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Disorders of the Pleural Space
Edward M. Omron MD, MPH, FCCP
Pulmonary Medicine
Alta Bates Summit
10-19-2010
Which of the following pleural fluid measurements is most compatible with an exudative pleural effusion?
• Cholesterol is 35 mg/dL• LDH is 0.40 times the upper limit of normal • LDH pleural fluid to serum ratio is 0.52• Total protein is 3.4 g/dL
• 67 yo male presents:– Dyspnea 8 weeks, fever, cough, pleuritic chest pain– 3 vessel CABG 3 months ago with internal mammary
artery graft– Decreased breath sounds on left– WBC 11,000, ESR = 80 mm/h, – CXR: left effusion with atelectasis– Thoracentesis: 800 mL straw colored fluid removed
• 70% lymphocytes, 20% PMNS, and 40,000 RBC/mm3• Protein 4.2 g/dL, glucose 90 mg/dL, LDH 300 U/L• pH = 7.3
What is the next step in this patients management?
• Consult CT surgery• Begin antiinflammatory agent• Begin therapeutic low molecular weght heparin
while awaiting CT angiogram• Begin piperacillin/tazobactam with Vancomycin
• Post-cardiac injury syndrome or Dressler Syndrome– Post CABG effusions (common)– Exaggerated immune response to cardiac
antigens– Pleuritic chest pain, fever, elevated ESR,
leukocytosis, antimyocardial antibodies– Initially neutrophil predominat <30 days then
lymphocyte predominant >30 days– Often requires NSAIDS or steroids for
resolution– 1 -12 months after surgery, 3 weeks is median
Normal Pleural Physiology
• Functions of pleural space– Couples the lungs to the chest wall– Lubricant between the chest wall and lungs– Obliteration of space compatible with life
• Composition– 2 separate semipermeable membranes– Visceral and Parietal layers– Both linings subject to disease and disorders
• Visceral Pleura– Envelops entire surface of both lungs– The two pleural cavities are separate– Mesothelial cells– Artery Supply: bronchial arteries– Lymphatics drain the pulmonary
parenchyma– No nerve fibers– The vein drain is pulmonary vein
• Parietal Pleura– Covers the inner surface of chest wall– Blood supply intercostal arteries– Lymphatics drain the pleural space– Pain fibers are present from intercostal
nerves– Mesothelial cells are immunoreactive– 5 to 15 mL fluid present in space– Normally high fluid flux 1 Liter /day– Vein drain is the superior vena cava
Normal Composition Pleural Fluid
• Volume 0.2 mL/kg• Cells/ mm3 1000 – 5000
– Mesothelial cells 60%– Monocytes 30%– Lymphocytes 5% – PMN’s 5%
• Protein 1-2 g/dL• LDH <50% plasma level• Glucose plasma level• pH ≥ plasma level
Visceral and Parietal Pleura
Pleural Histology
The visceral pleura is made from simple squamous epithelium (mesothelium)
Pleural Effusion
• Fluid in pleural space > 20 mL• Two mechanisms
– Excessive formation– Fluid resorption is disturbed
• Etiology– 40% cardiac causes– 60% other
• Pneumonia (48%)• Malignancy(24%)• Pulmonary embolism (18%)• Cirrhosis (6%)
Initial Evaluation of Pleural Effusion
• History and physical exam are critical– Dyspnea, cough and pleuritic chest pain are
common– Fever: pneumonia, empyema, tuberculosis (Tb)– Hemoptysis: lung cancer, PE, or Tb– Weight Loss: Malignancy, Tb, or lung abscess– Chest Exam
• Dullness to percussion• Decreased breath sounds
• Signs– Orthopnea, jvd, or peripheral edema (CHF)– Unilateral extremity swelling (PE)– Ascites (hepatic hydrothorax or Meig’s)
• History– Chest trauma (hemothorax)– Abdominal surgery (post-op effusion)– Post CABG surgery (Dressler’s syndrome)– Alcoholism (pancreatic effusion)
Imaging Pleural Effusion
• PA and Lateral CXR• Decubiti for layering• CT chest for complex spaces• US for direct visualization
Right-sided Pleural Effusion
Right Side Down Ducubitus
Bilateral Pleural Effusions CT Chest
Ultrasound Pleural Effusion
• Should thoracentesis be performed?
• If thoracentesis is done– Is the fluid a transudate or exudate?
• If the fluid is an exudate– What is the etiology?
Pleural Effusion Confirmed
Should Thoracentesis Be Performed?
• Most patients should be tapped– Newly recognized effusion
• Two exceptions– Small Effusions ( < 1 cm on decubitus, US
required)– Congestive Heart Failure
• Thoracentesis only if bilateral effusions not equal• Fever• Pleuritic chest pain• Impending respiratory faillure
Is the Fluid a Transudate or Exudate?
