Hepatic Failure/GI/Endocrine Emergencies

Drainage is used to prevent the accumulation of fluid and the development of infection.

Most enterocutaneous fistulas will drain to skin spontaneously; however, some fluid may be

retained in the fistula tract, which may lead to infection.

Vacuum-assisted closure (VAC) devices administer negative pressure wound therapy and can

increase blood flow and decrease fluid collections. For enterocutaneous fistulas, a VAC system can

help protect skin and decrease fistula output.

Nutrition

Nutritional deficiencies are present in 55%–90% of patients with GI fistulas, particularly with

upper GI fistulas, because there is substantial fluid, electrolyte, and protein loss from the upper GI

tract.

Because of nutritional deficits, patients may need nutritional supplementation in excess of daily

demands. Patients with low-output fistulas may need additional protein, and patients with high-

output fistulas may need additional daily caloric and protein requirements (e.g., 1.5–2 times basal

daily expenditure).

Enteral feedings are the preferred method for nutritional supplementation because enteral feedings

provide direct stimulation to the enterocyte, which may enhance mucosal proliferation.

In a retrospective cohort study of 335 patients with high-output small intestine fistulas (median

output 1350 mL/day), 85% (n=285) were treated with enteral nutrition. Spontaneous closure

rates were acceptable.

ii.

Tolerability may limit the use of enteral feeding (e.g., high gastric residuals, diarrhea).

GI secretions and reduction in fistula output volumes, particularly for patients with high-output

fistulas and when combined with antisecretory agents (e.g., octreotide).

Fistula site may also influence the choice of enteral nutrition compared with TPN. In general, enteral

feeding is provided for fistulas from the esophagus, lower small intestine, and colon, whereas TPN

is used for fistulas from the stomach, pancreas, or upper small intestine.

Some evidence supports adding supplements to enteral feeding. These include fish oil, omega-3

fatty acids, and glutamine, which may improve immune function or increase blood flow to the

intestinal tissue. In a study of 28 patients with high-output fistulas, patients who received glutamine

supplementation (0.3 g/kg/day orally) in addition to TPN were significantly more likely to have

spontaneous fistula closure.

Somatostatin and octreotide

Somatostatin is a tetradecapeptide that is naturally found in the GI tract and the nervous system.

It has several biological effects, including inhibition of hormone secretion (i.e., gastrin,

cholecystokinin, secretin, insulin, glucagon), inhibition of exocrine secretory response (i.e.,

gastric acid and pancreatic secretion), inhibition of motor activity in the GI tract, inhibition of

nutrient absorption, and stimulation of water and electrolyte absorption.

ii.

Octreotide is an octapeptide synthetic analog of somatostatin with similar activity.

iii.

Because output volume is correlated with spontaneous closure, drugs such as somatostatin and

octreotide are used to reduce output volumes.

Somatostatin vs. octreotide

Somatostatin has a very short half-life (about 1–2 minutes), which requires a continuous

infusion, whereas octreotide has a half-life of around 2 hours, allowing for intermittent dosing

(e.g., three times daily).

ii.

Effect of octreotide appears to diminish with repeated dosing, possibly because of down-

regulation of somatostatin receptors.

iii.

Somatostatin is active at all somatostatin receptors, whereas octreotide has variable affinity at

the somatostatin receptors.