Question 22

College answer

Enterocutaneous fistula (ECF) with inadequate source control

Or ECF with undrained collection

Or ECF with septic shock

• Management
  • Fluid and electrolyte
    • Match losses with crystalloid replacement
    • High sodium loss in high output fistulae
    • Supplement magnesium, phosphate and potassium
  • Sepsis management
    • Source control
    • Target antibiotics, antifungal
• Surgical or percutaneous drainage of associated collections
• Definitive surgical management may be delayed 
• Rule out other sources of infection
   
• Nutrition
  • TPN often required particularly if proximal fistulae
  • Enteral intake may not be possible if < 75cm bowel remaining
  • Trial elemental feed if intolerant or increased output with polymeric feed
  • Role of zinc and vitamin supplement controversial
• Wound management and effluent control
  • Principle is effective drainage allowing wound healing
  • Ostomy appliance 
  • VAC dressing controversial as may cause harm, but can be very effective in effluent management of high output fistula
• Reducing fistulae output
  • Reduce enteral intake and/or consider elemental feed
  • Antidiarrheal – loperamide
  • Somatostatin analogues – octreotide
• Definition of fistulae anatomy
  • Often difficult to define single source
  • Define and/or exclude distal obstruction
  • CT, fistulography etc

Definitive surgery - may be much later

Examiner Comments:

Not well answered. Many candidates described a generic approach to intra-abdominal sepsis without considering the specific issues related to enterocutaneous fistulae.

Discussion

An approach more directly relevant to enterocutaneous fistulae is described by Cohen et al (2016),  Lundy & Fischer (2010) and Evenson (2016).

• Stabilisation where you resuscitate the septic shock
  • Fluid resuscitation should be conservative to prevent intestinal oedema
  • Vasopressor support should be careful to prevent intestinal ischaemia
• Diagnosis where you confirm the location and extent of the fistula, by:
  • Methylene blue dyed feeds
  • Contrast "fistulogram" using water-soluble contrast and plain films or fluoroscopy (contrsat both rectal and oral)
  • Contrast CT, which has largely surpassed the fistulogram
• Evaluation for spontaneous resolution where you decide whether this needs to go to theatre urgently, or whether you can sit on it for a month. Apart from imaging and historicla features, this includes
  • Nutritional assessment, incl. prealbumin, transferrin and clinical assessment
  • Attempted early surgery if you think you can't wait for it to get better on its own (and if the patient is likely to survive)
• Trial of non-operative management if the impression is that surgery can be delayed
• Management of infectious complications during conservative management:
  • Intra-abdominal faecal contamination initially - managed with broad-spectrum antibiotics (eg. peperacillin/tazobactam) as well as an antifungal if there are risk factors (malignancy, re-laparotomy, long term antibiotics)
  • Abdominal collections after a prolonged course of systemic antibiotics
• Management of non-infectious complications during conservative management: 
  • Fluid losses particularly of high-output fistulas: strategies to decrease output include
    • avoidance of vac dressings
    • TPN
    • Octreotide, l​​​​​operamide, opiates
    • Diverting proximal stoma
    • Relief of distal bowel obstruction
  • Malnutrition: TPN and vitamin supplementation
  • Gut atrophy: low volume enteral feeds, or enteral nutrition given via the fistula
  • Electrolyte disturbance resulting from high stoma output (management of this depends mainly on vigilant replacement)
  • Skin excoriation due to spills (management of this requires a dedicated stoma service, or plastic surgical input to deal with tissue loss)
• Definitive surgical management; or, when it becomes clear that this is not an option,
• Palliative care