Internal Medicine

3151 questions

All types3,151 Multiple choice1,611 Multiple select73 Numeric81 Matching714 Ordering672

A $58$ -year-old man is brought to the emergency department after coughing up approximately $600 \text{ mL}$ of bright red blood over the past two hours. He has a history of treated pulmonary tuberculosis with known residual cavitary disease in the right upper lobe. On arrival, he is in severe respiratory distress, coughing continuously, and expectorating fresh blood. His temperature is $37.2^\circ\text{C}$ ( $99.0^\circ\text{F}$ ), blood pressure is $105/65 \text{ mmHg}$ , pulse is $118/\text{min}$ , and respiratory rate is $28/\text{min}$ . Pulse oximetry shows an oxygen saturation of $86\%$ on room air. Physical examination reveals coarse crackles over the right hemithorax, while the left lung field is relatively clear. The patient is unable to speak in full sentences due to the ongoing hemoptysis.

Arrange the following interventions in the most appropriate sequential order for managing this patient's condition.

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Answer

The correct sequence is to first secure the airway with endotracheal intubation, then position the patient with the bleeding lung down (right lateral decubitus), followed by bronchoscopy to evaluate the airways, and finally consult for bronchial artery embolization.

In massive hemoptysis (defined as expectorating

>600 \text{ mL}

of blood in

24

hours or a rate that threatens gas exchange), the immediate cause of mortality is asphyxiation, not blood loss. Therefore, the initial step in management is always securing the airway, typically with endotracheal intubation using a large-bore tube to facilitate suctioning and bronchoscopy. Following intubation, the patient should immediately be placed in a lateral decubitus position with the suspected bleeding lung down. In this scenario, the history of right upper lobe cavitary disease and right-sided crackles point to a right-sided source; placing the patient in the right lateral decubitus position uses gravity to protect the healthy left lung from blood spillage. Once the airway is secure and the good lung is protected, bedside flexible bronchoscopy should be performed to suction clots, identify the exact site of bleeding, and potentially provide temporary tamponade. Finally, after stabilization and localization, the patient should undergo bronchial artery embolization, which is the definitive treatment of choice for controlling massive hemoptysis.

Step-by-Step Solution

Recognize massive hemoptysis with impending respiratory failure.

Prioritize immediate airway management through endotracheal intubation.

Asphyxiation due to airways filling with blood is the primary cause of death in massive hemoptysis. Securing the airway takes precedence over all other interventions.

Protect the unaffected lung.

Place the patient in the right lateral decubitus position (bleeding side down).

Gravity prevents blood from the actively bleeding right lung from spilling into the healthy contralateral left lung, thereby maintaining gas exchange.

Visualize and clear the airways.

Perform flexible bronchoscopy.

Bronchoscopy allows for suctioning of blood and clots, identification of the specific anatomic bleeding source, and potential temporary hemostatic measures.

Achieve definitive hemostasis.

Proceed with bronchial artery embolization.

Once the patient is stable and the bleeding source is identified, embolization is the most effective first-line definitive therapy to stop massive bleeding.

Key Concept

The management of massive hemoptysis follows a strict algorithmic priority: secure the airway (intubation), protect the non-bleeding lung (dependent positioning of the bleeding side), localize the bleeding (bronchoscopy), and finally achieve definitive hemostasis (bronchial artery embolization).

Estimated Time:1m 30s

Question 2502Question →

Match the following classic arterial pulse abnormalities with their most likely underlying cardiovascular pathology.

Click a left item, then click its matching right item

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Answer

Pulsus paradoxus matches with cardiac tamponade, pulsus parvus et tardus matches with severe aortic stenosis, pulsus alternans matches with severe left ventricular systolic dysfunction, and water-hammer pulse matches with severe aortic regurgitation.

Each specific arterial pulse waveform abnormality corresponds to a unique hemodynamic derangement. Cardiac tamponade causes inspiratory ventricular interdependence (pulsus paradoxus). Aortic stenosis causes restricted outflow (parvus et tardus). Heart failure causes alternating stroke volumes (pulsus alternans). Aortic regurgitation causes widened pulse pressure and rapid runoff (water-hammer pulse).

Step-by-Step Solution

Analyze the hemodynamic mechanism of an exaggerated respiratory drop in blood pressure (pulsus paradoxus).

This indicates restricted right ventricular expansion leading to leftward bowing of the interventricular septum during inspiration.

This ventricular interdependence is the classic pathophysiologic hallmark of cardiac tamponade.

Evaluate the cause of a low-amplitude, delayed arterial upstroke (pulsus parvus et tardus).

This reflects a prolonged, restricted ejection of blood from the left ventricle.

This is characteristic of the fixed obstruction seen in severe aortic stenosis.

Determine the significance of beat-to-beat variation in pulse amplitude with a regular rhythm (pulsus alternans).

This reflects an alternating stroke volume from a failing myocardium.

It is a highly specific sign of severe left ventricular systolic dysfunction.

Identify the condition that produces a rapid upstroke and rapid collapse of the peripheral pulse (water-hammer pulse).

This requires a massive stroke volume combined with a low diastolic pressure (widened pulse pressure).

This hemodynamic profile is produced by the severe diastolic backward flow into the left ventricle in severe aortic regurgitation.

Key Concept

Classic arterial pulse abnormalities and their associated structural heart diseases

Question 2503Question →

A 24-year-old man is brought to the emergency department after being involved in a high-speed motor vehicle collision. He is in severe respiratory distress and complains of right-sided chest pain. His blood pressure is 80/50 mm Hg, heart rate is 135/min, and respiratory rate is 32/min. Oxygen saturation is 86% on room air. Physical examination reveals significantly decreased breath sounds over the right hemithorax, hyperresonance to percussion on the right, and distended neck veins. The trachea is deviated to the left. Arrange the following management steps in the most appropriate chronological sequence for this patient.

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Answer

The correct sequence is: Administer oxygen and assess airway, perform needle decompression, insert a tube thoracostomy, and finally obtain a chest radiograph.

Tension pneumothorax in an unstable patient is a clinical diagnosis. The correct sequence prioritizes immediate life-saving interventions (ABCs and needle decompression) before definitive management (chest tube) and post-procedure confirmation (radiograph).

Step-by-Step Solution

Recognize the clinical presentation of tension pneumothorax.

The patient has hypotension, tachycardia, tracheal deviation, distended neck veins, and unilateral absent breath sounds with hyperresonance.

Identifying these classic signs is critical because tension pneumothorax is a life-threatening clinical diagnosis that does not require imaging.

Prioritize interventions based on ATLS guidelines.

Airway and oxygenation are established first, followed immediately by needle decompression.

Airway and breathing take absolute priority. Needle decompression rapidly relieves intrathoracic pressure and restores venous return.

Determine the definitive treatment and follow-up.

A chest tube is placed, followed by a chest radiograph.

Needle decompression is a temporary measure. A chest tube provides definitive management, and a radiograph is subsequently needed to confirm proper placement and lung re-expansion.

Key Concept

Tension pneumothorax is a clinical diagnosis that requires immediate treatment with needle or finger thoracostomy before obtaining diagnostic imaging.

Question 2504Question →

A $72$ -year-old man is brought to the emergency department by his daughter due to a $2$ -day history of progressively worsening shortness of breath, a cough productive of yellow sputum, and palpitations. His medical history is significant for hypertension, hyperlipidemia, and chronic obstructive pulmonary disease (COPD). He has a $50$ -pack-year smoking history. Current medications include inhaled tiotropium, inhaled fluticasone, and oral amlodipine. His temperature is $37.6^\circ\text{C}$ ( $99.7^\circ\text{F}$ ), blood pressure is $138/86$ mmHg, pulse is $134$ /min and irregular, and respirations are $26$ /min. Pulse oximetry is $87\%$ on room air. Physical examination reveals a barrel chest with prominent use of accessory muscles of respiration. Lung auscultation demonstrates a prolonged expiratory phase and diffuse wheezing bilaterally. There is no jugular venous distention or peripheral edema. An electrocardiogram reveals an irregular rhythm with narrow QRS complexes, absent flutter waves, and $3$ distinct P wave morphologies in lead II. Which of the following is the most appropriate initial management for this patient?

