Lung Abcess

Question 1

Lung Abscess overview

Answer 1

necrosis and cavitation of the lung
caused by microbial associated with aspiration
CA-MRSA
pseudomonas aegilonsa
streptococcus pneumoniae

aspiration risk factors
AMS, alcoholism, drug overdose, seizures
stroke, neuromuscular disease, or esophageal dysmotility

decreased incidence
significant morbidity and mortality

lung abscess characterization
primary vs. secondary
acute vs. chronic

acute < 4-6 weeks
chronic accounts for > 40% of cases
typically single dominant > 2cm

Question 2

primary lung abcess

Answer 2

anaerobic bacteria
produce extensive tissue necrosis

absence of underlying pulmonary or systemic condition

clinical manifestations
pneumonitis
parenchymal necrosis and cavitation develop
posterior upper and superior lower lobs
right lung field
foul-smelling breath, sputum, or empyema

putrid abscess: diagnostic of anaerobic lung abscess
anaerobic etiology

Question 3

secondary lung abcess

Answer 3

Underlying abscess:
underlying condition
post obstructive process ( foreign body or tumor)
systemic process (HIV)

Common organisms:
pseudomonas aeruginosa & gram neg rods most common
staphylococcus aureus
legionella spp
pneumocystis jirovecii
fungal

Question 4

lung abscess diagnosis

Answer 4

CT chest
air-fluid levels with the development of abscess

putrid sputum odor
virtually diagnostic for anaerobes

sputum culture and gram stain
failure of treatment
yield polymicrobial

secondary abscess specific
failure of treatment
sputum and blood cult
needs target therapy

Question 5

lung abscess treatment plan

Answer 5

clindamycin 600mg IV TID
duration of treatment
clinical improvement

Alternative:
transition to augmentin
total treatment duration
3-4 weeks

Secondary lung abscess:
specific coverage

abscess > 6-8 cm
less likely to respond to ABX alone
surgical resection
percutaneous drainage