GI Disorders & Infections Flashcards
What type of bacteria is C. difficile?
Gram-positive bacteria
Where does C. Difficile typically colonise?
Colon
What effect do C. difficile toxins have?
Cytotoxic effect on enterocytes which results in excessive fluid leakage from intestinal epithelium and patchy necrosis
What is the characteristic appearance of a c. difficile necrosis of the colon?
The sloughing of necrotic tissue results in a pseudomembranous appearance
Which antibiotics are associated with an increased risk of C. difficile infections?
Ciprofloxacin, cephalosporins and clindamycin
What are the symptoms associated with a C. dificile infection?
Diarrhoea -> Dehydration, dry oral mucosa and reduced skin turgor
Abdominal pain - severe in fulminant colitis
Fever
Abdominal tenderness
What are the investigations of suspected C.diff?
Elevated WBC
Raised CRP, low albumin reveals inflammation/infective process
+ For occult blood
Abdominal X-ray reveals colonic dilation
Stool cultures confirm toxins A and B
what are the four main causative pathogens in infectious diarrhoea?
Clostridium difficle
Klebsiella oxytoca
Clostridium perfringens
Salmonella spp.
What are the causes of non-infectious diarrhoea?
Antibiotics side effects Post-infectious IBS Inflammatory bowel disease Microscopic or ischaemic colitis Coeliac disease
What is ischaemic colitis?
Occurs during a period where there is an acute, transient compromise in blood flow, below that is required for the metabolic demands of the colon.
• Mucosal ulcerations
• Inflammation
• Haemorrhage
It is the duration and severity of hypoperfusion that determines whether colonic injury is predominantly ischaemic or as a consequence of reperfusion.
What WCC and Creatinine parameters classify non-severe colitis?
Non-severe infection
• WCC <15, Creatinine <150.
What are the parameters for severe colitis?
• WCC > 15, Creatinine >150.
What are the associated symptoms with fulminant colitis?
• Hypotension, or shock, ileus, toxic megacolon.
What is the management of non-severe C.diff infection?
• Oral vancomycin, fidaxomicin or metronidazole.
• Role of faecal microbiota transplantation (FMT) – in which patients do not appropriately respond to antibiotic treatment and develop fulminant colitis.
• Withdrawal of causative agent (Antibiotics) – avoid ampicillin, cephalosporins and fluoroquinolones.
• Management of fluids, nutrition and diarrhoea.
N. B: The majority of C. Difficle cases occur during hospitalisations, therefore as a form of infection control, the patient should be transferred to a side room to minimise transmission.
What is the management of fulminant colitis?
Severe disease or fulminant colitis management:
• Antibiotic therapy, supportive care and close monitoring
• Surgical consultation upon early diagnosis can ensure a good clinical outcome – intervention should be considered in patients who are unresponsive to medical therapy or have a rising WBC or lactate level.
-Subtotal colectomy with preservation of the rectum.
• Fluid status should be evaluated within a patient, especially in those who are hospitalised – hydration and electrolyte replacement should be initiated.
