A 52-year-old woman with type 2 diabetes mellitus on metformin and glibenclamide presents with hyperosmolar hyperglycemic state (blood glucose 650 mg/dL, osmolality 330 mOsm/kg, pH 7.35). After aggressive fluid resuscitation, what is the preferred insulin regimen?

Explanation

## Insulin Management in Hyperosmolar Hyperglycemic State (HHS) **Key Point:** Although HHS typically has less severe acidosis than DKA, intravenous regular insulin infusion remains the gold standard because the primary defect is severe hyperglycemia and hyperosmolality, which require rapid glucose lowering. ### Rationale for IV Regular Insulin in HHS 1. **Severe hyperglycemia** — blood glucose often > 600 mg/dL; requires rapid, controlled reduction 2. **Hyperosmolality** — osmolality > 320 mOsm/kg; insulin reduces glucose and osmotic load 3. **Titration capability** — IV infusion allows adjustment of glucose reduction rate (target 50–100 mg/dL/hr) to avoid osmotic diuresis complications 4. **Fluid shifts** — rapid glucose lowering without IV control risks cerebral edema ### Comparison: DKA vs. HHS Insulin Management | Feature | DKA | HHS | |---------|-----|-----| | **Insulin route** | IV regular | IV regular | | **Initial bolus** | 0.1 U/kg IV | Usually omitted (slower onset) | | **Infusion rate** | 0.1 U/kg/hr | 0.05–0.1 U/kg/hr | | **Glucose target** | 150–200 mg/dL | 200–250 mg/dL (slower reduction) | | **Acidosis** | Severe (pH < 7.3) | Mild or absent (pH > 7.30) | **Clinical Pearl:** HHS patients are typically older, more dehydrated, and at higher risk of thromboembolism and acute coronary syndrome. Slower glucose reduction (over 24–48 hours) is safer than rapid correction. **High-Yield:** Unlike DKA, HHS may not require a loading bolus of insulin; a lower infusion rate (0.05–0.1 U/kg/hr) is often used to avoid overcorrection and hypokalemia.