When should feeding be initiated in patients with diabetic ketoacidosis (DKA)?

When to Initiate Feeding in DKA

Feeding should be initiated within 24 hours of admission for patients with DKA once they are hemodynamically stable and able to tolerate oral intake, as early nutrition is associated with shorter ICU and hospital length of stay without increasing complications. 1

Timing of Oral Nutrition Initiation

Early feeding (within 24 hours) is safe and beneficial in DKA patients. A retrospective study of 128 DKA admissions demonstrated that patients receiving oral nutrition within the first 24 hours had significantly decreased hospital and ICU length of stay compared to those fed after 24 hours, with no difference in mortality, DKA resolution time, or complication rates. 1

Prerequisites Before Starting Feeding

Before initiating oral nutrition, ensure the following conditions are met:

• Patient must be hemodynamically stable with adequate fluid resuscitation completed 1
• Patient must be able to tolerate oral intake without significant nausea or vomiting 1
• Mental status should be adequate to safely swallow and protect the airway 2

Management During DKA Resolution

Continue IV Insulin While Feeding

• Do not discontinue intravenous insulin when starting oral nutrition, as interruption of insulin therapy is a common cause of persistent or worsening ketoacidosis 3
• Add dextrose to IV fluids when glucose falls below 250 mg/dL while continuing insulin infusion to prevent hypoglycemia and allow continued ketosis resolution 3, 2
• Target glucose between 150-200 mg/dL until DKA fully resolves (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) 3

Transition to Subcutaneous Insulin

Once DKA is resolved and the patient can eat:

• Start a multiple-dose subcutaneous insulin regimen combining short/rapid-acting and intermediate/long-acting insulin 4, 3
• Continue IV insulin for 1-2 hours after starting subcutaneous insulin to ensure adequate plasma insulin levels and prevent rebound ketoacidosis 3, 2
• Administer basal insulin 2-4 hours before stopping IV insulin when transitioning to prevent recurrence 2

Nutritional Insulin Coverage

For patients on enteral feedings who require insulin:

• Bolus feedings: Give regular or rapid-acting insulin subcutaneously before each feeding, starting with 1 unit per 10-15 g carbohydrate 4
• Continuous feedings: Use NPH/detemir every 12 hours or glargine/degludec daily for basal coverage, plus regular insulin every 6 hours or rapid-acting every 4 hours for nutritional needs 4
• Add correctional insulin subcutaneously every 4-6 hours as needed for hyperglycemia 4

Critical Pitfalls to Avoid

• Never stop IV insulin prematurely when glucose normalizes, as ketonemia takes longer to clear than hyperglycemia 3, 5
• Do not withhold feeding until complete DKA resolution, as early nutrition does not prolong ketoacidosis or increase complications 1
• Avoid overzealous insulin without glucose supplementation, which can lead to hypoglycemia 3
• Monitor for rebound hyperglycemia if IV insulin is discontinued before adequate subcutaneous insulin coverage 2

Special Considerations for NPO Patients

If the patient remains NPO after DKA resolution:

• Continue IV insulin and fluid replacement 3
• Supplement with subcutaneous regular insulin every 4 hours as needed: give 5-unit increments for every 50 mg/dL increase above 150 mg/dL (up to 20 units for glucose of 300 mg/dL) 3
• Ensure basal insulin coverage continues, particularly critical for type 1 diabetes patients even when not eating 4, 2