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Parapneumonic effusion and empyema in adults

Charlie Strange, MD
Section Editors
John G Bartlett, MD
V Courtney Broaddus, MD
Deputy Editor
Geraldine Finlay, MD


Parapneumonic effusions are pleural effusions that form in the pleural space adjacent to a bacterial pneumonia. They are found in at least 40 percent of bacterial pneumonias [1]. The usual parapneumonic effusion is small and resolves with appropriate antibiotic therapy. However, if bacteria invade the pleural space, a complicated parapneumonic effusion or empyema may result, which will require antibiotic therapy plus additional interventions. Infected pleural effusions can also rarely develop without the presence of an adjacent pneumonia.

The pathogenesis, clinical presentation, evaluation, and management of parapneumonic effusions and empyema are reviewed here. The evaluation and management of parapneumonic effusions and empyema in infants and children are discussed separately. (See "Epidemiology; clinical presentation; and evaluation of parapneumonic effusion and empyema in children" and "Management and prognosis of parapneumonic effusion and empyema in children".)


Parapneumonic pleural effusions are divided into three groups or stages based upon pathogenesis.

Uncomplicated parapneumonic effusion — An uncomplicated parapneumonic effusion forms when lung interstitial fluid increases during pneumonia and moves across the adjacent visceral pleural membrane. The pleural fluid is characterized by "exudative" chemistries and an influx of neutrophils into the pleural space. An effusion forms when the resorptive capacity of the pleural space is exceeded; it resolves with resolution of the pneumonia. (See "Mechanisms of pleural liquid turnover in the normal state" and "Mechanisms of pleural liquid accumulation in disease".)

Among patients with bacteremic pneumococcal pneumonia, pleural effusions are common and are usually sterile. (See "Pneumococcal pneumonia in adults", section on 'Pulmonary complications'.)


