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 (EA) 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. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 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
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