Diabetic ketoacidosis (DKA) is an acute, severe, life-threating complication seen primarily in patients with type 1 diabetes mellitus (DM) in which there is a relative insulin deficiency that results in hyperglycemia and excessive oxidation of fats. This produces a buildup of fatty acids and ketone bodies in the blood with concurrent hyperglycemia, leading to acidosis and dehydration. DKA can also be seen in patients with type 2 DM but is less common and often less severe.

Relative insulin deficiency prevents the normal uptake of glucose from the blood into cells, resulting in hyperglycemia and an osmotic diuresis due to glucosuria causing serum hyperosmolarity and dehydration. Without glucose as a fuel source, cells break down triglycerides and other fats, creating free fatty acids (FFA) and ketone bodies, which results in acidosis. Patients may present with varying degrees of severity, ranging from mild acidosis to life-threating acidosis with hyperosmolarity that may result in coma or death.

DKA may be seen at the initial presentation (30%) of type 1 DM or in a previously diagnosed patient with DM who has a concurrent infectious illness or very poor DM control / medication compliance. Presenting symptoms may include weight loss, polyuria, polydipsia, abdominal pain, nausea, vomiting, dehydration, lethargy, and tachypnea. Symptoms of the underlying illness that triggered the DKA episode may also be present. In more severe cases, mental status changes, seizures, and Kussmaul respirations may be seen. The patient's breath may have a fruity smell due to respiratory acetone elimination.

Urinalysis will show glucosuria with high ketones. An anion gap metabolic acidosis will be present with hyperglycemia and increased blood osmolality. Hypokalemia (less than 3.5 mEq/L) may also be present and may worsen with treatment. Treatment must be expeditious but careful to avoid the complication of cerebral edema.

Initial acute management consists of general resuscitation measures to address airway, breathing, and circulatory (ABC) issues to stabilize the patient. A comatose patient may require intubation. Two large-bore intravenous (IV) lines should be obtained. An insulin drip with short-acting insulin is initiated with careful correction of fluid and electrolyte deficits. Laboratory tests and clinical status need to be carefully monitored on a frequent basis to avoid complications.