemia.
- While useful for long-term management, it does not take priority over assessing cardiac risk with an ECG.
*Administer potassium bicarbonate 50mEq per oral*
- **Potassium bicarbonate** is contraindicated in this patient with **metabolic alkalosis** (HCO3- 33 mEq/L), as it would worsen the alkalosis.
- The correct form for repletion in metabolic alkalosis is **potassium chloride**, which addresses both the hypokalemia and hypochloremia.
- Oral repletion is also too slow for severe hypokalemia and may cause gastrointestinal side effects.
*Administer isotonic saline 1 liter via peripheral IV*
- While the patient shows signs of volume depletion (elevated BUN/Cr ratio, likely prerenal azotemia from diuretic use), the immediate priority is assessing the cardiac impact of severe hypokalemia.
- **Isotonic saline** without potassium supplementation could potentially worsen hypokalemia through dilution and increased renal potassium excretion.
- Volume resuscitation should be considered after ECG assessment and in conjunction with potassium repletion.
Question 779: A 22-year-old woman presents to the emergency department with a chief concern of shortness of breath. She was hiking when she suddenly felt unable to breathe and had to take slow deep breaths to improve her symptoms. The patient is a Swedish foreign exchange student and does not speak any English. Her past medical history and current medications are unknown. Her temperature is 99.5°F (37.5°C), blood pressure is 127/68 mmHg, pulse is 120/min, respirations are 22/min, and oxygen saturation is 90% on room air. Physical exam is notable for poor air movement bilaterally and tachycardia. The patient is started on treatment. Which of the following best describes this patient's underlying pathology?
FEV1 = Forced expiratory volume in 1 second
FVC = Forced vital capacity
DLCO = Diffusing capacity of carbon monoxide
A. Increased FVC
B. Increased FEV1
C. Increased FEV1/FVC
D. Decreased airway tone
E. Normal DLCO (Correct Answer)
Explanation: ***Normal DLCO***
- This patient presents with an acute exacerbation of what is likely **asthma**, showing symptoms of **shortness of breath**, **tachycardia**, poor air movement bilaterally, and improvement with slow deep breaths. **Asthma** characteristically affects the airways and not the alveoli, thus the **diffusing capacity of carbon monoxide (DLCO)**, which measures gas exchange across the alveolar-capillary membrane, would be expected to be normal.
- In asthma, the primary problem is **bronchoconstriction** and **airway inflammation**, which restricts airflow but does not typically impair the diffusion of gases like carbon monoxide across the alveolar-capillary membrane.
*Increased FVC*
- **Forced vital capacity (FVC)** is often normal or even slightly reduced in asthma due to **air trapping** and early airway closure, not increased.
- An increased FVC is usually not associated with obstructive lung diseases like asthma but could potentially be seen in conditions where lung volumes are pathologically large, which is not the case here.
*Increased FEV1*
- **Forced expiratory volume in 1 second (FEV1)** is typically **decreased** in obstructive lung diseases like asthma due to **airflow limitation**.
- An increased FEV1 would indicate better-than-average expiratory flow, which contradicts the symptoms of shortness of breath and poor air movement in this patient.
*Increased FEV1/FVC*
- The **FEV1/FVC ratio** is characteristically **decreased** in obstructive lung diseases like asthma, indicating that a disproportionately smaller amount of air can be exhaled in the first second relative to the total forced vital capacity.
- An increased FEV1/FVC ratio would be a sign of a restrictive lung disease or normal lung function, not an exacerbation of an obstructive process.
*Decreased airway tone*
- The underlying pathology in asthma is typically **bronchoconstriction**, which means an **increased airway tone** and narrowing of the airways, rather than decreased.
- Decreased airway tone would imply bronchodilation, which would alleviate, not cause, the patient's symptoms of shortness of breath and poor air movement.
Question 780: A 29-year-old woman presents with progressive vision loss in her right eye and periorbital pain for 5 days. She says that she has also noticed weakness, numbness, and tingling in her left leg. Her vital signs are within normal limits. Neurological examination shows gait imbalance, positive Babinski reflexes, bilateral spasticity, and exaggerated deep tendon reflexes in the lower extremities bilaterally. FLAIR MRI is obtained and is shown in the image. Which of the following is the most likely cause of this patient’s condition?
A. Amyotrophic lateral sclerosis
B. Multiple sclerosis (Correct Answer)
C. Acute disseminated encephalomyelitis
D. Lead intoxication
E. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)
Explanation: ***Multiple sclerosis***
- This patient's presentation with **optic neuritis** (vision loss, periorbital pain), disseminated neurological symptoms (**weakness, numbness, tingling in the left leg**, gait imbalance, spasticity, exaggerated DTRs, Babinski reflexes), and multifocal white matter lesions on MRI (FLAIR image would show **Dawson's fingers** or juxtacortical/infratentorial lesions) is highly characteristic of **multiple sclerosis**.
- The symptoms are **disseminated in space and time**, meaning different neurological deficits occurring at different locations in the CNS at different times, as suggested by the right eye and left leg involvement.
*Amyotrophic lateral sclerosis*
- Primarily a **motor neuron disease** affecting both upper and lower motor neurons, causing progressive muscle weakness, atrophy, and fasciculations.
- It does not typically involve **sensory deficits** (numbness, tingling), **optic neuritis**, or extensive white matter lesions on MRI.
*Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)*
- A genetic (NOTCH3 gene) small vessel disease causing recurrent **strokes, migraine with aura**, and progressive cognitive decline, typically starting in middle age.
- While it causes white matter abnormalities on MRI, it does not typically present with **inflammatory demyelination** causing optic neuritis or the diverse neurological relapses seen in MS.
*Acute disseminated encephalomyelitis*
- This is a monophasic, immune-mediated demyelinating disorder that typically occurs **after an infection or vaccination**.
- It often has a more **acute and severe onset** with encephalopathy, and while it causes multifocal white matter lesions, it is typically a single event rather than relapsing-remitting course seen in MS.
*Lead intoxication*
- Lead poisoning can cause a variety of neurological symptoms, including **peripheral neuropathy** (motor and sensory), **encephalopathy**, and cognitive impairment.
- It does not typically cause **optic neuritis**, demyelinating lesions in the CNS, or the specific pattern of neurological deficits characteristic of MS.