Lung Abscess Surgery 

Updated: May 03, 2018
Author: Shabir Bhimji, MD, PhD; Chief Editor: Jeffrey C Milliken, MD 

Overview

Background

A lung abscess is a subacute infection that destroys lung parenchyma. Furthermore, chest radiographs reveal one or more cavities, often with an air-fluid level. Because the development of a cavity requires some amount of prior tissue damage and necrosis, it may be presumed that lung abscesses usually begin as a localized pneumonia.

Before the availability of antibiotics, a typical abscess arose from complications after oral surgical procedures (ie, tonsillectomy), resulting in aspiration of infected material into the lungs. In the absence of satisfactory antibiotic treatment, this event usually led to a lung abscess or to a necrotizing pneumonia with or without pleural empyema.

In the preantibiotic era, the clinical course of a patient with a lung abscess would gradually worsen. At one time, mortality was in excess of 50%, and many patients were left with significant residual symptomatic disease. Most patients underwent surgery during the latter stages of the disease, and the results were discouraging.

The availability of effective antibiotic therapy for primary lung abscess has drastically modified the natural history of the disease and diminished the role of surgery. In current practice, operative indications are less frequent, and these procedures are undertaken electively for chronic illnesses only after medical therapy has been unsuccessful.

In addition to antibiotics, pulmonary care has advanced and now includes postural drainage. Currently, bronchoscopy is occasionally employed as an adjunct to expedite drainage and to identify underlying occult lesions such as foreign bodies and malignancies.

The increasing use of corticosteroids, immunosuppressive drugs, and chemotherapeutic agents has changed the natural milieu of the oropharyngeal cavity and contributed to the mounting frequency of opportunistic lung abscesses.

Lung abscesses are commonly classified on the basis of their duration, as follows:

  • Acute - <6 weeks
  • Chronic - >6 weeks

They may also be classified as follows:

  • Bronchogenic (due to inhalation or aspiration)
  • Hematologic (spread via the bloodstream from other infected sites)

For patient education resources, see the Infections Center, Lung and Airway Center, Pneumonia Center, and Procedures Center, as well as Bacterial Pneumonia, Abscess, Antibiotics, and Bronchoscopy.

Pathophysiology

Aspiration of infectious material is the most frequent pathogenetic mechanism in the development of pyogenic lung abscess. Aspiration due to dysphagia (eg, achalasia) or to compromised consciousness (eg, alcoholism, seizure, cerebrovascular accident, or head trauma) appears to be a predisposing factor. Poor oral hygiene, dental infections, and gingival disease are also common in these patients.

Although lung abscesses can occur in edentulous patients, an occult carcinoma should be considered. Edentulous patients very seldom, if ever, develop a putrefied abscess, because they lack periodontal flora.[1]

Patients with alcoholism and those with chronic illnesses frequently have oropharyngeal colonization with gram-negative bacteria, especially when they undergo prolonged endotracheal intubation and receive agents that neutralize gastric acidity. A pyogenic lung abscess can also develop from aspiration of infectious material from the oropharynx into the lung when the cough reflex is suppressed in a patient with gingivodental disease.

Abscesses generally develop in the right lung and involve the posterior segment of the right upper lobe, the superior segment of the lower lobe, or both. This is due to gravitation of the infectious material from the oropharynx into these dependent areas. Initially, the aspirated material settles in the distal bronchial system and develops into a localized pneumonitis. Within 24-48 hours, a large area of inflammation results, consisting of exudate, blood, and necrotic lung tissue. The abscess frequently connects with a bronchus and partially empties.

After pyogenic pneumonitis develops in response to the aspirated infected material, liquefactive necrosis can occur secondary to bacterial proliferation and an inflammatory reaction to produce an acute abscess. As the liquefied necrotic material empties through the draining bronchus, a necrotic cavity containing an air-fluid level is created. The infection may extend into the pleural space and produce an empyema without rupture of the abscess cavity. The infectious process can also extend to the hilar and mediastinal lymph nodes, and these too may become purulent. (See the images below.)

