pneumonia Flashcards
1
Q
describe features of bronchitis (compared to pneumonia)
A
- S. pneumonia doesn’t cause it (mainly viral)
- antibiotics only useful in early stages
- bronchi can block, causing V/Q mismatch
- cough, fever, sometimes sputum
- doesn’t cause SOB, hypoxia
2
Q
pneumonia symptoms in elderly
A
- crackles = 80%
- tachypnoea = 70%
- fever/chills = 50%
- consolidation (dull percuss, bronchial breathing) = 30%
- non-pulmonary = 20%
3
Q
causative bacteria of pneumonia
A
- Streptococcus pneumonia = 70%
- mycoplasma pneumonia = 15%
- viral cause = 10%
- haemophilus influenza = 5%
- S. aureus = 2%
4
Q
S pneumonia
A
- alpha haemolytic (viridian group)
- colonises nasopharynx
- increased colonisation during winter
5
Q
S. pneumonia virulence factors
A
- polysaccharide capsule
(prevents phagocytosis and complement binding) - surface protein A binds epithelial cells
(prevents C3b deposition) - pneumolysin (toxin) lyses neutrophils, epithelial cells
- PspC prevents complement activation
6
Q
investigations
A
- chest x-ray
- kidney function important (indicator of severity)
7
Q
diagnosis of bacteria (if severe)
A
- sputum culture
- nasopharyngeal swab
- blood culture
- urine immune-chromatography test
8
Q
treatment
A
antibiotics (effective and required)
- some S. pneumonia resistant to penicillin
- most cases oral is appropriate
- however if severe infection or meningitis caused by s. pneumonia give IV
9
Q
macrolide antibiotics
A
bind at transpeptidation site
- e.g. erythromycin, clarimycin
- broad spectrum
- active against step, staph (limited against gram-negative)
- used in skin infections if allergic to penicillin
10
Q
adverse effects of macrolide antibiotics
A
erythromycin gives GI upset
sudden death rare
