IV Insulin Infusion and Titration Protocols

An IV regular-insulin infusion is used when hospitalized adults have persistent hyperglycemia that requires rapid, adjustable control. Initiate the infusion when capillary or plasma glucose is at least 180 mg/dL on two separate measurements within 24 hours. For critically ill patients, the usual treatment target is 140–180 mg/dL. This is not a “normalize the glucose at all costs” treatment. Tight control increases hypoglycemia risk, while persistent hyperglycemia worsens outcomes in acute illness. The target range balances both problems. Do not place a patient with diabetic ketoacidosis (DKA), hyperglycemic hyperosmolar state (HHS), or active severe hypoglycemia on a routine IV insulin titration pathway. DKA and HHS require condition-specific protocols with distinct fluid, electrolyte, and insulin decisions. Active hypoglycemia requires immediate glucose rescue before insulin can be considered. A patient who is sedated, intubated, delirious, or unable to report symptoms deserves special attention. They may not report tremor, hunger, diaphoresis, or palpitations before the glucose becomes dangerously low. In these patients, the scheduled glucose measurement is the warning system.