Thick-walled lung abscess. Thick-walled lung abscess.
Histologic evaluation of lung abscess shows dense Histologic evaluation of lung abscess shows dense inflammatory reaction (low power).

Etiology

Lung abscesses have numerous infectious causes. Anaerobic bacteria continue to be accountable for most cases. These bacteria predominate in the upper respiratory tract and are heavily concentrated in areas of oral-gingival disease. Other bacteria involved in lung abscesses are gram-positive and gram-negative organisms.

More specifically, gram-negative organisms associated with lung abscess include the following:

  • Bacteroides species
  • Fusobacterium species
  • Proteus species
  • Aerobacter species
  • Escherichia coli

Gram-positive organisms associated with lung abscess include the following:

  • Peptostreptococcus species
  • Microaerophilic Streptococcus
  • Clostridium species
  • Staphylococcus species
  • Actinomyces species

Opportunistic organisms associated with lung abscess include the following:

  • Candida species
  • Legionella species
  • Mycobacterium species

However, lung cavities may not always be due to an underlying infection. Some evidence suggests that individuals with cyanotic heart disorders may also be more prone to lung abscess formation. The continuous hypoperfusion of the pulmonary tissues may predispose the individuals to chronic pulmonary infections.[2]

Factors contributing to lung disease include the following:

  • Oral cavity disease - Periodontal disease, gingivitis
  • Sinus infections
  • Altered consciousness - Alcoholism, coma, drug abuse, anesthesia, seizures
  • Immunocompromised host - Steroid therapy, chemotherapy, malnutrition, multiple trauma
  • Esophageal disease - Achalasia, reflux disease, depressed cough and gag reflex, esophageal obstruction
  • Bronchial obstruction - Tumor, foreign body, stricture, enlarged lymph nodes
  • Generalized sepsis
  • Persistent vomiting
  • Mechanical ventilation, tracheostomy
  • Intravenous drug use
  • Infected central venous catheters

Prognosis

The prognosis of patients with lung abscesses depends on the underlying or predisposing pathologic event and the speed with which appropriate therapy is established. Negative prognostic factors include the following:

  • Large (>6 cm) cavity
  • Necrotizing pneumonia
  • Multiple abscesses
  • Immunocompromise
  • Age extremes
  • Associated bronchial obstruction
  • Aerobic bacterial pneumonia

The mortality associated with an anaerobic lung abscess is less than 15%, though it is slightly higher in patients with necrotizing anaerobic pneumonia and pneumonia caused by gram-negative bacteria. The prognosis associated with amebic lung abscess is good when treatment is prompt. Overall, lung abscess can have a better prognosis and shorter length of hospital admission if the diagnosis is made promptly and a consensus on antibiotics is available.[3]

Most cases of empyema have an infectious cause and add high morbidity, as well as increase hospital costs. In patients who have empyema with a lung abscess, morbidity is even higher; hence, more aggressive early treatment is recommended.[4]

Over the years, numerous prognostic factors have been identified in patients with lung abscess. The two main factors are advanced age and the presence of comorbidity. The rate of reduction of the abscess is also felt to be predictive of recurrence. This again emphasizes the importance of follow-up with an imaging study, such as computed tomography (CT).[5]

In a study of 91 patients who underwent major thoracic surgery for infectious lung abscess at six centers for general thoracic surgery in Europe and and the United States, Schweigert et al found that the following were significant predictors of fatal outcome[6] :

  • Pulmonary sepsis
  • Septic complications (air leak, pleural empyema)
  • Septic organ failure (respiratory, acute renal failure)
  • Preexisting comorbidity (Charlson index of comorbidity ≥3)

The extent of surgical resection was not found to have a significant influence on the risk of a fatal outcome.[6]

 

Presentation

History and Physical Examination

Lung abscesses are considered to be acute or chronic, depending on the duration of symptoms at the time of patient presentation. The arbitrary dividing time is 4-6 weeks. Primary lung abscess are commonly observed in patients who are predisposed to aspiration or in otherwise healthy individuals, whereas secondary lung abscesses represent complications of a preexisting local lesion such as a bronchogenic carcinoma or a systemic disease (eg, HIV infection) that compromises immune function.

