The serum brain natriuretic peptide and N-terminal pro-BNP are elevated. A diagnosis of heart failure with preserved ejection fraction is made. In addition to supplemental oxygen therapy, which of the following is the most appropriate initial step in management?
Q52
A 72-year-old man presents to the emergency department with difficulty breathing for the past 3 hours. He also mentions that over the last week he was frequently breathless and fatigued after walking a few blocks. He has had diabetes mellitus and hypertension for the past 10 years, and his regular medications include metformin, glipizide, and lisinopril. However, he did not take his medications last week due to unplanned travel. Review of his medical records reveals an episode of acute viral hepatitis about 6 months ago from which he recovered well. His temperature is 37.0°C (98.6°F), the pulse is 108/min, the blood pressure is 170/94 mm Hg, and the respiratory rate is 24/min. On physical examination, periorbital edema is present with pitting edema over both ankles and pretibial regions. Pallor and icterus are absent. Auscultation of the chest reveals crackles over the infrascapular regions bilaterally. Abdominal examination shows tender hepatomegaly. Which of the following is the most likely diagnosis?
Q53
A 55-year-old woman recently underwent kidney transplantation for end-stage renal disease. Her early postoperative period was uneventful, and her serum creatinine is lowered from 4.3 mg/dL (preoperative) to 2.5 mg/dL. She is immediately started on immunosuppressive therapy. On postoperative day 7, she presents to the emergency department (ED) because of nausea, fever, abdominal pain at the transplant site, malaise, and pedal edema. The vital signs include: pulse 106/min, blood pressure 167/96 mm Hg, respirations 26/min, and temperature 40.0°C (104.0°F). The surgical site shows no signs of infection. Her urine output is 250 mL over the past 24 hours. Laboratory studies show:
Hematocrit 33%
White blood cell (WBC) count 6700/mm3
Blood urea 44 mg/dL
Serum creatinine 3.3 mg/dL
Serum sodium 136 mEq/L
Serum potassium 5.6 mEq/L
An ultrasound of the abdomen shows collection of fluid around the transplanted kidney with moderate hydronephrosis. Which of the following initial actions is the most appropriate?
Q54
A 68-year-old man comes to the emergency department because of a 1-week history of worsening bouts of shortness of breath at night. He has had a cough for 1 month. Occasionally, he has coughed up frothy sputum during this time. He has type 2 diabetes mellitus and long-standing hypertension. Two years ago, he was diagnosed with Paget disease of bone during a routine health maintenance examination. He has smoked a pack of cigarettes daily for 20 years. His temperature is 37°C (98.6°F), pulse is 110/min, respirations are 25/min, and blood pressure is 145/88 mm Hg. Current medications include metformin, alendronate, hydrochlorothiazide, and enalapril. Examination shows bibasilar crackles. Cardiac examination shows a dull, low-pitched sound during late diastole that is best heard at the apex. There is no jugular venous distention or peripheral edema. Arterial blood gas analysis on room air shows:
pH 7.46
PCO2 29 mm Hg
PO2 83 mm Hg
HCO3- 18 mEq/L
Echocardiography shows a left ventricular ejection fraction of 55%. Which of the following is the most likely underlying cause of this patient’s current condition?
Q55
A 65-year-old male with multiple comorbidities presents to your office complaining of difficulty falling asleep. Specifically, he says he has been having trouble breathing while lying flat very shortly after going to bed. He notes it only gets better when he adds several pillows, but that sitting up straight is an uncomfortable position for him in which to fall asleep. What is the most likely etiology of this man's sleeping troubles?
Q56
A 71-year-old, hospitalized man develops abnormal laboratory studies 4 days after starting treatment for exacerbation of congestive heart failure. He also has a history of osteoarthritis and benign prostatic hyperplasia. He recently completed a course of amikacin for bacterial prostatitis. Before hospitalization, his medications included simvastatin and ibuprofen. Blood pressure is 111/76 mm Hg. Serum studies show a creatinine of 2.3 mg/dL (previously normal) and a BUN of 48 mg/dL. Urinalysis shows a urine osmolality of 600 mOsm/kg and urine sodium of 10 mEq/L. Which of the following is the most likely explanation for this patient's renal insufficiency?
