The management of infections of the pleura, many of which progress to frank thoracic empyema, has long been a challenge for physicians and surgeons. During the past century, advances in surgical technique, introduction of powerful antibiotic drugs, and, more recently, introduction of better imaging techniques and use of powerful adjunct drugs, have caused an ongoing reexamination of the role of surgical vs nonsurgical treatment.
The debate of one therapeutic approach vs another continues in this issue of Mayo Clinic Proceedings. Levinson and Pennington,
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from the Mercy Medical Center of North Iowa in Mason City, report their experience with 27 consecutive patients treated with a combination of image-guided chest tube drainage and intrapleural fibrinolytics during a period of 10.5 years. All patients had clinical evidence of pneumonia and the fibropurulent stage of pleural infection. Chest tubes were placed either at the bedside or with computed tomographic (CT) or ultrasound guidance. Urokinase was used initially as an intrathoracic infusion but was later replaced with tissue-type plasminogen activator. Changes on chest radiography were graded using improvement in the percent opacification of the hemithorax. Although the authors report a significant improvement in most of their patients and that no patient required surgery, they also report a 10% early mortality.This retrospective review raises interesting questions about the management of pleural infections and empyema, the latter defined as frank accumulation of pus in the pleural cavity. Although treatment of the infecting agent and removal of pus are fundamental elements of treatment, the success of management also is influenced by numerous other important factors.
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Levinson and Pennington report that their approach to nonsurgical therapy provides favorable results compared to other treatment options; however, several bits of critical information are missing. These include the following.Early Detection of Pleural Effusion. Early detection and early initiation of therapy are critical to the success of treating pleural infections and any associated pleural effusions, including pus. Unfortunately, in the report by Levinson and Pennington, the exact timing of first chest tube insertion in relationship to the diagnosis of effusion is unclear. They report a median period of 9 days between onset of illness and placement of the first tube; however, one wonders if earlier intervention would have resulted in even greater improvement.
Accurate Definition of the Stage of Pleural Infection and Precise Anatomic Characterization of the Pleural Space, Including an Estimation of Pleural Fluid Volume and Identification of Loculations if Present. Not surprisingly, the extent of infection and the involvement of surrounding anatomic structures are critical to the success in treating pleural infection, ie, earlier treatment of less-serious infections yields better outcomes. To the authors' credit, all their patients were diagnosed at the fibropurulent stage, and all underwent initial CT for appropriate imaging of the chest.
Appropriate Antimicrobial Therapy. Antimicrobial therapy that is accurately targeted to the infecting organism is also critical to the success in treating pleural infection. Levinson and Pennington treated all patients with antibiotics tailored to positive cultures of the pleural fluid, but readers are not informed of the duration of therapy. Clearly, the duration of antibiotic administration will be dictated by the patient's condition and cannot be overly generalized. However, in our surgical practice at the Mayo Clinic in Rochester, Minn, we tend to give antibiotics for 1 month after decortication for pleural infection, as suggested by our microbiologists.
Treatment of Underlying Conditions When Present. Two of the patients in the study by Levinson and Pennington had underlying conditions. One had a chest tube placed for a pneumothorax 1 month before the diagnosis of pleural infection. We are not told whether a bronchopleural fistula was ruled out in this patient. Nor are we adequately informed of the management of the patient with a subdiaphragmatic abscess and whether it was adequately drained. Clearly, these issues have a bearing on patient outcomes.
Effective and Complete Treatment of the Pleural Infection. Levinson and Pennington relied on abnormalities on chest radiography to determine whether further CT imaging and possibly more chest tube insertion and fibrinolytic therapy were necessary. They elected not to drain residual collections of less than 3 to 4 cm or containing less than 50 to 75 mL. That is a concern. Specifically, their approach does not adequately guide other clinicians in determining how to manage persistent fluid collections, especially when the patient is asymptomatic.
Provision of Adequate Nutrition. Levinson and Pennington's study patients presented challenges, as suggested by the high incidence (80%) of preexistent comorbidities. No details are given regarding the nutritional status of these patients. Because patients with pleural infection are likely to become hypermetabolic and their ability to obtain adequate oral nutrition may be compromised, nutritional assessment and support are important.