Administration of supplemental oxygen and nebulized ipratropium-albuterol

Administration of intravenous furosemide

Administration of intravenous piperacillin-tazobactam

Administration of intravenous diltiazem

Immediate synchronized electrical cardioversion

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Answer: Administration of supplemental oxygen and nebulized ipratropium-albuterol

Answer

The correct answer is the administration of supplemental oxygen and nebulized ipratropium-albuterol.

The correct answer involves treating the underlying pulmonary cause. This patient's electrocardiogram shows multifocal atrial tachycardia (MAT), characterized by a heart rate

> 100

/min, irregular R-R intervals, and at least

3

different P wave morphologies in the same lead. MAT is strongly associated with severe pulmonary disease, particularly chronic obstructive pulmonary disease (COPD) exacerbations, which lead to hypoxia and right atrial stretch. The primary and most effective initial management for MAT is optimizing the patient's pulmonary status and oxygenation (e.g., supplemental oxygen, bronchodilators, and corticosteroids). Antiarrhythmic therapy is not indicated as first-line treatment.

Step-by-Step Solution

Analyze the patient's clinical presentation.

The patient is a 72-year-old man with a history of COPD presenting with worsening dyspnea, productive cough, hypoxia, and diffuse wheezing, indicating an acute COPD exacerbation.

To establish the primary underlying pathophysiology driving the patient's symptoms.

Interpret the electrocardiogram (ECG) findings.

The ECG shows an irregularly irregular narrow-complex tachycardia with three distinct P wave morphologies and an isoelectric baseline, which is diagnostic of multifocal atrial tachycardia (MAT).

To identify the specific cardiac rhythm abnormality.

Determine the appropriate management for the identified condition.

MAT is most commonly secondary to underlying pulmonary disease, hypoxia, or right atrial stretch. The first-line therapy is correcting the underlying cause rather than administering primary antiarrhythmic medications.

To select the safest and most effective initial intervention.

Select the best pharmacologic option based on the primary etiology.

Supplemental oxygen (to correct hypoxia) and bronchodilators like ipratropium-albuterol (to treat the COPD exacerbation) represent the most appropriate initial management.

Optimizing pulmonary function typically resolves MAT without the need for rate-controlling drugs.

Key Concept

Multifocal Atrial Tachycardia (MAT) is an irregularly irregular supraventricular arrhythmia characterized by

\ge 3

distinct P wave morphologies. It is most often caused by exacerbation of underlying pulmonary disease (e.g., COPD), and initial management focuses on treating the underlying respiratory condition rather than administering antiarrhythmic drugs.

Question 2505Question →

A $61$ -year-old man with known liver cirrhosis secondary to chronic hepatitis C infection is hospitalized due to an acute onset of fever, diffuse abdominal discomfort, and confusion. Diagnostic paracentesis performed on the day of admission yielded ascitic fluid with an absolute neutrophil count of $550$ cells/mm $^3$ . Consequently, he was initiated on an empiric antimicrobial regimen of intravenous piperacillin-tazobactam and vancomycin.

Now, on his third day in the hospital, his clinical status has markedly improved. He is fully oriented, his temperature is $37.0^\circ$ C ( $98.6^\circ$ F), and his abdominal pain has subsided. The ascitic fluid cultures from admission demonstrate the growth of *Escherichia coli*. The susceptibility report indicates that this organism is resistant to ampicillin but highly susceptible to ceftriaxone, cefotaxime, and ciprofloxacin.

Which of the following is the most appropriate next step in management?

Maintain the current regimen of intravenous piperacillin-tazobactam and vancomycin

Discontinue vancomycin but maintain intravenous piperacillin-tazobactam

Switch the antimicrobial regimen to intravenous ceftriaxone

Switch the antimicrobial regimen to intravenous meropenem

Add intravenous fluconazole to the current antimicrobial regimen

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Answer: Switch the antimicrobial regimen to intravenous ceftriaxone

Answer

Switch the antimicrobial regimen to intravenous ceftriaxone

The correct answer demonstrates the appropriate application of antibiotic stewardship in a patient with spontaneous bacterial peritonitis (SBP). The patient was initially treated appropriately with broad-spectrum antibiotics (piperacillin-tazobactam and vancomycin), which is indicated for critically ill patients with severe infections. However, once clinical improvement is noted and specific culture data identify a susceptible pathogen (*E. coli* sensitive to ceftriaxone), the standard of care requires de-escalating to a narrower-spectrum, targeted agent. Ceftriaxone provides excellent coverage for this infection while minimizing adverse effects and selective pressure for resistance.

Step-by-Step Solution

Identify the patient's current clinical status and initial diagnosis.

The patient was diagnosed with spontaneous bacterial peritonitis (SBP) and is now clinically stable after three days of empiric broad-spectrum therapy.

Establishing the clinical trajectory is necessary to decide whether therapy can be safely modified.

Analyze the ascitic fluid culture and susceptibility results.

The culture grew *Escherichia coli* that is sensitive to ceftriaxone, cefotaxime, and ciprofloxacin.

Culture data provides the definitive microbiological diagnosis and guides targeted pharmacotherapy.

Apply the principles of antibiotic stewardship to determine the next step.

The current broad-spectrum regimen (piperacillin-tazobactam and vancomycin) should be de-escalated to a narrow-spectrum agent (ceftriaxone).

Targeted therapy minimizes toxicity, reduces the risk of superinfections, and prevents the development of antimicrobial resistance.

Key Concept

In patients treated empirically for spontaneous bacterial peritonitis who demonstrate clinical improvement, the antibiotic regimen should be de-escalated to a targeted, narrower-spectrum agent as soon as culture and susceptibility results are available.

Question 2506Question →

A $48$ -year-old man is brought to the emergency department via ambulance due to a severe episode of coughing up blood. The patient has a history of treated pulmonary tuberculosis $10$ years ago, which left residual cavitary lesions in his right upper lobe. Over the last $4$ hours, he estimates coughing up approximately $600$ mL of bright red blood. Upon arrival, he has another paroxysm of coughing, producing an additional $250$ mL of fresh blood. He appears distressed and diaphoretic. Vital signs show a blood pressure of $105/65$ mm Hg, heart rate of $122$ /min, respiratory rate of $28$ /min, and oxygen saturation of $88\%$ on room air. Auscultation reveals coarse rhonchi and gurgling sounds predominantly over the right hemithorax, with relatively clear breath sounds on the left. The patient is immediately placed on high-flow supplemental oxygen.

Arrange the following subsequent interventions in the most appropriate sequential order for managing this patient's life-threatening condition.

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Answer

The correct sequence for managing massive hemoptysis with a known bleeding side is to first place the bleeding lung in a dependent position, followed by securing the airway with a large-bore endotracheal tube, performing bronchoscopy for localization and airway clearance, and finally proceeding to definitive therapy with bronchial artery embolization.

The correct sequence prioritizes the immediate survival of the patient by preventing the healthy lung from drowning in blood. Positioning the bleeding lung down (right lateral decubitus) is the fastest, non-invasive way to protect the left lung. Once protected, the airway is definitively secured via intubation with a large-bore tube to allow for subsequent bronchoscopy. Bronchoscopy is then utilized to clear clots and provide temporary tamponade, paving the way for definitive hemostasis via bronchial artery embolization.

Step-by-Step Solution

Identify the life-threatening condition and lateralize the pathology.

The patient is experiencing massive hemoptysis (>

600

mL) originating from the right lung due to prior tuberculosis cavitary lesions.

Recognizing the severity and the bleeding side is critical for immediate airway protection maneuvers.

Protect the non-bleeding lung from asphyxiation.

The patient is placed in the right lateral decubitus position.

Placing the bleeding lung in the dependent (down) position utilizes gravity to prevent blood from spilling over the carina into the healthy left lung.

Secure a definitive airway.

Endotracheal intubation is performed using a large-bore tube (

\geq 8.0

mm).

