Dumping Syndrome

Dumping syndrome results from rapid delivery of hyperosmolar gastric contents into the small bowel after gastric or oesophageal surgery.

It occurs after gastrectomy, gastrojejunostomy, oesophagectomy and bariatric procedures.

Two overlapping patterns occur.

Early dumping develops within approximately 10 to 60 minutes after eating. Rapid nutrient entry causes an osmotic fluid shift into the intestinal lumen and release of vasoactive gastrointestinal peptides.

Late dumping usually develops 1 to 3 hours after eating. Rapid glucose absorption produces exaggerated insulin release, followed by postprandial hypoglycaemia.

Early dumping

Patients develop:

• Abdominal cramping
• Bloating
• Diarrhoea
• Nausea
• Palpitations
• Tachycardia
• Flushing
• Weakness or dizziness
• Occasionally hypotension or syncope

Late dumping

Neuroglycopenic and adrenergic symptoms predominate:

• Tremor
• Sweating
• Palpitations
• Hunger
• Weakness
• Confusion
• Visual disturbance
• Syncope or seizure in severe hypoglycaemia

Symptoms occurring reproducibly after meals are highly suggestive.

Diagnosis is primarily clinical.

A modified oral glucose tolerance test can confirm uncertain cases.

Evidence of early dumping includes:

• Rise in pulse rate greater than 10 beats/min at 30 minutes

or

• Haematocrit increase greater than 3% at 30 minutes

Late dumping is supported by glucose falling below approximately 50 mg/dL, 2.8 mmol/L after the glucose load.

Continuous glucose monitoring is particularly useful when late postprandial hypoglycaemia is the dominant problem, although results should be correlated with symptoms.

Gastric emptying studies are not routinely required to diagnose dumping syndrome.

Dietary treatment

This is first line and controls symptoms in many patients.

Use:

• Five or six small meals rather than large meals
• High protein intake
• Higher fibre and complex carbohydrate content
• Avoidance of rapidly absorbed sugars
• Avoidance of sweet drinks and liquid carbohydrate loads
• Delay fluids until at least 30 minutes after meals
• Eat slowly and chew thoroughly

Lying down after meals may help severe early vasomotor symptoms in selected patients, although it is not essential for all patients.

Late dumping

If dietary treatment is insufficient:

Acarbose 50 mg orally with the first mouthful of each carbohydrate containing meal, three times daily.

Increase to:

100 mg three times daily if required and tolerated.

Acarbose delays carbohydrate digestion and is particularly effective for late hypoglycaemia. Flatulence, diarrhoea and bloating are common dose limiting effects.

Refractory early or late dumping

Use a somatostatin analogue when severe symptoms persist despite dietary therapy and acarbose where appropriate.

A practical starting regimen is:

Octreotide 25 to 50 micrograms subcutaneously, approximately 15 to 30 minutes before meals, two to three times daily.

Titrate according to response, commonly up to:

100 micrograms subcutaneously three times daily.

Long acting octreotide can be considered after response to short acting treatment has been demonstrated.

Monitor for gallstones, diarrhoea, steatorrhoea, glucose disturbance and injection site effects.

Surgical revision is a last resort for severe disabling symptoms after full nutritional and pharmacological therapy. Before reoperation, confirm the anatomy and ensure that symptoms are genuinely due to dumping rather than another postgastrectomy disorder.