Transitioning from IV to Subcutaneous Insulin in HHS

Introduction to Insulin Transition

For a 70 kg insulin-naive male with T2DM transitioning from IV insulin after overnight HHS treatment, administer subcutaneous basal insulin at 50% of the total 24-hour IV insulin dose, given as a single evening dose of long-acting insulin, with the remaining 50% divided equally as rapid-acting insulin before each meal 1, 2, 3

Calculate the total units of IV insulin infused over the previous 24 hours when glucose levels have been stable, ideally <180 mg/dL or 10 mmol/L, to determine the total 24-hour IV insulin requirement 1, 3
Give 50% of the 24-hour IV insulin total as once-daily long-acting (basal) insulin, such as glargine, administered subcutaneously in the evening 1, 2, 3
The remaining 50% of the 24-hour IV insulin total should be divided by 3 for rapid-acting insulin before each meal 1, 2, 3

The IV insulin infusion must overlap with subcutaneous insulin administration to prevent rebound hyperglycemia, with basal insulin given 2-4 hours before discontinuing IV insulin 5, 6
Administer basal insulin immediately after stopping the IV infusion to prevent rebound hyperglycemia 1, 3

Intensive glucose monitoring is mandatory during transition, with capillary blood glucose checked every 2-4 hours initially 5, 6
Monitor serum potassium closely as insulin drives potassium intracellularly, and ensure adequate renal function before full insulin dosing 5, 6

HHS resolution criteria must be met before transition, including calculated serum osmolality <315 mOsm/kg, patient alert and able to tolerate oral intake, and glucose target 200-250 mg/dL during HHS treatment 5, 6
For insulin-naive T2DM patients, this basal-bolus regimen may be temporary, and once stable, many patients can transition to oral agents plus basal insulin only 1, 2