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.
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:
- Question 3 from the first paper of 2012
- Question 27 from the second paper of 2005
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.
- Broad spectrum antibiotics in particular clindamycin, quinolones, amoxycillin, cephalosporins