A 72-year-old man is brought to the emergency department due to severe, worsening shortnes… — USMLE Step 2 CK

A 72-year-old man is brought to the emergency department due to severe, worsening shortness of breath for the past 24 hours. He reports waking up in the middle of the night gasping for air and can only sleep propped up on three pillows. His medical history includes a 40-pack-year smoking history, type 2 diabetes mellitus, and hypertension. He was evaluated at an urgent care clinic three days ago for a mild cough; a sputum culture from that visit has finalized, growing normal respiratory flora with *Streptococcus pneumoniae* that is susceptible to penicillin and amoxicillin.

In the emergency department, his temperature is 37.1°C (98.8°F), blood pressure is 165/95 mmHg, heart rate is 112/min, and respiratory rate is 26/min. Pulse oximetry shows 88% on room air. Physical examination reveals elevated jugular venous pressure, bilateral basilar lung crackles, and diffuse expiratory wheezes. Cardiac auscultation demonstrates a normal $S_1$ and $S_2$ with an $S_3$ gallop.

Laboratory and diagnostic evaluation shows:

Test	Result	Reference Range
Leukocyte count	8,500/mm³	4,500 - 11,000/mm³
TSH	0.2 µU/mL	0.4 - 4.0 µU/mL
Free T4	0.5 ng/dL	0.8 - 1.8 ng/dL

Arterial blood gas on room air:

Parameter	Result	Reference Range
pH	7.28	7.35 - 7.45
PaCO2	60 mmHg	35 - 45 mmHg
HCO3-	27 mEq/L	22 - 28 mEq/L
PaO2	55 mmHg	75 - 105 mmHg

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

Intravenous furosemideCevap
B
Inhaled albuterol and systemic corticosteroids
C
Intravenous piperacillin-tazobactam
D
Administer intravenous sodium bicarbonate using Winter's formula to calculate compensation
E
Initiate oral levothyroxine for primary hypothyroidism

Cevap

Intravenous furosemide is the most appropriate next step in management.

The correct answer is intravenous furosemide because the patient's clinical picture is highly characteristic of acute decompensated heart failure (ADHF). Key indicators include orthopnea, paroxysmal nocturnal dyspnea, elevated jugular venous pressure, an

S_3

gallop, and bilateral crackles. Although he has a history of smoking and presents with wheezing, this represents 'cardiac asthma'—bronchospasm triggered by peribronchial edema—rather than a primary COPD exacerbation. The immediate priority in a patient with ADHF and signs of volume overload is to reduce left ventricular preload and pulmonary congestion, which is rapidly achieved with intravenous loop diuretics.

Adım Adım Çözüm

Analyze the patient's primary symptoms and physical exam findings.

The patient has severe dyspnea, orthopnea, an S3 gallop, elevated jugular venous pressure, crackles, and wheezing.

Identifying these classic signs helps differentiate acute decompensated heart failure from primary pulmonary pathologies like COPD exacerbation.

Evaluate the arterial blood gas and laboratory findings.

The ABG shows acute uncompensated respiratory acidosis (pH 7.28, PaCO2 60 mmHg). The thyroid panel shows low TSH and low free T4 (euthyroid sick syndrome or central hypothyroidism), and WBC is normal.

This confirms respiratory failure due to fluid overload (pulmonary edema) and rules out a primary infectious or metabolic etiology as the immediate life-threatening issue.

Determine the optimal immediate pharmacological intervention.

Administering an intravenous loop diuretic (furosemide).

Loop diuretics provide rapid symptom relief in acute decompensated heart failure by reducing intravascular volume and decreasing left ventricular preload.

Anahtar Kavram

Management of acute decompensated heart failure (ADHF)

Tahmini Süre:1m 30s

Soru

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Konular

Bu konudan daha fazla soru