A 64-year-old man with a moderate right-sided pleural effusion seen on initial chest x-ray was admitted for pneumonia. Initial admission testing showed a white blood cell count of 14,800/mm³ with 92% neutrophils. He was started on ceftriaxone and azithromycin, and his symptoms improved over the next few hours. The patient's other medical problems include hypertension, hyperlipidemia, and hypothyroidism. He is a former smoker with a 25-pack-year history.
His blood pressure this morning is 142/90 mm Hg, pulse is 88/min, and respirations are 16/min. Oxygen saturation is 93% on room air. The patient speaks in full sentences, without respiratory distress. Jugular venous pressure is estimated at 5 cm H₂O. Lung examination shows decreased breath sounds, decreased tactile fremitus, and dullness to percussion less than halfway up the right chest. A soft second heart sound and 3/6 systolic ejection murmur are heard at the upper right sternal border with radiation to the carotids.
The white blood cell count is 12,200/mm³ with 78% neutrophils. A right lateral decubitus chest x-ray demonstrates a 20-mm free-flowing effusion. Further imaging shows an effusion in the right base without pleural thickening.
Which of the following is the best next step in management of this patient?

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Quizplus · Accepted Answer

11ec193a_971c_3b30_853d_ddc4a1b53cb4_MD0002_00 Parapneumonic effusions can occur in the adjacent pleural space in up to 40% of bacterial pneumonias. Most parapneumonic effusions are minimal and resolve with antibiotics. Effusions that are free-flowing and ≤10 mm on lateral decubitus film should be observed with serial imaging alone as they are most likely to resolve with antibiotics. Effusions >10 mm need to be evaluated further with chest imaging (ultrasonography or chest CT). Loculations, pleural thickening, and large (>½ hemithorax) effusions are considered high-risk features as they are associated with a higer rate of adverse outcomes. Diagnostic thoracentesis is recommended for effusions >10 mm with no high-risk features on imaging, as in this patient. Negative Gram stain, negative culture, and pH >7.2 with glucose ≥60 mg/dL on fluid analysis show that the effusion is uncomplicated and may respond to antibiotics alone. By contrast, complicated effusions (positive Gram stain or culture, pH <7.2, glucose <60 mg/dL) require drainage, usually with tube thoracostomy; similarly, effusions >10 mm with high-risk features require drainage (Choice C). Drainage also may be needed if there is no clinical improvement with antibiotics, the effusions persist on serial imaging, or the patient subsequently develops any high-risk features. (Choice A) Furosemide may decrease pleural effusions due to heart failure or renal disease. However, this patient's normal jugular venous pressure and absence of peripheral edema make these less likely. (Choices B and E) Although this patient has noted clinical improvement on current antimicrobial therapy, he needs a diagnostic thoracentesis (eg, to exclude a complicated effusion and to potentially identify the causative organism) as the pleural effusion is >10 mm. Antibiotics may need to be changed after the suspected organism and its antibiotic susceptibility are identified. Educational objective: Free-flowing effusions ≤10 mm usually resolve with antibiotic therapy alone. Larger effusions should be imaged with ultrasound and/or CT. Effusions without high-risk features (loculation, >½ hemithorax, pleural thickening) should undergo diagnostic thoracentesis. Effusions with high-risk features or pH <7.2, glucose <60 mg/dL, or positive Gram stain/culture should be drained. __________ References: Parapneumonic pleural effusion and empyema. (http://www.ncbi.nlm.nih.gov/pubmed/18367849) Management of infectious processes of the pleural space: a review. (http://www.ncbi.nlm.nih.gov/pubmed/22536502)

A 64-Year-Old Man with a Moderate Right-Sided Pleural Effusion Seen