Cerebral Edema: A Complication of DKA

DKA, or diabetic ketoacidosis, is a severe life-threatening medical complication that must be treated by doctors in a hospital. DKA is a condition in which blood glucose levels have risen dangerously high due to lack of insulin and insulin resistance. Fat begins to break down in response to energy requirements leading to high ketone levels in the blood causing your blood to become too acidic. DKA sometimes leads to cerebral edema, which is brain swelling, and if left untreated, cerebral edema can cause brain damage or lead to death.

Cerebral Edema: Its relationship to DKA

In order to understand cerebral edema, you must understand diabetic ketoacidosis (DKA). DKA is a situation in which blood sugar levels rise to dangerous levels in response to a lack of insulin and insulin resistance. The liver keeps producing glucose, which collects in the blood. Normally, insulin will move that glucose out of the blood and into the cells that need it, but when there is insufficient insulin or significant insulin resistance, the glucose builds up to dangerous levels (severe hyperglycemia). Because the cells that need the glucose are not getting it (remember the glucose is stuck in the blood), they signal the body to produce more glucose through the breakdown of fat.

The breakdown of fat results in fat components called ketones. When ketones continue to build up in your blood stream, the patient develops a condition called diabetic ketoacidosis or DKA. Symptoms include:

  • Abdominal pain
  • Signifant thirst
  • Blurry vision
  • Nausea and vomiting[1]
    • Polyuria (Frequent urination)
    • Polydipsia – excessive thirst that lasts for a day or more
  • Weight loss
  • Weakness
  • Confusion
  • Cold body temperature
  • Acetone  on the breath,
    • Rapid breathing that is shallow then deep and labored– called Kussmaul’s respiration[2]
    • Dehydration
  • Coma

The first step in treating the condition is to replace the lost fluids which is usually done by IV. The second step is providing adequate insulin. Both are provided intravenously to put an end to the breakdown of fatty acids into ketones. The treatment, however, does involve certain risks: DKA recur and cerebral edema.

Care must be taken to prevent a recurrance of DKA. A relapse would occur after the flow of insulin into the body through the IV is terminated. In order to rectify this problem, it is necessary to provide the patient with long acting insulin 2 hours prior to the intravenous short acting insulin being discontinued.

In certain cases, although DKA is being treated appropriately, brain cerebral edema does occur. This is because of the significant amount of fluids that are required for the treatment.

What is Cerebral Edema?

Simply stated, cerebral edema is a swelling of the brain due to an accumulation of water. The brain compresses because of the swelling against the skull. It can lead to brain damage and eventually death. Cerebral edema influenced by DKA it is much more common among children than adults. It is also more common among those children who are newly diagnosed as being diabetic.

Symptoms

The symptoms of cerebral edema due to DKA are overt, meaning they are definable and clearly indicate the potential for neurological damage. It is important that a doctor quickly recognize the clinical signs in order to prevent possible brain damage and potential death.[3]

Symptoms indicating the presence of DKA and possible development of cerebral edema include the following:

  • Headaches
  • Steady decline in consciousness
  • Seizures
  • Urinary incontinence
  • Specific changes in blood pressure and heart rate

Research has also indicated that there are other characteristics of cerebral edema that can be recognized. It has been specifically noted in studies that those children that had DKA in conjunction with higher serum urea nitrogen concentrations as well as a more severe form of hypocapnia (the carbon dioxide is below normal levels in the blood stream) were at greater risk for suffering from a cerebral edema.4

While DKA can be successfully treated, the risk for cerebral edema can be due to several complex reasons.

Statistics

DKA occurs most often in adults over 40 years old with the rate at 60%. The death rate from DKA in adults is 1%; however, it rises to greater than 5% in adults over the age of 65. The initial diagnosis of Type 1 diabetes (T1DM) often occurs because of a DKA diagnosis. This is true for 30% of all children and 20% of all adults.

In the case of cerebral edema, the incidents occur most frequently among children. About 1% of all children who have DKA suffer an incident of cerebral edema. Unfortunately, it also has a mortality rate of approximately 25% (ranges between 20% to 90% depending on which study is consulted). DKA is the most common cause of death in children with type 1 diabetes.

Treatment

Various treatments are used for cerebral edema, and they basically focus on first relieving the pressure on the brain to prevent brain damage and then determining if the root cause of the swelling can be addressed.

Diuretics, such as mannitol or hypertonic saline, are sometimes used to reduce the level of accumulated water in the brain. Dehydration will reduce the pressure from the swelling of the brain. However, this must be balanced with the fact that patients in DKA usually start out significantly dehydrated and are in the process of being rehydrated with IV fluids.

Surgery in which part of the skull is removed to relieve pressure is possible in this situation, but would be used only as a last resort as it can be very dangerous.5

Prevention

Preventing cerebral edema due to DKA is possible by preventing DKA in the first place. Blood glucose should be tested frequently and monitored regularly so that therapeutic insulin is properly administered based on food intake and exercise levels.  Some researchers believe that cerebral edema is more common in children experiencing the first DKA episode simply because hyperglycemia was not recognized and treated in time. By preventing hyperglycemia you can drastically reduce the risk of developing DKA which in turn lowers the risk of cerebral edema. As parents become more knowledgeable about the signs and treatment of hyperglycemia, DKA and cerebral edema risks are reduced.

Knowing DKA may be associated with infection or other illnesses can also lower the risk of DKA and cerebral edema if you take precautions including closer monitoring of blood glucose. Early detection is one of the best prevention techniques available. It would allow intervention in time to prevent severe brain damage and death.

References

[1] Wolfsdorf, J; Craig, ME; Daneman, D; Dunger, D; Edge, J; Lee, W; Rosenbloom, A; Sperling, M; and Hanas, R (2009). “Diabetic Ketoacidosis in Children and Adolescents with Diabetes.” Pediatric Diabetes, 10 (Supplement s12): 118–133.

[2] Trachtenbarg, DE (2005). “Diabetic Ketoacidosis.” American Family Physician, 71(9):1705-1714.

[3] Glaser, N; Barnett, P; McCaslin, I; Nelson,D; Trainor, J; Louie, J; Kaufman, F; Quayle, K; Roback, M; Malley,R; and Kuppermann, N (2001). “Risk Factors for Cerebral Edema in Children with Diabetic Ketoacidosis.” New England J Medicine, 344:264-269

4 Marcovitch, H (2006). Black’s Medical Dictionary 41st edition. Lantham, Maryland: Scarecrow Press.

5 Muir, AB; Quisling, RG; Yang, MCK; and Rosenbloom, AL (2004). “Cerebral Edema in Childhood Diabetic Ketoacidosis. Natural History, Radiographic Findings, and Early Identification.” Diabetes Care, 27 (7): 1541-1546.

This article was originally published July 12, 2012 and last revision and update of it was 9/10/2015.