NCLEX · Pharmacological Therapies

A client is receiving a continuous IV infusion of regular insulin for DKA. The blood glucose has decreased from 480 to 310 mg/dL over the past 2 hours. At what blood glucose level should the nurse add dextrose to the IV fluids?

Correct answer

When the blood glucose reaches 200-250 mg/dL — dextrose is added to the IV fluid at this point to prevent hypoglycaemia while the insulin infusion continues to resolve the underlying ketoacidosis

  1. A When the blood glucose reaches 70 mg/dL
  2. B When the blood glucose reaches 200-250 mg/dL — dextrose is added to the IV fluid at this point to prevent hypoglycaemia while the insulin infusion continues to resolve the underlying ketoacidosis
  3. C Dextrose is never added during insulin infusion
  4. D Only when the client complains of feeling hypoglycaemic

Why this is the answer

DKA MANAGEMENT requires a critical understanding of why insulin therapy continues even after blood glucose normalises. THE DKA PRINCIPLE: DKA is resolved when the anion gap normalises and ketones are cleared — NOT simply when blood glucose returns to normal. The insulin infusion is the treatment for the ketoacidosis, not just the hyperglycaemia. DEXTROSE ADDITION PROTOCOL: When blood glucose falls to 200-250 mg/dL (typical threshold), dextrose 5% or 10% is added to the maintenance IV fluid; this prevents hypoglycaemia while the insulin infusion continues at a reduced rate to resolve the ketoacidosis; the insulin must continue until the anion gap closes and bicarbonate normalises; WITHOUT dextrose addition: continuing insulin without dextrose when glucose reaches 200 mg/dL would cause hypoglycaemia before the acidosis is resolved; STOPPING INSULIN TOO EARLY: If insulin is stopped when glucose normalises but before ketosis resolves, the underlying metabolic problem is not treated and DKA will rebound. MONITORING PARAMETERS DURING DKA TREATMENT: Blood glucose every 1-2 hours; BMP every 2-4 hours (anion gap, bicarbonate, potassium, creatinine); strict I&O; vital signs every 1-4 hours; mental status; POTASSIUM REPLACEMENT: Critical — insulin drives potassium into cells, causing hypokalaemia; potassium must be checked before starting insulin; hold insulin if K+ below 3.5 mEq/L and replace first.
Source: NCLEX-RN Physiological Integrity — DKA Management, Dextrose Addition