Persistent Air Leak

There are three simple scenarios that describe persistent air leak: persistent air leak after parenchyma injury, after anatomic lung resection, and in ventilated patients. Persistent air leak after parenchyma injury can occur because of penetrating injury, blunt trauma with maceration or rib penetration, or in patients with underlying predisposing parenchyma lesions, primarily bullous disease. In this setting, management has followed the algorithm for spontaneous pneumothorax. Simple tube thoracostomy suffices in more than 80% of cases as long as there is full expansion. Occasionally, placing the chest drain to water seal will actually hasten resolution as the transpleural gradient is diminished. Air leak during more than 3 days or associated with recurrent pneumothorax appear to be most efficiently managed by thoracoscopic approaches than persistent chest drainage. Schermer and colleagues reviewed the course of 39 trauma patients who, except for air leak, were ready for discharge. This was determined by air leakage over more than 3 days. Twenty-five agreed to video-assisted thoracoscopic surgery (VATS) with reduced chest tube duration (total 8 vs. 12 days) and length of stay (10 vs. 17 days). Of course, technical factors should be ruled out (tube dislodgement or disconnection). Computed tomography (CT) scans can help define local lesions that may be amenable to thoracoscopic wedge resection or glue application, which may also prompt earlier VATS. In many instances, simply breaking down soft loculations and placing a chest drain under direct vision is the primary therapeutic benefit of thoracoscopy. We prefer to not use chemical pleurodesis, but rather pleural abrasion as we feel that this reduces the risk of parenchyma trapping and the uncertain long-term impact of chemical agents in younger patients. Patients with underlying lung lesions should be managed as they would in nontrauma circumstances. A final option in patients with prohibitive operative risks or small leaks is to convert the patients to Heimlich valve and manage them outpatient. As many as 80% will seal within 3 weeks using this approach.

As lobectomy and pneumonectomy are rarely performed for traumatic injury, it follows that the incidence of air leak (bronchopleural fistula [BPF]) is also small. However, the nature of acute lung resections is such that the risk is higher than after elective resection. Risk factors include long stumps, devascularization, and contaminated hemothorax. Ideally, after lobectomy/pneumonectomy, the stump should be reinforced either at the time of original resection or second-look exploration with pleural, intercostals, or other flap. Once it occurs, management is determined by timing (less than or more than 7 days postoperatively), degree (ventilatory compromise and whether the defect can be visualized endoscopically), physiologic status, and whether the patient is ventilated. BPF may present in stable patients as a new productive cough, with a drop in pleural fluid levels (after pneumonectomy) of two or more rib spaces, or new air–fluid level. In ventilated patients, empyema and loss of tidal volume may predominate. The primary goal is to prevent aspiration. In nonintubated patients, this is best accompanied by upright positioning or affected side down. Then, drainage should be instituted if a chest drain is not in place. If a drain is not in place, the new drain should be placed above the thoracotomy scar, as the diaphragm tends to rise to the level of the scar and adhere. If the leak is small, and endoscopically the hole cannot be clearly visualized, it is reasonable to attempt bronchoscopic glue application. Reoperation and stump closure are possible within 7 days, but the associated empyema increases the risk of failure. The longer the interval between the initial and second operation, the greater the difficulty. After pneumonectomy, the mediastinum becomes inflamed, the stump can only with difficulty be visualized, and mobilization is essentially impossible. Thus, after pneumonectomy, the best option is probably to occlude the stump with omentum, pack the chest with packs, and plan serial washouts until the leak scarifies closed. An alternative approach, particularly after right-sided pneumonectomy, is to perform transcarinal right mainstem resection. The residual stump cannot be removed as it tends to be fixed, but the mucosa should be cauterized and omentum or other viable tissue should be used to reinforce the new stump. The empyema cavity can then be treated by the drainage procedure of the surgeon’s choice. After lobectomy, similar options are possible, but further resection may be required (e.g., right middle lobectomy after right lower lobe stump leak).

