Clostridium difficile infection (CDI)

Question 1

What are the risk factors of CDI?

Answer 1

• **Recent abx (esp within 8-12 weeks)
• Chemotherapy
• PPI – decreases acid destruction
• IBD
• GI Surgery
• NGT – provides route of entry

Question 2

how do patients present?

Answer 2

usually have >3 diarrhoeal stools/ 24 hours period

Question 3

What are the markers of severe CDI?

Answer 3

• AKI (Cr > 1.5x baseline)
• Raised WCC > 15
• Elderly
• ICU status (e.g. shock, toxic megacolon)
• Pseudomembranes (may not be present in some)

Question 4

How is CDI investigated?

Answer 4

• Stool toxin test (can be positive for months after)
• Colonoscopy: appearance of pseudomembranes: Do not routinely do (unless otherwise indicated) as insufflation during colonoscopy can cause toxic megacolon
• FBC: raised TW (check if TW > 15 🡪 severe CDI)

Question 5

How is CDI managed?

Answer 5

Mild/moderate

• PO metronidazole 500mg TDS, x10/7, OR
• PO vancomycin 125mg QDS x10/7

Severe (TW > 15 or Cr > 1.5x baseline)
- PO vancomycin 125mg QDS, x10-14/7

Severe, complicated/fulminant (hypotension/shock, ileus, megacolon)
- PO vancomycin 500mg QDS + IV metronidazole 500mg Q8H