Complications of Pneumonia: Pulmonary Abscess

Complications of Pneumonia: Pulmonary Abscess

Oren Kupfer, MD, and Paul C. Stillwell, MD, FAAP

Introduction/Etiology/Epidemiology

•The incidence of pulmonary abscess has decreased with the expansion of available antibiotics to treat respiratory infections.

•Pulmonary abscesses tend to occur in children with altered consciousness, either transiently (eg, anesthesia, intoxication, seizure) or as part of a neurological disability (eg, cerebral palsy, traumatic brain injury).

•The organisms most commonly associated with pulmonary abscesses are listed in Box 64-1; many are anaerobic mouth flora that proliferate after aspiration.

Box 64-1. Organisms Associated with Aspiration Pneumonia and Pulmonary Abscess

Anaerobes	Aerobes
Pseudomonas aeruginosa	Peptostreptococcus spp
Streptococcus pneumoniae	Prevotella
Escherichia coli	Porphyromonas spp
Klebsiella pneumoniae	Fusobacterium nucleatum
Staphylococcus aureus	Bacteroides fragilis
α-hemolytic Streptococcus	Bacteroides spp
Haemophilus influenzae	Bifidobacterium spp

From Brook I. Anaerobic pulmonary infections in children. Pediatr Emerg Care. 2004;20(9):636–640. Copyright © 2004 Lippincott Williams & Wilkins, Inc. http://journals.lww.com/pec-online/toc/2004/09000

Clinical Features

•Symptoms may be indolent, with low-grade fever, malaise, and fatigue.

•Chest pain and cough are common.

•Symptoms tend to occur a week or more after the aspiration event (if the event can be identified).

• Because the abscess is usually localized and often not very large, examination findings may be limited or minimal.

Diagnostic Considerations

•Obtaining bacterial confirmation of the infection is difficult because communication with the airway is uncommon, and sputum production is infrequent.

•Most often, the diagnosis is established via the following:

—Chest radiographs or chest computed tomographic findings, including (Figure 64-1) presence of a thick-walled, rounded opacity, with central aeration or an air-fluid level

—A history that indicates a risk for an abscess

—Exclusion of causes of similar-appearing lesions, such as tuberculosis, granulomatosis with polyangiitis, pulmonary lymphoma, pneumatocele, and pulmonary embolus

• If an abscess seems to be the most probable etiologic origin, biopsy, resection, or needle aspiration is not required.

•Consideration of immunodeficiency may be relevant, particularly diseases of granulocyte function or hyper–immunoglobulin E syndromes (Job syndrome).

•If there is concern for a retained foreign body as the underlying cause of the abscess, bronchoscopy might be useful.

Treatment

•Oral antibiotics usually suffice.

—The choice of antibiotics can be clindamycin, ampicillin, or ampicillin plus clavulanate, and the duration of therapy should be ≥2 weeks.

—If a gram-negative pathogen is suspected, ciprofloxacin may be the appropriate antibiotic.

•Surgical drainage is no longer used as a primary mode of therapy, because it may lead to dissemination of infection.

Prognosis

•The prognosis for full recovery and normal chest radiographic findings is good in an otherwise healthy child, with no ongoing risks for further lung injury.

•It may take several weeks for the chest radiographic findings to normalize.

When to Admit

•Progressive fevers or worsening radiographic appearance suggests the need for more invasive evaluation and perhaps intravenous antibiotic therapy, as well as reassessment of the precise etiologic origin of the abnormal radiographic findings.