A secured airway ensures ventilation and oxygenation. A large-bore tube is mandatory to accommodate a bronchoscope for subsequent interventions.

Localize the bleeding and attempt initial hemostasis.

Emergent bronchoscopy is performed.

Bronchoscopy allows for the clearance of obstructing clots, precise localization of the bleeding vessel, and temporary control via cold saline or balloon tamponade.

Perform definitive treatment.

Bronchial artery embolization is executed.

Embolization is the first-line definitive therapy to occlude the hypertrophied bronchial arteries supplying the bleeding site.

Key Concept

Sequential management of massive hemoptysis

Estimated Time:2m 0s

Question 2507Question →

A $74$ -year-old man presents to the emergency department with a $2$ -day history of worsening shortness of breath and a nonproductive cough. He has a past medical history of hypertension, ischemic cardiomyopathy, and chronic obstructive pulmonary disease (COPD). His daily medications include lisinopril, metoprolol, low-dose aspirin, and a tiotropium inhaler. He has a $40$ -pack-year smoking history but quit $5$ years ago. He reports waking up several times last night gasping for air. His temperature is $37.0^\circ\text{C} (98.6^\circ\text{F})$ , blood pressure is $158/92 \text{ mmHg}$ , pulse is $112/\text{min}$ , and respiratory rate is $26/\text{min}$ . Pulse oximetry on room air is $88\%$ . Physical examination shows jugular venous distention $8 \text{ cm}$ above the sternal angle. Lung auscultation reveals diffuse expiratory wheezes bilaterally; no crackles are heard. Cardiac auscultation demonstrates a regular tachycardia with a prominent $S_3$ gallop. There is $2+$ pitting edema in the bilateral lower extremities. A bedside portable chest radiograph shows prominent perihilar vasculature and indistinct vascular margins without focal opacities. Arterial blood gas analysis on room air shows:

pH: $7.47$
$\text{PaCO}_2$ : $30 \text{ mmHg}$
$\text{PaO}_2$ : $58 \text{ mmHg}$
$\text{HCO}_3^-$ : $22 \text{ mEq/L}$

Which of the following is the most appropriate initial therapy for this patient?

Intravenous furosemide

Inhaled albuterol

Intravenous methylprednisolone

Intravenous levofloxacin

Intravenous sodium bicarbonate

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Answer: Intravenous furosemide

Answer

Intravenous furosemide

The patient is presenting with acute decompensated heart failure (ADHF). Despite his history of COPD and the presence of wheezing, the clinical findings of paroxysmal nocturnal dyspnea (waking up gasping), jugular venous distention, an

S_3

gallop, and lower extremity edema strongly point to left ventricular failure causing pulmonary edema. The wheezing is due to peribronchial edema, a condition often termed 'cardiac asthma.' The chest radiograph showing prominent perihilar vasculature further supports ADHF. The arterial blood gas demonstrates an acute respiratory alkalosis driven by hypoxia-induced hyperventilation. The most appropriate initial therapy is a loop diuretic, such as intravenous furosemide, which reduces preload and quickly relieves pulmonary congestion.

Step-by-Step Solution

Analyze the patient's history and symptoms.

The patient has a history of ischemic cardiomyopathy and COPD. He presents with acute orthopnea, paroxysmal nocturnal dyspnea, and a nonproductive cough.

Identifies risk factors and classic symptoms that differentiate between volume overload and primary airway disease.

Interpret the physical examination and diagnostic findings.

Findings include hypoxia, elevated jugular venous pressure, an S3 gallop, bilateral edema, and prominent perihilar vasculature. The ABG reveals an acute respiratory alkalosis.

These findings strongly point to cardiogenic pulmonary edema (cardiac asthma) rather than a COPD exacerbation or bacterial pneumonia.

Determine the appropriate initial management.

Administer an intravenous loop diuretic (e.g., furosemide).

Loop diuretics rapidly reduce cardiac preload and relieve pulmonary congestion in acute decompensated heart failure.

Key Concept

Differentiating acute decompensated heart failure (cardiac asthma) from COPD exacerbation and managing it with preload reduction.

Estimated Time:1m 30s

Question 2508Question →

During a routine outpatient evaluation, a physician examines a patient with a long-standing history of severe chronic obstructive pulmonary disease. The patient reports a three-month history of progressive bilateral leg swelling and a noticeable decline in exercise tolerance. Vital signs are stable. On physical examination, the physician notes prominent jugular venous distention and a palpable parasternal heave. Auscultation reveals globally decreased breath sounds without inspiratory crackles. A subsequent point-of-care echocardiogram demonstrates marked right ventricular dilation alongside a completely normal left ventricular ejection fraction. Which of the following underlying pathophysiologic mechanisms most likely initiated this patient's cardiac findings?

Hypoxic pulmonary vasoconstriction

Impaired left ventricular contractility

Chronic elevation of left atrial pressure

Primary degeneration of the tricuspid valve leaflets

Autoimmune destruction of the alveolar-capillary membrane

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Answer: Hypoxic pulmonary vasoconstriction

Answer

The correct answer is hypoxic pulmonary vasoconstriction.

The correct answer identifies the primary mechanism of cor pulmonale in chronic obstructive pulmonary disease (COPD). In patients with advanced COPD, chronic alveolar hypoxia triggers a physiologic compensatory response known as hypoxic pulmonary vasoconstriction. While this mechanism is beneficial in localized lung disease to optimize ventilation-perfusion matching by redirecting blood to better-oxygenated alveoli, global hypoxia causes widespread, unremitting pulmonary vasoconstriction. Over time, this chronic increased resistance leads to vascular remodeling, pulmonary hypertension, and ultimately right ventricular hypertrophy and dilation (cor pulmonale). The normal left ventricular ejection fraction on the echocardiogram confirms that the right-sided failure is strictly secondary to a pulmonary process rather than left-sided heart disease.

Step-by-Step Solution

Analyze the patient's physical examination findings.

The patient exhibits classic signs of right-sided heart failure, including jugular venous distention, lower extremity edema, and a parasternal heave.

Identifying the specific clinical syndrome (isolated right heart failure) is necessary to determine the underlying etiology.

Evaluate the echocardiographic data in the context of the physical exam.

The right ventricle is dilated, but the left ventricular ejection fraction is completely normal, ruling out left-sided heart failure as the cause of the systemic venous congestion.

This confirms that the right-sided heart failure is secondary to a pulmonary process (cor pulmonale) rather than a cardiac one.

Link the primary pulmonary disease (COPD) to the cardiac findings.

Chronic alveolar hypoxia from advanced COPD causes global pulmonary arterial vasoconstriction, resulting in pulmonary hypertension and eventual right ventricular failure.

Understanding the precise pathophysiologic trigger for cor pulmonale is required to select the correct mechanism.

Key Concept

Cor Pulmonale Pathophysiology

Question 2509Question →

A 62-year-old man collapses while walking in the hospital corridor. He is unresponsive, apneic, and has no palpable carotid pulse. A crash cart is immediately brought to the scene, and chest compressions are initiated. The cardiac monitor displays coarse ventricular fibrillation. Arrange the following critical resuscitation steps in the most appropriate chronological order according to standard advanced cardiovascular life support (ACLS) guidelines.

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Answer

The correct sequence prioritizes immediate defibrillation, followed by uninterrupted CPR with IV/IO access, a second shock followed by epinephrine, and a third shock followed by an antiarrhythmic like amiodarone.

According to the adult ACLS cardiac arrest algorithm for shockable rhythms (VF/pVT), the correct chronological sequence is: 1) Deliver a shock as soon as the defibrillator is ready. 2) Immediately resume CPR for 2 minutes while establishing IV/IO access. 3) Perform a rhythm check, and if VF persists, deliver a second shock. 4) Resume CPR and administer epinephrine (1 mg every 3-5 minutes). 5) If VF persists at the next rhythm check, deliver a third shock and administer an antiarrhythmic (e.g., amiodarone 300 mg) during the subsequent CPR cycle.

Step-by-Step Solution

Identify the rhythm and prioritize initial interventions.

The rhythm is ventricular fibrillation (VF), an immediately shockable rhythm.

