Anaerobic Infections, Chest

KEY FEATURES

• Frequently occur in the setting of poor oral hygiene and periodontal disease

• Aspiration of saliva may lead to necrotizing pneumonia, lung abscess, and empyema

• Polymicrobial infection is the rule

• Anaerobes are frequently isolated etiologic agents, particularly

  • Prevotella species

  • Fusobacteria

  • Peptostreptococci

CLINICAL FINDINGS

• Fever

• Productive cough

• Night sweats

• Weight loss

• Chronic course of illness

• Poor dentition (frequently)

DIAGNOSIS

• Pleural fluid culture

• Chest radiograph

• Chest CT scan

TREATMENT

• Most pulmonary infections respond to antimicrobial therapy alone

• Preferred regimens include

  • Ampicillin-sulbactam, 3 g intravenously every 6 hours, followed by amoxicillin/clavulanic acid, 875/125 mg orally twice daily, or

  • Moxifloxacin, 400 mg intravenously or orally once daily

  • Clindamycin, 300–450 mg orally three times daily, could also be used

• Metronidazole is an alternative

  • But it does not cover facultative streptococci, which are often present

  • So, if used, a second agent active against streptococci, such as ceftriaxone, 1 g intravenously or intramuscularly daily, should be added

• Because these infections respond slowly, a prolonged course of therapy (eg, 4–6 weeks) may be recommended for complicated infections

• Percutaneous chest tube or surgical drainage is indicated for empyema