Persistent air leak in a ventilated patient without a discrete lesion is better thought of as an alveolar-pleural fistula rather than a BPF. Clearly, the underlying lung injury affects outcome, with alveolar-pleural leak in adult respiratory distress syndrome patients being associated with up to 80% mortality. Whatever the underlying anatomy, air leak in ventilated patients can be a significant marker of increased mortality. Pierson and colleagues reviewed the course of 39 patients (out of a population of 1700 mechanically ventilated patients) who presented with air leak lasting more than 24 hours, of whom 27 were trauma patients. The risk factors for mortality correlated with the following: air leak not present on admission or shortly thereafter (45% early vs. 94% if developed later); leak greater than 500 ml per breath (57% if less vs. 100% if greater); and post–chest trauma (56% for trauma admissions vs. 92% for nontrauma admissions). These findings illustrate that while the course in trauma admissions is more benign, it still represents a major concern. On the other hand, the air leak itself is rarely the cause of death. These air leaks can lead to persistent or even tension pneumothorax that compromises ventilation. Pleural tubes (at times multiple) may be required. Less commonly, air leak is significant enough to affect oxygenation. The primary treatment is to minimize alveolar pressure, using end-inspiratory plateau pressure as an (admittedly crude) reflection of this. Ideally, the end-inspiratory plateau pressure should be less than 30 cm H₂O. The most common method of attaining this is to combine low tidal volume and permissive hypercapnia. Alternative methods if this approach fails are high-frequency jet ventilation or independent lung ventilation. It should be stressed that high-frequency jet ventilation, although used successfully in patients with central airway disruption and in the operating room, does not reduce mean airway pressure consistently, nor does it uniformly reduce air leak or improve oxygenation. Thus, it should not be used routinely in patients with alveolar-pleural fistula. A temporizing technique is to isolate the lobe that is the primary source of leak bronchoscopically. This is done by sequentially occluding bronchi with a Swan-Ganz or other balloon catheter. If this results in elimination or significant reduction in air leak, occlusive material (Gelfoam, fibrin glue, blood mixed with tetracycline, etc.) can be injected. In most cases, the air leak will diminish as airway pressure decreases. Surgery can be performed, but in the setting of diffuse parenchyma injury, lung inflammation, severe emphysema, and/or steroids, the risk is that staple lines will fail and the leak will be exacerbated. If surgery is felt to be needed, reinforced staple lines (i.e., with bovine strips, etc.), apical tents (mobilizing the apical pleura so that it falls onto the area of resection), and/or anatomic lobectomy (if predominantly one lobe) should be considered.

Pneumatocoele/Hematoma

Pneumatocoeles occur when disruption of lung parenchyma leads to internal rather than external leak of air and/or blood. They occur more commonly after blunt injury, but can be seen occasionally with deep stab or low-caliber missile injuries. These lesions are thus best described as a pulmonary laceration. They are usually solitary, at times multilobulated, and occasionally multiple. They are typically not apparent on initial radiographs, because small size and/or a superimposed contusion or hemorrhage obscures them. Over time, they evolve into thin-walled cavities with air and/or fluid. The location and size are affected by the mechanism. Compression leading to rupture, the most common mechanism, tends to be associated with central lesions. Compression, leading to shear forces, tends to present as an elongated paramediastinal cavity extending from hilum to diaphragm, and may be confused with loculated pneumothorax. Rib penetration forms tend to be small and peripheral. Adhesion tears are the least common. In the vast majority of cases, pneumatocoeles are benign. In rare cases, they may result in persistent air leak or become infected, in which case they are treated as abscesses.

Hematomas are formed by the same mechanisms that result in pneumatocoeles. They may remain solid, or with partial evacuation they can develop an air-fluid level or even a fibrin wall resulting in a crescent of air on the superior surface that mimics a fungus ball. Usually these lesions resolve over 3–6 months, and recognizing the shrinking process is one method to avoid confusing these with malignant processes.

