Garrett Waagmeester
4/25/2014


Total pleural fluid volume: 0.2-0.3 mL/kg
Fluid produced by systemic vessels of the parietal
pleura, primarily less dependent capillaries, based
on:
◦ Permeability of the pleural vessels
◦ Hydrostatic and oncotic gradients


Fluid removed by pleural lymphatics in dependent
portions of parietal pleura
Rate of production at homeostasis: 0.1 mL/kg/h
Theodore et al, 2010; Suratt, 2003; Noppen et al, 2000



Low in protein: <100 mg/dL
Slightly alkaline compared to
serum: pH = 7.60-7.64
Hypocellular compared to
serum
◦ 1000-2000 WBC/μL
 75% macrophages (IR 64-81%)*
 23% lymphocytes (IR 16-31%)*
* Median values; IR= interquartile range
Suratt, 2003; Noppen et al., 2000
1.
Increased pulmonary capillary pressure (CHF)
2.
Increased pulmonary capillary permeability (PNA)
3.
Decreased intrapleural pressure (Atelectasis)
4.
Decreased plasma oncotic pressure (Hypoalbuminemia)
5.
Increased pleural membrane permeability and obstructed lymphatic
flow (pleural malignancy, infection)
6.
Diaphragmatic defects (hepatic hydrothorax)
7.
Thoracic Duct Rupture (chylothorax)
Porcel and Light, 2006
Symptoms
 Dyspnea
◦ Often disproportionate to
hypoxemia


Cough
Pleuritic Chest Pain
Physical Exam
 Decreased breath sounds
 Dullness to percussion
 Decreased tactile fremitus
 Egophony (EA)
 May find rales or pleuritic
friction rub

>50-75 mL of fluid on lateral
radiograph to blunt
costophrenic angle

>175-200 mL of fluid on P/A
view to blunt lateral
costophrenic angle

Clinically significant pleural
effusion: >10mm fluid
present on lateral decubitus
radiograph (or U/S)

Delayed thoracentesis in
parapneumonic effusion
associated with:
◦ Longer hospital stay
◦ Greater healthcare cost

Initial pleural fluid analysis:
◦
◦
◦
◦
◦
◦
◦
Protein
LDH
Cell count with differential
Gram stain/culture
Glucose
Cytology
pH
Heffner et al, 1995; Light, 2002
Light, 2002
Light, 2002
Transudative Effusion
Exudative Effusion
Increased hydrostatic pressure
• Congestive Heart Failure
• Constrictive Pericarditis
• Pulmonary Embolism*
Lymphocytic predominance
• Tuberculous/Fungal pleuritis *
• Malignant disease (30-35%)*
• Sarcoidosis
Reduced oncotic pressure
• Nephrotic syndrome
• Malnutrition
Neutrophilic predominance
• Parapneumonic effusion*
• Empyema*
• Rheumatoid disease
• Pulmonary infarction*
Transdiagphragmatic leakage
• Cirrhosis with ascites*
• Peritoneal dialysis
• Urinothorax*
Decreased intrapleural pressure
•Atelectasis
* Predominantly unilateral
Neutrophilic or lymphocytic
•Postcardiac injury (Dressler’s) syndrome
•Pulmonary embolism*
• Connective tissue disease
Eosinophilic predominance
• Trauma
• Asbestos
• Drug-induced pleural disease
RBC count >100,000
• Malignancy*
• Trauma
• Pulmonary infarction*
Other
• Chylothorax/Pseudochylothorax
Suratt, 2003; Ansari and Idell, 1998; Light, 2006

CT has higher sensitivity
than CXR or MRI for:
◦ Pleural thickening and
loculation
◦ Pleural vs. parenchymal disease
 Empyema vs. abscess
◦ Pulmonary embolism
 Helical CT
◦ Malignancy
◦ Mediastinal disease
Porcell and Light, 2006; Davies et al, 2003;
Qureshi and Gleeson, 2006; Sahn, 2007

However, there are no trials demonstrating benefits of
CT in terms of:
◦ Shorter time to diagnosis
◦ Decreased need for diagnostic procedures (e.g. thoracentesis)
◦ Shorter hospital stay/decreased cost

Management guidelines recommend CT scans for
complicated cases after failed initial diagnostic
workup
Porcell and Light, 2006; Davies et al, 2003;
Qureshi and Gleeson, 2006; Sahn, 2007

Ultrasound

Needle biopsy of pleura

Bronchoscopy

Thoracoscopy

Open biopsy
◦ Guided thoracentesis
◦ Identifies locultated effusion
◦ Tuberculous pleuritis and
malignancy
◦ Bronchial invasion by malignancy
or infiltrate
◦ Allows for pathologic analysis
◦ Option for pleurodesis
Davies et al, 2003; Light, 2006; Sahn, 2007

Pleural fluid is produced
and removed by parietal
pleura
◦ Multiple mechanisms to
disrupt homeostasis

Thoracentesis essential to
diagnosis
◦ Light’s criteria: sensitive and
specific for identifying
exudative effusions

CT scan can be helpful for
complicated cases
1.
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4.
5.
6.
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8.
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12.
Theodore PR, Jablons D. Chapter 18. Thoracic Wall, Pleura, Mediastinum, & Lung. In: Doherty GM. eds. CURRENT
Diagnosis & Treatment: Surgery, 13e.New York, NY: McGraw-Hill; 2010.
http://accessmedicine.mhmedical.com.liboff.ohsu.edu/content.aspx?bookid=343&Sectionid=39702805. Accessed
April 18, 2014.
Suratt BT. Chapter 22. Pleural Effusions, Excluding Hemothorax. In:Hanley ME, Welsh CH. eds. CURRENT Diagnosis &
Treatment in Pulmonary Medicine. New York, NY: McGraw-Hill; 2003.
http://accessmedicine.mhmedical.com.liboff.ohsu.edu/content.aspx?bookid=346&Sectionid=39883273. Accessed
April 18, 2014.
Noppen M, De Waele M, Li R, Gucht KV, D’Haese J, Gerlo E. Volume and Cellular Content of Normal Pleural Fluid in
Humans Examined by Pleural Lavage. Am J Respir Crit Care Med 2000; 162: 1023-1026.
Porcel JM, Light RW. Diagnostic Approach to Pleural Effusion in Adults. Am Fam Physician 2006; 73: 1211-1220.
Heffner JE, McDonald J, Barbieri C, Klein J. Management of Parapneumonic Effusion: an analysis of physician practice
patterns. Arch Surg 1995; 130:433-438.
Light RW. Pleural Effusion. NEJM 2002; 346: 1971-1977
Ansari T, Idell S. Management of Undiagnosed Persistent Pleural Effusion. Clin Chest Med 1998; 19(2): 407-417.
Light RW. The Undiagnosed Pleural Effusion. Clin Chest Med 2006; 27: 309-319.
Qureshi NR, Gleeson FV. Imaging of Pleural Disease. Clin Chest Med 2006; 27: 193-213.
Davies CWH, Gleeson FV, Davies RJO. BTS Guidelines for the management of pleural infection. Thorax 2003; 58(ii): 1828.
Sahn SA. Diagnosis and Management of Parapneumonic Effusions and Empyema. Clin Infect Disease 2007; 45: 14801486.
Light RW. Pleural Effusions. Med Clin N Am 2011; 95: 1055-1070