Lung Abscess Treatment & Management

Updated: Sep 25, 2020
  • Author: Nader Kamangar, MD, FACP, FCCP, FCCM; Chief Editor: Guy W Soo Hoo, MD, MPH  more...
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Approach Considerations

The treatment of lung abscess is guided by the available microbiology with consideration of the underlying or associated conditions. No treatment recommendation has been issued by major societies specifically for lung abscess. Some clinical trials referred to below have included patients with aspiration pneumonia with or without lung abscess.

For the following reasons, inpatient care is advisable in patients with lung abscess:

  • Evaluation and management of patient's respiratory status

  • Administration of intravenous antibiotics

  • Drainage of the abscess or empyema as needed

In patients who have small lung abscess, who are not clinically ill, and who are reliable, outpatient care may be considered after obtaining appropriate diagnostic studies such as sputum culture, blood culture, and blood work.

Following initial intravenous antibiotic therapy, the patient may be treated on an outpatient basis for completion of prolonged therapy, which is often required for cure.


Antibiotic Therapy

Standard treatment of an anaerobic lung infection is clindamycin (600 mg IV q8h followed by 150-300 mg PO qid). This regimen has been shown to be superior over parenteral penicillin in published trials. Several anaerobes may produce beta-lactamase (eg, various species of Bacteroides and Fusobacterium) and develop resistance to penicillin; therefore, treatment with a beta-lactamase inhibitor in conjunction with a beta-lactam or carbapenems should be considered. [13]

Although metronidazole is an effective drug against anaerobic bacteria, metronidazole in treating lung abscess has been rather disappointing because these infections are generally polymicrobial. A failure rate of 50% has been reported. [14, 15] Metronidazole is not recommended; however, if metronidazole is used, it must be paired with another agent, typically penicillin.

In hospitalized patients who have aspirated and developed a lung abscess, antibiotic therapy should include coverage against S aureus and Enterobacter and Pseudomonas species. When methicillin-resistant S aureus (MRSA) is the source of lung abscesses, vancomycin and linezolid should be considered. Vancomycin 15 mg/kg IV every 12 hours, with a goal trough of 15-20 mcg/mL, is adjusted renally. Linezolid therapy should be started at a dose of 600 mg IV every 12 hours. Once the patient has defervesced once, consider switching to an equivalent oral regimen. Linezolid has been shown to have improved response times over vancomycin, with no difference in mortality overall when compared with vancomycin treatment. Ceftaroline, a fifth-generation cephalosporin, has been shown to have activity against MRSA lung abscesses based on a 2012 study with data from 43 medical centers around the United States. Ceftaroline, however, has not been formally approved by the US Food and Drug Administration (FDA) for the treatment of MRSA lung abscesses. [16, 17]

Ampicillin plus sulbactam is well tolerated and as effective as clindamycin with or without a cephalosporin in the treatment of aspiration pneumonia and lung abscess. [18]

Moxifloxacin is clinically effective and as safe as ampicillin plus sulbactam in the treatment of aspiration pneumonia and lung abscess. [19]

Actinomyces, Nocardia species, fungal species, and tuberculous abscesses tend to occur mostly in immunocompromised hosts, including chronic glucocorticoid therapy or patients with lung transplants. Data regarding Actinomyces abscesses are limited, but treatment with high-dose penicillin is generally recommended for the treatment of Actinomyces, as penicillin resistance is minimal. Case reports exist of successful treatment of pulmonary Actinomyces with ciprofloxacin. [20, 21]

Treatment of Nocardia species, when suspected as a source of pulmonary abscesses, involves 6-12 months of trimethoprim-sulfamethoxazole (TMP-SMZ), though the clear duration of therapy has not been clearly defined. Additionally, for initial induction therapy TMP-SMZ (15 mg/kg IV of the trimethoprim component per day, divided in 2-4 doses) can be used in addition to amikacin at 7.5 mg/kg IV every 12 hours. An alternative regimen involves imipenem 500 mg IV every 6 hours with amikacin. [22, 23] The patient can then be transitioned to TMP-SMZ 10 mg/kg of the trimethoprim component, divided into twice- or thrice-daily doses after intravenous therapy. [24]

Treatment of fungal abscesses should follow the therapy of each individual fungal organism indicated.

Tuberculous abscesses, especially MAC should follow MAC treatment guidelines.

Duration of therapy

Although the duration of therapy is not well established, most clinicians generally prescribe antibiotic therapy for 4-6 weeks. Expert opinion suggests that antibiotic treatment should be continued until the chest radiograph has shown either the resolution of lung abscess or the presence of a small stable lesion. The rationale for extended treatment maintains that risk of relapse exists with a shorter antibiotic regimen. Treatment can be as long as 2-3 months in some cases of large abscesses. The duration is guided in part by the radiographic appearance, with a favorable response manifesting as a decrease in the size of the abscess cavity.

Response to therapy

Patients with lung abscesses usually show clinical improvement, with improvement of fever, within 3-4 days after initiating the antibiotic therapy. Defervescence is expected in 7-10 days. Persistent fever beyond this time indicates therapeutic failure, and these patients should undergo further diagnostic studies to determine the cause of failure.

Considerations in patients with poor response to antibiotic therapy include bronchial obstruction with a foreign body or neoplasm or infection with a resistant bacteria, mycobacteria, or fungi.

Large cavity size (ie, > 6 cm in diameter) usually requires prolonged therapy. Because empyema with an air-fluid level could be mistaken for parenchymal abscess, a CT scan may be used to differentiate this process from lung abscess.

A nonbacterial cause of cavitary lung disease may be present, such as lung infarction, cavitating neoplasm, and vasculitis. The infection of a preexisting sequestration, cyst, or bulla may be the cause of delayed response to antibiotics.


Surgical Care

Surgery is very rarely required for patients with uncomplicated lung abscesses. The usual indications for surgery are failure to respond to medical management, suspected neoplasm, or congenital lung malformation. Other indications may include ongoing sepsis syndrome (fever, tachycardia, leukocytosis), signs of progressive infection (enlarging cavity, infection of other lobes of the lung), and life-threatening complications such as respiratory failure and uncontrolled hemoptysis.

The surgical procedure performed is either lobectomy or pneumonectomy. Lung-sparing surgery is preferred (ie, segmentectomy or lobectomy). Rarely is pneumonectomy indicated or performed for a lung abscess with current medical options available for care.

When conventional therapy fails, either percutaneous catheter drainage or surgical resection is usually considered. Endoscopic lung abscess drainage is considered if an airway connection to the cavity can be demonstrated. Endoscopic drainage, however, is not without significant risk to the patient. [25, 26, 27]



Consulting a pulmonary medicine or infectious diseases specialist is often helpful in workup and follow-up of patients with lung abscess.



Prevention of aspiration is important to minimize the risk of lung abscess. Early intubation in patients who have diminished ability to protect the airway from massive aspiration (cough, gag reflexes), should be considered.

Positioning the supine patient at a 30° reclined angle minimizes the risk of aspiration. Vomiting patients should be placed on their sides.

Improving oral hygiene and dental care in elderly and debilitated patients may decrease the risk of anaerobic lung abscess.