Generally, most patients admitted to the hospital with a diagnosis of lung abscess have had symptoms for at least 2 weeks. These patients typically have an intermittent febrile course, productive cough, weight loss, general malaise, and night sweats.

Initially, foul sputum is not observed in the course of the infection; however, after cavitation occurs, putrid expectorations are quite prevalent. The odor of the breath and sputum of a patient with an anaerobic lung abscess is often quite pronounced and noxious and may provide a clue to the diagnosis. Hemoptysis may occasionally follow the expectoration of putrid sputum. In patients with chronic lung abscess, one may observe digital clubbing.

Primary lung abscesses that occur after staphylococcal suppurative pneumonia in infants and children lack the typical indolent recurrent course of the more common postaspiration infections. Their onset tends to be abrupt and more threatening, producing chills, fever, tachycardia, tachypnea, and unremitting production of putrid sputum. The sputum is rarely without odor, because an anaerobic infection has no indolent course.

The physical findings are similar to those of pneumonia, with or without a pleural effusion. Auscultation may reveal coarse rhonchi and absent breath sounds. Clubbing of the fingers is sometimes noted.

Classification

Anaerobic necrotizing pneumonia

Usually, anaerobic necrotizing pneumonia is chiefly restricted to one pulmonary segment or lobe, though it may progress to encompass an entire lung or both lungs. This type of anaerobic lung infection is the most serious. The inflammatory process often spreads quickly and causes destruction characterized by greenish staining of the lung and a huge amount of putrid tissue, resulting in pulmonary gangrene. These patients are gravely ill with a progressive septic course. Leukocytosis is obvious, and the sputum is putrid.

Secondary lung abscess

In cases of secondary lung abscess, the fundamental process (eg, bacteremia, endocarditis, septic thrombophlebitis, or subphrenic infection) is generally apparent along with the pulmonary pathology. Infections below the diaphragm may extend to the lung or pleural space by way of the lymphatics, either directly through the diaphragm or via defects in it.

The most typical hematogenous lung abscesses are observed in persons with staphylococcal bacteremia, especially in children. These abscesses are multiple and are located in the periphery of the lung. Infections may arise in or posterior to an obstruction (eg, an enlarged mediastinal lymph node) and migrate to the lungs. Septic emboli from bacterial endocarditis or emboli from deep pelvic veins may result in metastatic lung abscess. Septic emboli are suggested when multiple lesions appear over an extended period.

Fewer than 5% of bland pulmonary infarcts become secondarily infected. Secondary infection of infarcts is suggested if fever and leukocytosis are present. Abscess formation may also occur within a necrotic pulmonary tumor.

Amebic lung abscess

Patients who develop an amebic lung abscess often have symptoms associated with a liver abscess. These may include right-upper-quadrant pain and fever. After perforation of the liver abscess into the lung, the individual may develop a cough and expectorate a chocolate or anchovy paste–like sputum that has no odor. The patient may give a history of diarrhea and travel outside the country.

Complications

Potential complications of lung abscess include the following:

  • Hemothorax or pneumothorax (from chest tube insertion)
  • Hemoptysis (from invasion of the bronchus) - This common complication can often be treated with bronchial artery embolization; occasionally, it can be massive, necessitating urgent surgical intervention
  • Empyema - Approximately one third of lung abscesses are complicated by  empyema; this may be observed with or without bronchopleural fistulas
  • Sepsis
  • Bronchopleural fistula
  • Acute respiratory distress syndrome (ARDS)
  • Brain abscess - This may occur in patients who receive inadequate treatment for their lung abscess
 

DDx

Diagnostic Considerations

Cavitary lesions in the lung parenchyma have several causes, but a patient with an acute presentation of an illness with air-fluid levels should elicit consideration of a lung abscess. Lung parenchymal cystic lesions and secondarily infected bullae can occasionally confuse the picture. The prior existence of these lesions, as documented by old radiographs and the segmental location, are not typical of lung abscess.