The absolute highest priority for VF is defibrillation. Chest compressions should occur while the machine charges, but the shock is the primary definitive intervention.

Determine the immediate post-shock management.

High-quality CPR is resumed immediately for 2 minutes without checking for a pulse, while vascular access is obtained.

Minimizing pauses in chest compressions is critical for survival. Rhythm checks only occur after 2-minute cycles.

Sequence the subsequent pharmacological interventions.

Epinephrine is given during CPR after the second shock, and amiodarone is given during CPR after the third shock.

ACLS guidelines sequentially escalate therapy for refractory shockable rhythms, starting with a vasopressor to maintain perfusion pressure, followed by an antiarrhythmic if the arrest persists.

Key Concept

Advanced Cardiovascular Life Support (ACLS) Pulseless Arrest Algorithm (Ventricular Fibrillation/Pulseless Ventricular Tachycardia)

Question 2510Question →

A $71$ -year-old man is brought to the emergency department by emergency medical services due to severe shortness of breath and confusion. His wife reports that he has had a productive cough with thick, greenish sputum and subjective fevers for the past three days. His medical history is significant for severe chronic obstructive pulmonary disease (FEV1 $30\%$ of predicted) and ischemic cardiomyopathy (left ventricular ejection fraction $35\%$ ).

Upon arrival, his temperature is $38.8^\circ\text{C}$ ( $101.8^\circ\text{F}$ ), blood pressure is $82/48\text{ mm Hg}$ , pulse is $128/\text{min}$ , and respiratory rate is $36/\text{min}$ . Oxygen saturation is $81\%$ on room air. Physical examination reveals a lethargic, confused patient using accessory muscles of respiration. The jugular venous pulsation is visible $4\text{ cm}$ above the sternal angle. Lung auscultation reveals diffuse expiratory wheezes and coarse crackles over the right lower lung field. The extremities are exceptionally warm, and peripheral pulses are bounding.

Arterial blood gas analysis on room air reveals:
pH: $7.12$
PaCO $_2$ : $58\text{ mm Hg}$
PaO $_2$ : $48\text{ mm Hg}$
HCO $_3^-$ : $18\text{ mEq/L}$

Which of the following initial interventions are indicated in the management of this patient? (Select all that apply)

Select all that apply

Endotracheal intubation and mechanical ventilation

Administration of intravenous piperacillin-tazobactam

Initiation of a continuous intravenous furosemide infusion

Administration of an intravenous sodium bicarbonate bolus

Initiation of empiric therapy with intravenous ceftriaxone monotherapy

Show answer & explanation

Answer: Endotracheal intubation and mechanical ventilation; Administration of intravenous piperacillin-tazobactam

Answer

The correct initial interventions are endotracheal intubation with mechanical ventilation and the administration of intravenous piperacillin-tazobactam.

The correct interventions address the patient's critical respiratory and infectious issues simultaneously. The patient has severe hypercapnic and hypoxemic respiratory failure with altered mental status and hemodynamic instability, which are absolute contraindications to noninvasive positive-pressure ventilation (NIPPV). Invasive mechanical ventilation via endotracheal intubation is required to secure the airway and correct the ventilatory failure. Concurrently, broad-spectrum antibiotics with antipseudomonal coverage, such as piperacillin-tazobactam, are indicated because he has a severe COPD exacerbation with suspected pneumonia and septic shock, placing him at high risk for Pseudomonas aeruginosa.

Step-by-Step Solution

Evaluate the patient's hemodynamic status and tissue perfusion.

The patient is in distributive (septic) shock.

Hypotension, tachycardia, fever, and warm extremities with bounding pulses point to sepsis rather than cardiogenic shock, despite his history of heart failure.

Analyze the arterial blood gas results to determine the primary and secondary acid-base disorders.

The patient has a mixed metabolic acidosis and severe respiratory acidosis.

Winter's formula predicts an expected PaCO2 of

35 \pm 2\text{ mm Hg}

(

1.5 \times 18 + 8

). The actual PaCO2 is

58\text{ mm Hg}

, indicating concomitant ventilatory failure.

Determine the appropriate airway and ventilatory management.

Endotracheal intubation and invasive mechanical ventilation are required.

The patient has severe mixed acidemia, hypoxemia, altered mental status, and hemodynamic instability, which are absolute contraindications to noninvasive ventilation.

Select the appropriate empiric antibiotic regimen for a critically ill patient with severe COPD.

Initiate intravenous piperacillin-tazobactam.

The patient is at high risk for Pseudomonas aeruginosa due to severe COPD and critical illness requiring ICU admission; therefore, antipseudomonal coverage is mandatory.

Key Concept

Management of severe mixed respiratory and metabolic acidosis complicated by septic shock in a patient with advanced chronic obstructive pulmonary disease.

Question 2511Question →

A $68$ -year-old woman comes to the urgent care clinic complaining of progressive shortness of breath and a cough productive of clear, frothy sputum for the past two days. She reports needing to sleep propped up on three pillows at night. Her past medical history includes hypertension, type 2 diabetes mellitus, and a $35$ -pack-year smoking history. Her temperature is $37.1^\circ\text{C}$ ( $98.8^\circ\text{F}$ ), blood pressure is $165/95\text{ mmHg}$ , pulse is $105/\text{min}$ , and respiratory rate is $22/\text{min}$ . Oxygen saturation is $89\%$ on room air. Physical examination reveals distended jugular veins. Pulmonary auscultation shows bilateral crackles at the lung bases and scattered expiratory wheezes. Bilateral $2+$ pitting edema is noted in the lower extremities. Which of the following is the most appropriate initial therapy for this patient?

Intravenous furosemide

Inhaled albuterol

Systemic methylprednisolone

Intravenous piperacillin-tazobactam

Oral azithromycin

Show answer & explanation

Answer: Intravenous furosemide

Answer

Intravenous furosemide

The correct answer provides the standard first-line therapy for acute decompensated heart failure. The patient's orthopnea, jugular venous distention, basilar crackles, and bilateral pitting edema are hallmark signs of volume overload. The wheezing present on exam is known as 'cardiac asthma,' which occurs secondary to peribronchial edema from elevated left heart pressures. Intravenous furosemide quickly initiates diuresis, reducing preload and alleviating pulmonary congestion.

Step-by-Step Solution

Analyze the patient's vital signs and physical examination findings.

The patient is hypoxic and tachypneic. Exam shows jugular venous distention, basilar crackles, wheezing, and lower extremity edema.

Identifying the clinical signs of volume overload is essential for establishing the correct diagnosis.

Differentiate between primarily pulmonary and primarily cardiac causes of dyspnea.

The combination of orthopnea, elevated venous pressure (JVD), and peripheral edema confirms acute decompensated heart failure. The wheezing represents 'cardiac asthma' caused by airway edema, rather than a primary COPD exacerbation.

Patients with a smoking history can have overlapping presentations, but the right-sided heart failure signs clearly point to a cardiac etiology.

Select the most appropriate initial management for the confirmed diagnosis.

Intravenous loop diuretics (e.g., furosemide) are indicated to quickly relieve pulmonary congestion and volume overload.

Diuresis is the mainstay of therapy for acute decompensated heart failure.

Key Concept

Patients with acute decompensated heart failure can present with wheezing ('cardiac asthma') due to peribronchial edema. The presence of fluid overload signs (JVD, crackles, orthopnea, peripheral edema) distinguishes this from a COPD exacerbation and dictates initial treatment with loop diuretics.

Question 2512Question →

A 65-year-old man is brought to the emergency department by emergency medical services after collapsing at home. His wife reports that he had been complaining of palpitations and dizziness for the past several hours. He has a history of heart failure with reduced ejection fraction and atrial fibrillation, for which he takes carvedilol, sacubitril-valsartan, and amiodarone. Three days ago, he was evaluated at an urgent care clinic and prescribed oral ciprofloxacin for a suspected urinary tract infection. On arrival, the patient is minimally responsive. His temperature is $37.1^\circ\text{C}$ ( $98.8^\circ\text{F}$ ), blood pressure is $72/40\text{ mmHg}$ , pulse is $185\text{/min}$ , and respirations are $22\text{/min}$ . Cardiopulmonary examination reveals cold, clammy extremities and faint distal pulses. Continuous cardiac monitoring displays a rapid, irregular, wide-complex tachycardia with cyclic alterations in the QRS axis amplitude, appearing to twist around the isoelectric line. What is the most appropriate initial step in the management of this patient?

