With regards to Clostridium difficile (C. difficile) infection in critically ill patients:

a) What are the risk factors for development of this condition?

b) What complications can occur as a result of this infection?

c) How is the diagnosis of C. difficile and its complications established?

d) Briefly outline the options for prevention and treatment.

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College Answer

a) Risk factors:
 Exposure to antibiotics
 Clindamycin
 Cephalosproins
 Fluoroquinolones
 Extended spectrum penicillins
 Extremes of age
 Immunosuppression
 Proton pump inhibitors and H2 antagonists
 Nursing home or group care home

b) Complications:
 Related to the diarrhoea
o Hypovolaemia
o Electrolyte disturbance; hypokalaemia, hypomagnesaemia
 Related to the intestinal infection
o Sepsis and septic shock
o Perforation
o Toxic megacolon
o Bleeding

c) Diagnosis:
Clinical and investigation:
 Clinical findings
o Diarrhoea, but may have severe disease without diarrhoea
o Abdominal pain, colic in nature
o Fever
o Shock
 Microbiology
o Stool; C. difficile toxin (false negatives problematic)
o PCR for C. difficile (false positives problematic)
o ELISA for C difficile glutamate dehydrogenase
 Sigmoidoscopy, colonoscopy
o Pseudomembranes
 CT scan
o Abdominal and pelvis
o Oral and ivi contrast
o Helps to diagnose complications such as toxic megacolon, perforation and exclude differential diagnosis

d)
Prevention and treatment:
Prevention
 Antibiotics stewardship, limitation of broad spectrum antibiotics
 Isolation of C diff positive cases with notices advising contact precautions
 Limit spread with hand washing with soap and water, alcohol hand rub is ineffective
Treatment
 Supportive care and resuscitation
 Specific
o Medical
 Antibiotics;

Oral vancomycin (250 – 500 mg enteral q6h)
o Metronidazole oral or ivi
o Tigecycline

o Surgical
 For perforation or toxic megacolon
 Subtotal colectomy
o Monoclonal antibodies and vaccine under development
o Faecal transplant
 More for recurrent infection than for acute severe illness

Examiners' comments: Overall, candidates' knowledge of this topic was limited.

Discussion

This question resembles several other C.difficile questions:

They usually ask about the same things.

Oh well, here we go again.

Risk factors for C.difficile infection

The risk factors for C.difficile infection are discussed here, in a NEJM article.