Episode Details

Date: May 20, 2026 Guest Skeptic: Dr. Matt McArthur is an ED Physician working primarily in Guelph and Kitchener with occasional rural locums in the small town of Walkerton, where he grew up. His clinical interests include POCUS, emergency cardiology, QI, knowledge translation, motivational interviewing, and vertigo. He is very active in medical education, including as a clinical skills and POCUS instructor, a Contributing Editor with the EMCases Podcast, and Regional Education Lead for Undergraduate Family Medicine at the Waterloo Regional Campus of McMaster University. Reference: Qiang et al. Safety and Effectiveness of Subcutaneous Insulin for Management of Mild to Moderate Diabetic Ketoacidosis in Non-Pregnant Patients: A retrospective cohort study at a tertiary care centre. Canadian Journal of Diabetes. Oct 2025 Case: A 56-year-old woman with insulin-treated type 2 diabetes presents to the emergency department (ED) with 24 hours of nausea, vomiting, polyuria, and weakness after missing insulin doses during a viral illness. She is alert, mildly tachycardic, normotensive, breathing slightly fast, and appears dry but not toxic. Her labs show glucose 23 mmol/L, pH 7.26, bicarbonate 14 mmol/L, an anion gap of 22, and positive serum ketones. You diagnose her with diabetic ketoacidosis (DKA). After initial IV fluids, she has clinically improved and does not require any vasopressors or airway support. The practical question is whether she really needs an intravenous (IV) insulin drip and intensive care unit (ICU)-level care, or whether a structured subcutaneous (SC) insulin pathway would be safe and effective. Background: DKA is one of the classic endocrine emergencies that lands squarely in the wheelhouse of emergency medicine. It is a state of insulin deficiency that leads to progressive dehydration, electrolyte deficits, and acidemia, which together can be fatal if untreated. Clinically, these patients show up with some combination of polyuria, polydipsia, nausea, vomiting, abdominal pain, tachypnea or Kussmaul respirations, dehydration, and sometimes altered mental status. Since the discovery of insulin by Fredrick Banting in Toronto in 1921, the treatment of DKA has changed dramatically in the last 100 years. Prior to insulin, the mortality from DKA was thought to exceed 95%. In modern times, the mortality is less than 1%. As a reminder, Sir Frederick Banting, Charles Best and James Collip, sold the patent for insulin to the University of Toronto for just $1 in January 1923. Banting famously stated, “Insulin does not belong to me, it belongs to the world”. DKA treatment involves protocol-based care, including IV rehydration to address hypovolemia; insulin therapy to stop ketoacidosis and restore normal metabolism; electrolyte and dextrose replacement to correct deficits, with regular monitoring of glucose and electrolytes (especially potassium) during treatment. Most hospitals have labour-intensive DKA protocols involving IV insulin infusion, which often require patients to be admitted to the ICU due to high nursing demands. However, with the introduction of rapid-acting subcutaneous (SC) insulin analogues in the late 1990s, such as insulin lispro and aspart, some clinicians have evaluated the use of rapid-acting SC insulin boluses as an alternative to IV infusion. SGEM has already dipped a toe into these waters in SGEM#414, which covered the SQuID protocol. That episode asked whether adults with mild-to-moderate DKA could be treated with fast-acting subcutaneous insulin on a non-ICU floor, resulting in shorter ED length of stay. That study by Griffey et al in AEM highlighted the operational appeal of avoiding an insulin drip and an ICU bed for every uncomplicated DKA patient. Between 2004 and 2016, six small randomized controlled trials found no difference in safety between SC insulin boluses and IV infusions in adults. Given the safety evidence and out of a desire to provide more efficient DKA care and avoid unnecessary IC