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Difficulty: MediumPulmonary and Critical Care

A 68-year-old man is evaluated on postoperative day 6 following an elective right inguinal hernia repair. On postoperative day 3, he developed a cough, fever, and right-sided chest pain. A chest radiograph at that time revealed a right lower lobe infiltrate. Sputum cultures grew *Streptococcus pneumoniae* sensitive to ceftriaxone, and he was appropriately started on targeted intravenous ceftriaxone therapy. Today, the patient reports worsening dyspnea and persistent pleuritic chest pain. His temperature has spiked to 38.8∘C38.8^\circ\text{C} (101.8∘F101.8^\circ\text{F}). Blood pressure is 118/76 mmHg, pulse is 112/min, and respirations are 26/min. Pulse oximetry shows 91% on room air. Physical examination reveals decreased breath sounds and dullness to percussion at the right lung base. Jugular venous pressure is 6 cm H 2_2 O, and there is no lower extremity edema.

An arterial blood gas analysis on room air shows:

ParameterValue
pH7.28
pCO2_254 mmHg
pO2_262 mmHg
HCO3−_3^-24 mEq/L

A repeat chest radiograph demonstrates the known right lower lobe infiltrate and a new, moderate-sized, free-flowing right pleural effusion. A diagnostic thoracentesis is performed, yielding cloudy yellow fluid.

Pleural fluid analysis shows:

ParameterValue
pH7.12
Glucose32 mg/dL
Lactate dehydrogenase1,250 U/L
Gram stainGram-positive diplococci

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

  1. Placement of a tube thoracostomyAnswer
  2. B
    Transition to intravenous vancomycin and piperacillin-tazobactam
  3. C
    Administration of nebulized albuterol and intravenous furosemide
  4. D
    Calculation of expected respiratory compensation using Winter's formula
  5. E
    Lower extremity venous duplex ultrasonography

Answer

Placement of a tube thoracostomy is the most appropriate next step for managing a complicated parapneumonic effusion.
The correct action is mechanical drainage of the pleural space. This patient developed a parapneumonic effusion (an effusion adjacent to a pneumonia). The pleural fluid analysis definitively categorizes this as a complicated parapneumonic effusion because it meets standard criteria: pH < 7.2, glucose < 60 mg/dL, and a positive Gram stain. Complicated parapneumonic effusions and empyemas (frank pus) indicate bacterial invasion of the pleural space. Because the pleural space becomes highly acidic and loculated, systemic antibiotics alone are insufficient for clearance. The standard of care mandates prompt mechanical drainage, typically via tube thoracostomy, alongside continued antibiotic therapy.

Step-by-Step Solution

1
Analyze the patient's presentation and imaging.
The patient has worsening pulmonary symptoms, a new fever spike on hospital day 3 of antibiotics, and a new pleural effusion adjacent to a known pneumonia.
Identifying the timeline and new findings points toward a complication of the initial pneumonia rather than a new disease process.
2
Interpret the pleural fluid analysis.
The pleural fluid shows a pH of 7.12, glucose of 32 mg/dL, LDH of 1,250 U/L, and a positive Gram stain.
These findings are the defining biochemical criteria for a complicated parapneumonic effusion.
3
Determine the definitive management for the identified effusion.
Tube thoracostomy (chest tube placement) must be performed.
Antibiotics alone cannot effectively clear an infected, highly acidic pleural space; mechanical drainage is mandatory to achieve source control.

Key Concept

Management of complicated parapneumonic effusions
Estimated Time:1m 30s
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Topics

Pulmonary and Critical Care

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