A 70-year-old woman is currently hospitalized on the general medical ward for a deep vein … — USMLE Step 2 CK

A 70-year-old woman is currently hospitalized on the general medical ward for a deep vein thrombosis of the left lower extremity, which is being treated with a direct oral anticoagulant. On hospital day 3, she reports a sudden increase in shortness of breath, a "tight" chest, and a productive cough with greenish sputum that started yesterday. Her past medical history includes severe emphysema and hypertension. She appears anxious and is utilizing her scalene muscles for respiration. Her temperature is $37.4^\circ\text{C}$ ( $99.3^\circ\text{F}$ ), pulse is $108/\text{min}$ , respirations are $26/\text{min}$ , and blood pressure is $142/88 \text{ mm Hg}$ . Oxygen saturation is $86\%$ on room air. Physical examination is notable for a prolonged expiratory phase and prominent diffuse polyphonic rhonchi. Jugular veins are not distended. A bedside echocardiogram shows a normal left ventricular ejection fraction and normal right ventricular size. An arterial blood gas analysis reveals a pH of $7.27$ , $PaCO_2$ of $65 \text{ mm Hg}$ , $PaO_2$ of $52 \text{ mm Hg}$ , and $HCO_3^-$ of $29 \text{ mEq/L}$ .

Which of the following are the most appropriate immediate steps in the management of this patient's respiratory status? (Select all that apply)

Application of bilevel positive airway pressureAnswer
Administration of systemic methylprednisoloneAnswer
C
Administration of intravenous bumetanide
D
Initiation of intravenous imipenem-cilastatin
E
Intravenous infusion of sodium bicarbonate

Answer

The correct management steps are the application of bilevel positive airway pressure and the administration of systemic methylprednisolone.

The correct management consists of applying noninvasive positive pressure ventilation and administering systemic corticosteroids. The patient is experiencing an acute exacerbation of chronic obstructive pulmonary disease (COPD) complicated by acute-on-chronic hypercapnic respiratory failure, as evidenced by a pH less than

7.30

and an elevated

PaCO_2

. Bilevel positive airway pressure improves gas exchange, decreases the work of breathing, and reduces mortality and intubation rates. Systemic corticosteroids (e.g., methylprednisolone) are indicated to reduce airway inflammation, improve forced expiratory volume in 1 second (

FEV_1

), and shorten recovery time.

Step-by-Step Solution

Analyze the patient's clinical presentation and vital signs.

The patient is experiencing an acute exacerbation of chronic obstructive pulmonary disease (COPD), characterized by increased dyspnea, wheezing, and purulent sputum.

To establish the primary diagnosis driving the respiratory failure.

Interpret the arterial blood gas values.

The ABG reveals a pH of 7.27, PaCO2 of 65 mm Hg, and HCO3 of 29 mEq/L, indicating acute-on-chronic hypercapnic respiratory acidosis.

To determine the severity of respiratory failure and guide ventilatory support.

Evaluate the indications for noninvasive positive pressure ventilation (NIPPV).

The patient has a COPD exacerbation with a pH < 7.30, which is a strong indication for NIPPV (bilevel positive airway pressure) to improve gas exchange and avoid intubation.

To select the appropriate level of respiratory support.

Identify the appropriate pharmacologic management for the exacerbation.

Standard therapy includes systemic corticosteroids (e.g., methylprednisolone) to reduce inflammation, along with bronchodilators and targeted antibiotics (not broad-spectrum carbapenems).

To treat the underlying inflammatory trigger of the exacerbation.

Key Concept

The acute management of a severe COPD exacerbation complicated by hypercapnic respiratory failure requires noninvasive positive pressure ventilation (when pH < 7.30), systemic corticosteroids, bronchodilators, and narrow-spectrum antibiotics if purulent sputum is present.

Estimated Time:1m 30s

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