Q57
A 59-year-old woman comes to the physician for a 3-month history of progressively worsening shortness of breath on exertion and swelling of her legs. She has a history of breast cancer, which was treated with surgery followed by therapy with doxorubicin and trastuzumab 4 years ago. Cardiac examination shows an S3 gallop; there are no murmurs or rubs. Examination of the lower extremities shows pitting edema below the knees. Echocardiography is most likely to show which of the following sets of changes in this patient?
$$$ Ventricular wall thickness %%% Ventricular cavity size %%% Diastolic function %%% Aorto-ventricular pressure gradient $$$
Q58
An 85-year-old man with hypertension and type 2 diabetes mellitus is brought to the emergency department because of a 2-day history of shortness of breath. He has smoked one pack of cigarettes daily for 30 years. His temperature is 36.9°C (98.4°F), pulse is 100/min, respirations are 30/min, and blood pressure is 138/75 mm Hg. Pulmonary function testing shows decreased tidal volume and normal lung compliance. Which of the following is the most likely underlying etiology of this patient's tachypnea?
Q59
A 72-year-old man with coronary artery disease comes to the emergency department because of chest pain and shortness of breath for the past 3 hours. Troponin levels are elevated and an ECG shows ST-elevations in the precordial leads. Revascularization with percutaneous coronary intervention is performed, and a stent is successfully placed in the left anterior descending artery. Two days later, he complains of worsening shortness of breath. Pulse oximetry on 3L of nasal cannula shows an oxygen saturation of 89%. An x-ray of the chest shows distended pulmonary veins, small horizontal lines at the lung bases, and blunting of the costophrenic angles bilaterally. Which of the following findings would be most likely on a ventilation-perfusion scan of this patient?
Q60
A 63-year-old male is admitted to the Emergency Department after 3 days difficulty breathing, orthopnea, and shortness of breath with effort. His personal medical history is positive for a myocardial infarction 6 years ago and a cholecystectomy 10 years ago. Medications include metoprolol, lisinopril, atorvastatin, and as needed furosemide. At the hospital his blood pressure is 108/60 mm Hg, pulse is 88/min, respiratory rate is 20/min, and temperature is 36.4°C (97.5°F). On physical examination, he presents with fine rales in both lungs, his abdomen is non-distended non-tender, and there is 2+ lower limb pitting edema up to his knees. Initial laboratory testing is shown below
Na+ 138 mEq/L
K+ 4 mEq/L
Cl- 102 mEq/L
Serum creatinine (Cr) 1.8 mg/dL
Blood urea nitrogen (BUN) 52 mg/dL
Which of the following therapies is the most appropriate for this patient?
Heart failure US Medical PG Practice Questions and MCQs
Question 51: The serum brain natriuretic peptide and N-terminal pro-BNP are elevated. A diagnosis of heart failure with preserved ejection fraction is made. In addition to supplemental oxygen therapy, which of the following is the most appropriate initial step in management?
A. Intravenous dobutamine
B. Intravenous furosemide therapy (Correct Answer)
C. Intravenous morphine therapy
D. Thoracentesis
E. Intermittent hemodialysis
Explanation: ***Intravenous furosemide therapy***
- Heart failure with **preserved ejection fraction (HFpEF)** often presents with **pulmonary congestion** due to elevated filling pressures.
- **Furosemide**, a loop diuretic, effectively reduces fluid overload and associated symptoms by increasing renal excretion of sodium and water.
*Intravenous dobutamine*
- **Dobutamine** is an inotropic agent that increases myocardial contractility and heart rate.
- It is typically used for **acute decompensated heart failure with low cardiac output** and is generally avoided in HFpEF unless there is significant hypoperfusion, as it can worsen myocardial oxygen demand and diastolic dysfunction.
*Intravenous morphine therapy*
- **Morphine** can be used in acute heart failure to reduce preload and anxiety, but it is not a primary treatment for the underlying fluid overload.
- It can cause respiratory depression and hypotension, and its use is typically reserved for patients with severe pain or dyspnea not adequately managed by other therapies.
*Thoracentesis*
- **Thoracentesis** is indicated for symptomatic **pleural effusions** causing respiratory distress.
- While pleural effusions can occur in heart failure, initial management of generalized fluid overload typically involves diuretics, making thoracentesis a secondary intervention if diuretic therapy is insufficient.
