From the Guidelines
When transitioning from diabetic ketoacidosis (DKA) treatment, insulin calculation involves shifting from intravenous to subcutaneous administration once the patient is clinically improved, able to eat, and has a blood glucose below 200-250 mg/dL, with the most recent guidelines from 2025 1 recommending a transition protocol to a subcutaneous insulin regimen to lower morbidity and costs of care. To calculate the total daily insulin dose, start by multiplying the hourly insulin rate by 24 to estimate the total daily requirement, then reduce this by 20-30% to account for improved insulin sensitivity, as suggested by the 2016 American Diabetes Association standards of medical care in diabetes 1. The total daily dose can then be divided into basal and bolus components, with approximately 50% as basal insulin and 50% as prandial insulin split between meals. Some key points to consider when transitioning from IV to subcutaneous insulin include:
- Administering the first dose of basal insulin 1-2 hours before discontinuing the insulin infusion to ensure adequate overlap and prevent recurrence of hyperglycemia or ketosis, as recommended by the 2016 American Diabetes Association standards of medical care in diabetes 1.
- Using a basal-plus-correction insulin regimen for patients with poor oral intake or those who are receiving nothing by mouth, as suggested by the 2016 American Diabetes Association standards of medical care in diabetes 1.
- Avoiding the sole use of sliding-scale insulin in the inpatient hospital setting, as strongly discouraged by the 2016 American Diabetes Association standards of medical care in diabetes 1. For example, if a patient was receiving 3 units/hour of IV insulin, calculate 3 × 24 = 72 units total daily, reduce by 20% to 58 units, then divide into 29 units basal and 29 units prandial (split as approximately 10 units per meal), similar to the approach outlined in the 2025 standards of care in diabetes 1. This approach prevents dangerous gaps in insulin coverage while transitioning to a sustainable outpatient regimen, and is supported by the most recent and highest quality evidence available 1.
From the Research
Calculating Insulin when Transitioning from DKA
- The process of transitioning from continuous intravenous insulin infusion to subcutaneous maintenance therapy in patients with Diabetic Ketoacidosis (DKA) involves careful consideration of several factors, including the patient's insulin requirements and the resolution of ketoacidosis 2.
- Studies have shown that concomitant administration of basal insulin analogues with regular insulin infusion can accelerate ketoacidosis resolution and prevent rebound hyperglycemia 2.
- The use of basal insulin in the management of DKA has been investigated in several studies, including those involving pediatric and adult patients, and has been found to be feasible and well-tolerated 2.
- When transitioning to subcutaneous insulin, the anion gap and serum bicarbonate levels can be used as predictors of successful transition, with an anion gap of ≤12 mEq/L and serum bicarbonate levels of >16 mEq/L associated with a lower risk of transition failure 3, 4.
Factors to Consider when Calculating Insulin
- Insulin requirements: The patient's insulin requirements should be taken into account when calculating the dose of subcutaneous insulin 2.
- Resolution of ketoacidosis: The resolution of ketoacidosis, as indicated by the closure of the anion gap and the normalization of serum bicarbonate levels, is an important factor in determining the success of the transition to subcutaneous insulin 3, 4.
- Basal insulin dose: The basal insulin dose should be adjusted based on the patient's insulin requirements and the results of blood glucose monitoring 5.
Monitoring and Adjusting Insulin Doses
- Blood glucose monitoring: Regular blood glucose monitoring is essential for adjusting insulin doses and preventing hyperglycemia or hypoglycemia 5.
- Electrolyte monitoring: Electrolyte levels, including potassium and bicarbonate, should be monitored regularly to prevent electrolyte imbalances 2, 4.
- Adjustment of insulin doses: Insulin doses should be adjusted based on the results of blood glucose monitoring and electrolyte levels, as well as the patient's clinical condition 2, 5.