Pneumonia

Pneumonia may be the most common complication of chest trauma. Risk factors include aspiration, need for ventilation, direct injury, pulmonary contusion, and persistent atelectasis secondary to pain. The incidence is as low as 6% in nonintubated patients to as high as 44% in ventilated patients. Despite the high incidence, there are no data supporting prophylactic antibiotics. Of all patients admitted with a diagnosis of pulmonary contusion, nearly 50% will develop pneumonia, barotrauma, and/or major atelectasis. One-fourth will progress to adult respiratory distress syndrome. Ventilatorassociated pneumonia (VAP), defined as pneumonia arising more than 48 hours after initiation of mechanical ventilation, is difficult to define and diagnose. At our institution, we have found that the incidence in patients ventilated for more than 7 days ranges from 20% to 30%. Clinical suspicion is often raised by new infiltrates, recurring fever, rising leukocytes, and/or a change in endotracheal secretions. However, distinguishing between colonization and infection may require specialized techniques. Quantitative cultures obtained from a variety of approaches increase the specificity (although perhaps with reduced sensitivity) of endobronchial cultures, and each institution must define cut-off values based on whether the patient is already receiving antibiotics (Table 1).

Necrotizing Lung Infection

Necrotizing lung infections comprise a triad of clinical scenarios that overlap or can be present concomitantly. These are lung abscess, necrotizing pneumonia, and lung gangrene. All three are similar in that lack of perfusion is combined with tissue devitalization. In simplistic terms, lung abscess can be described as a region of necrosis less than a lobe with viable surrounding or bordering parenchyma. Lung gangrene represents complete lobar or entire lung destruction, often with only a rim of tissue remaining. Lung necrosis is best represented by patchy, often nonanatomic, loss of perfusion with variable parenchyma destruction, often seen on radiograph as multiple small abscess-like cavities. Although the three can be discussed separately, in most cases two or three coexist and so the management can also overlap.

The cause(s) of lung abscess in the surgical intensive care unit (ICU) population include aspiration, complications of pneumonia, retained foreign body, septic emboli, and/or infected traumatic injury. More specific etiologies in the trauma population include aspiration (with or without bronchial obstruction), infected pneumatocoele, infected site of resection (in particular emergent tractotomy), and late complications of ventilatorassociated pneumonia. As a whole, these are less common in trauma patients than nontrauma patients. Of 45 thoracotomies performed at our institution over 7 years for abscess, necrotizing pneumonia, and lung gangrene, only 4 were in patients initially admitted after traumatic injury.

The diagnosis of lung abscess may be relatively simple. Fever, purulent sputum production, or hemoptysis may prompt chest radiograph, which will identify an air-fluid cavity. On the other extreme, a persistently febrile patient in the ICU with dense consolidation may require CT scan before the underlying cavity can be recognized.

Over the three decades of approximately the 1950s through the 1970s, a number of advances reduced the mortality rates from approximately 50% to 10%. These advances included recognizing the importance of antibiotics, the role of aspiration, the need for pulmonary toilet (including liberal use of bronchoscopy), and finally the benefit in selected patients of operative intervention. Subsequently, the major addition to the armamentarium has been image-guided catheter drainage as an intermediate category between medical and surgical management. Percutaneous catheter drainage can be performed even in ventilated patients and has reduced the number of thoracotomies required. While there is always concern about the risk of empyema and/or bronchopleural fistula, the former can be usually easily managed by chest drainage, and the latter is rarely so significant as to impair oxygenation. Some patients will require thoracotomy, which, in the trauma population, usually results from persistent sepsis and inability or incomplete drainage, hemoptysis, or persistent or major bronchopleural fistula (see Table 1). The two primary operations are lobectomy for large central cavities, or debridement (plus muscle flap to help close the space) for smaller peripheral cavities. At operation, there are several technical points that can help reduce complications: prevent aspiration by isolating the affected lung before posterolateral positioning; expose the main pulmonary artery early in the case so that control can be achieved should hemorrhage result; place a nasogastric tube or esophagoscope in the esophagus because the anatomy may be obliterated; and refrain from resecting small abscesses (<2 cm) that are in otherwise viable parenchyma. Air leak is not uncommon, and, as will be discussed under the empyema section, a residual space can be managed with continuous postoperative irrigation.

