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A 68-year-old man presented to the pulmonary clinic at Mayo Clinic for evaluation of chronic cough and weight loss. He had a medical history of stroke, insomnia, chronic mucocutaneous candidiasis, spontaneous left-sided pneumothorax, and pneumonia. He had been in good health until experiencing a left pontine stroke in 2006, which caused transient right-sided weakness and dysphagia. Although these symptoms resolved, a cough continued for 18 months before evaluation. Findings on chest radiography and a pulmonary function test were normal 5 months before evaluation. The cough had recently become productive, and the sputum was occasionally red. The patient thought the cough was worse when he was in certain positions. His cough was not triggered by exertion or fumes. He denied sinus disease, postnasal drip, gastroesophageal reflux, and asthma. He had never been a smoker. He had no relevant chemical, occupational, or animal exposures. He reported fever, chills, and a weight loss of 13.6 kg (30 lbs) during the previous 2 months. One month before evaluation, he developed hemoptysis. He was found to have a pleural effusion and was treated for pneumonia at another hospital. Cultures from a bronchoscopy and thoracentesis were reportedly negative. He did not complete the antibiotic course because of mucocutaneous candidiasis.
Pleural effusions are frequently seen in hospitalized patients, and almost all of these patients should undergo a diagnostic thoracentesis for further evaluation.3 Effusions can evolve into empyema, which has considerable morbidity and mortality.4 The annual incidence in the United States is 60,000 cases,4 and mortality rates of 10% to 20% have been reported.4,5 Thus, performing a thoracentesis and analyzing the pleural fluid is of paramount importance.
The causes of empyema include bronchopulmonary infection, thoracic or esophageal surgery, infradiaphragmatic sepsis, and idiopathic causes. Bronchopulmonary infection may be due to pneumonia, aspiration, or bronchopleural fistulas.4,9 In one study, neurologic injury or illness was the contributing cause of empyema in 13 (18%) of 71 patients; in 7 of the 13 patients, empyema was caused by aspiration.10 Other risk factors for empyema include diabetes mellitus, alcohol abuse, gastroesophageal reflux disease, intravenous drug use, carcinoma, cirrhosis of the liver, malnutrition, bronchiectasis, and HIV.4,9 Up to one-third of cases occur with no identified risk factor.4
Diagnostic thoracentesis can aid in the diagnosis and the treatment plan for almost all pleural effusions. The exceptions to this rule are patients with typical chronic heart failure or patients with a very small effusion (<10 mm on lateral decubitus chest radiography).1,4 Pleural fluid analysis can be the basis of a definitive diagnosis if cytology is positive or an organism is isolated.1 It is especially helpful in determining if an effusion will require drainage because radiologic findings and an elevated white blood cell count cannot reliably predict who will need this intervention.4 Antibiotic therapy and chest tube placement are the initial treatment measures for patients with a complicated parapneumonic effusion and empyema.4 Some evidence supports that a pleural fluid pH of less than 7.2 is the best predictor of effusions requiring chest tube drainage.4 How long the chest tube should remain in place for optimal treatment remains unclear, but removal of the chest tube can be considered when the patient has clinically improved and output has markedly decreased.4 Empiric antibiotics should be initiated while waiting for culture results. Community-acquired infections should have coverage for gram-positive cocci such as Streptococcus species with a second-generation cephalosporin or an aminopenicillin with a β-lactamase inhibitor plus anaerobic coverage.4 Hospital-acquired infections require broad-spectrum antibiotics with coverage for MRSA.4 The duration of therapy has not been adequately studied, but most information recommends at least 3 weeks of antibiotic therapy with at least 1 week of intravenous antibiotics.4
If antibiotic therapy and chest tube placement fail, the next best step in management remains controversial. Some randomized controlled trials have demonstrated a high success rate with the use of fibrinolytic agents.4,6,8,11 One study of 53 patients by Diacon et al11 showed a higher clinical success rate with intrapleural streptokinase vs intrapleural saline, with 9% vs 45% of patients requiring surgical intervention, respectively. However, this advantage for intrapleural streptokinase was brought into question by a 2006 meta-analysis showing that the benefits associated with its use (eg, decreased hospital stay, improved radiographic appearance, and decreased rate of surgery) were inconsistent across studies.4,6 The controversy developed after the MIST1 study, which included 454 patients with empyema who were randomized to receive intrapleural fibrinolytic therapy or intrapleural saline in addition to antibiotics and chest tube drainage, showed no difference in the rates of death or surgery at 3 or 12 months.4,6,7 This has been the only study powered to address mortality and the need for surgery.4 Although fibrinolytic agents are not part of the initial management of empyema, they have been found to aid in thoracic decompression; thus, they may have a role in the treatment of selected patients.4,6 More studies are needed to determine the utility of fibrinolytic agents. Patients whose condition does not clinically and radiographically improve after 7 days of standard treatment should have a consultation to determine if they are candidates for surgical intervention. Video-assisted thoracoscopic surgery can be used to divide adhesions and septae to allow for better drainage through the chest tube.4,8 However, this procedure may not be sufficient, and thoracotomy with decortication may be needed.4 Thoracotomy with decortication has been reported to have a 95% success rate in certain groups with associated decreases in length of stay and drainage times.4 This surgical treatment may aid in the recovery of lung function and in the prevention of sepsis.4
When evaluating a patient with chronic cough, fever, and weight loss, the differential diagnosis commonly includes lung cancer, M tuberculosis infection, HIV, COPD, and interstitial lung disease. In this case, chronic aspiration with empyema was the cause. Aspiration is a known risk factor for empyema, and patients with dysphagia after stroke are at risk of aspiration. Recognition of this risk and appropriate diagnostic work-up can help prevent morbidity and mortality. This case demonstrates the potential long-term risks of chronic aspiration and the importance of performing a diagnostic thoracentesis in patients with significant effusions.
See end of article for correct answers to questions.
correct answers: 1. a, 2. b, 3. d, 4. c, 5. c