MI: Respiratory Tract Infections Pt.1 Flashcards
List some ways in which the body can be compromised, thereby increasing the risk of respiratory tract infection.
- Poor swallow (aspiration)
- Abnormal ciliary function (e.g. smoking)
- Abnormal mucus (e.g. CF)
- Dilated airways (e.g. bronchiectasis)
- Defect in host immunity
What type of bacterium is Streptococcus pneumoniae?
- Gram-positive cocci in chains
- Alpha-haemolytic and optochin-sensitive
Way to differentiate S. pneumoniae from other alpha-haemolytic streptocci
Optochin
Epidemiology of S. Pneumoniae infection in CAP
20-50% of CAP
Almost always penicillin sensitive
What is pneumonia and what are its presenting symptoms
Inflammation of alveoli due to infection
Presentation:
- Fever
- Cough
- SoB
- Pleuritic chest pain
Why is no microbiological identification of the pathogen made in the most cases of CAP?
Difficult to obtain a good sputum sample and early treatment is usually initiated with empirical antibiotics
List the main organisms that cause CAP.
- VIRUSES
- Streptococcus pneumoniae
- Haemophilus influenzae
- Mycoplasma pneumoniae
- Moraxella catarrhalis
- Staph aureus
List the most prevalent pathogens causing CAP in the following age groups:
- 0-1 months
- 1-6 months
- 6 months - 5 years
- 16 - 30 years
0 - 1 months:
- Escherichia coli
- Group B Streptococcus
- Listeria monocytogenes
1-6 months:
- Chlamydia trachomatis
- Staphylococcus auerus
- RSV
6 months - 5 years:
- Mycoplasma pnaeumoniae
- Influenza
16-30 years:
- Mycoplasma pneumoniae
- Streptococcus pneumoniae
List the causes of CAP that fall into the following two categories:
- Typical
- Atypical
Typical (85%):
- Streptococcus pnaeumoniae - lobar
- Haemophilus influenzae - bronchopneumonia
Atypical:
- Legionella - Summer/ Water exposure
- Mycoplasma - barking cough, normal CXR
- Coxiella burnetii (Q fever) - farm animals, hepatitis
- Chlamydia psittaci - Exposure to birds, splenomegaly, rash, haemolytic anaemia
What investigations would you consider in pneumonia
FBC, U&E, CRP
Blood culture, sputum culture
ABG
CXR
What is the CURB-65 score? How is it interpreted?
- Confusion
- Urea > 7 mmol/L
- Respiratory rate > 30/min
- BP < 90 systolic, < 60 diastolic
Score of 2 = consider hospital admission
Score of more than 2 = severe pneumonia that may need ITU admission
What is bronchitis and in which group of people does it most likely occur
Inflammation of bronchi and medium-sized airways
Mainly affects smokers
Outline the presentation of bronchitis.
- Cough
- Fever
- Increased sputum production
- Increased SOB
- CXR often normal
Which organisms cause bronchitis?
- Viruses
- Streptococcus pneumoniae
- Haemophilus influenzae
- Moraxella catarrhalis
How is bronchitis managed
- Smoking cessation
- Bronchodilators
- Physiotherapy
- +/- Antibiotics
