Euglycemic Ketoacidosis: An Overlap of Diabetic and Non-diabetic Causes

Ketoacidosis is the most common cause of high anion gap metabolic acidosis in acute medical settings. Although bedside detection is straightforward, identifying the underlying aetiology may be challenging, particularly in patients with diabetes, in whom multiple mechanisms may coexist.

We report a case of a middle-aged woman with type 1 diabetes who presented with vomiting and reduced oral intake. Initial investigations demonstrated high anion gap metabolic acidosis with severe ketoacidosis (ketones 4.8 mmol/L), hypoglycaemia (glucose 3.3 mmol/L), and profound acute kidney injury (eGFR 5 ml/min/1.73 m² from a baseline of 47 ml/min/1.73 m²). She was initially managed for diabetic ketoacidosis (DKA) with hypoglycaemia using a fixed-rate insulin infusion; however, no clinical or biochemical improvement was observed. Re-evaluation of her clinical presentation and investigations by the multidisciplinary team prompted consideration of other differential diagnoses, such as euglycemic DKA, starvation ketosis, and metabolic acidosis secondary to acute tubular necrosis. Targeted treatment for these causes of metabolic acidosis was initiated, and remarkable clinical and biochemical improvements were noted within 48 hours, suggesting an overlapping metabolic pathophysiology. The patient made a full recovery and was discharged after 10 days.

This case highlights the diagnostic complexities that may be encountered in managing ketoacidosis, especially in patients with diabetes, and underscores the importance of correctly identifying the different causes of ketoacidosis. It draws the attention of acute and general physicians to the possibility of overlapping metabolic processes in the aetiology of ketoacidosis and that successful treatment often targets all identified causes, rather than a single cause. Additionally, other causes of metabolic acidosis, such as lactic acidosis and acute kidney injury, should be identified and treated.