Pneumonia

Question 1

Define Pneumonia

Answer 1

Pneumonia is an acute infection of the lower respiratory tract in which there is filling of the alveolar spaces with exudate

Question 2

Pneumonia Causes

Answer 2

CAP - Typical and Atypical
Nosocomial (HAP)
Aspiration
Compromised Individuals

Question 3

Typical CAP Organism

Answer 3

Strepococcus pneumoniae (65%)

Question 4

Atypical CAP Organism

Answer 4

Mycoplasma pneumoniae (18%)
- usually presents as a non-productive cough and doesn’t grow on a gram stain
Legionella pneumoniae (3%)
- presents with diarrhoea also

Question 5

Nosocomial (HAP) Organism

Answer 5

MRSA
MDR (Multi-Drug Resistent) enterobacteriaceae
Actinetobactor spp.
Pseudomonas aeruginosa

Question 6

Aspirational Pneumonia Organism

Answer 6

MRSA

Pseudomonas aeruginosa

Question 7

Organisms of Pneumonia in Compromised Individuals

Answer 7

COPD - Haemophilus influenzae
Diabetics/alcoholics - Klebsiella pneumoniae
Bronchiectasis - Pseudomonas aeruginosa
Post influenza - Staph aureus
AIDS - pneumocystis carinii/jerovecii

Question 8

Pneumonia Pathology

Answer 8

Traditional it is divided into lobar pneumonia and broncho- pneumonia. Both share processes of consolidation, where distal airspaces are filled with acute inflammatory exudate.

• Lobar pneumonia
  
  • Affects one lobe and occurs in previously fit individuals.
• Bronchopneumonia
  
  • Present in the elderly and debilitated and is not lobe specific.
  • Resolution is not as complete and may generate bronchiectasis.

Question 9

Pneumonia Investigations

Answer 9

• Chest X-ray - for diagnostics
  
  • Oxygen saturation on Room air +/- ABG
  • Investigations for the causal pathogen
    
    • Sputum MCS (Gram stain) (up to 40% detection)
    • Blood cultures (5-10% detection)
  • Other investigations
    
    • Urinary antigen
    • PCR of nose and throat swabs
    • Serology
    • Bronchoalveolar lavage - low yield and risky

Question 10

Pneumonia Urinary Antigen Investigations

Answer 10

• Pneumococcal urinary antigen

* Legionella urinary antigen

Question 11

Pneumonia PCR of nose and throat Investigation

Answer 11

• Respiratory viruses (including influenza)

Question 12

Pneumonia Serological Investigations

Answer 12

• Mycoplasma
  
  • Legionella
  • Chlamydophila (Chlamydia)
  • influenza

Question 13

Pneumonia Severity Assessment

Answer 13

The Pneumonia Severity Index (PSI) and CURB-65

Question 14

Outline CURB65 / CORB65

Answer 14

• Confusion
  
  • Urea > 7 or O2 sats < 90%
  • Resp rate > 30
  • BP: SBP < 90 and DBP < 60
  • Age > 65
  • Score 0-1 = Treat as outpatient
  • Score 2 = Admit to hospital
  • Score 3+ = often require ICU care

Question 15

Pneumonia Complications

Answer 15

• Pleural effusion and empyema
  
  • Lobar collapse (sputum retention)
  • Pneumothorax (in caveatting pneumonia)

Question 16

Pneumonia Management Overview

Answer 16

General supportive measures

• IV fluids
• Oxygen
• Physiotherapy
• Pharmacotherapy

Question 17

CAP Pharmacological Management

Answer 17

Mild

• Typical Amoxycillin (oral)
• Atypical Doxycyline or clarithromycin

Moderate

• Typical Benzylpenicillin (IV)
• Atypical Doxycyline or clarithromycin

Severe
- Typical 
Ceftriaxone (IV)
OR
Benzylpenicillin (IV) PLUS Gentamicin
- Atypical Azithromycin

Question 18

Aspiration Pharmacological Management

Answer 18

• Benzylpenicillin PLUS metronidazol (IV)

Question 19

HAP Pharmacological Management

Answer 19

Low Risk MDR - Mild Symptoms
- Amoxycillin PLUS clavulanate
OR
- Benzylpenicillin PLUS gentamycin

Low Risk MDR - Moderate/Severe Symptoms
- Ceftriaxone

High Risk MDR - All
(High-risk ward > 5 days)
- Piperacillin PLUS tazobactam