An empyema is a collection of pus within an anatomical cavity. Usually, the term refers to empyema thoracis which is the collection of pus in the pleural space. It is a pleural effusion that has become infected with bacteria resulting in the formation and collection of pus in the pleural cavity.
An empyema should be suspected in patients with pulmonary infection if there is persisting or recurrent pyrexia despite treatment with a suitable antibiotic. Patients with empyema due to aerobic bacterial infection usually have high and remittent pyrexia, rigors, sweating, malaise and weight loss. Blood counts show polymorphonuclear leukocytosis and high C-reactive protein. Locally, there is pleural pain, breathlessness, cough and sputum. Empyema with anaerobic bacterial infections involving the pleural space presents with a subacute illness with symptoms for more than 7 days.
Low grade fever, weight loss and anemia is commonly seen. Clinical signs of pleural effusion are present such as decreased or absent breath sounds, dull notes on percussion, a decreased tactile fremitus. Large pleural effusions may show an evidence of tension and contralateral tracheal shift .
An empyema will only heal if infection is eradicated and the empyema space is obliterated, allowing apposition of the visceral and parietal pleural layers.
Treatment of non-tuberculous empyema
Treatment of tuberculous empyema
Immediate initiation of antitubercular chemotherapy is essential. The pus in the pleural space is aspirated through a wide-bore needle with intercostal tube drainage if necessary until the pus ceases to reaccumulate. Surgery is occasionally required to ablate a residual empyema space.
Mortality rate from empyema is higher in the presence of cardiac and respiratory comorbidities, immunosuppressive states and old age. Surgical procedures including decortication and/or an open drainage procedure are required in 15-25% of patients. Fibrothorax with restriction and encasement of the lung in thickened, often calcified pleura, is a late complication in tuberculous empyema. Death rates are estimated to be approximately 10% .
70% of empyema thoracis are caused by bacterial pneumonia. 30% cases arise as complications of previous cardiothoracic surgery, in which case Staphylococcus aureus is the most common bacteria. Apart from surgery, empyema may arise with the bacterial spread locally or through blood such as from esophageal perforation or septicemia. Streptococcus pneumoniae and Staphylococcus aureus account for nearly 70% of aerobic gram-positive cultures isolated in empyema. Aerobic gram-negative organisms are mainly Klebsiella, Pseudomonas and Hemophilus species .
In the United States, approximately 500,000 to 750,000 patients are diagnosed with parapneumonic effusions per year- of which nearly 5 to 10% require a drainage or surgical procedure. Children, elderly and debilitated persons are at a higher risk for developing empyema. Other risk factors include pneumonia requiring hospitalization and coexisting diseases like rheumatoid arthritis, bronchiectasis, diabetes mellitus, alcoholism and gastroesophageal reflux disease. Chalmers et al identified 7 clinical factors that predict the development of empyema: an albumin value of less than 30 g/L, a platelet count of greater than 400,000,000,000/L, a C-reactive protein level of greater than 100 mg/L, a serum sodium value of less than 130 mmol/L, and a history of intravenous drug or alcohol abuse. A decreased risk was found in a history of chronic obstructive pulmonary disease .
5 to 10 days after the onset of pneumonia, bacterial invasion of the pleural space occurs leading to the accumulation of polymorphonuclear leukocytes, bacteria, and cellular debris in the form of a thick inflammatory exudate in the pleural space. The pleural fluid may test positive for microorganisms. The pus in the pleural space is often under considerable pressure and if the condition is not adequately treated, pus may rupture into a bronchus causing a bronchopleural fistula and pyopneumothorax or track through the chest wall with the formation of a subcutaneous abscess or sinus (termed empyema necessitans). Loculation and septation may occur .
An empyema is a collection of pus within an anatomical cavity. The condition may occur for example in the uterus, the appendix or the gallbladder. Usually, the term refers to thoracic empyema which is mostly caused by bacterial invasion of the pleural space. It may present with acute symptoms of fever, chest pain and sputum in case of aerobic infections; or a more indolent subacute febrile illness with weight loss in anaerobic infections.
Clinically, empyema is characterized by decreased or absent breath sounds and dullness on percussion. Complete blood counts, microbiological analysis of sputum or pleural fluid, imaging studies of chest and ultrasound are used for diagnosis. Treatment modalities include pleural drainage, surgery, broad spectrum antibiotics and infusion of intrapleural thrombolytic agents. Mortality rates are around 10% .
Empyema is a collection of pus inside the thin space between the inner lining of your chest wall and the surface of the lungs. Most commonly, empyema results as a complication of pneumonia or lung abscess. Sometimes it may happen after a surgery on the chest. The patients have fever, cough, shortness of breath, and chest pain that increases on breathing or movement of chest. They may have a low grade fever, loss of appetite and weight loss in some infections. Antibiotics to treat the bacterial infection and medications for the fever are given to treat this condition. The pus is drained using chest tube to allow the lungs to expand normally.