Editing Medical-Surgical Nursing (section)

=== Diabetes Mellitus ===

Type 1 diabetes results from autoimmune beta cell destruction with absolute insulin deficiency and requires insulin. Type 2 diabetes results from insulin resistance with relative insulin deficiency and is managed with lifestyle change, oral agents, and often eventually insulin. Classic findings are polyuria, polydipsia, polyphagia, fatigue, blurred vision, and poor wound healing; weight loss is typical in type 1.

Hemoglobin A1c reflects average glycemic control over roughly the preceding two to three months, with a general adult target below seven percent, individualized by patient.

Insulin timing matters at the bedside. Rapid-acting insulin such as lispro or aspart begins to work within about fifteen minutes and must be given with food available. Short-acting regular insulin begins in about thirty minutes to an hour and is the only insulin routinely given intravenously. Intermediate-acting NPH peaks in roughly four to twelve hours, which is when hypoglycemia is most likely. Long-acting glargine and detemir are relatively peakless and are not mixed with other insulins. When mixing regular and NPH in one syringe, draw up regular first, remembering clear before cloudy.

Hypoglycemia presents with shakiness, diaphoresis, tachycardia, hunger, irritability, confusion, and eventually seizure and coma. In a conscious patient with a functional swallow, give fifteen grams of fast-acting carbohydrate, recheck the blood glucose in fifteen minutes, repeat if still low, and then follow with a protein-containing snack if a meal is not imminent. In an unconscious patient give intravenous dextrose or intramuscular or subcutaneous glucagon and never give anything by mouth.

Diabetic ketoacidosis occurs mainly in type 1 and presents with blood glucose usually above 250 mg/dL, arterial pH below 7.35 with low bicarbonate, positive serum and urine ketones, Kussmaul respirations, fruity breath odor, dehydration, and abdominal pain. Treatment order matters: intravenous isotonic fluid replacement comes first, then a regular insulin infusion, with continuous potassium monitoring. Serum potassium may look normal or high initially even though total body potassium is depleted, and insulin drives potassium into cells; insulin should be withheld and potassium replaced first if the serum potassium is below about 3.3 mEq/L. Dextrose is added to the fluids when the glucose falls to roughly 200 to 250 mg/dL to prevent hypoglycemia while the acidosis clears.

Hyperosmolar hyperglycemic state occurs mainly in type 2, with extremely high glucose often above 600 mg/dL, profound dehydration, and altered mental status, but without significant ketosis or acidosis because enough insulin remains to prevent lipolysis. Treatment centers on large-volume fluid resuscitation and insulin.

Nursing application: teach sick day rules. The patient continues taking insulin even when not eating well, checks glucose and ketones more frequently, maintains fluid and carbohydrate intake with liquids if solid food is not tolerated, and calls the provider for persistent vomiting, ketones, or glucose that remains uncontrolled.

Long-term complications include retinopathy, nephropathy, neuropathy, and accelerated atherosclerosis. Daily foot inspection, well-fitted shoes, never walking barefoot, cutting nails straight across, and testing water temperature with the hand or a thermometer rather than the foot are core teaching points.