Intestinal Failure

Intestinal failure is reduction of gut function below the minimum required for absorption of nutrients, water or electrolytes such that intravenous supplementation is necessary to maintain health. If the patient can maintain health without intravenous supplementation, the condition is intestinal insufficiency rather than intestinal failure.

Mechanisms include short bowel syndrome, intestinal dysmotility, enterocutaneous fistula, mechanical obstruction and extensive mucosal disease.

Functional classification:

• Type I: acute, short duration and usually reversible, commonly after surgery or critical illness.
• Type II: prolonged acute intestinal failure lasting weeks to months in a metabolically unstable patient requiring multidisciplinary care.
• Type III: chronic intestinal failure in a metabolically stable patient requiring intravenous support for months or years.

Presentation depends on mechanism.

The common clinical expression is inability to maintain hydration, electrolyte balance, nutritional status or body weight through oral or enteral intake alone.

Look for high stoma or fistula output, diarrhoea, thirst, oliguria, recurrent dehydration, muscle weakness, weight loss and micronutrient deficiency.

Long term parenteral support introduces its own complications, particularly catheter related bloodstream infection, central venous thrombosis, metabolic bone disease and intestinal failure associated liver disease.

Diagnosis is functional rather than based on bowel length alone.

Document oral intake, stoma or stool output, urine volume, body weight and actual intravenous fluid and nutrition requirements.

Measure sodium, potassium, magnesium, phosphate, calcium, renal function, liver profile, full blood count, iron indices, vitamin B12, folate and fat soluble vitamins according to anatomy and duration.

Define the anatomical mechanism with operative records and imaging. Residual bowel length, presence of terminal ileum, ileocaecal valve and colon profoundly affect prognosis.

Management should occur through a multidisciplinary intestinal failure service whenever available.

The immediate priorities are correction of dehydration and electrolyte deficits, control of sepsis, treatment of the underlying gastrointestinal disease and provision of sufficient nutrition.

Use the gut whenever it is functional. Oral and enteral feeding help preserve intestinal adaptation and should be maximised without causing uncontrolled fluid losses.

Parenteral nutrition or intravenous fluid support is life saving therapy for patients whose intestine cannot independently maintain hydration or nutrition. ESPEN recommends home parenteral nutrition as primary therapy for chronic intestinal failure when the underlying problem is not immediately reversible.

Parenteral prescriptions must be individualised according to energy requirements, enteral absorption, renal function, stoma losses and biochemical monitoring. A fixed universal electrolyte formula is inappropriate.

Central venous access must be treated as an organ preserving resource. Prevent catheter infection using meticulous aseptic technique and investigate fever during infusion promptly for bloodstream infection.

Correct the mechanism whenever possible. This may include fistula closure, relief of obstruction, restoration of intestinal continuity or treatment of inflammatory bowel disease.

Patients with potentially reversible Type II disease should undergo nutritional rehabilitation before major reconstructive surgery.

Intestinal rehabilitation seeks to progressively reduce intravenous support through dietary optimisation, antimotility and antisecretory therapy, restoration of bowel continuity and, in selected short bowel syndrome, treatment with GLP 2 analogue therapy.

Intestinal transplantation is reserved for selected patients with irreversible intestinal failure and life threatening complications of parenteral support, such as progressive intestinal failure associated liver disease, loss of central venous access or recurrent severe catheter related sepsis.