Endocrine Abstracts

Introduction: Diabetic ketoacidosis (DKA) can be easily confirmed with the triad of hyperglycaemia, metabolic acidosis and ketonaemia/ketonuria when suspected. DKA presenting as acute abdomen sometimes is well known, but not vice versa. We describe a rare presentation of acute abdomen with stress hyperglycaemia masquerading as DKA.

Case Report: 2 year old boy presented with abdominal pain for 8 hours, vomiting & lethargy and tachypnoea & tachycardia. A working diagnosis of new onset diabetes with DKA was considered as he had hyperglycaemia (blood glucose 22.2 mmol/l) and severe metabolic acidosis (pH 7.09, base excess −12.8 mmol/l & bicarbonate 12.5 mmol/l); he received cautious fluid bolus (10 ml/kg), gradual dehydration correction over 48 hours and continuous low dose intravenous insulin infusion (0.05 units/kg per hr). He also had lowish blood pressure (94/42 mmHg) and poor urine output; first urine sample obtained 12 hours after admission revealed mild ketonuria (trace) only. Over the next 24 hours, insulin infusion was weaned & stopped due to hypoglycaemia despite glucose infusion, metabolic acidosis persisted and abdominal signs appeared indicating possible peritonitis. An urgent laparotomy revealed internal hernia with strangulated small bowel, due to mesenteric non-attachment; the mesentery was fixed and untwisted small bowel was viable and did not need resection.

Discussion: Establishing diagnosis of DKA is often straightforward if hyperglycaemia, metabolic acidosis and ketonaemia/ketonuria are evident; inappropriate mild or no ketonuria for the degree of acidosis, low urine output and hypotension should alert a clinician to explore other causes of acidosis. Excessive fluid administration is detrimental to patient outcomes with DKA, whereas septicaemia or shock patients need enthusiastic fluid replacement therapy. Erroneous diagnosis of DKA prevents adequate fluid administration in septicaemia or shock patients, worsening the clinical situation.

Learning points: Hyperglycaemia is a high urine output state due to obligatory osmotic diuresis; thus low urine output is unusual in DKA unless renal function is compromised. Low urine output and hypotension are two good clinical indicators for septicaemia or shock even in a DKA patient and warrants careful reassessment - as avoiding excessive fluids is important in DKA whereas aggressive fluid resuscitation is needed for septicaemia or shock.