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.
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.
This question resembles several other C.difficile questions:
They usually ask about the same things.
Oh well, here we go again.
The risk factors for C.difficile infection are discussed here, in a NEJM article.