C. Difficile Flashcards
What is CDAD?
clostridioides difficile associated diarrhea
- > 3 unformed stools/day for > 2 days with no other recognized cause
- AND detection of toxin A or B in the stool or toxin-producing C.difficile in the stool
-OR visualization of pseudomembranes via colonoscopy
When should we suspect CDAD?
patients with recent antibiotic use
-within the previous 3 months
What are the clinical manifestations of CDAD?
diarrhea (almost never grossly bloody)
-distinct odour
fever
abdominal pain
leukocytosis
may present wild mild diarrhea to life-threatening megacolon
Explain the pathogenesis of CDAD.
- exposure to antimicrobial agent establishes susceptibility to CDI through disruption of normal colonic microflora
- exposure to toxigenic C.diff
- virulent strain or high risk antibiotic or inadequate immune response
How is C.diff acquired?
exogenously
-most commonly in hospitals or nursing homes
note: carried in the stool, can be asymptomatic, high rates of colonization in neonates and children
Describe C.diff itself.
gram positive
spore forming
anaerobic bacillus
causes toxin mediated disease (toxin A and B)
Which antibiotics cause CDI?
ALL antibiotics have been associated with CDI, including those used to treat it
Which antibiotics are the highest risk for CDI?
clindamycin
fluoroquinolones
cephalosporins (esp 3rd/4th gen)
ampicillin
carbapenems
Which antibiotics are the lowest risk for CDI?
penicillin
macrolides
tetracyclines
TMP/SMX
aminoglycosides
How long is the risk of CDI present for after completion of antibiotic therapy?
until 3 months past therapy
What are the risk factors for CDI?
older age
greater severity of underlying illness
gastrointestinal surgery
enteral tube feeding
use of rectal electronic thermometers
antacid therapy: PPI > H2RA
hospitalization - linked to # of days
What are the important features of CDI?
recurrences are common
recurrence can be relapse (same strain) or new infection (new strain)
NAP1/BI/027: produce greater amounts of toxin
What are some general management strategies for CDI?
stop the offending antibiotic (if possible)
fluid and electrolyte replacement therapy
avoid drugs which inhibit peristalsis
-diphenoxylate/atropine and loperamide
How is CDI categorized?
mild-moderate vs severe and complicated vs uncomplicated
severe: leukocytes > 15,000 cell/uL and/or SCr > 1.5 baseline
severe-complicated: shock, hypotension, ileus or megacolon
What is first line therapy for initial mild-moderate CDI?
vancomycin 125mg po QID x 10-14d
What are alternative therapies for initial mild-moderate CDI?
fidaxomicin 200mg po BID x 10d
metronidazole 500mg po TID x 10-14d if mild diarrhea and $$$ is a problem
What is the treatment for initial severe uncomplicated CDI?
vancomycin 125mg po QID x 10-14d
OR
fidaxomicin 200mg po BID x 10d
What is the treatment for initial severe complicated CDI?
vancomycin 125-500mg po QID x 10-14d or via NG tube in conjunction with metronidazole 500mg IV q8h
-vancomycin retention enema sometimes added if ileus
alt: fidaxomicin 500mg po BID x 10d with IV metronidazole if severe allergy to po vancomycin
What is the treatment for a first recurrence of CDI?
same as initial episode
-vancomycin or fidaxomicin, same doses
What is the treatment for second or subsequent recurrences of CDI?
vancomycin prolonged taper and/or pulsed regimen
fecal microbiota transplantation
monoclonal antibody that binds toxin
-actoxumab (toxin A)
-bezlotoxumab (toxin B)
surgery
How long do paeds show asymptomatic colonization of C.diff for?
until 2 years
What are the principles of treatment of CDI for pediatrics?
same principles of treatment:
-stop antibiotic
-supportive care: fluids, nutrition, antipyretics
-specific tx for pathogen if no improvement after d/c antibiotics
What are the complications of CDI in pediatrics?
complications are infrequent
-associated with comorbid immunosuppression and GI dx
What are monitoring parameters for CDI?
resolution of diarrhea
resolution of fever, abdominal pain, other sx
electrolytes, WBC
check for antimotility agents
adherence with therapy (esp complex tapers)
AE of drugs
