As DKA is a result of an absolute or relative insulin-deficient state, the cornerstone of DKA therapy is insulin. Insulin is essential to normalize blood glucose levels and to suppress further lipolysis and ketogenesis. The delivery of insulin should be in the form of a continuous infusion using regular- or short-acting insulin at 0.05–0.1 units/kg/h. Recent pediatric studies found comparable effectiveness and safety and a more gradual reduction in the effective plasma osmolality over the first 12 h with 0.05 units/kg/h insulin infusion rate. Younger and newly diagnosed patients are likely to be more insulin sensitive, requiring lower dosing. As with initial fluid resuscitation, the blood glucose levels generally drop quite rapidly; it is recommended to commence the insulin infusion at 1–2 h following fluid resuscitation. Insulin boluses are not recommended to be used at the start of therapy, as they may increase the risk of CE.[33,34]
It is not recommended to stop an already initiated insulin infusion, but rather to introduce dextrose infusion with a 'two-bag system' if the blood glucose fall is more than 100 mg/dl/h (5.6 mmol/l/h) or the blood glucose level is less than 300 mg/dl (<17 mmol/l). Details of the two-bag system are given in the following section. In severe hypokalemia not responding to maximal doses of potassium supplementation, a decrease in insulin infusion may be considered.
After Resolution of DKA
Transition to subcutaneous insulin is recommended when ketoacidosis resolves, and generally coincides with the introduction of oral fluids and tolerating an oral diet. Therefore, it is ideal to transition patients around mealtimes. In certain circumstances, transition to only basal insulin is recommended when resolution of acidosis occurs at night, when the patient is likely to remain asleep and not eat. To prevent rebound hyperglycemia, the first subcutaneous insulin injection should be given at least 30 min before stopping the insulin infusion. The dose and type of subcutaneous insulin used is dependent on local preferences and the insulin types available. The authors recommend a basal–bolus insulin regimen with glargine or detemir as basal insulin and aspart or lispro as short-acting insulin.
Expert Rev Endocrinol Metab. 2012;7(4):433-443. © 2012 Expert Reviews Ltd.