Recurrent diabetic ketoalkalosis in type 1 diabetes and gastroparesis

Usually, absolute insulin deficiency in type 1 diabetes rapidly leads to hyperglycaemia and ketosis. We describe a patient who has recurrently presented with diabetic ketoalkalosis, an infrequently described metabolic derangement. He was admitted with a series of three acute presentations over a one‐year period with persistent vomiting, abdominal pain, hyperglycaemia, ketonuria and biochemical evidence of metabolic alkalosis (pH >7.68, plasma bicarbonate >36mmol/L, chloride 65–84mmol/L). There was no history of alkaline ingestion. On each occasion he was treated with intravenous insulin and 0.9% sodium chloride rehydration, which corrected his biochemical abnormality. Upper gastrointestinal endoscopy after the first episode showed duodenal ulceration with no pyloric obstruction, for which he was treated with a proton pump inhibitor. Because of his recurrent vomiting and clinical signs of gastric outlet obstruction he underwent gastric emptying studies after a period of in‐patient euglycaemia. These showed significant delay in solid and liquid phase gastric emptying.

We propose that his recurrent presentation with ketoalkalosis and hypochloraemia is due to gastroparesis leading to vomiting of gastric hydrochloric acid in excess of duodenal bicarbonate loss. The alkalosis is exacerbated by potassium depletion and by hypovolaemia resulting from persistent vomiting and glucose driven osmotic diuresis (contraction alkalosis). Copyright © 2007 John Wiley & Sons.