Diabetic ketoacidosis masked by both Euglycemia and a primary metabolic alkalosis

Diabetic ketoacidosis (DKA) is an acute, life-threatening metabolic complication of diabetes classically associated with hyperglycemia, metabolic acidosis, and ketosis. Though relatively uncommon, patients can also develop DKA with relative euglycemia, further complicating diagnosis. Here, we describe the case of a patient who presented with intractable vomiting secondary to diabetic gastroparesis. He was euglycemic, non-acidemic, and serum bicarbonate was within normal limits. However, labs were significant for ketonuria, an elevated anion gap, and an elevated beta-hydroxybutyrate. Given the high concern for euglycemic DKA in the setting of a competing primary metabolic alkalosis, he was transferred to the intensive care unit for intravenous insulin infusion and fluid resuscitation with significant clinical improvement and normalization of laboratory results. This serves as an important reminder that DKA can be masked by euglycemia as well as additional metabolic derangements, and should be suspected in any diabetic patient with an anion gap and/or ketosis.