Chapter 154 Lung Abcess Flashcards
_____ arise in the setting of an underlying condition, such as a postobstructive process (e.g., a bronchial foreign body or tumor) or a systemic process (e.g., HIV infection or another immunocompromising condition).
Secondary lung abscesses
Acute Lung abscesses
characterized as acute (<4–6 weeks in duration)
chronic lung abcess occurs in
(~40% of cases).
More than 6 weeks
The major risk factor for primary lung abscesses is .
aspiration
Lung abscesses also arise from septic emboli such as I. tricuspid valve endocarditis which often involving what pathogen?
Staphylococcus aureus
Lemierre’s syndrome, in which an infection begins in the pharynx and then spreads to the neck and the carotid sheath (which contains the jugular vein) to cause septic thrombophlebitis.
What pathogen causes the lung abcess?
classically involving Fusobacterium necrophorum
In primary lung abscesses, what are the dependent segments that are the most common locations, given the predisposition of aspirated materials to be deposited in these areas.
posterior upper lobes and superior lower lobes
When no pathogen is isolated from a primary lung abscess (which is the case as often as 40% of the time), the abscess is termed
nonspecific lung abscess, and the presence of anaerobes is often pre- sumed.
___ refers to foul-smelling breath, sputum, or empyema and is essentially diagnostic of an anaerobic lung abscess.
A putrid lung abscess
Most common cause of secondary lung abcess
Pseudomonas aeruginosa and other gram-negative rods
For primary lung abscesses, the recommended regimens are
1) clindamycin (600 mg IV three times daily; then, with the disappearance of fever and clinical improvement, 300 mg PO four times daily) or (2) an IV-administered β-lactam/β-lactamase combination, followed—once the patient’s condition is stable—by orally administered amoxicillin-clavulanate.
This therapy should be continued until imaging demonstrates that the lung abscess has cleared or regressed to a small scar. Treatment duration may range from
3–4 weeks to as long as 14 weeks.
Poor prognosis
poor prognostic factors include an age >60
the presence of aerobic bacteria, sepsis at presentation
symptom duration of >8 weeks
and abscess size >6 cm.
earlier diagnostics should be con- sidered, such as
bronchoscopy with biopsy or CT-guided needle aspiration.
Or sputum samples for Ptb suspect