Community acquired Pneumonia

Condition: Pneumonia


What bacteria commonly cause pneumonia in Australia?
- Most common cause is streptococcus pneumonia
- atypical pathogens mycoplasma pneumoniae, chlamydophila pneumoniae and legionella species
- Haemophilus influenzae < 5 % CAP, predominately in people with COPD
- In tropical regions of Australia, gram negative organisms Burkholderia pseudomallei and Acinetobacter baumanni

How do patients present?
- fever
- rigors
- malaise
- anorexia
- dysnoea
- cough
- purulent sputum
- haemoptysis
- pleuritic chest pain

What are the examination findings?
- fever, cyanosis, confusions, tachypnoea, tachycardia, hypotension, signs of consolidation (diminished expansion, dull percussion note, increase tactile vocal fremitus/vocal resonance, bronchial breathing) and a pleural rub.

How do you treat pneumonia ?

Risk stratification. Assess severity and cater treatment according to severity.


If the following features are present, it is likely that the patient suffers from severe pneumonia and will require in-patient management.

Red flags for community acquired pneumonia in adults
- RR> 30
- Systolic bp < 90
- SaO2 < 92 %
- Acute onset confusion
- HR > 100 bpm
- Multilobar involvement on chest x-ray

CAP treatment flowchart from therapeutic guideline

Mild pneumonia: amoxycillin 1g orally 8 hourly 5 to 7 days or doxycycline 100 mg orally 12 hourly for 5-7 days. (Use this regime if patient can return for review in 48 hrs, if not, give both)

If hypersensitve to amoxycillin, use doxycycline. If can't tolerate doxycycline, use clarithromycin

Other options if hypersensitiv to penicillin, cefuroxime 500 mg 12 hourly (given it is not immediate hypersensitive), consider switching to moxifloxacin 400 mg orally for patients with immediate hypersensitivity to penicillins

Moderate pneumonia: Try to obtain culture before starting treatment.

Benzylpenicillin 1.2 g IV 6 hourly until significant improvement then amoxycillin 1g orally 8 holy for a total of 7 days + doxycycline 100 mg orally 12 hourly for 7 days. (If doxycycline is in appropriate e.g. in pregnant women, switch to clarithromycin)

If hypersensitive to penicillin, use ceftriaxone 1 g IV daily until significant improvement, then cefuroxime 500 mg orally, 12 hourly for a total of 7 days

References:
- Therapeutic guideline