The distinguishing characteristics of lung gangrene are central vascular thrombosis and bronchial obstruction, leading to significant cavitation and/or lobar or whole-lung liquefaction. As opposed to lung abscess, there is no firm, well-defined capsule. Both these features are defined by CT with intravenous contrast, and either one predicts the failure of medical therapy. This is because medical therapy relies on both blood supply for antibiotic therapy to be effective and on bronchial patency to allow expectoration of purulent material. Schamaun and colleagues followed 14 patients with unilateral complete lung gangrene. Four were treated medically and all died, while 10 underwent surgical resection with 100% survival. Some patients have diffuse bilateral disease. In the face of persistent signs of infection, if there is a primary target site, surgery is still possible and can be performed even if the patient cannot tolerate independent lung ventilation. Interestingly, dissection in the fissures and of the vessels is relatively easy, as the necrotic tissue tends to be easily swept aside. However, surgery resection should not be performed if the patient is pressor dependent. In this setting, it is better to temporize with pleuroscopy to treat associated empyema and percutaneous drainage of the large cavitary lesions.

Necrotizing pneumonia is characterized by areas of dense consolidation, patchy perfusion, and often multiple small cavitary changes. Percutaneous drainage does not help in this setting. Generally, parenchyma resection is not indicated. However, serial CT scans can identify areas that are developing demarcation lines, and in the setting of persistent pulmonary sepsis resection can be a reasonable option.

Bronchial Stricture

Of patients with blunt traumatic injury to the distal trachea or bronchi, 10%–20% are not diagnosed acutely, but in a delayed fashion as stricturing occurs. In approximately two-thirds of these cases, suppuration, persistent atelectasis, and/or hemoptysis develop within 1–2 weeks of injury. In the remainder, presentation may be delayed years until “asthma,” dyspnea on exertion, and/or delayed parenchyma necrosis develops. Any young patient with new-onset asthma should be considered for airway evaluation if this develops 1–2 years after blunt traumatic chest injury, even if initial radiographic and bronchoscopic work-up was done and was normal. Bronchoscopy, CT scan, CT (or “virtual”) bronchography, and/or flow-volume loops can help make the diagnosis depending on clinical circumstances. If postobstructive parenchyma destruction has occurred, then distal lung resection is required. If not, airway resection and reconstruction can salvage the distal lung. In chronic settings, there may be a suggestion of lack of perfusion to the affected lung. In the absence of clinical signs of sepsis and evidence of lung necrosis, attempts should be made to reconstruct the airway, as in most cases this lack of perfusion is a hypoxic vasoconstrictive response that reverses when ventilation is restored. In patients who are too unstable, airway stenting can be tried to maintain airway patency as a temporizing measure. In patients who present years later with a chronic fibrotic stricture, balloon dilation and repeat stenting may be an alternative to operative repair as well.

