Lung Abscess Flashcards
Represents necrosis and cavitation of the lung following microbial infection.
Lung abscess
Lung abscesses can be single or multiple but usually are marked by a single dominant cavity ___
> 2 cm in diameter.
Primary lung abscesses generally arise from aspiration, often are caused principally by ______, and occur in the absence of an underlying pulmonary or systemic condition.
anaerobic bacteria
Acute Lung Abscess
<4-6 weeks
Major risk factor for Lung abscess is __
Aspiration
Patients at risk for Lung Abscess
- Altered mental status
- Alcoholism
- Drug overdose
- Seizures
- Bulbar dysfunction
- Prior cerebrovascular or cardiovascular events
- Neuromuscular disease
Additional Risk factors:
-esophageal dysmotility or esophageal lesions (strictures or tumors)
-gastric distention
-gastroesophageal reflux
-spend substantial time in the recumbent position
Pathogens: Primary Lung Abscess
Anaerobes
Microaerophilic streptococci
Pathogens: Secondary lung abscess
Staphylococcus aureus
Gram-negative rods
Pathogens: Embolic lesions
Staphylococcus aureus (Tricuspid valve endocarditis)
Fusobacterium necrophorum (Lemierre’s syndrome)
Endemic infections
Mycobacterium tuberculosis
Coccidioides spp.
Histoplasma capsulatum
Blastomyces spp.
Parasites
An infection that begins in the pharynx and then spreads to the neck and the carotid sheath to cause septic thrombophlebitis
Lemierre’s syndrome
Most common locations of primary lung abscesses
Posterior Upper Lobe
Superior Lower Lobe
When no pathogen is isolated from a primary lung abscess
Nonspecific lung abscess
(presence of anaerobes is often presumed)
Cases with foul-smelling breath, sputum, or empyema
Putrid Lung Abscess
Recommended regimen for Primary Lung Abscess
(1) Clindamycin (600 mg IV three times daily; then, with the disappearance of fever and clinical improvement, 300 mg PO four times daily)
(2) an IV-administered β-lactam/β-lactamase combination, followed—once the patient’s condition is stable—by orally administered amoxicillin-clavulanate.
An abscess _______ is less likely to respond to antibiotic therapy without additional interventions.
> 6–8 cm in diameter
Alternative procedure if patient is a poor surgical candidate
Percutaneous drainage of the abscess
Mortality rate of Primary Lung Abscess
<2%
Possible complications of percutaneous drainage include :
- Bacterial contamination of the pleural
- Pneumothorax
- Hemothorax
Mortality rate of Secondary Lung abscess
as high as 75%
Poor prognostic Factors for Lung Abscess
- Age >60 years old
- Presence of aerobic bacteria
- Sepsis at presentation
- Symptom duration >8 weeks
- Abscess size >6 cm
Presents with a more fulminant course characterized by high fevers and rapid progression.
Non-anaerobic organisms (S. aureus)
It takes ____ days before defervescence during treatment
7 days
Duration of treatment for Lung Abscess
3-4 weeks, can extend to 14 weeks, until imaging has cleared/regressed to a small scar