Patients with squamous cell bronchial carcinomas can also present with cavitary lesions that are sometimes difficult to differentiate from lung abscesses. Realizing that the wall of the carcinomatous abscess is usually thicker and more irregular than that of the primary abscess is helpful. Furthermore, foul sputum, no response to antibiotics, and the absence of fever may help distinguish the two entities.

Because an abscess distal to bronchial obstruction usually occurs in an area of lobar pneumonitis and atelectasis—but otherwise appears as a primary abscess—early bronchoscopy is recommended in all cases.

The differential diagnosis of a cavitary lung lesion includes the following:

  • Anaerobic infection - Gram-negative bacteria, Pseudomonas species, Legionella species, Haemophilus influenzae species
  • Infection by gram-positive bacteria - Staphylococcus species, Streptococcus species, Mycobacterium species
  • Fungal infection
  • Parasitic infection - Entamoeba histolytica, Paragonimus westermani
  • Sepsis - Embolism, cavitary infarction, bland infarction, Wegener vasculitis
  • Neoplasms - Bronchogenic carcinoma, metastatic carcinoma, lymphoma
  • Sequestration - Bulla with fluid, empyema with air fluid levels
  • Cystic lesions of the lung, infected emphysematous bullae and sequestration can be difficult to distinguish from a lung abscess
 

Workup

Approach Considerations

The diagnosis of a typical lung abscess can usually be confirmed on the basis of history and physical examination findings. Approximately 10-20% of patients with anaerobic lung abscess have no obvious oral cavity disease or predisposition to aspiration, which are the two most important factors in the development of anaerobic lung infection. Various laboratory studies, imaging modalities, and invasive diagnostic procedures may be useful in the workup of a lung abscess.

Lung abscesses tend to have a predilection for certain locations in the lung segments, of which the following are the most common:

  • Apical segment of the right lower lobe
  • Apical segment of the left lower lobe
  • Posterior segment of the right upper lobe

Middle-lobe involvement may occur in patients who are vomiting and aspirating in the prone position.

Laboratory Studies

Evaluation of expectorated sputum is the first step in the diagnosis of a patient with a lung abscess. Perform a Gram stain and culture for both gram-positive and gram-negative organisms and special staining for acid-fast bacteria and fungi.

Generally, in patients with a typical anaerobic lung abscess, sputum analysis is not useful, but such analysis can be helpful for excluding other causes of lung abscess (eg, tuberculosis and aerobic bacteria). The sputum Gram stain in patients with anaerobic lung abscesses often shows numerous polymorphonuclear leukocytes along with a mixture of bacteria, some of which are contaminants of oral flora.

Because of the presence of anaerobes in the oral cavity, cultures of these microorganisms are not worthwhile. Regular aerobic culture of expectorated sputum should always be performed. When a single predominant organism is cultured, it is considered to be the pathogen.

Empyema fluid, if accessible, provides an excellent medium. Occasionally, particularly with metastatic lung abscesses, blood culture findings may be positive. Most patients never have appropriate specimens obtained for culture; the majority are treated empirically and do well despite the lack of exact microbiologic culture results.

Imaging Studies

Radiography

The chest radiograph of a lung abscess is not pathognomic in the early stages (ie, before communication is achieved between the abscess cavity and the draining bronchus).

An area of thick pneumonic consolidation precedes the emergence of the typical cavitary air-fluid form. The distinctive characteristic of lung abscess, the air-fluid level, can only be observed on a chest radiograph taken with the patient upright or in the lateral decubitus position (see the images below). In the presence of associated pleural thickening, atelectasis, or pneumothorax, the air-fluid level may be obscured. When better anatomic interpretation is required, computed tomography (CT) has proved useful.

Lateral chest radiograph shows air-fluid level cha Lateral chest radiograph shows air-fluid level characteristic of lung abscess.
Chest radiograph reveals lung abscess occurring as Chest radiograph reveals lung abscess occurring as complication of necrotizing pneumonia.