Pulmonary Torsion

Lobar torsion is exceedingly rare after trauma and is reported more commonly after upper lobectomy when the middle lobe can swing freely in the residual space. Recognizing this potential, stapling the middle lobe to the lower lobe can prevent this from occurring. Alternatively, the lung may torsed during thoracotomy, during retraction to expose posterior mediastinal structures, particularly if the inferior pulmonary ligament has been divided. The key to prevent this complication is to observe that the lung expands properly before closing the chest. Primary pulmonary torsion is exceedingly rare, but not unheard of. Schamaun reviewed 26 cases of torsion in the literature and found that 5 were post-traumatic. Possible mechanisms include focal injury to one lobe, in the setting of a complete fissure, resulting in a focal immediate twisting or delayed torsion as hemorrhage and edema create a lead point. The diagnosis may be suggested by lobar consolidation and the development of fever and hemoptysis, eventually developing into frank pulmonary sepsis. The diagnosis can be confirmed by bronchoscopy, which documents a “fish-mouth” appearance of the affected bronchus, occasionally with blood and/or purulent material intermittently draining. When diagnosed, immediate operation is required. If not frankly gangrenous, the lobe should be “de-torsed” to assess viability. If not viable, lobectomy is required. If viable, it should be stapled to an adjacent lobe to prevent retorsion.

Retained Parenchyma Missiles

The need for removal of parenchyma foreign objects is based on the risk of developing complications, which appear to be more common with irregularly shaped missiles compared with smooth objects. The University of Heidelberg reviewed the course of 55 patients who had retained bullets. Thirty-four experienced recurrent hemoptysis (single episode in eight). A Finnish review of 502 patients over several years noted that 20% developed complications requiring surgery. These included chronic bronchitis (39), lung abscess (31), bronchiectasis (5), empyema (24), and/or bronchopleural fistula (10). Many contemporary recommendations are based on data from World War II and in the two decades following, including the aforementioned studies. In World War II, early removal of retained missiles was associated with 0.9% mortality, while late removal of symptomatic objects was associated with 7.3% mortality. However, it was noted then and subsequently that waiting 2–6 weeks to allow parenchyma inflammation to resolve was also associated with easier removal, with reduced complications, notably less bleeding, air leak, and empyema. The technique of removal obviously depends on the location and nature of the missile. Peripheral objects can be removed by wedge resection. Deeper objects can be retrieved via tractotomy or occasionally lobectomy if there is significant associated destruction, necrosis, or infection. Uncommonly, over time central foreign objects can erode into the bronchi, leading to obstructive pneumonitis and abscess formation. These may be retrieved endoscopically, while severe tissue destruction, if present, mandates lobectomy. Alternatively, these objects may migrate peripherally, resulting in empyema. These can be retrieved and the empyema managed by VATS or thoracotomy.

Retained Hemothorax

Tube thoracostomy fails to completely evacuate hemothorax in approximately 5% of cases. Complications that may arise include empyema and/or fibrothorax. Conditions that predispose patients to both include prolonged ventilation, development of pneumonia, break in the pleura with residual blood (as is the case after tube thoracostomy), and/or other sites of infection. On the other hand, stable, nonventilated patients with small effusions (less than one-quarter hemothorax) following blunt trauma with no obvious pleural disruption usually will resolve without sequelae. In these patients the cornerstone of therapy should be observation.

The use of antibiotics, in particular with Gram-positive coverage, in many, but not all, reviews show a reduction in the risk of empyema. However, even those papers that support prophylactic antibiotics do not show an advantage to giving one dose, 24 hours worth, or keeping the antibiotic coverage until the drains are removed; all are equivalent. Thus, our practice is to give one dose only, unless there are other risk factors.

Early evacuation of hemothorax has been shown to reduce the incidence of complications preferably within 7 days when loculations begin to complicate pleural debridement. In particular, the risk of empyema is reduced. However, recognizing the extent of hemothorax can be difficult. Chest radiography can underestimate both the extent of parenchyma consolidation and the volume of retained blood, particularly in ventilated patients. Chest CT is much more accurate in this setting, but interpretation requires some individualization. Moderate effusions in ventilated patients or those with other risk factors should be aggressively drained when detected by CT.