*Intermittent hemodialysis*
- **Intermittent hemodialysis** is an invasive procedure primarily used for severe renal failure or refractory fluid overload that has not responded to maximal diuretic therapy.
- It is not the initial step in managing heart failure with preserved ejection fraction and would only be considered in highly selected cases with **acute kidney injury** or diuretic resistance.
Question 52: A 72-year-old man presents to the emergency department with difficulty breathing for the past 3 hours. He also mentions that over the last week he was frequently breathless and fatigued after walking a few blocks. He has had diabetes mellitus and hypertension for the past 10 years, and his regular medications include metformin, glipizide, and lisinopril. However, he did not take his medications last week due to unplanned travel. Review of his medical records reveals an episode of acute viral hepatitis about 6 months ago from which he recovered well. His temperature is 37.0°C (98.6°F), the pulse is 108/min, the blood pressure is 170/94 mm Hg, and the respiratory rate is 24/min. On physical examination, periorbital edema is present with pitting edema over both ankles and pretibial regions. Pallor and icterus are absent. Auscultation of the chest reveals crackles over the infrascapular regions bilaterally. Abdominal examination shows tender hepatomegaly. Which of the following is the most likely diagnosis?
A. Acute decompensated heart failure (Correct Answer)
B. Acute hepatic failure
C. Acute renal failure
D. Pulmonary embolism
E. Diabetic ketoacidosis
Explanation: ***Acute decompensated heart failure***
- The patient presents with **acute dyspnea**, **pitting edema**, **periorbital edema**, and **crackles** on lung auscultation, all consistent with **fluid overload** due to **heart failure**.
- His history of **hypertension** and **diabetes mellitus** are significant risk factors, and his recent non-adherence to **lisinopril** (an ACE inhibitor) likely worsened his cardiac function, precipitating decompensation.
*Acute hepatic failure*
- Although **tender hepatomegaly** can be seen in acute hepatic failure, the patient's presentation is predominantly respiratory and edematous, and he has a history of *resolved* acute viral hepatitis, making acute hepatic failure less likely to be the primary cause of his *current* acute symptoms.
- Acute hepatic failure would typically present with **jaundice**, **coagulopathy**, and **encephalopathy**, which are not described here.
*Acute renal failure*
- While **pitting edema** and **fluid overload** can occur in acute renal failure, his history of **hypertension** and **diabetes** would predispose to chronic kidney disease rather than acute renal failure as the initial presentation of his current symptoms without clear nephrotoxic exposure.
- **Acute renal failure** would also likely present with significantly altered laboratory values such as elevated **creatinine** and **blood urea nitrogen**, which are not mentioned.
*Pulmonary embolism*
- **Dyspnea** is a key symptom of pulmonary embolism, but the extensive **edema** (periorbital, bilateral ankle, pretibial) and **crackles** are more indicative of fluid overload than a primary thromboembolic event.
- Though his pulse is elevated, there are no other classic signs of PE such as **pleuritic chest pain**, **hemoptysis**, or a history of **deep vein thrombosis**.
*Diabetic ketoacidosis*
- While the patient has diabetes and recent medication non-adherence, this condition is characterized by **hyperglycemia**, **metabolic acidosis**, and **ketonuria**, typically presenting with **Kussmaul respirations** and **abdominal pain**.
- The patient's symptoms of significant fluid overload and respiratory distress with crackles are not typical of DKA.
Question 53: A 55-year-old woman recently underwent kidney transplantation for end-stage renal disease. Her early postoperative period was uneventful, and her serum creatinine is lowered from 4.3 mg/dL (preoperative) to 2.5 mg/dL. She is immediately started on immunosuppressive therapy. On postoperative day 7, she presents to the emergency department (ED) because of nausea, fever, abdominal pain at the transplant site, malaise, and pedal edema. The vital signs include: pulse 106/min, blood pressure 167/96 mm Hg, respirations 26/min, and temperature 40.0°C (104.0°F). The surgical site shows no signs of infection. Her urine output is 250 mL over the past 24 hours. Laboratory studies show:
Hematocrit 33%
White blood cell (WBC) count 6700/mm3
Blood urea 44 mg/dL
Serum creatinine 3.3 mg/dL
Serum sodium 136 mEq/L
Serum potassium 5.6 mEq/L
An ultrasound of the abdomen shows collection of fluid around the transplanted kidney with moderate hydronephrosis. Which of the following initial actions is the most appropriate?