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Literature review current through: Sep 2016. | This topic last updated: Oct 18, 2016.
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  1. Light RW, Girard WM, Jenkinson SG, George RB. Parapneumonic effusions. Am J Med 1980; 69:507.
  2. Mavroudis C, Ganzel BL, Cox SK, Polk HC Jr. Experimental aerobic-anaerobic thoracic empyema in the guinea pig. Ann Thorac Surg 1987; 43:298.
  3. Strange C, Tomlinson JR, Wilson C, et al. The histology of experimental pleural injury with tetracycline, empyema, and carrageenan. Exp Mol Pathol 1989; 51:205.
  4. Sellares J, López-Giraldo A, Lucena C, et al. Influence of previous use of inhaled corticoids on the development of pleural effusion in community-acquired pneumonia. Am J Respir Crit Care Med 2013; 187:1241.
  5. Dean NC, Griffith PP, Sorensen JS, et al. Pleural Effusions at First ED Encounter Predict Worse Clinical Outcomes in Patients With Pneumonia. Chest 2016; 149:1509.
  6. Rahman NM, Kahan BC, Miller RF, et al. A clinical score (RAPID) to identify those at risk for poor outcome at presentation in patients with pleural infection. Chest 2014; 145:848.
  7. White HD, Henry C, Stock EM, et al. Predicting Long-Term Outcomes in Pleural Infections. RAPID Score for Risk Stratification. Ann Am Thorac Soc 2015; 12:1310.
  8. Heffner JE, Klein JS, Hampson C. Diagnostic utility and clinical application of imaging for pleural space infections. Chest 2010; 137:467.
  9. Tsujimoto N, Saraya T, Light RW, et al. A Simple Method for Differentiating Complicated Parapneumonic Effusion/Empyema from Parapneumonic Effusion Using the Split Pleura Sign and the Amount of Pleural Effusion on Thoracic CT. PLoS One 2015; 10:e0130141.
  10. Smolikov A, Smolyakov R, Riesenberg K, et al. Prevalence and clinical significance of pleural microbubbles in computed tomography of thoracic empyema. Clin Radiol 2006; 61:513.
  11. Aquino SL, Webb WR, Gushiken BJ. Pleural exudates and transudates: diagnosis with contrast-enhanced CT. Radiology 1994; 192:803.
  12. Waite RJ, Carbonneau RJ, Balikian JP, et al. Parietal pleural changes in empyema: appearances at CT. Radiology 1990; 175:145.
  13. Kearney SE, Davies CW, Davies RJ, Gleeson FV. Computed tomography and ultrasound in parapneumonic effusions and empyema. Clin Radiol 2000; 55:542.
  14. Sahn SA, Light RW. The sun should never set on a parapneumonic effusion. Chest 1989; 95:945.
  15. Colice GL, Curtis A, Deslauriers J, et al. Medical and surgical treatment of parapneumonic effusions : an evidence-based guideline. Chest 2000; 118:1158.
  16. Moffett BK, Panchabhai TS, Anaya E, et al. Computed tomography measurements of parapneumonic effusion indicative of thoracentesis. Eur Respir J 2011; 38:1406.
  17. Heffner JE, Brown LK, Barbieri C, DeLeo JM. Pleural fluid chemical analysis in parapneumonic effusions. A meta-analysis. Am J Respir Crit Care Med 1995; 151:1700.
  18. Sahn SA. State of the art. The pleura. Am Rev Respir Dis 1988; 138:184.
  19. Putnam B, Elahi A, Bowling MR. Do we measure pleural fluid pH correctly? Curr Opin Pulm Med 2013; 19:357.
  20. Porcel JM, Vives M, Cao G, et al. Biomarkers of infection for the differential diagnosis of pleural effusions. Eur Respir J 2009; 34:1383.
  21. Porcel JM, Bielsa S, Esquerda A, et al. Pleural fluid C-reactive protein contributes to the diagnosis and assessment of severity of parapneumonic effusions. Eur J Intern Med 2012; 23:447.
  22. Lee SH, Lee EJ, Min KH, et al. Procalcitonin as a diagnostic marker in differentiating parapneumonic effusion from tuberculous pleurisy or malignant effusion. Clin Biochem 2013; 46:1484.
  23. Chung CL, Hsiao SH, Hsiao G, et al. Clinical importance of angiogenic cytokines, fibrinolytic activity and effusion size in parapneumonic effusions. PLoS One 2013; 8:e53169.
  24. Khosla R, Khosla SG, Becker KL, Nylen ES. Pleural fluid procalcitonin to distinguish infectious from noninfectious etiologies of pleural effusions. J Hosp Med 2016; 11:363.
  25. Kawanami T, Fukuda K, Yatera K, et al. A higher significance of anaerobes: the clone library analysis of bacterial pleurisy. Chest 2011; 139:600.
  26. Menzies SM, Rahman NM, Wrightson JM, et al. Blood culture bottle culture of pleural fluid in pleural infection. Thorax 2011; 66:658.
  27. Brook I, Frazier EH. Aerobic and anaerobic microbiology of empyema. A retrospective review in two military hospitals. Chest 1993; 103:1502.
  28. Bartlett JG, Gorbach SL, Thadepalli H, Finegold SM. Bacteriology of empyema. Lancet 1974; 1:338.
  29. Civen R, Jousimies-Somer H, Marina M, et al. A retrospective review of cases of anaerobic empyema and update of bacteriology. Clin Infect Dis 1995; 20 Suppl 2:S224.