Opportunistic lung abscesses are more difficult to diagnose. They occur in patients at the extremes of age and in patients with multiple medical problems. Under these conditions, multiple abscesses often evolve, and most of these are nosocomial. Typically, the microbial flora in these patients is gram-negative. Much as with aspiration-induced lung abscess, cavitation is generally apparent on chest radiographs 2 weeks after the onset of cough, fever, and pleuritic chest pain.

Computed tomography

Chest CT scans are valuable for demonstrating cavitation within an area of consolidation, for evaluating the thickness and regularity of the abscess wall, and for determining the exact position of the abscess with regard to the chest wall and bronchus. (See the image below.) They can also aid in evaluating the extent of bronchial involvement proximal or distal to the abscess.

CT reveals lung abscess with air-fluid level occur CT reveals lung abscess with air-fluid level occurring as complication of necrotizing pneumonia.

Procedures

Invasive diagnostic techniques occasionally recommended for diagnosis of lung abscesses include the following:

  • Transtracheal aspiration
  • Transthoracic aspiration
  • Fiberoptic bronchoscopy

To obtain dependable microbiologic data, these procedures must be performed before antibiotic therapy is instituted. The indications and comparative benefits of such procedures are controversial and depend to a great extent on operator ability. Most pulmonologists believe that these diagnostic procedures should not be performed routinely in patients with possible anaerobic lung abscesses but should be reserved for patients with atypical presentations.

Fiberoptic bronchoscopy is a useful adjunct in the diagnostic evaluation of patients with lung abscess. Secretions obtained from the lower respiratory tract via either lavage or brush can be submitted for culture and sensitivity. Rigid, sterile, and aseptic technique is crucial (including use of lidocaine without preservatives, minimal use of topical anesthetic, specimen transport under anaerobic conditions, and avoidance of delays in processing), though prior or concurrent antibiotic therapy can cause confusing results.

Thus, in patients who have a classic history and radiologic presentation of anaerobic lung abscess, the medically sound decision may be to start with empiric antibiotic therapy without prior bronchoscopy. However, for patients with atypical presentations or unclear diagnoses, bronchoscopy should be considered. Bronchoscopy may also be used to exclude the presence of a foreign body or neoplasm.

If no specimens are available for analysis and diagnosis, percutaneous transtracheal aspiration is an easy, safe, and dependable way of establishing the specific cause of a lung abscess. This procedure should be avoided in patients with coagulation disorders or bleeding tendencies and in those for whom it is difficult to provide adequate oxygenation.

In patients with amebic liver abscess, E histolytica may be recovered from the sputum. The vast majority of patients with extraintestinal amebiasis have high titers of hemoagglutinin in the serum.

Histologic Findings

An acute lung abscess tends to have a border that is not well circumscribed, and the central core is usually filled with putrid and necrotic fluid. The necrotic mixture consists predominantly of neutrophils and bacteria. There is marked inflammation in the adjacent lung tissue, as well as dilated blood vessels.

A chronic lung abscess is almost always irregular in shape, with a very well defined surrounding border, and the inner core is again filled with putrid material with or without bacteria. The predominant cells are lymphocytes, histiocytes, and plasma cells.

 

Treatment

Approach Considerations

Current management of lung abscesses focuses on antibiotic therapy that covers gram-positive, gram-negative, and anaerobic organisms. The majority of lung abscesses can be treated successfully with antibiotics alone. Any patient who shows no response to antibiotic therapy after 7-10 days should be reevaluated for resistant organisms or airway obstruction.

It is important to note that surgery is required for only a minor percentage of lung abscesses. Only cases that have failed to respond to antibiotics or the organism is resistant are considered for surgery. Surgery is also considered when there is a complication associated with the abscess (eg, bleeding).

Medical Therapy

Antibiotic therapy

Because effective broad-spectrum antibiotics are available, primary or nonspecific abscesses can frequently be arrested in the early stage of suppurative pneumonitis. Whereas penicillin was long the antibiotic of choice, trials subsequently showed clindamycin to be superior.[7] Intravenous (IV) therapy is appropriate for adults until an initial clinical response is observed, after which time oral therapy is safe. Although the overall efficacy of penicillin seems to diminish with time, it remains a practical drug for most patients, especially if clindamycin is contraindicated.