A. Re-operate and remove the failed kidney transplant
B. Continue with an ultrasound-guided biopsy of the transplanted kidney (Correct Answer)
C. Start on pulse steroid treatment or OKT3
D. Supportive treatment with IV fluids, antibiotics, and antipyretics
E. Consider hemodialysis
Explanation: ***Continue with an ultrasound-guided biopsy of the transplanted kidney***
- The patient's symptoms (fever, malaise, abdominal pain, rising creatinine) and ultrasound findings (fluid collection, hydronephrosis) are highly suggestive of **acute renal allograft rejection** or an **obstructive uropathy**, necessitating a definitive diagnosis through biopsy.
- A biopsy will differentiate between rejection, drug toxicity, or other causes of allograft dysfunction, guiding appropriate and specific treatment.
*Re-operate and remove the failed kidney transplant*
- Removing the transplanted kidney is a drastic measure and premature at this stage, as the cause of dysfunction is not yet confirmed.
- The elevated creatinine and hydronephrosis could be reversible with proper treatment once the underlying cause is identified.
*Start on pulse steroid treatment or OKT3*
- While pulse steroids or OKT3 (muromonab-CD3) are used to treat acute rejection, administering them without a definitive diagnosis from a biopsy could be inappropriate and potentially harmful.
- The symptoms could also be due to infection or obstruction, which would not respond to these immunosuppressive therapies and could worsen with increased immunosuppression.
*Supportive treatment with IV fluids, antibiotics, and antipyretics*
- Supportive care alone is insufficient given the potential for acute allograft rejection or severe obstruction, which requires specific intervention.
- Although the patient has fever, there are no clear signs of infection, and empirical antibiotics may delay necessary diagnostic steps.
*Consider hemodialysis*
- While the patient's creatinine is elevated and potassium is high, these parameters alone do not immediately warrant hemodialysis without exploring the underlying cause of allograft dysfunction.
- Dialysis is typically considered when there are severe indications like refractory hyperkalemia, fluid overload, acidosis, or uremic symptoms that cannot be otherwise managed, and the primary goal should be to treat the cause of decreasing kidney function.
Question 54: A 68-year-old man comes to the emergency department because of a 1-week history of worsening bouts of shortness of breath at night. He has had a cough for 1 month. Occasionally, he has coughed up frothy sputum during this time. He has type 2 diabetes mellitus and long-standing hypertension. Two years ago, he was diagnosed with Paget disease of bone during a routine health maintenance examination. He has smoked a pack of cigarettes daily for 20 years. His temperature is 37°C (98.6°F), pulse is 110/min, respirations are 25/min, and blood pressure is 145/88 mm Hg. Current medications include metformin, alendronate, hydrochlorothiazide, and enalapril. Examination shows bibasilar crackles. Cardiac examination shows a dull, low-pitched sound during late diastole that is best heard at the apex. There is no jugular venous distention or peripheral edema. Arterial blood gas analysis on room air shows:
pH 7.46
PCO2 29 mm Hg
PO2 83 mm Hg
HCO3- 18 mEq/L
Echocardiography shows a left ventricular ejection fraction of 55%. Which of the following is the most likely underlying cause of this patient’s current condition?
A. Impaired myocardial relaxation (Correct Answer)
B. Diuretic overdose
C. Systemic arteriovenous fistulas
D. Destruction of alveolar walls
E. Decreased myocardial contractility
Explanation: **Impaired myocardial relaxation**
- The patient's symptoms of nocturnal dyspnea, frothy sputum, and bibasilar crackles, coupled with a **preserved ejection fraction (55%)**, are highly suggestive of **diastolic heart failure**. The isolated **S4 heart sound** at the apex further points to a stiff, non-compliant left ventricle.
- **Long-standing hypertension** commonly leads to left ventricular hypertrophy and impaired relaxation, and the history of **Paget disease of bone** may also contribute to high-output states and myocardial stiffness, although diastolic dysfunction is a more direct consequence of the hypertrophy from hypertension.