  30. Boyanova L, Gergova G, Petrov D, et al. Anaerobic microbiology in 198 cases of pleural empyema: a Bulgarian study. Anaerobe 2004; 10:261.
  31. Bhattacharyya N, Umland ET, Kosloske AM. A bacteriologic basis for the evolution and severity of empyema. J Pediatr Surg 1994; 29:667.
  32. Chapman SJ, Davies RJ. Recent advances in parapneumonic effusion and empyema. Curr Opin Pulm Med 2004; 10:299.
  33. Le Monnier A, Carbonnelle E, Zahar JR, et al. Microbiological diagnosis of empyema in children: comparative evaluations by culture, polymerase chain reaction, and pneumococcal antigen detection in pleural fluids. Clin Infect Dis 2006; 42:1135.
  34. Maskell NA, Davies CW, Nunn AJ, et al. U.K. Controlled trial of intrapleural streptokinase for pleural infection. N Engl J Med 2005; 352:865.
  35. Ahmed RA, Marrie TJ, Huang JQ. Thoracic empyema in patients with community-acquired pneumonia. Am J Med 2006; 119:877.
  36. Maskell NA, Batt S, Hedley EL, et al. The bacteriology of pleural infection by genetic and standard methods and its mortality significance. Am J Respir Crit Care Med 2006; 174:817.
  37. Grijalva CG, Zhu Y, Nuorti JP, Griffin MR. Emergence of parapneumonic empyema in the USA. Thorax 2011; 66:663.
  38. Chen KY, Hsueh PR, Liaw YS, et al. A 10-year experience with bacteriology of acute thoracic empyema: emphasis on Klebsiella pneumoniae in patients with diabetes mellitus. Chest 2000; 117:1685.
  39. Morens DM, Taubenberger JK, Fauci AS. Predominant role of bacterial pneumonia as a cause of death in pandemic influenza: implications for pandemic influenza preparedness. J Infect Dis 2008; 198:962.
  40. Luh SP, Chou MC, Wang LS, et al. Video-assisted thoracoscopic surgery in the treatment of complicated parapneumonic effusions or empyemas: outcome of 234 patients. Chest 2005; 127:1427.
  41. Lisboa T, Waterer GW, Lee YC. Pleural infection: changing bacteriology and its implications. Respirology 2011; 16:598.
  42. Vaudaux P, Waldvogel FA. Gentamicin inactivation in purulent exudates: role of cell lysis. J Infect Dis 1980; 142:586.
  43. Berger HA, Morganroth ML. Immediate drainage is not required for all patients with complicated parapneumonic effusions. Chest 1990; 97:731.
  44. Wozniak CJ, Paull DE, Moezzi JE, et al. Choice of first intervention is related to outcomes in the management of empyema. Ann Thorac Surg 2009; 87:1525.
  45. Scarci M, Abah U, Solli P, et al. EACTS expert consensus statement for surgical management of pleural empyema. Eur J Cardiothorac Surg 2015; 48:642.
  46. Davies HE, Davies RJ, Davies CW, BTS Pleural Disease Guideline Group. Management of pleural infection in adults: British Thoracic Society Pleural Disease Guideline 2010. Thorax 2010; 65 Suppl 2:ii41.
  47. Rahman NM, Maskell NA, Davies CW, et al. The relationship between chest tube size and clinical outcome in pleural infection. Chest 2010; 137:536.
  48. Davies CW, Gleeson FV, Davies RJ, Pleural Diseases Group, Standards of Care Committee, British Thoracic Society. BTS guidelines for the management of pleural infection. Thorax 2003; 58 Suppl 2:ii18.
  49. Jerjes-Sánchez C, Ramirez-Rivera A, Elizalde JJ, et al. Intrapleural fibrinolysis with streptokinase as an adjunctive treatment in hemothorax and empyema: a multicenter trial. Chest 1996; 109:1514.
  50. Temes RT, Follis F, Kessler RM, et al. Intrapleural fibrinolytics in management of empyema thoracis. Chest 1996; 110:102.
  51. Davies RJ, Traill ZC, Gleeson FV. Randomised controlled trial of intrapleural streptokinase in community acquired pleural infection. Thorax 1997; 52:416.
  52. Bouros D, Schiza S, Tzanakis N, et al. Intrapleural urokinase versus normal saline in the treatment of complicated parapneumonic effusions and empyema. A randomized, double-blind study. Am J Respir Crit Care Med 1999; 159:37.
  53. Diacon AH, Theron J, Schuurmans MM, et al. Intrapleural streptokinase for empyema and complicated parapneumonic effusions. Am J Respir Crit Care Med 2004; 170:49.
  54. Thomson AH, Hull J, Kumar MR, et al. Randomised trial of intrapleural urokinase in the treatment of childhood empyema. Thorax 2002; 57:343.
  55. Thommi G, Nair CK, Aronow WS, et al. Efficacy and safety of intrapleural instillation of alteplase in the management of complicated pleural effusion or empyema. Am J Ther 2007; 14:341.
  56. Tuncozgur B, Ustunsoy H, Sivrikoz MC, et al. Intrapleural urokinase in the management of parapneumonic empyema: a randomised controlled trial. Int J Clin Pract 2001; 55:658.
  57. Tokuda Y, Matsushima D, Stein GH, Miyagi S. Intrapleural fibrinolytic agents for empyema and complicated parapneumonic effusions: a meta-analysis. Chest 2006; 129:783.
