Case Study: Recurrent Diabetic Ketoacidosis Resulting From Spurious Hypoglycemia: A Deleterious Consequence of Inadequate Detection of Partial Strip Filling by a Glucose Monitoring System

Abstract

E.K., a 28-year-old woman with poorly controlled type 1 diabetes of 10 years' duration, presented with mild nausea, occasional vomiting, dizziness, and recurrent, asymptomatic severe hypoglycemia. In phone consultations with the physician's office in the preceding week, she had reduced her insulin in half because of recurrent, very low (usually asymptomatic) glucose readings but sporadic low glucose levels continued to be problematic. She also had episodic, marked hyperglycemia complicating her dosing decisions. Her patterns of high and low glucose appeared discordant with food intake and insulin dosing. Her history was remarkable for diabetes and recurrent, intermittent nausea, vomiting, and diarrhea presumed to be manifestations of autonomic neuropathy. She had known hypoglycemia unawareness but had not had problems with unconscious hypoglycemia or seizures. She had no other known autoimmune disorders and no retinopathy or renal dysfunction. She often missed office appointments and, until recently, had been erratic in her glucose monitoring. At the time of her presentation, she was on 10 units of NPH insulin in the morning and 5 units at night, with small doses of lispro only taken to compensate for very high glucose readings. Her exam was remarkable for dry mucous membranes and orthostatic hypotension, with a sitting blood pressure of 98/74 mmHg and pulse of 102 bpm and a standing blood pressure of 72/40 mmHg and pulse of 120 bpm. Otherwise, she had normal skin pigmentation and no lipohypertrophy or lipoatrophy, and her neck, heart, lung, abdomen, and extremities were all unremarkable. Because of the frequent low glucose levels, her insulin was further decreased, down to 7 units in the morning and 2 units at night, and she was provided new bottles of her insulins and test strips. She was instructed to aggressively hydrate and closely monitor her blood glucose and urine ketone levels. Fasting laboratory tests …