*Diuretic overdose*
- Diuretic overdose would typically present with symptoms of **dehydration** and electrolyte abnormalities, such as hypokalemia or hyponatremia.
- While diuretics can be used to treat heart failure symptoms, an overdose would not explain the specific cardiac findings like an **S4 heart sound** or the underlying pathophysiology of heart failure with preserved ejection fraction.
*Systemic arteriovenous fistulas*
- Systemic arteriovenous fistulas can cause **high-output heart failure** due to increased venous return, but this usually manifests as a wide pulse pressure and signs of hyperdynamic circulation.
- They are less likely to cause isolated diastolic dysfunction with a preserved ejection fraction and a prominent **S4 heart sound**.
*Destruction of alveolar walls*
- Destruction of alveolar walls is characteristic of **emphysema**, a form of chronic obstructive pulmonary disease (COPD).
- While the patient has a smoking history and cough, the primary presentation with paroxysmal nocturnal dyspnea, frothy sputum, and bibasilar crackles, along with a prominent **S4 heart sound**, points more specifically to a cardiac etiology rather than isolated COPD.
*Decreased myocardial contractility*
- **Decreased myocardial contractility** would lead to **systolic heart failure**, characterized by a **reduced left ventricular ejection fraction**.
- The patient's ejection fraction is preserved at 55%, ruling out systolic dysfunction as the primary cause of his symptoms.
Question 55: A 65-year-old male with multiple comorbidities presents to your office complaining of difficulty falling asleep. Specifically, he says he has been having trouble breathing while lying flat very shortly after going to bed. He notes it only gets better when he adds several pillows, but that sitting up straight is an uncomfortable position for him in which to fall asleep. What is the most likely etiology of this man's sleeping troubles?
A. Left-sided heart failure (Correct Answer)
B. Amyotrophic lateral sclerosis (ALS)
C. Obstructive sleep apnea
D. Right-sided heart failure
E. Myasthenia gravis
Explanation: ***Left-sided heart failure***
- The patient's inability to breathe while lying flat (orthopnea) and the relief obtained by elevating his head with pillows is a classic symptom of **left-sided heart failure**.
- In this condition, accumulation of fluid in the lungs (pulmonary congestion) due to the heart's inability to pump blood effectively leads to difficulty breathing, especially in the recumbent position.
*Amyotrophic lateral sclerosis (ALS)*
- ALS primarily affects **motor neurons**, leading to progressive muscle weakness, atrophy, and spasticity.
- While it can eventually cause respiratory muscle weakness, it typically presents with more generalized motor symptoms and does not specifically manifest as acute orthopnea relieved by elevating the head of the bed shortly after lying down.
*Obstructive sleep apnea*
- Obstructive sleep apnea is characterized by recurrent upper airway collapse during sleep, leading to **pauses in breathing** and loud snoring.
- While it can cause fragmented sleep and daytime sleepiness, the primary relief is not typically from simply adding pillows but rather from CPAP therapy or surgical interventions to open the airway.
*Right-sided heart failure*
- Right-sided heart failure primarily leads to **systemic venous congestion**, causing symptoms like peripheral edema, ascites, and jugular venous distension.
- It does not typically cause orthopnea as a primary symptom, as pulmonary congestion is not the predominant feature.
*Myasthenia gravis*
- Myasthenia gravis is an **autoimmune disorder** characterized by fluctuating weakness of voluntary muscles, which worsens with activity and improves with rest.
- While it can affect respiratory muscles in severe cases, leading to respiratory compromise, the symptom presentation is more varied than isolated orthopnea, and it does not typically manifest acutely only when lying flat to sleep.
Question 56: A 71-year-old, hospitalized man develops abnormal laboratory studies 4 days after starting treatment for exacerbation of congestive heart failure. He also has a history of osteoarthritis and benign prostatic hyperplasia. He recently completed a course of amikacin for bacterial prostatitis. Before hospitalization, his medications included simvastatin and ibuprofen. Blood pressure is 111/76 mm Hg. Serum studies show a creatinine of 2.3 mg/dL (previously normal) and a BUN of 48 mg/dL. Urinalysis shows a urine osmolality of 600 mOsm/kg and urine sodium of 10 mEq/L. Which of the following is the most likely explanation for this patient's renal insufficiency?
