Curing Diabetes

The treatment goals for DKA are to replace fluid and electrolytes, provide enough insulin to maintain normal glucose metabolism, and prevent complications.

Replacing Fluids and Electrolytes

Your patient with DKA needs fluid therapy to increase her circulating blood volume and to enhance glucose excretion through the kidneys. The fluid of choice is usually I.V. 0.9% normal saline solution (an isotonic solution) infused at a rate of 1 L/hour for the first hour of therapy. Normal saline solution prevents a rapid fall in extracellular osmolality, reducing the risk of cerebral edema. After the first hour, adjust the infusion rate based on your patient’s blood pressure and any persistent fluid loss caused by vomiting and diuresis.

When the patient’s blood glucose level drops to between 250 and 300 mg/dl, expect to change the I.V. solution to 5% dextrose mixed with 0.45% normal saline solution to prevent hypoglycemia.

In a patient with DKA, significant diuresis usually leads to a profound electrolyte imbalance. Administering insulin promotes potassium movement into the cells, lowering the blood potassium level even further. Therefore, unless your patient has renal failure and her blood potassium level is too high, expect to replace her potassium, usually 4 to 8 hours after fluid therapy has begun. If her potassium level is below 2.5 mEq/L, however, don’t delay potassium replacement: Add 30 to 40 mEq/L of potassium chloride to the first bag of I.V. fluid, as ordered.

If your patient’s blood pH is below 7.1, the physician may prescribe sodium bicarbonate. If so, be sure to infuse it slowly-at a rate of 1 to 2 mEq/kg over 2 hours-because sodium bicarbonate can cause metabolic alkalosis if infused to rapidly.

Administering Insulin

The goal of insulin therapy is to reverse hyperglycemia and ketoacidosis without causing hypoglycemia.

The physician may prescribe a low-dose continuous I.V. infusion of regular insulin because its rapid action allows fast changes in titration. Anticipate starting with a bolus of 0.1 to 0.15 U/kg. This initial treatment will saturate the insulin receptors in the tissues. After the bolus, the physician may prescribe 0.1 U/kg/hour until the blood glucose level returns to normal. For most patients, this dosage decreases the blood glucose level by 80 to 100 mg/dl/hour. While insulin is being infused, monitor your patient’s blood glucose level every hour to assess the treatment’s effectiveness. Adjust the infusion rate as needed.

Eventually, your patient can resume subcutaneous insulin therapy. But keep the insulin infusion going for 30 minutes after the first subcutaneous injection.

Preventing Complications

Preventing complications is an integral part of DKA treatment. The most common complications are electrolyte imbalances, hypoglycemia, heart failure and cerebral edema. You can reduce the likelihood of these complications by carefully replacing fluids and electrolytes and closely monitoring laboratory values.

Cerebral edema, a potentially fatal complication, may result from correcting osmolality, acidosis, or hyperglycemia too quickly. Signs and symptoms include headache, lethargy and loss of consciousness. On physical examination, your patient’s pupils will be fixed, unequal, and dilated, and she’ll have papilledema. She’ll also have bradycardia and hypertension.

Filed under: Acute Complication