Bacterial Respiratory Tract Infection

Question 1

What is the definition of pneumonia?

Answer 1

• Infection of lung tissue
• Inflammation of the lung tissue and sputum filling the airways and alveoli
• Consolidation seen on CXR

Question 2

What typical pathogens cause pneumonia?

Answer 2

• Streptococcus pneumoniae (most common)
• Haemophilus influenza
• Moraxella catharralis (immunocompromised or those with COPD)
• Pseudomonas aeruginosa (hospital-acquired, CF, bronchiectasis)
• Staphylococcus aureus (CF or after flu)
• MRSA (hospital-acquired)

Question 3

What atypical pathogens cause pneumonia?

Answer 3

• Mycoplasma pneumniae (can cause erythema multiforme - target lesions and neurological symptoms)
• Legionella pneumoniae (infected water supplies or AC units - can cause hyponatraemia from SIADH)
• Chlamydophila pneumoniae (school aged child)
• Chlamydophila psittaci (contact with affected birds)

Question 4

What are the signs and symptoms of bacterial RTIs?

Answer 4

• SOB
• Fever
• Cough
• Sputum
• Haemoptysis
• Pleuritic chest pain
• Delirium
• Sepsis
• High RR
• High HR
• Hypoxia
• Hypotension
• Bronchial breath sounds
• Dullness to percussion
• Coarse crepitations
• Increased vocal resonance

Question 5

What are the CURB65 scoring system criteria?

Answer 5

• Confusion
• Urea >7
• RR ≥30
• BP diastolic <60 or systolic <90
• Age >65 years

Question 6

What are the SIRS scoring system criteria?

Answer 6

• Temperature >38oC or < 36oC
• HR >90bpm
• RR >20/min
• WBC >12 or <4

Question 7

What are the symptoms of atypical pneumonia?

Answer 7

• Headache
• Malaise
• Fever
• Can present with typical features

Question 8

Investigation of pneumonia

Answer 8

• CURB-65 0 or 1 require no investigation
• CXR
• FBC (raised WCC)
• U&Es (for urea)
• CRP (raised in inflammation/infection)
• Moderate-severe cases should also have sputum and blood cultures as well as legionalla and pneumococcal urinary antigens

Question 9

Management of pneumonia

Answer 9

• Local empirical guidelines