A. Volume depletion (Correct Answer)
B. Antibiotic use
C. Glomerulonephritis
D. Urinary tract infection
E. Bladder outlet obstruction
Explanation: ***Volume depletion***
- The patient's presentation with **elevated BUN** and **creatinine**, along with **high urine osmolality** (600 mOsm/kg) and **low urine sodium** (10 mEq/L), are classic signs of **prerenal azotemia**, indicating effective circulating volume depletion.
- The patient has **congestive heart failure exacerbation**, which is often treated with **diuretics**, and a history of **ibuprofen** use, both of which can contribute to volume depletion and impaired renal perfusion.
*Antibiotic use*
- While **amikacin** is nephrotoxic, the urinalysis findings (**high urine osmolality**, **low urine sodium**) are not typical of established acute kidney injury (e.g., acute tubular necrosis) caused by aminoglycosides, which generally cause an inability to concentrate urine and higher urine sodium due to tubular damage.
- The timing of the renal insufficiency, occurring 4 days after starting CHF treatment and after completing amikacin, points away from amikacin as the primary, immediate cause.
*Glomerulonephritis*
- **Glomerulonephritis** typically presents with active urine sediment (e.g., **red blood cell casts**, **proteinuria**), which is not mentioned here.
- The urine osmolality and sodium values are not characteristic of glomerulonephritis, which is a cause of intrinsic renal disease.
*Urinary tract infection*
- A **urinary tract infection (UTI)** primarily causes symptoms like dysuria, frequency, and urgency, and can lead to pyelonephritis with fever and flank pain.
- While UTIs can worsen renal function, they do not directly explain the specific laboratory findings of **prerenal azotemia**.
*Bladder outlet obstruction*
- **Bladder outlet obstruction** (due to **benign prostatic hyperplasia** in this patient) causes **postrenal azotemia**, which would typically manifest with **bilateral hydronephrosis** on imaging and often leads to an inability to concentrate urine effectively over time, with less dramatic changes in urine sodium initially.
- The given urine osmolality and sodium values are very suggestive of prerenal causes, not obstruction.
Question 57: A 59-year-old woman comes to the physician for a 3-month history of progressively worsening shortness of breath on exertion and swelling of her legs. She has a history of breast cancer, which was treated with surgery followed by therapy with doxorubicin and trastuzumab 4 years ago. Cardiac examination shows an S3 gallop; there are no murmurs or rubs. Examination of the lower extremities shows pitting edema below the knees. Echocardiography is most likely to show which of the following sets of changes in this patient?
$$$ Ventricular wall thickness %%% Ventricular cavity size %%% Diastolic function %%% Aorto-ventricular pressure gradient $$$
A. ↓ ↑ normal normal (Correct Answer)
B. Normal normal ↓ normal
C. ↑ ↓ ↓ normal
D. ↑ ↓ ↓ ↑
E. ↓ ↑ ↓ normal
Explanation: ***↓ ↑ normal normal***
- Doxorubicin is an **anthracycline** known to cause **dilated cardiomyopathy**, characterized by **decreased ventricular wall thickness**, **increased ventricular cavity size**, and **preserved diastolic function**.
- The S3 gallop and pitting edema indicate **heart failure with reduced ejection fraction (HFrEF)**, consistent with dilated cardiomyopathy.
*Normal normal ↓ normal*
- This option suggests a primary issue with **diastolic function**, which is not the typical presentation of doxorubicin-induced cardiomyopathy.
- While diastolic dysfunction can occur, doxorubicin characteristically causes **systolic dysfunction** manifesting as chamber dilation and wall thinning.
*↑ ↓ ↓ normal*
- This pattern of **increased wall thickness** and **decreased cavity size** is characteristic of **hypertrophic cardiomyopathy** or **restrictive cardiomyopathy**, which are generally not caused by doxorubicin.
- Doxorubicin typically causes **cardiac muscle fiber damage** leading to thinning and dilation.
*↑ ↓ ↓ ↑*
- This option also suggests **increased wall thickness** and **decreased cavity size**, inconsistent with doxorubicin's effects on the heart.
- The **elevated aorto-ventricular pressure gradient** might indicate outflow tract obstruction or significant aortic stenosis, which are not typical sequelae of doxorubicin.
