Diabetes Mellitus Q 80

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The nurse expects that a type 1 diabetic may receive how much of his or her morning dose of insulin preoperatively?

  

    A. 10-20%

    B. 25-40%

    C. 50-60%

    D. 85-90%

    

    

Correct Answer: C. 50-60%

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Surgical procedures may result in a number of metabolic perturbations that can alter normal glucose homeostasis. Patients with type 1 diabetes mellitus who are using long-acting insulins, such as glargine, should continue these as normal when fasting. Patients taking premixed insulins or fixed-combination insulins are more of a challenge. It may not be feasible or economical to change the patient’s premixed insulin just before surgery. In these situations, the patient can take ½ – ¾ of the morning dose, followed by administration of a dextrose-containing intravenous fluid and frequent blood glucose checks.

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Option A: However, in patients who take high doses of basal insulin (>60% of total daily insulin) or total daily insulin dose is greater than 80 units or are at high risk of hypoglycemia (elderly, renal or hepatic insufficiency, prior hypoglycemic episodes); basal insulin dose should be reduced by 50 to 75% to minimize hypoglycemia risk.

Option B: Patients who are on home insulin therapy should reduce the dose of long-acting basal insulin (glargine, detemir) by 20-25% the evening before surgery. If they routinely take basal insulin only in the morning, then the reduced dose should instead be administered on the morning of surgery.

Option D: If the patient is prone to morning hypoglycemia, the dose can be reduced by 20%. Thus, the diabetic patient may receive 80% of his or her morning dose of insulin preoperatively.

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