Intravenous magnesium sulfate

Unsynchronized electrical cardioversion

Intravenous amiodarone bolus

Synchronized electrical cardioversion

Intravenous furosemide and noninvasive positive-pressure ventilation

Show answer & explanation

Answer: Unsynchronized electrical cardioversion

Answer

Unsynchronized electrical cardioversion

The correct answer is unsynchronized electrical cardioversion (defibrillation). This patient is presenting with hemodynamically unstable Torsades de Pointes (TdP), characterized by a polymorphic ventricular tachycardia with a cyclic shifting of the QRS axis. His instability is evidenced by profound hypotension (

72/40\text{ mmHg}

), altered mental status, and signs of poor peripheral perfusion (cold, clammy extremities). According to Advanced Cardiac Life Support (ACLS) guidelines, any patient with a tachyarrhythmia causing severe hemodynamic instability requires immediate electrical therapy. Because TdP has multiple rapidly varying QRS morphologies, a standard defibrillator cannot accurately track the R waves to synchronize the shock. Therefore, an unsynchronized high-energy shock (defibrillation) is the definitive and life-saving initial step.

Step-by-Step Solution

Identify the patient's hemodynamic status based on vital signs and physical examination.

The patient is hemodynamically unstable, evidenced by profound hypotension (

72/40\text{ mmHg}

), altered mental status (minimally responsive), and poor perfusion (cold, clammy extremities).

Hemodynamic stability dictates whether medical (pharmacologic) or electrical therapy is the primary intervention for tachyarrhythmias.

Interpret the continuous cardiac monitoring description.

The rhythm is Torsades de Pointes (TdP), a specific form of polymorphic ventricular tachycardia characterized by a continuously shifting QRS axis that twists around the isoelectric line.

Accurate rhythm identification is necessary to select the correct specific treatment algorithm.

Determine the underlying etiology of the arrhythmia.

The patient is taking amiodarone (which prolongs the QT interval) and was recently started on ciprofloxacin (which also prolongs the QT interval). This dangerous drug-drug interaction precipitated acquired Long QT Syndrome, leading to TdP.

Understanding the etiology prevents the administration of contraindicated medications (like further QT-prolonging agents).

Select the most appropriate initial step in management according to ACLS guidelines.

Unsynchronized electrical cardioversion (defibrillation).

For hemodynamically unstable TdP, immediate defibrillation is required because the polymorphic nature of the QRS complexes prevents reliable synchronization by the defibrillator.

Key Concept

Management of hemodynamically unstable polymorphic ventricular tachycardia (Torsades de Pointes)

Question 2513Question →

A 48-year-old man with a history of alcohol-associated cirrhosis is brought to the emergency department after vomiting a large amount of bright red blood. On arrival, he is lethargic but actively protecting his airway. His blood pressure is 85/50 mm Hg, and his pulse is 120/min. Physical examination reveals scleral icterus, spider angiomas, and a distended abdomen with a positive fluid wave. Arrange the following interventions in the most appropriate chronological sequence for the management of this patient's acute presentation.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct sequence is: 1) Volume resuscitation, 2) Octreotide and antibiotics, 3) EGD, 4) TIPS.

The correct chronological order follows the standard protocol for life-threatening gastrointestinal hemorrhage. Initial management always prioritizes restoring intravascular volume and reversing shock via large-bore intravenous access and fluids. Second, targeted pharmacologic therapy must be initiated; octreotide reduces splanchnic blood flow, and prophylactic antibiotics prevent life-threatening infections in cirrhotic patients. Third, once the patient is hemodynamically stable, an urgent EGD is performed to definitively control the bleeding via variceal ligation. Finally, TIPS is kept in reserve strictly as a rescue therapy for uncontrolled or recurrent bleeding despite medical and endoscopic interventions.

Step-by-Step Solution

Assess airway and hemodynamics.

The patient is hypotensive and tachycardic, requiring immediate circulation support.

The foundational principle of emergency management is addressing Airway, Breathing, and Circulation (ABCs) before definitive therapy.

Initiate pharmacologic management for suspected variceal hemorrhage.

Octreotide and prophylactic antibiotics are administered.

Octreotide decreases portal venous inflow, while antibiotics decrease the risk of mortality and rebleeding from infections like spontaneous bacterial peritonitis.

Proceed with endoscopic evaluation.

An EGD is performed to identify and ligate bleeding varices.

Endoscopy provides definitive mechanical control of the bleeding, but requires prior hemodynamic stabilization for safety.

Plan for rescue interventions if necessary.

TIPS is considered only if other measures fail.

TIPS carries a high risk of worsening hepatic encephalopathy and is reserved for refractory bleeding cases.

Key Concept

The management of acute variceal hemorrhage follows a strict stepwise algorithm: hemodynamic stabilization (IV fluids), medical optimization (octreotide and antibiotics), endoscopic therapy (band ligation), and finally rescue therapy (TIPS).

Question 2514Question →

A 72-year-old man is evaluated in the intensive care unit for progressive lethargy and worsening shortness of breath over the past 12 hours. The patient was admitted 5 days ago for an acute exacerbation of heart failure. His medical history is significant for ischemic cardiomyopathy with a left ventricular ejection fraction of $25\%$ and severe chronic obstructive pulmonary disease (COPD) with a baseline $\text{FEV}_1$ of $35\%$ of predicted. Since admission, he has been treated with a continuous intravenous furosemide infusion, resulting in a net negative fluid balance of 8 liters and resolution of his peripheral edema. Vital signs currently show a temperature of $37.0^\circ\text{C}$ ( $98.6^\circ\text{F}$ ), blood pressure of $100/60\text{ mm Hg}$ , heart rate of $105/\text{min}$ , and respiratory rate of $10/\text{min}$ . Oxygen saturation is $89\%$ on a $3\text{ L/min}$ nasal cannula. Physical examination reveals a somnolent but arousable patient. The jugular venous pressure is estimated at $4\text{ cm H}_2\text{O}$ . Pulmonary examination shows diminished breath sounds bilaterally with prolonged expiration and scattered end-expiratory wheezes, but no crackles are heard. Cardiovascular examination reveals distant heart sounds with a regular rate and rhythm.

Laboratory studies show the following:

Test	Result
Sodium	$135\text{ mEq/L}$
Potassium	$2.9\text{ mEq/L}$
Chloride	$85\text{ mEq/L}$
Bicarbonate	$40\text{ mEq/L}$
Blood urea nitrogen	$55\text{ mg/dL}$
Creatinine	$1.8\text{ mg/dL}$ (baseline $1.1\text{ mg/dL}$ )

Arterial blood gas analysis on

3\text{ L/min}

nasal cannula:

Parameter	Result
pH	$7.52$
$\text{pCO}_2$	$50\text{ mm Hg}$
$\text{pO}_2$	$58\text{ mm Hg}$

Which of the following is the most appropriate next step in the management of this patient's respiratory status?