*↓ ↑ ↓ normal*
- While doxorubicin leads to **decreased wall thickness** and **increased cavity size**, the diastolic function is usually preserved early on, not decreased.
- A decrease in diastolic function might occur in later stages, but the primary and most characteristic feature due to doxorubicin is **systolic dysfunction** and chamber remodeling.
Question 58: An 85-year-old man with hypertension and type 2 diabetes mellitus is brought to the emergency department because of a 2-day history of shortness of breath. He has smoked one pack of cigarettes daily for 30 years. His temperature is 36.9°C (98.4°F), pulse is 100/min, respirations are 30/min, and blood pressure is 138/75 mm Hg. Pulmonary function testing shows decreased tidal volume and normal lung compliance. Which of the following is the most likely underlying etiology of this patient's tachypnea?
A. Diabetic ketoacidosis
B. Rib fracture
C. Pulmonary edema (Correct Answer)
D. Emphysema exacerbation
E. Tension pneumothorax
Explanation: ***Pulmonary edema***
- This patient's **hypertension** and **diabetes** are major risk factors for heart failure, and the acute onset of **shortness of breath** with **tachypnea** suggests cardiogenic pulmonary edema.
- **Decreased tidal volume** occurs because fluid accumulation in the interstitium and alveoli reduces functional lung capacity, prompting rapid, shallow breathing to maintain minute ventilation.
- While pulmonary edema typically causes **decreased lung compliance** due to fluid-stiffened lungs, early or mild cases may show relatively preserved compliance, or the normal compliance here may reflect measurement timing or technique. The clinical picture and decreased tidal volume strongly support pulmonary edema.
- The combination of cardiac risk factors, acute dyspnea, tachypnea, and altered breathing pattern make this the most likely diagnosis.
*Diabetic ketoacidosis*
- DKA causes **Kussmaul respirations** (deep, labored breathing) to compensate for metabolic acidosis, not the shallow breathing pattern (decreased tidal volume) seen here.
- DKA typically presents with polyuria, polydipsia, abdominal pain, nausea, and fruity breath odor, which are not mentioned.
- While this patient has diabetes, the respiratory pattern and absence of typical DKA symptoms make this less likely.
*Rib fracture*
- Rib fractures cause **pleuritic chest pain** that worsens with breathing, leading to voluntary splinting and reduced tidal volume.
- However, there is **no history of trauma** or chest pain reported.
- Pain from rib fractures would be localized, and the acute 2-day onset of dyspnea without trauma makes this unlikely.
*Emphysema exacerbation*
- Emphysema is characterized by **increased lung compliance** (hyperinflation) due to alveolar wall destruction, which contradicts the normal compliance finding.
- While the patient has a significant smoking history, the **normal lung compliance** argues against emphysema.
- COPD exacerbations typically present with wheezing, productive cough, and hyperinflation, not decreased tidal volume with normal compliance.
*Tension pneumothorax*
- Tension pneumothorax presents with **severe respiratory distress**, unilateral absent breath sounds, **hypotension**, tracheal deviation, and jugular venous distension.
- This patient's **blood pressure is normal** (138/75 mm Hg) and there's no mention of absent breath sounds or hemodynamic compromise.
- The clinical presentation does not support this life-threatening emergency.
Question 59: A 72-year-old man with coronary artery disease comes to the emergency department because of chest pain and shortness of breath for the past 3 hours. Troponin levels are elevated and an ECG shows ST-elevations in the precordial leads. Revascularization with percutaneous coronary intervention is performed, and a stent is successfully placed in the left anterior descending artery. Two days later, he complains of worsening shortness of breath. Pulse oximetry on 3L of nasal cannula shows an oxygen saturation of 89%. An x-ray of the chest shows distended pulmonary veins, small horizontal lines at the lung bases, and blunting of the costophrenic angles bilaterally. Which of the following findings would be most likely on a ventilation-perfusion scan of this patient?
A. Matched ventilation and perfusion bilaterally
B. Normal ventilation with multiple, bilateral perfusion defects
C. Normal perfusion with bilateral ventilation defects (Correct Answer)
D. Normal perfusion with decreased ventilation at the right base
E. Increased apical ventilation with normal perfusion bilaterally
Explanation: ***Normal perfusion with bilateral ventilation defects***
- The patient's presentation with **worsening shortness of breath** after an acute coronary event, along with chest x-ray findings of **distended pulmonary veins, Kerley B lines (small horizontal lines at the lung bases), and blunting of the costophrenic angles**, is highly suggestive of **pulmonary edema** due to heart failure.
