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Difficulty: Very hardPulmonary and Critical Care

A 75-year-old man is admitted to the progressive care unit with worsening shortness of breath, increased sputum purulence, and subjective fever over the past 33 days. His medical history includes severe chronic obstructive pulmonary disease (FEV 1_1 35%35\% of predicted) and ischemic cardiomyopathy (left ventricular ejection fraction 30%30\%).

Vital signs are temperature 38.2∘C38.2^\circ\text{C} (100.8∘F100.8^\circ\text{F}), blood pressure 135/85135/85 mm Hg, pulse 112112/min, and respirations 2626/min. Pulse oximetry shows 86%86\% on room air. Physical examination reveals a barrel-shaped chest, prolonged expiratory phase with diffuse wheezing, and coarse rhonchi at the right lung base. Jugular venous pressure is 77 cm H 2_2 O. There is no lower extremity edema. A chest radiograph demonstrates hyperinflated lungs, flattened diaphragms, and a new patchy right lower lobe infiltrate.

Arterial blood gas analysis on room air reveals:

ParameterValueReference Range
pH7.287.287.35−7.457.35-7.45
PaCO2_26565 mm Hg35−4535-45 mm Hg
PaO2_25252 mm Hg75−10575-105 mm Hg
HCO3−_3^-2929 mEq/L22−2822-28 mEq/L

Sputum Gram stain reveals numerous polymorphonuclear leukocytes and Gram-negative diplococci. The patient is started on noninvasive positive pressure ventilation and intravenous methylprednisolone.

Which of the following additional therapies are indicated for this patient? (Select all that apply)

  1. Administration of intravenous levofloxacinAnswer
  2. Administration of inhaled albuterol and ipratropium bromideAnswer
  3. C
    Administration of intravenous furosemide
  4. D
    Administration of intravenous sodium bicarbonate
  5. E
    Administration of intravenous vancomycin and cefepime

Answer

The indicated therapies are the administration of intravenous levofloxacin (or a similar targeted antibiotic) and inhaled albuterol and ipratropium bromide.
The patient is experiencing an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) triggered by a community-acquired pneumonia. The sputum Gram stain reveals Gram-negative diplococci, pointing toward Moraxella catarrhalis, a frequent culprit in AECOPD. He requires targeted antibiotic therapy (such as intravenous levofloxacin or a third-generation cephalosporin plus a macrolide) and inhaled short-acting bronchodilators (albuterol and ipratropium) to reduce airway resistance. He has already been appropriately started on noninvasive positive pressure ventilation and systemic corticosteroids to address his acute-on-chronic hypercapnic respiratory failure.

Step-by-Step Solution

1
Analyze the clinical presentation and physical examination.
The presence of fever, purulent sputum, right lower lobe infiltrate, and normal JVP without edema confirms an infectious exacerbation of COPD (community-acquired pneumonia) rather than acute decompensated heart failure.
To determine the primary etiology of the patient's acute respiratory failure.
2
Interpret the arterial blood gas (ABG) values.
The ABG shows acidemia (pH 7.287.28) with hypercapnia (PaCO 2_2 6565 mm Hg) and elevated bicarbonate (2929 mEq/L), indicating an acute-on-chronic respiratory acidosis without an underlying primary metabolic acidosis.
To assess ventilation status and identify any concurrent metabolic derangements.
3
Evaluate the sputum Gram stain results.
The presence of Gram-negative diplococci strongly suggests Moraxella catarrhalis, a common respiratory pathogen in COPD exacerbations.
To guide appropriate targeted antimicrobial therapy.
4
Select the appropriate targeted interventions.
Intravenous levofloxacin provides excellent coverage for M. catarrhalis. Inhaled albuterol and ipratropium will alleviate acute bronchospasm.
To address both the infectious trigger and the resulting obstructive airway pathophysiology using tailored, evidence-based therapies.

Key Concept

Management of an acute exacerbation of COPD complicated by community-acquired pneumonia involves targeted antimicrobial therapy based on likely pathogens (e.g., M. catarrhalis), short-acting inhaled bronchodilators, systemic corticosteroids, and noninvasive ventilation. Careful interpretation of acid-base status and hemodynamics prevents harmful interventions like unnecessary diuresis or bicarbonate administration.
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Topics

Pulmonary and Critical Care

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