Administer intravenous acetazolamide and potassium chloride

Initiate noninvasive positive-pressure ventilation

Administer intravenous methylprednisolone and nebulized ipratropium-albuterol

Administer a rapid bolus of 0.9% normal saline

Administer intravenous levofloxacin and send sputum for culture

Show answer & explanation

Answer: Administer intravenous acetazolamide and potassium chloride

Answer

Administer intravenous acetazolamide and potassium chloride

This patient presents with a severe metabolic alkalosis (pH

7.52

, bicarbonate

40\text{ mEq/L}

) secondary to aggressive loop diuretic therapy, known as contraction alkalosis. The elevated

\text{pCO}_2

(

50\text{ mm Hg}

) is the expected physiological respiratory compensation for metabolic alkalosis (

\text{Expected pCO}_2 = 40 + 0.7 \times (\Delta\text{HCO}_3^-) = 40 + 0.7 \times 16 \approx 51\text{ mm Hg}

). The patient's hypoventilation (respiratory rate

10/\text{min}

) is a compensatory mechanism to retain

\text{CO}_2

, which in turn causes secondary hypoxemia and lethargy. To improve his respiratory status, the underlying alkalosis must be corrected. Isotonic saline is the standard treatment for saline-responsive contraction alkalosis; however, it is strictly contraindicated in this patient with a left ventricular ejection fraction of

25\%

who recently required

8\text{ L}

of diuresis, as it would precipitate flash pulmonary edema. Acetazolamide, a carbonic anhydrase inhibitor, promotes renal bicarbonate excretion to safely reverse the alkalosis, which will normalize his

\text{pH}

, restore normal respiratory drive, and resolve the hypoxemia. Concurrent potassium repletion is required because both the prior furosemide use and the new acetazolamide promote urinary potassium loss.

Step-by-Step Solution

Analyze the arterial blood gas values to identify the primary acid-base disorder.

The pH of 7.52 indicates alkalemia, and the elevated bicarbonate of 40 mEq/L confirms a primary metabolic alkalosis.

Establishing the primary disorder is essential to interpret the altered pCO2 and clinical presentation accurately.

Calculate the expected respiratory compensation for the metabolic alkalosis.

Expected pCO2 = 40 + 0.7 * (40 - 24) = 51.2 mm Hg. The patient's pCO2 of 50 mm Hg represents appropriate compensation.

This differentiates between an expected compensatory response and a superimposed primary respiratory disorder, such as an acute COPD exacerbation.

Correlate the acid-base derangement with the patient's clinical history and current symptoms.

Aggressive loop diuresis caused contraction alkalosis and severe hypokalemia. The patient is hypoventilating (RR 10/min) to retain CO2 as compensation, which leads to secondary hypoxemia and lethargy.

Understanding the physiologic mechanism allows for targeted, definitive therapy rather than symptomatic masking.

Select the most appropriate intervention that corrects the alkalosis without harming the patient.

Acetazolamide with potassium repletion is chosen. Isotonic saline is avoided.

While normal saline typically treats contraction alkalosis, it is absolutely contraindicated in this patient due to his recent severe acute decompensated heart failure and very low ejection fraction.

Key Concept

Patients with severe metabolic alkalosis compensate via alveolar hypoventilation, which can cause significant hypoxemia. In patients with concurrent severe heart failure where normal saline is contraindicated, acetazolamide is the treatment of choice to induce bicarbonate diuresis and reverse the alkalosis.

Estimated Time:2m 30s

Question 2515Question →

A $72$ -year-old man presents to the emergency department complaining of severe lightheadedness, generalized weakness, and near-syncope that started one hour ago. His blood pressure is $78/50$ mmHg, heart rate is $32$ /min, and respiratory rate is $16$ /min. Oxygen saturation is $96\%$ on room air. An electrocardiogram (ECG) reveals sinus bradycardia with a heart rate of $32$ /min. The patient remains persistently hypotensive and symptomatic despite initial intravenous fluid resuscitation. Arrange the following interventions in the most appropriate chronological sequence for the management of this patient, from the most immediate initial step to definitive long-term therapy.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct chronological sequence for managing symptomatic, unstable bradycardia escalates from immediate, easily accessible pharmacological therapy to definitive long-term device implantation: Atropine -> Transcutaneous Pacing -> Temporary Transvenous Pacemaker -> Permanent Pacemaker.

The correct sequence mirrors the standard Advanced Cardiac Life Support (ACLS) algorithm for symptomatic bradycardia. Care escalates based on the invasiveness and time required to implement the therapy. Atropine is given instantly via an existing IV. Transcutaneous pacing pads can be applied in seconds if atropine fails. Transvenous pacing requires a sterile procedure and central line, acting as a stable bridge. A permanent pacemaker requires a formal surgical procedure and serves as the definitive treatment.

Step-by-Step Solution

Administer intravenous atropine.

Provides rapid, first-line pharmacological treatment to increase the heart rate.

It is the most immediately available treatment for symptomatic bradycardia and can rapidly reverse vagally mediated bradycardia.

Initiate transcutaneous pacing.

Electrically stimulates the heart externally through pacing pads on the chest.

Required when pharmacological interventions like atropine fail to improve the patient's hemodynamic status, serving as a rapid non-invasive bridge.

Place a temporary transvenous pacemaker.

Provides stable, internal pacing via a wire inserted into the right ventricle.

Transcutaneous pacing is painful and unreliable for extended use; transvenous pacing is needed as a secure bridge until a permanent solution is available.

Implant a permanent pacemaker.

Provides long-term, definitive electrical stimulation to the heart.

Indicated when the underlying cause of the symptomatic bradycardia is deemed irreversible and persistent.

Key Concept

The acute management of symptomatic bradycardia follows a stepwise escalation from rapid pharmacological intervention (atropine) to non-invasive electrical therapy (transcutaneous pacing), followed by temporary invasive pacing (transvenous pacemaker), and finally definitive long-term therapy (permanent pacemaker).

Estimated Time:1m 0s

Question 2516Question →

A 63-year-old woman is brought to the emergency department from an inpatient rehabilitation facility due to sudden-onset severe shortness of breath and lightheadedness. Two weeks ago, she underwent an uncomplicated right total hip arthroplasty. Her medical history includes chronic obstructive pulmonary disease, essential hypertension, and hypothyroidism. Upon arrival, her blood pressure is 76/45 mmHg, heart rate is 126/min, respiratory rate is 28/min, and oxygen saturation is 84% on room air. She appears diaphoretic, agitated, and is using accessory muscles of respiration. Physical examination reveals jugular venous distention up to the angle of the mandible while seated upright. Auscultation of the lungs demonstrates scattered expiratory wheezes. Cardiac examination shows a prominent right ventricular heave, a loud P2, and a grade 2/6 holosystolic murmur at the left lower sternal border. The right thigh and calf are moderately swollen and tender. An electrocardiogram shows sinus tachycardia, new-onset complete right bundle branch block, and T-wave inversions in leads V1 through V4. Laboratory studies show a serum troponin I of $0.8$ ng/mL (normal $<0.04$ ), thyroid-stimulating hormone of $1.2$ $\mu U/mL$ (normal $0.4-4.0$ ), and free T4 of $0.6$ ng/dL (normal $0.9-1.7$ ). Which of the following is the most appropriate next step in the management of this patient?

Bedside transthoracic echocardiography

Computed tomography angiography of the chest

Intravenous furosemide

Intravenous piperacillin-tazobactam and vancomycin

Intravenous levothyroxine and hydrocortisone

Show answer & explanation

Answer: Bedside transthoracic echocardiography

Answer

Bedside transthoracic echocardiography

The correct action is bedside transthoracic echocardiography. This patient's presentation is highly suspicious for a massive acute pulmonary embolism (PE) causing right ventricular (RV) failure and obstructive shock. Clues include recent major surgery, sudden dyspnea, unilateral leg swelling, and signs of acute RV strain (elevated jugular venous pressure, RV heave, right bundle branch block, and right-sided ischemic ECG changes). In a hemodynamically unstable patient (blood pressure 76/45 mmHg) with suspected PE, standard diagnostic imaging with computed tomography (CT) pulmonary angiography is contraindicated because transferring the patient poses an unacceptable risk of hemodynamic collapse. Instead, bedside transthoracic echocardiography is the most appropriate next step. If the echocardiogram shows evidence of acute severe RV dysfunction, it provides sufficient clinical justification to administer systemic thrombolytic therapy (or pursue catheter-directed therapies) without a confirmatory CT scan.

Step-by-Step Solution

Identify the primary pathophysiological state based on vitals and examination.

The patient is in obstructive shock (hypotension, tachycardia) complicated by acute right heart failure (jugular venous distention, right ventricular heave, loud P2, complete right bundle branch block).

Sudden dyspnea, hypoxia, and shock in a patient with a recent orthopedic surgery and unilateral leg swelling strongly suggests massive pulmonary embolism.