• Transudative Effusions– Mechanical– No capillary leak or cytokine activation– Excessive formation or impaired absorption– Limits the differential with no additional workup
• CHF, Cirrhosis, or Nephrotic Syndrome
– If Exudative, more investigation required– Method: LIGHT’s Criteria
Light’s Criteria (Exudate)
• Pleural fluid total protein/ serum protein >0.5– Pleural total protein > 2.9 g/dL
• Pleural fluid LDH/serum LDH > 0.6– Pleural fluid LDH > 0.45 upper limit normal
• Serum albumin minus pleural albumin < 1.2• Pleural fluid total cholesterol > 45 mg/dL
Chest 2003; 121: 1916-1920
Transudative Effusions
• Congestive Heart Failure• Nephrotic syndrome• Cirrhosis• Meig’s Syndrome• Hydronephrosis• Peritoneal Dialysis
Exudative Effusions
• Parapneumonic• Malignancy• Pulmonary Embolism• Tuberculosis• Traumatic• Collagen Vascular (SLE, RA)• Drug induced, Uremia, Dressler’s …
Other Useful Criteria
• Brain Natriuretric Peptide <1000 pg/mL– > 1000 in CHF
• Glucose < 60 mg/dL– Empyema or Rheumatoid Arthritis
• pH < 7.2 Empyema• Triglycerides > 110 mg/dL
– Chylothorax
• Amylase – malignancy, pancreatic disease, esophageal
Other Useful Tests
• Pleural to blood HCT > 0.5– Hemothorax
• Cell Count– PMN predominate in parapneumonic pneumonia– Lymphocte predominate in malignancy, Tb, CABG– Eosinophills when blood or air in pleural space
• Fluid Culture– Grams stain, bacterial culture, acid fast bacilli
smear and culture, and fungal culture.
• Cytology for malignancy
Appearance Pleural Fluid
• Odour– Fetid = Empyema– Urine = Urinothorax
• Bloody r/o hemothorax• Milky appearance
– Chylothorax (Triglyceride > 110 mg/dL)– Pseudochylothorax (Cholesterol > 200 mg/dL)
• Pus – Empyema and complex pleural space
Pleural Fluid Appearance
54 yo female cough, pleuritic chest pain
Empyema
• Parapneumonic effusion– Any pleural effusion associated with bacterial or
viral pneumonia
• Loculated parapneumonic effusion– Not free flowing
• Multiloculated parapneumonic effusion– Noncommunicating compartments
• Empyema (fibrosuppurative exudate)– Pus is the pleural space, gram stain (+)– pH < 7.2, Glucose < 60 mg/dL, High LDH
Natural History Parapneumonic Effusion
• Exudative stage– Rapid accumulation of inflammatory fluid– Normal pH, Glucose, and LDH level– Antibiotics effective
• Fibropurulent stage– PMN’s, Fibrin deposition, loculations occur– Low pH and glucose, high LDH
• Organization stage (fibrothorax)– Fibroblast proliferation between pleural layers– Pleural peel develops, decortication required
Etiology Empyema
• Infectious Pneumonias– Staph aureus– Strep pneumonia– Gram negative bacilli– Tuberculous pleuritis (Uncommon in US)
• Thoracic trauma• Severe Sepsis
Management of Parapneumonic Effusions
• Selection of appropriate antibiotic coverage– Early administration improves outcome– Community acquired, healthcare acquired vs
hospital acquired pneumonias• Different organisms for each category• Community acquired = Strep pneumo• Health care acquired = Staph aureus• Hospital acquired = gram negative bacilli
– Severity of illness a factor
Pleural Fluid Management
• Observation– Defervesce quickly– Uncomplicated pleural effusion
• Therapeutic drainage (thoracentesis)– Early exudative phase
• Tube thoracostomy– Complex pleural fluid spaces
• VATS (Video assisted thoracoscopic sur)– Poor clinical response to above interventions
• Decortication: removal of pleural peel
Noninfectious Inflammatory Pleuritis
• Systemic Autoimmune disease– Systemic Lupus Erythematosus– Sjogren’s– Rheumatoid Arthritis– Wegener’s Granulomatosis
• Drug Induced (Nitrofurantion, Hydralazine)• Thoracic Radiation• Post cardiac injury syndrome• Pneumoconioses(asbestosis)• Uremia
• References– Eur Resp J 1997; 10: 476-481.– Clin Pulm Med 2003; 10: 336-342.– Clin Chest Med 2006; 27: 309-319.– Clin Chest Med 2006; 27: 157-180– Clin Chest Med 2006; 27: 369-381.