- In pulmonary edema, the alveoli fill with fluid, impeding gas exchange. This leads to **impaired ventilation** in the affected areas, while **pulmonary blood flow (perfusion) remains intact**. This results in **ventilation-perfusion (V/Q) mismatch** with impaired ventilation.
*Matched ventilation and perfusion bilaterally*
- This pattern would indicate a **normal ventilation-perfusion scan**, which is inconsistent with the patient's severe shortness of breath, hypoxemia, and radiographic signs of pulmonary edema.
- A matched V/Q scan suggests **healthy lung function** and gas exchange.
*Normal ventilation with multiple, bilateral perfusion defects*
- This pattern is characteristic of **pulmonary embolism**, where blood clots obstruct pulmonary arteries, leading to areas of the lung being ventilated but not perfused.
- The clinical picture and chest x-ray findings in this patient are not consistent with pulmonary embolism.
*Normal perfusion with decreased ventilation at the right base*
- While a focal ventilation defect could occur, the patient's symptoms and chest x-ray findings (distended pulmonary veins, Kerley B lines, bilateral blunting of costophrenic angles) suggest **generalized rather than localized pulmonary edema**.
- This option describes a unilateral and focal issue, whereas heart failure typically causes bilateral findings.
*Increased apical ventilation with normal perfusion bilaterally*
- This finding is not typical in any common pulmonary pathology. Increased apical ventilation is not a characteristic of pulmonary edema or other V/Q mismatch disorders.
- This scenario does not align with the patient's symptoms or imaging findings.
Question 60: A 63-year-old male is admitted to the Emergency Department after 3 days difficulty breathing, orthopnea, and shortness of breath with effort. His personal medical history is positive for a myocardial infarction 6 years ago and a cholecystectomy 10 years ago. Medications include metoprolol, lisinopril, atorvastatin, and as needed furosemide. At the hospital his blood pressure is 108/60 mm Hg, pulse is 88/min, respiratory rate is 20/min, and temperature is 36.4°C (97.5°F). On physical examination, he presents with fine rales in both lungs, his abdomen is non-distended non-tender, and there is 2+ lower limb pitting edema up to his knees. Initial laboratory testing is shown below
Na+ 138 mEq/L
K+ 4 mEq/L
Cl- 102 mEq/L
Serum creatinine (Cr) 1.8 mg/dL
Blood urea nitrogen (BUN) 52 mg/dL
Which of the following therapies is the most appropriate for this patient?
A. Furosemide (Correct Answer)
B. Hyperoncotic starch
C. Terlipressin
D. Normal saline
E. Norepinephrine
Explanation: ***Furosemide***
- The patient presents with classic signs of **acute decompensated heart failure**, including **dyspnea, orthopnea, bilateral rales, and pitting edema**. This indicates **volume overload**.
- **Furosemide**, a loop diuretic, is the most appropriate initial therapy to rapidly reduce fluid overload, alleviate symptoms, and improve cardiac function.
*Hyperoncotic starch*
- **Hyperoncotic starch** is a colloid solution used for **volume expansion** in cases of hypovolemia or shock.
- Administering a volume expander to a patient with **fluid overload due to heart failure** would worsen their condition.
*Terlipressin*
- **Terlipressin** is a **vasopressin analog** primarily used in the management of **hepatorenal syndrome** and **esophageal variceal bleeding**.
- It is not indicated for the treatment of **acute decompensated heart failure** or fluid overload.
*Normal saline*
- **Normal saline** is an **isotonic crystalloid solution** used for volume resuscitation in hypovolemic states.
- Providing additional fluids to a patient already in **fluid overload** would exacerbate fluid retention and worsen heart failure symptoms.
*Norepinephrine*
- **Norepinephrine** is a **vasopressor** used to increase blood pressure in patients with **hypotensive shock**.
- While the patient's blood pressure is on the lower side (108/60 mmHg), immediate **volume reduction** with diuretics is paramount for heart failure, not vasopressor support unless overt cardiogenic shock develops.