When recognized acutely after injury, the simplest and most expeditious treatment is to place a second chest tube. When recognized after 1–2 days, this may not be helpful in that it may simply increase pain, splinting, and the risk of pneumonia with subsequent seeding of the pleural space. Intrapleural streptokinase (250,000 units) or urokinase (40,000 units) has efficacy of 65%–90%. Complications include fever and pain, but the risk of re-starting bleeding is negligible. The downside of this approach is that it takes several days longer than more direct operative drainage and will not break down loculations. Thus, it may be more useful after debridement when it is suspected that the clot is relatively “soft.”

Thoracoscopy offers the advantage of complete removal of all clots without the excess morbidity of a formal thoracotomy. Meyer et al. compared placement of a second chest tube versus thoracoscopy for treatment of retained traumatic hemothorax. Patients undergoing thoracoscopy had a shortened length of time requiring chest tube drainage, a shortened hospital stay (2.7 days less), and decreased total hospital costs ($6000 less) compared with patients treated with a second chest tube. There were no failures, no complications, and no patients who required conversion to a formal thoracotomy in the group randomized to early thoracoscopy. In contrast, a second chest tube failed to completely evacuate the retained hemothorax requiring operative treatment in over 40% of the patients.

Thoracotomies through “mini” approaches are often sufficient to allow removal of soft gelatinous visceral and pleural rind, permitting full lung expansion. Irrigation with warm saline facilitates clot removal. The denser the adhesions, the greater the exposure must be, and if a formal decortication of a formed visceral peel is anticipated, a standard approach is required. This can be facilitated by excising a rib subperiosteally to allow safe identification of the pleura.

In summary, patients with retained hemothorax, at risk of empyema, should be managed aggressively, preferably by early thoracoscopic drainage.²⁷ Occasionally, there are patients who present with delayed effusions, days after blunt injury, presumably partially because of missed small hemothorax and partially secondary to reactive fluid accumulation. If these patients have adequate pain control, have small effusions (less than one-fourth of the hemithorax), and have no signs of infection, tube thoracostomy does not need to be performed, as the risk of fibrothorax is negligible. Patients who present late (usually more than 3 months after injury) with an element of fibrothorax (but with no infection) should be managed nonoperatively, as at 6–9 months there is some remodeling and adaptation in most cases, and if surgery is required there is no increased difficulty if it is undertaken at a later date.

Empyema

Empyema occurs in 2%–7% of patients who undergo tube thoracostomy after trauma. Patients at risk include those with residual hemothorax noted on chest radiograph, concurrent pneumonia, pain with diminished cough, extrathoracic sites of infection, and/or possibly those who are ventilated and who have a chest tube in place. Trauma patients are at risk of developing Gram-positive empyema, characterized by early loculations and formation of dense adhesions because of hemothorax, which offers both a rich supply of bacterial nutrients as well as fibrin. These factors also tend to make empyema in trauma patients less amenable to simple drainage than the more common parapneumonic empyema seen in medical patients.

The diagnosis of empyema is based on the documentation of an exudative effusion, characterized in particular by an elevated pleural/serum lactate dehydrogenase ration (>0.6). In approximately 25%–30% of cases, cultures will be negative because of suppression but not eradication by antibiotics. It is not uncommon for patients to present with indolent courses, often characterized by a failure to wean from ventilation, with persistent fluid noted by CT or chest x-ray, despite tube drainage. Contrast CT scans often reveal a “rim sign” of enhancing pleura, indicative of ongoing inflammation. In many cases, once these “contaminated hemothoraces” are drained, the clinical picture rapidly improves.

Empyema has been described as having three stages. The first, usually within 1–7 days, is referred to as the “acute” or “serous” phase. This distinction is important because at this stage there is the best chance for draining the thin, exudative fluid by simple thoracostomy. There have been attempts to treat this early stage by simple aspiration. Evidence of vigorous inflammation (pH<7.0) almost universally predicts failure of this technique. Tapping may be appropriate in patients who have complex effusions, with or without loculations, but who have other potential sites of infection. However managed, it is imperative that complete drainage be achieved, or failing that, early operative drainage is performed before progressive pleural obliteration occurs, characteristic of progression to the second or “subacute” phase, and thence the final or “chronic” phase. Palpation at the time of thoracostomy and/or loculations noted on CT can alert the surgeon to the presence of loculations that would indicate simple tube drainage will fail.

