What type of insulin infusion should a nurse initiate for a client with diabetic ketoacidosis?

In managing diabetic ketoacidosis (DKA), one of the primary goals is to rehydrate the patient and improve circulatory volume. The correct choice here is to initiate an insulin infusion with a fluid that is appropriate for treating DKA, which is typically isotonic saline, such as 0.9% normal saline. This fluid helps to restore intravascular volume and dilute serum glucose levels, which is critical in managing DKA.

Insulin is also administered intravenously to lower blood glucose levels and decrease ketone production. While insulin glargine is a long-acting insulin and might be suitable for daily management of diabetes, it is not appropriate for acute DKA treatment because DKA requires rapid control of hyperglycemia, which is best achieved with a fast-acting insulin infusion instead of a long-acting formulation.

Additionally, while both 5% dextrose and 0.45% sodium chloride serve specific purposes in medical treatment, they are not indicated for initial DKA management. 5% dextrose could increase blood glucose levels, which is counterproductive during a DKA crisis, while 0.45% sodium chloride does not provide the appropriate isotonic fluid needed to restore intravascular volume effectively.

Thus