How long should glucose normal saline (GNS) be continued after the anion gap has closed in diabetic ketoacidosis (DKA)?

From the Guidelines

Glucose normal saline (GNS) should be continued for at least 1-2 hours after the anion gap has closed in diabetic ketoacidosis (DKA) to ensure a smooth transition to subcutaneous insulin therapy. According to the most recent guidelines 1, successful transition from intravenous to subcutaneous insulin requires administration of basal insulin 2–4 h before the intravenous insulin is stopped to prevent recurrence of ketoacidosis and rebound hyperglycemia.

Key Considerations

• The typical GNS solution used is 5% dextrose in 0.45% or 0.9% normal saline, infused at 150-250 mL/hour, with the exact rate adjusted based on the patient's hydration status and electrolyte levels.
• The dextrose component helps prevent hypoglycemia while insulin therapy continues, and the saline component supports ongoing volume repletion and electrolyte stabilization.
• Potassium supplementation should be adjusted based on serum levels during this period.
• Premature discontinuation of GNS can lead to rebound hyperglycemia, persistent ketosis, or hypoglycemia during continued insulin administration.

Transition to Subcutaneous Insulin

• Basal insulin should be administered 2–4 h before the intravenous insulin is stopped to prevent recurrence of ketoacidosis and rebound hyperglycemia.
• The use of bicarbonate in people with DKA is generally not recommended, as it has been shown to make no difference in the resolution of acidosis or time to discharge 1.
• Frequent point-of-care blood glucose monitoring, treatment of any concurrent infections, and appropriate follow-up are crucial to avoid recurrent DKA.

From the Research

Duration of Glucose Normal Saline in DKA

• The optimal duration for continuing glucose normal saline (GNS) after the anion gap has closed in diabetic ketoacidosis (DKA) is not explicitly stated in the provided studies 2, 3, 4, 5, 6.
• However, study 6 suggests that insulin treatment should be continued until the anion gap has normalized, implying that GNS may be continued until this point to maintain euglycemia.
• Study 4 investigates the effects of large-volume normal saline resuscitation on clinical outcomes in DKA management, but does not provide specific guidance on the duration of GNS after anion gap closure.
• Study 2 discusses the implementation of a DKA-Power Plan, which includes guidelines for IV insulin therapy and subcutaneous insulin administration, but does not address the specific question of GNS duration.
• Studies 3 and 5 provide general guidance on DKA management, including fluid resuscitation and insulin therapy, but do not provide explicit recommendations on the duration of GNS after anion gap closure.

Considerations for GNS Duration

• The decision to continue or discontinue GNS after anion gap closure may depend on individual patient factors, such as the presence of underlying conditions or comorbidities 5.
• Study 4 suggests that large-volume resuscitation with isotonic normal saline may be associated with increased ICU length of stay, prolonged insulin infusion, and a higher incidence of non-anion gap metabolic acidosis, which may inform decisions about GNS duration.
• Close monitoring of serum glucose levels and adjustment of insulin therapy as needed is crucial to avoid hypoglycemia and ensure optimal patient outcomes 6.