Determine the diagnostic constraints imposed by the patient's hemodynamic status.

The patient has a blood pressure of 76/45 mmHg, making her severely hemodynamically unstable.

Unstable patients cannot be safely transported to the radiology department for advanced imaging such as computed tomography.

Select the safest, most immediate diagnostic modality that alters management.

Bedside transthoracic echocardiography.

Echocardiography can rapidly visualize right ventricular enlargement and hypokinesis (McConnell's sign), justifying the immediate administration of life-saving thrombolytic therapy in a patient too unstable for a CT scan.

Key Concept

Management of suspected massive pulmonary embolism in a hemodynamically unstable patient requires bedside echocardiography to confirm right ventricular strain before administering thrombolytics.

Estimated Time:1m 30s

Question 2517Question →

A $42$ -year-old woman is admitted to the intensive care unit with severe community-acquired pneumonia. Twelve hours after admission, she requires endotracheal intubation and mechanical ventilation due to worsening hypoxemic respiratory failure. Her current medications include intravenous ceftriaxone and azithromycin.

Vital signs are temperature $38.9^\circ\text{C}$ ( $102^\circ\text{F}$ ), blood pressure $105/65\text{ mm Hg}$ , and heart rate $118/\text{min}$ .

Current mechanical ventilator settings (Volume Assist-Control mode):

Parameter	Value
Tidal volume	$380\text{ mL}$ ( $6\text{ mL/kg}$ of predicted body weight)
Respiratory rate	$24/\text{min}$
Fraction of inspired oxygen ( $FiO_2$ )	$0.90$ ( $90\%$ )
Positive end-expiratory pressure (PEEP)	$8\text{ cm H}_2\text{O}$

Arterial blood gas analysis on these settings reveals:

Parameter	Value
pH	$7.31$
$PaCO_2$	$48\text{ mm Hg}$
$PaO_2$	$55\text{ mm Hg}$
Bicarbonate	$24\text{ mEq/L}$

A chest radiograph demonstrates diffuse, bilateral alveolar opacities. A bedside echocardiogram reveals normal left and right ventricular function with an estimated ejection fraction of $65\%$ .

Which of the following interventions are appropriate for the ongoing management of this patient? (Select all that apply)

Select all that apply

Increase the positive end-expiratory pressure (PEEP)

Initiate prone positioning

Administer intravenous sodium bicarbonate to correct the acid-base derangement

Administer intravenous furosemide to manage the bilateral alveolar opacities

Escalate current antimicrobial therapy to piperacillin-tazobactam and vancomycin

Show answer & explanation

Answer: Increase the positive end-expiratory pressure (PEEP); Initiate prone positioning

Answer

The appropriate interventions are to increase the positive end-expiratory pressure (PEEP) and to initiate prone positioning.

This patient meets the Berlin criteria for severe acute respiratory distress syndrome (ARDS): acute onset, bilateral diffuse alveolar opacities, no evidence of left heart failure (normal echocardiogram), and a severe oxygenation defect with a

PaO_2/FiO_2

ratio of approximately

61\text{ mm Hg}

(

55 \div 0.90

). The fundamental tenets of mechanical ventilation in ARDS include low tidal volume ventilation to prevent volutrauma (already appropriately set at

6\text{ mL/kg}

) and adequate positive end-expiratory pressure (PEEP) to recruit collapsed alveoli. According to ARDS protocols, a PEEP of

8\text{ cm H}_2\text{O}

is insufficient for an

FiO_2

requirement of

90\%

; therefore, increasing the PEEP is a critical next step. Furthermore, prone positioning is strongly indicated for patients with moderate-to-severe ARDS (

PaO_2/FiO_2 < 150\text{ mm Hg}

). Proning improves ventilation-perfusion (

V/Q

) matching by relieving the weight of the heart and anterior lungs on the dependent posterior lung regions, thereby recruiting posterior alveoli and reducing mortality.

Step-by-Step Solution

Calculate the PaO2/FiO2 ratio to determine the severity of hypoxemia.

The ratio is 55 / 0.90 = 61.1 mm Hg.

Categorizing the degree of hypoxemia (ratio < 100 indicates severe ARDS) dictates subsequent management steps like proning.

Evaluate the current ventilator settings against ARDS management guidelines.

Tidal volume is appropriately low (6 mL/kg). However, a PEEP of 8 cm H2O is inadequate for an FiO2 of 90%.

ARDSNet protocols require high PEEP levels when high fractions of inspired oxygen are needed to prevent alveolar collapse.

Assess the indications for prone positioning.

The patient meets criteria for proning.

Prone positioning is strongly recommended in ARDS patients who remain severely hypoxemic (PaO2/FiO2 < 150 mm Hg) despite optimized ventilator settings.

Rule out concurrent conditions mimicking ARDS or requiring alternative treatments.

The normal echocardiogram rules out cardiogenic edema, and the ABG shows expected respiratory acidosis, not metabolic acidosis.

Ensures targeted therapies (like furosemide or bicarbonate) are not inappropriately administered.

Key Concept

Management of severe acute respiratory distress syndrome (ARDS) centers on treating the underlying cause, employing lung-protective mechanical ventilation (low tidal volumes, adequate PEEP), and initiating prone positioning for severe hypoxemia (PaO2/FiO2 < 150 mm Hg).

Question 2518Question →

A 69-year-old male is transported to the acute care bay by paramedics following an abrupt onset of severe respiratory distress and profound diaphoresis that commenced one hour prior to arrival. His past medical history includes long-standing essential hypertension, type 2 diabetes mellitus, and a 40-pack-year smoking history. Upon arrival, he is extremely agitated, using accessory muscles of respiration, and cannot speak in full sentences.

Vital signs are temperature $36.8^\circ$ C ( $98.2^\circ$ F), blood pressure $235/125$ mm Hg, pulse $122$ /min, and respirations $38$ /min. Oxygen saturation is $82\%$ on room air.

Physical examination reveals neck veins distended to the angle of the jaw while the patient is sitting upright. Lung auscultation demonstrates diffuse, high-pitched expiratory wheezes bilaterally with a significantly prolonged expiratory phase; no crackles are appreciated. Cardiac auscultation reveals a regular, rapid rhythm with a loud S2, though other heart sounds are obscured by the respiratory noise.

Arterial blood gas analysis on room air shows:
pH: $7.18$
PaCO $_2$ : $65$ mm Hg
PaO $_2$ : $48$ mm Hg
HCO $_3^-$ : $24$ mEq/L

An electrocardiogram reveals sinus tachycardia with voltage criteria for left ventricular hypertrophy and secondary ST-segment repolarization abnormalities.

Which of the following is the most appropriate initial management step for this patient?

Administration of nebulized albuterol, intravenous magnesium sulfate, and systemic corticosteroids

Administration of intravenous labetalol and a bolus of intravenous furosemide

Initiation of noninvasive positive pressure ventilation and an intravenous nitroglycerin infusion

Immediate endotracheal intubation and empiric intravenous piperacillin-tazobactam

Intravenous administration of sodium bicarbonate and continuous nebulized ipratropium

Show answer & explanation

Answer: Initiation of noninvasive positive pressure ventilation and an intravenous nitroglycerin infusion

Answer

The most appropriate initial management step is the initiation of noninvasive positive pressure ventilation (NPPV) and an intravenous nitroglycerin infusion.

The correct response addresses both the respiratory failure and the underlying hemodynamic derangement. The patient is suffering from Sympathetic Crashing Acute Pulmonary Edema (SCAPE). The intense sympathetic surge causes severe vasoconstriction, massive afterload, and subsequent rapid shifting of fluid into the pulmonary interstitium. This interstitial fluid compresses the small airways, leading to wheezing ('cardiac asthma'). Noninvasive positive pressure ventilation (NPPV) provides immediate respiratory support by stenting open the airways, decreasing the work of breathing, and reducing preload and afterload. Intravenous nitroglycerin rapidly dilates the venous and arterial beds, effectively reducing the extreme afterload and breaking the cycle of sympathetic overactivation.

Step-by-Step Solution

Analyze the clinical presentation.