Tetracycline is considered inadequate therapy because most anaerobes are resistant to it. Similarly, metronidazole is ineffective in approximately 50% of patients, presumably because of the contribution of aerobic bacteria. Therefore, if this agent is to be used, it should be combined with either a penicillin derivative or a cephalosporin.[7]

After initial antibiotic therapy, the clinical and radiographic response is gradual. The fever generally subsides in 4-7 days, but normalization of the chest radiograph may require 2 months. The optimal duration of treatment is 4-6 weeks or until the chest x-ray shows complete resolution.

More specifically, antibiotics used to treat lung abscesses caused by anaerobic organisms include the following[7] :

  • First choice - Clindamycin
  • Alternative - Penicillin
  • Oral therapy - Clindamycin, metronidazole, amoxicillin

Antibiotics used to treat lung abscesses caused by gram-negative organisms include the following:

  • First choices - Cephalosporins, aminoglycosides, quinolones
  • Alternatives - Penicillins, cephalexin
  • Oral therapy - Trimethoprim-sulfamethoxazole

Antibiotics used to treat lung abscesses caused by pseudomonal organisms include the following:

  • First choices - Aminoglycosides, quinolones, cephalosporins

Antibiotics used to treat lung abscesses caused by gram-positive organisms include the following:

  • First choices - Oxacillin, clindamycin, cephalexin, nafcillin, amoxicillin
  • Alternatives - Cefuroxime, clindamycin
  • Oral therapy - Vancomycin
  • Macrolides (erythromycin, azithromycin and clarithromycin) have a good success rate

Aminoglycosides are not recommended for treatment of lung abscesses because they usually have poor penetrability past the fibrotic membrane that is formed in chronic cases.

Antibiotics used to treat lung abscesses caused by nocardial organisms include the following:

  • First choices - Trimethoprim-sulfamethoxazole, tetracycline

Postural drainage

Most lung abscesses communicate with the tracheobronchial tree early in the course of the infection and drain spontaneously during the course of therapy. Dependent drainage (with appropriate positions based on the pulmonary segment) is commonly advocated, using chest physical therapy and sometimes bronchoscopy. Bronchoscopy can also facilitate abscess drainage by aspirating the appropriate bronchus through the bronchoscope.[8] Transbronchial drainage by catheterization of the appropriate bronchus under fluoroscopy has been successfully performed. Overall, drainage is required for fewer than 10% of lung abscess.

Generally, augmenting this passive drainage with invasive procedures is unnecessary. In fact, attempts at therapeutic bronchoscopy may sometimes produce adverse consequences. Reports have been received of bronchoscopy-induced release of large amounts of purulent material from the involved lung segment into other parts of the lung, occasionally inducing acute respiratory failure, acute respiratory distress syndrome (ARDS), or both.

Lasers have also been used for endobronchial drainage of lung abscess. They can perforate the wall through the airways and provide a route for catheter drainage.[9]

Course of treatment

If treatment is started in the acute stage of the disease and is continued for 4-6 weeks, approximately 85-95% of patients with anaerobic lung abscesses respond to medical management alone. Successful medical therapy resolves symptoms with no radiographic evidence or only a residual thin-walled cystic cavity (<2 cm after 4-6 weeks of antibiotic therapy).

The success of medical therapy is dependent on the duration of symptoms and the size of the cavity before the initiation of therapy. Antibiotic therapy is rarely successful if symptoms are present for longer than 12 weeks before the initiation of antibiotic therapy or if the original diameter of the cavity is greater than 4 cm. When patients with lung abscesses do not respond to proper medical therapy, the probability of an underlying malignancy must be considered.

Surgical Therapy

Surgical treatment is now rarely necessary and is almost never the initial choice in the management of lung abscesses. In current practice, fewer than 15% of patients need surgical intervention for the unchecked disease and for complications that occur in both the acute and chronic stages of the disease. When surgery is performed, lobectomy is commonly done.