Probably the major reason for earlier intervention is that minimally invasive approaches are more successful early, whereas with the passage of time the combined impact of pleural space obliteration and visceral peel leading to parenchyma trapping increases both the likelihood of requiring thoracotomy as well as the incidence of primary failure. As noted earlier, compared with nontrauma patients, empyema after trauma is much more likely to require operative intervention.

The primary treatment of empyema is to both completely drain the thorax and to permit full lung expansion. There are several “local” considerations that may impact operative approach and outcomes (Table 2). Predominant among these are whether loculations and/or a restrictive visceral peel have formed. In the acute setting, particularly when clinical signs suggest active infection, the primary goal is simply to drain the pleura. Evidence of loculations suggests that simple tube drainage will fail. Alternative approaches could include image-directed catheter placement, thoracoscopic drainage, and “mini” or full thoracotomy. Thrombolytic therapy has been advocated as an alternative to operative intervention, but current data suggest that when compared with thoracoscopic approaches as primary intervention, thrombolytic therapy is associated with a higher failure rate, increased length of stay, and greater cost. Thrombolytic therapy is a reasonable alternative in patients who are deemed at high risk for operative intervention, and whose loculations may be diaphanous. In essence, these criteria would be in the uncommon scenario of a patient who is clinically infected and frail but not yet intubated, as once a patient is on the ventilator, the primary complication of operative approaches (respiratory failure) has already occurred. Thrombolytic therapy does have a role in the early postoperative period after operative decortication residual loculated fluid collections are present. In this setting, the fibrinous adhesions are “soft” and may be lysed.

Table 2 Considerations When Treating Empyema

Thoracoscopy, both VATS and pleuroscopy (using a mediastinoscope) have been compared with thoracotomy in a variety of series, which tend to be nonrandomized. VATS appears to be associated with decreased morbidity and shorter length of stay; however, it is usually performed much earlier in the hospital course when loculations are less formed and the patients clinically more stable. VATS may not be technically possible because of high ventilator requirements precluding lung isolation and/or dense pleural symphysis. An alternative approach is “rigid” thoracoscopy or pleuroscopy. Pleuroscopy can be performed on these patients, using CT imaging to direct the initial approach. The wider port allows easier debridement and suctioning, and visceral decortication is possible except in the most fibrotic cases.

Irrigation postoperatively is a useful adjunct in certain cases. The goal of irrigation may be to wash out blood from the operation, thus preventing new, vigorous adhesions. In addition, antibiotics can be added to improve local treatment of resistant organisms (such as Candida or methicillin-resistant organisms). Irrigation systems can be modified according to circumstances (e.g., a Jackson-Pratt drain connected to intravenous tubing via a three-way stop cock). The actual volume of irrigation is flexible, although we usually use 100 cc/hr. To avoid excessive drainage through the incision or drain sites, these need to be closed tightly. When the pleural effluent is clear and culture negative, the irrigation can be discontinued. One potential disadvantage of postoperative irrigation is that pleural symphysis may be prevented, resulting in residual spaces. On the other hand, if a residual space is anticipated, irrigation is particularly effective. In fact, in some cases, as the chest tubes are removed, it is possible, for example, to convert the Jackson-Pratt back into a simple bulb drain, which is better tolerated by the patient.

The residual pleural space remains a problem, requiring a flexible approach, depending primarily on whether the lung is capable of expanding (Table 3). In the trauma population, the primary reason for failure of lung expansion is visceral peel, while in nontraumatic empyema, the etiology is relatively equally divided among visceral peel, parenchyma consolidation, and/or space after lung resection.

Table 3 Managing Residual Space