  58. Cameron R, Davies HR. Intra-pleural fibrinolytic therapy versus conservative management in the treatment of adult parapneumonic effusions and empyema. Cochrane Database Syst Rev 2008; :CD002312.
  59. Thommi G, Shehan JC, Robison KL, et al. A double blind randomized cross over trial comparing rate of decortication and efficacy of intrapleural instillation of alteplase vs placebo in patients with empyemas and complicated parapneumonic effusions. Respir Med 2012; 106:716.
  60. Ozcelik C, Inci I, Nizam O, Onat S. Intrapleural fibrinolytic treatment of multiloculated postpneumonic pediatric empyemas. Ann Thorac Surg 2003; 76:1849.
  61. Gervais DA, Levis DA, Hahn PF, et al. Adjunctive intrapleural tissue plasminogen activator administered via chest tubes placed with imaging guidance: effectiveness and risk for hemorrhage. Radiology 2008; 246:956.
  62. Anevlavis S, Archontogeorgis K, Tzouvelekis A, et al. Intrapleural r-tPA in association with low-molecular heparin may cause massive hemothorax resulting in hypovolemia. Respiration 2011; 81:513.
  63. Skeete DA, Rutherford EJ, Schlidt SA, et al. Intrapleural tissue plasminogen activator for complicated pleural effusions. J Trauma 2004; 57:1178.
  64. Davies CW, Lok S, Davies RJ. The systemic fibrinolytic activity of intrapleural streptokinase. Am J Respir Crit Care Med 1998; 157:328.
  65. Rahman NM, Maskell NA, West A, et al. Intrapleural use of tissue plasminogen activator and DNase in pleural infection. N Engl J Med 2011; 365:518.
  66. Piccolo F, Pitman N, Bhatnagar R, et al. Intrapleural tissue plasminogen activator and deoxyribonuclease for pleural infection. An effective and safe alternative to surgery. Ann Am Thorac Soc 2014; 11:1419.
  67. Majid A, Kheir F, Folch A, et al. Concurrent Intrapleural Instillation of Tissue Plasminogen Activator and DNase for Pleural Infection. A Single-Center Experience. Ann Am Thorac Soc 2016; 13:1512.
  68. Piccolo F, Popowicz N, Wong D, Lee YC. Intrapleural tissue plasminogen activator and deoxyribonuclease therapy for pleural infection. J Thorac Dis 2015; 7:999.
  69. Potaris K, Mihos P, Gakidis I, Chatziantoniou C. Video-thoracoscopic and open surgical management of thoracic empyema. Surg Infect (Larchmt) 2007; 8:511.
  70. Cassina PC, Hauser M, Hillejan L, et al. Video-assisted thoracoscopy in the treatment of pleural empyema: stage-based management and outcome. J Thorac Cardiovasc Surg 1999; 117:234.
  71. Lardinois D, Gock M, Pezzetta E, et al. Delayed referral and gram-negative organisms increase the conversion thoracotomy rate in patients undergoing video-assisted thoracoscopic surgery for empyema. Ann Thorac Surg 2005; 79:1851.
  72. Lawrence DR, Ohri SK, Moxon RE, et al. Thoracoscopic debridement of empyema thoracis. Ann Thorac Surg 1997; 64:1448.
  73. Striffeler H, Gugger M, Im Hof V, et al. Video-assisted thoracoscopic surgery for fibrinopurulent pleural empyema in 67 patients. Ann Thorac Surg 1998; 65:319.
  74. Wurnig PN, Wittmer V, Pridun NS, Hollaus PH. Video-assisted thoracic surgery for pleural empyema. Ann Thorac Surg 2006; 81:309.
  75. Ravaglia C, Gurioli C, Tomassetti S, et al. Is medical thoracoscopy efficient in the management of multiloculated and organized thoracic empyema?. Respiration 2012; 84:219.
  76. Wait MA, Sharma S, Hohn J, Dal Nogare A. A randomized trial of empyema therapy. Chest 1997; 111:1548.
  77. Petrakis IE, Kogerakis NE, Drositis IE, et al. Video-assisted thoracoscopic surgery for thoracic empyema: primarily, or after fibrinolytic therapy failure? Am J Surg 2004; 187:471.
  78. Gates RL, Caniano DA, Hayes JR, Arca MJ. Does VATS provide optimal treatment of empyema in children? A systematic review. J Pediatr Surg 2004; 39:381.
  79. Coote N, Kay E. Surgical versus non-surgical management of pleural empyema. Cochrane Database Syst Rev 2005; :CD001956.
  80. Sonnappa S, Cohen G, Owens CM, et al. Comparison of urokinase and video-assisted thoracoscopic surgery for treatment of childhood empyema. Am J Respir Crit Care Med 2006; 174:221.
  81. Chan DT, Sihoe AD, Chan S, et al. Surgical treatment for empyema thoracis: is video-assisted thoracic surgery "better" than thoracotomy? Ann Thorac Surg 2007; 84:225.
  82. Mandal AK, Thadepalli H, Mandal AK, Chettipally U. Outcome of primary empyema thoracis: therapeutic and microbiologic aspects. Ann Thorac Surg 1998; 66:1782.
  83. Tong BC, Hanna J, Toloza EM, et al. Outcomes of video-assisted thoracoscopic decortication. Ann Thorac Surg 2010; 89:220.
  84. CLAGETT OT, GERACI JE. A procedure for the management of postpneumonectomy empyema. J Thorac Cardiovasc Surg 1963; 45:141.