The patient exhibits abrupt, severe respiratory distress, marked hypertension (

235/125

mm Hg), and signs of right-sided fluid overload (JVD) with wheezing.

Identifying the constellation of extreme hypertension and flash pulmonary edema points toward Sympathetic Crashing Acute Pulmonary Edema (SCAPE).

Differentiate the cause of the wheezing.

The wheezing represents 'cardiac asthma' caused by peribronchial interstitial edema, not primary bronchospasm.

Recognizing that left-sided heart failure can present with wheezing without crackles is critical to avoid mistakenly treating the patient for COPD.

Interpret the arterial blood gas.

The ABG shows an acute, uncompensated respiratory acidosis (pH

7.18

, PaCO

_2

65

mm Hg).

The severe work of breathing caused by noncompliant, fluid-filled lungs has led to acute ventilatory failure, necessitating immediate respiratory support.

Select the optimal therapeutic interventions.

NPPV (such as CPAP or BiPAP) and rapid afterload reduction with high-dose intravenous nitroglycerin.

NPPV rapidly decreases the work of breathing and improves oxygenation, while nitroglycerin drastically reduces the extreme afterload, breaking the vicious cycle of sympathetic overactivation and enabling forward flow from the left ventricle.

Key Concept

Sympathetic Crashing Acute Pulmonary Edema (SCAPE) is a severe form of acute decompensated heart failure characterized by extreme hypertension and rapid interstitial fluid shifts. It requires immediate management with noninvasive positive pressure ventilation (NPPV) and rapid afterload reduction (e.g., intravenous nitroglycerin).

Estimated Time:2m 0s

Question 2519Question →

A 55-year-old man with a long-standing history of chronic bronchitis presents to the emergency department reporting a 2-day history of progressively worsening dyspnea. He states that his daily cough has become more frequent and is now producing thick, yellow-green phlegm, which is a change from his baseline clear secretions. Vital signs show a temperature of $37.6^\circ\text{C}$ ( $99.7^\circ\text{F}$ ), heart rate of $112\text{ /min}$ , respiratory rate of $22\text{ /min}$ , and oxygen saturation of $89\%$ on ambient air. Physical examination is notable for diffuse bilateral expiratory wheezing and a prolonged expiratory phase. Cardiac auscultation reveals a regular rhythm with no murmurs or gallops. There is no jugular venous distention, and peripheral edema is absent. Chest radiography demonstrates lung hyperinflation without focal consolidations or pleural effusions.

Which of the following pharmacologic therapies are indicated as part of this patient's immediate acute management? (Select all that apply)

Select all that apply

Nebulized ipratropium bromide

Oral prednisone

Oral azithromycin

Intravenous bumetanide

Intravenous piperacillin-tazobactam

Show answer & explanation

Answer: Nebulized ipratropium bromide; Oral prednisone; Oral azithromycin

Answer

The correct indicated therapies are nebulized ipratropium bromide, oral prednisone, and oral azithromycin.

This patient is experiencing an acute exacerbation of chronic obstructive pulmonary disease (AECOPD), defined by an acute change in baseline dyspnea, cough, or sputum production. The standard initial pharmacologic management for AECOPD includes short-acting bronchodilators (e.g., ipratropium or albuterol) to relieve acute bronchospasm and systemic glucocorticoids (e.g., oral prednisone) to decrease airway inflammation and improve recovery time. Furthermore, antibiotics (e.g., azithromycin) are indicated because the patient exhibits all three cardinal symptoms of an exacerbation: increased dyspnea, increased sputum volume, and increased sputum purulence (yellow-green phlegm). Oral administration of steroids and antibiotics is preferred and highly effective in hemodynamically stable patients.

Step-by-Step Solution

Identify the patient's clinical syndrome.

The patient is experiencing an acute exacerbation of COPD (AECOPD), evidenced by worsening dyspnea, increased sputum volume, and increased sputum purulence.

Recognizing the triad of cardinal symptoms guides the indication for specific pharmacological therapies.

Determine the required baseline respiratory interventions.

Short-acting bronchodilators (e.g., ipratropium) and systemic corticosteroids (e.g., prednisone) should be administered.

These medications directly address the acute bronchospasm and underlying airway inflammation that characterize the exacerbation.

Evaluate the specific criteria for antibiotic therapy.

Because all three cardinal symptoms are present, narrow-spectrum targeted antibiotics (such as azithromycin) are indicated.

Bacterial infection is a common trigger for exacerbations presenting with purulent sputum, and antibiotics have been shown to improve outcomes in these specific patients.

Rule out alternative diagnoses and unnecessarily aggressive therapies.

Heart failure therapies and broad-spectrum intravenous antibiotics are ruled out.

The absence of volume overload signs (no JVD, no edema, no crackles) makes loop diuretics inappropriate, and the lack of specific risk factors makes antipseudomonal coverage unnecessary.

Key Concept

The standard initial pharmacologic management for an acute exacerbation of COPD includes short-acting bronchodilators, systemic glucocorticoids, and targeted narrow-spectrum antibiotics if cardinal symptoms (increased dyspnea, sputum volume, and sputum purulence) are present.

Estimated Time:1m 0s

Question 2520Question →

A 54-year-old man collapses in an airport terminal and is unresponsive. Bystanders immediately initiate cardiopulmonary resuscitation (CPR). Emergency medical services (EMS) arrive shortly after and confirm the patient is pulseless and apneic. The cardiac monitor displays coarse ventricular fibrillation. Arrange the following critical interventions in the correct chronological sequence for the management of this patient according to standard cardiac arrest algorithms.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct sequence is to deliver the initial shock, immediately resume CPR while obtaining access, deliver a second shock followed by epinephrine, and finally deliver a third shock followed by amiodarone.

The Advanced Cardiac Life Support (ACLS) algorithm for pulseless ventricular tachycardia (pVT) and ventricular fibrillation (VF) dictates a precise sequence to maximize survival. When VF is identified, the immediate step is to deliver an unsynchronized defibrillation shock. Following the shock, chest compressions must be resumed immediately for 2 minutes without checking a pulse, during which time intravenous or intraosseous access is established. After 2 minutes, the rhythm is checked; if VF persists, a second shock is given. CPR is again resumed immediately, and the first dose of epinephrine (1 mg) is administered. After another 2 minutes, if VF is still present, a third shock is delivered. During the subsequent CPR cycle, an antiarrhythmic medication, typically amiodarone (300 mg bolus) or lidocaine, is administered to treat the refractory arrhythmia. This sequence precisely balances the need for electrical therapy with the critical requirement of maintaining coronary perfusion pressures through uninterrupted compressions.

Step-by-Step Solution

Identify the shockable rhythm and perform the primary intervention.

The initial unsynchronized defibrillation shock is delivered.

Ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) require immediate defibrillation as the first definitive treatment to restore a perfusing rhythm.

Maintain systemic perfusion and prepare for medication administration.

High-quality CPR is resumed for 2 minutes without pausing for a pulse check, and intravenous/intraosseous access is established.

Defibrillation temporarily stuns the heart; immediate CPR provides necessary coronary and cerebral perfusion while the myocardium recovers. Access is needed for subsequent pharmacotherapy.

Address persistent ventricular fibrillation with a second shock and the first-line vasopressor.

A second defibrillation shock is delivered, followed by continued CPR and administration of intravenous epinephrine 1 mg.

If VF persists after the first shock and CPR cycle, a second shock is indicated. Epinephrine is added at this stage to increase aortic diastolic pressure and enhance coronary perfusion during CPR.

Address refractory ventricular fibrillation with a third shock and an antiarrhythmic agent.

A third defibrillation shock is delivered, followed by continued CPR and administration of intravenous amiodarone 300 mg.

For VF that is refractory to CPR, defibrillation, and a vasopressor, an antiarrhythmic drug (amiodarone or lidocaine) is administered to increase the likelihood of successful defibrillation on subsequent attempts.

Key Concept

Advanced Cardiac Life Support (ACLS) Pulseless Ventricular Tachycardia and Ventricular Fibrillation Algorithm

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Step-by-Step Solution

Key Concept