pneumonia

Question 1

describe features of bronchitis (compared to pneumonia)

Answer 1

• 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

Question 2

pneumonia symptoms in elderly

Answer 2

• crackles = 80%
• tachypnoea = 70%
• fever/chills = 50%
• consolidation (dull percuss, bronchial breathing) = 30%
• non-pulmonary = 20%

Question 3

causative bacteria of pneumonia

Answer 3

• Streptococcus pneumonia = 70%
• mycoplasma pneumonia = 15%
• viral cause = 10%
• haemophilus influenza = 5%
• S. aureus = 2%

Question 4

S pneumonia

Answer 4

• alpha haemolytic (viridian group)
• colonises nasopharynx
• increased colonisation during winter

Question 5

S. pneumonia virulence factors

Answer 5

• 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

Question 6

investigations

Answer 6

• chest x-ray

- kidney function important (indicator of severity)

Question 7

diagnosis of bacteria (if severe)

Answer 7

• sputum culture
• nasopharyngeal swab
• blood culture
• urine immune-chromatography test

Question 8

treatment

Answer 8

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

Question 9

macrolide antibiotics

Answer 9

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

Question 10

adverse effects of macrolide antibiotics

Answer 10

erythromycin gives GI upset

sudden death rare