Management of Complications Related to the Pleural Infection Itself or Its Treatment. No serious complications were reported directly related to treatment in the article by Levinson and Pennington. One patient had hemoptysis, which was treated successfully without interruption of the fibrinolytic treatment. This is encouraging.
Prompt Initiation of Surgical Intervention if Medical Measures Fail. Not enough information was provided to determine whether the approach used by Levinson and Pennington is generalizable to other patient populations. It is unclear whether surgeons were ever involved with the study patients and whether any surgical opinion was provided. One would hope that, in their quest to explore nonsurgical management, the authors did not resist surgical input in the care of these patients with challenging comorbidities. There were 3 early deaths and 2 additional deaths within 3 months of hospital admission. Two of the early deaths were due to respiratory failure. One wonders if timely surgical intervention may have had some bearing on the outcomes in these patients.
In agreement with the approach used by Levinson and Pennington, Robinson et al
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reported that fibrinolytic therapy appears to be safe and cost-effective and may result in patients not needing surgical intervention if therapy is given before formation of a pleural peel and lung entrapment. More recently, a United Kingdom-based randomized controlled trial reported that intrapleural administration of streptokinase did not improve mortality, rate of surgery, or length of hospital stay.4
Levinson and Pennington dismissed the importance of the latter study on the basis of methodology and an interpretation that streptokinase might be less effective in patients with pleural infections than the fibrinolytics they used.Levinson and Pennington provided a recommended protocol based on their experience (Table 4). I emphasize and add to their recommendations the importance of a multidisciplinary approach in the care of such patients. Would it not provide a better service to the patient if a surgeon and possibly an infection disease specialist were involved early in the course of treatment?
On the basis of the data presented, it is reasonable to accept the conclusion of the article that “intrapleural urokinase and tissue-type plasminogen activator in combination with careful image-guided placement of chest tubes are highly effective in resolving the effusion and curing the infection” (in selected patients). Unfortunately, it is also easily concluded from the article that surgical treatment “is rarely necessary,” an assessment that I question. The authors correctly point out the retrospective nature of the study and the small cohort during a 10.5-year period, both factors that must be weighed when interpreting their results and their optimism for their specific clinical approach.
If pleural infection is suspected, thoracocentesis is indicated to obtain fluid for immediate Gram stain and for both aerobic and anaerobic cultures. Once the diagnosis is established, appropriate parenteral antibiotics must be administered, adequate tube thoracostomy drainage obtained, and all residual pleural space obliterated. No sufficient level of evidence is available at this time to recommend routine fibrinolytic therapy for early-phase pleural infection. However, as demonstrated by Levinson and Pennington, that approach will often be successful for patients in the fibropurulent stage. If a bronchopleural fistula is absent, these measures are sufficient to successfully manage acute pleural infection in most patients. If the lung fails to expand fully, thoracoscopy may be of benefit in removing encapsulating fibrin and exudate in both the acute and the subacute phases. Once the pleural infection is chronic, thoracotomy with decortication is required.
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REFERENCES
- Intrapleural fibrinolytics combined with image-guided chest tube drainage for pleural infection.Mayo Clin Proc. 2007; 82: 407-413
- Current diagnostic methods and medical management of thoracic empyemas.Chest Surg Clin N Am. 1996; 6: 419-438
- Intrapleural fibrinolytic treatment of multiloculated thoracic empyemas.Ann Thorac Surg. 1994; 57: 803-813
- U.K. controlled trial of intrapleural streptokinase for pleural infection [published correction appears in N Engl J Med. 2005;352: 2146].N Engl J Med. 2005; 352: 865-874
- Empyema and bronchopleural fistula.Ann Thorac Surg. 1991; 51: 157-158
- Postoperatiuve empyema.Chest Surg Clin N Am. 1992; 2: 813-822
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© 2007 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.
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- Intrapleural Fibrinolytics Combined With Image-Guided Chest Tube Drainage for Pleural InfectionMayo Clinic ProceedingsVol. 82Issue 4
