LRTI Flashcards
What are some examples of acute lower respiratory tract infections?
- pneumonia
-bronchitis
-legionnaires disease
-whooping cough
What are some examples of chronic lower respiratory tract infections?
-TB
-aspergillosis
-cystic fibrosis
What are the 2 ways pneumonia can be acquired?
1) CAP = acquired in the community
2) HAP = acquired in hospitals
What can cause aspiration pneumonia?
if food travels to the lungs instead of to the intestine
What are the signs and symptoms of typical pneumonia?
1) cough and fever
2) cyanosis - lack of blood flow to fingertips aka blue fingertips
3) tachypnoea - low respiratory rate
4) tachycardia - increased heart rate
5) rust coloured sputum
What is the microorganism associated with CAP?
main one: streptococcus pneumoniae
less common: haemophilia influenzae
What are the signs and symptoms of atypical pneumonia?
- mostly non respiratory and common in the young AND old
1) rash
2) confusion, diarrhoea, incontinence
3) no sputum
4) cyanosis
5) tachypneoa and tachycardia
Which organism is associated with atypical CAP?
mycoplasma pneumoniae - fried egg appearance
What is the radiological difference in appearance of typical and atypical pneumonia?
-typical pneumonia is widespread in appearance
-whereas atypical pneumonia is patchy in appearance (occupies smaller area in lungs)
What are the risk factors for HAP?
- ventilatory support (ventilatory acquired pneumoniae)
- immunosuppression: organ transplant
- immobility and vomiting: aspiration pneumonia (viridian streptococci)
What are the treatments for pneumonia?
1) uncomplicated CAP: amoxicillin/ erythromycin, moxifloxacin (fluroquinolone)
2) severe CAP of unknown aetiology: cefuroxime and erythromycin
3) atypical pneumonia: erythromycin
4) HAP: cefotaxime and gentamicin
What is the mechanism of pathogenicity of strep pneumonia?
- has viral capsule and multiple types of capsule: makes it resistant to different antibiotics
- adhesion: interacts with carbohydrates on pulmonary epithelial surface
- protective antigen inhibits opsonisation of pneumococci
- autolysis: inflammation
- pneumolysin: inhibits phagocytosis and lymphocyte proliferation
What sample should be taken for pneumonia?
sputum
non culture techniques: microscopy and gram stain
culture techniques: sputum and sputloysin
Which sensitivity disc would you use for strep pneumoniae?
**optochin **sensitivity disk: large zone of inhibition differentiates pneumococci from normal oral streptococci
What does CbpA adhesion do in strep pneumoniae?
adhesion interacts with carbohydrates on pulmonary epithelial surface