Surgical management is reserved for specific indications such as the following:

  • Little or no response to medical treatment
  • Inability to eliminate a carcinoma as a cause
  • Critical hemoptysis
  • Complications of lung abscess (eg, empyema, bronchopleural fistula)

In addition, if after 4-6 weeks of medical treatment a notable residual cavity remains and the patient is symptomatic, surgical resection is advocated.

Several important factors must be considered before surgery is undertaken. Because of the high risk of spillage of the abscess into the uninvolved contralateral lung, it is almost essential that a double-lumen tube be used to protect the airway during anesthesia. If this is not available, surgery poses a very high risk of abscess in the other lung and a risk of ARDS. In such cases, postponing the surgical procedure is a wise decision.

Another, less satisfactory method of dealing with this problem is to position the patient in the prone position. The surgeon must be skilled in resecting the abscess and in rapid clamping of the bronchus to prevent spillage into the trachea. These factors are extremely important in dealing with the surgical aspects of treating a lung abscess. If doubt persists, it is best to postpone the surgical procedure.

Percutaneous drainage of a complicated abscess (ie, one associated with fever and signs of sepsis) is beneficial in selected patients who do not respond to adequate medical therapy.[10, 11] These are ventilator-dependent patients who are not candidates for extensive thoracic procedures.

Other indications for drainage include the following:

  • Ongoing sepsis despite adequate antimicrobial therapy
  • Progressively enlarging lung abscess in imminent danger of rupture
  • Failure to wean from mechanical ventilation
  • Contamination of the opposite lung

In current practice, most of these lung abscesses are drained under computed tomography (CT) guidance.[10]

Results achieved with percutaneous drainage show it to be safe and effective in comparison with surgery. Percutaneous drainage is rarely complicated by empyema, hemorrhage, or bronchopleural fistula. Although a few patients who undergo percutaneous drainage develop bronchopleural fistulas, most of these fistulas close spontaneously with resolution of the abscess cavity. Percutaneous drainage may be used to stabilize and prepare critically ill patients for surgery.[12, 13]

In rare cases where a patient has bleeding associated with a lung abscess, angiographic embolization may also be used.[14]

Intrathoracic vacuum-assisted closure has also been reported as a means of managing complex lung abscesses.[15, 16]

Bronchoscopy is an invaluable part of the treatment of lung abscess. In individuals who are not responding to antibiotic therapy, bronchoscopy can help determine the patency of the bronchus and aid with specimen collection. Bronchoscopy should not be used to drain the lung abscess, in that there is a real potential risk of spillage of pus into the other lung.

Abscess from gram-negative and opportunistic bacteria

Hospital-acquired gram-negative infections are usually due to nosocomial organisms (eg, Pseudomonas, Enterobacter, or Proteus). Patients with these infections are often elderly, debilitated with numerous major medical disorders, or have sustained multiple trauma. These patients are typically treated in a critical care unit.

The infection is usually with a resistant organism originating from a single source. The lung abscess appears rapidly as an area of pneumonitis with associated pleural involvement. These patients often require percutaneous drainage as an emergency procedure. Unfortunately, the infection is systemic and often out of control, and the pulmonary pathology represents only one aspect of a multiorgan involvement with a rapidly deteriorating course.

Among fungal infections, Candida albicans has become a major organism in lung abscesses. Fungal infections are difficult to treat, and amphotericin/fluconazole and surgical drainage remain the only modalities of treatment; however, at best, they have had only limited success.

Results

The results of surgical treatment are difficult to assess because of the varying patient population and the tremendous increase in illicit drug abuse, alcoholism, AIDS, and infections by gram-negative and opportunistic organisms. These factors have increased the incidence of lung abscess and the associated morbidity.

A study by Nagasawa et al showed that thoracoscopic surgery can lead to effective drainage of pediatric lung abscess without major complications.[17] In addition, other benefits of thoracoscopy include rapid recovery, less pain, and minimal morbidity.[18]