Diabetic Ketoacidosis Guidelines

Diabetic ketoacidosis is a complication of diabetes mellitus that results in blood glucose levels of more than 250 mg/dL, a serum bicarb level of less than 18 mEq/l, a blood pH level of less than 7.3, increased serum ketone levels, and clinical hydration.  The main cause of diabetic ketoacidosis (DKA) is a lack of insulin in the body.

Diabetic ketoacidosis can happen in any type of diabetic and in diabetics of all ages; however, it is most commonly seen in type 1 diabetics.  Statistically, 14 percent of DKA occurs in people who are 70 years of age or older, 23 percent of DKA is seen in people between 51 and 70, 27 percent is seen in those 30 to 50 years of age, while 36 percent occur in people who are under 30 years of age.

About one to five percent of people with DKA ultimately die from their condition.  About a third of all people with DKA do not know they have diabetes before having their first bout of ketoacidosis.  Typical symptoms seen in the disease include weight loss, increased thirst, increased frequency of urination, abdominal pain, shortness of breath, nausea and vomiting, and a history of a recent fever.

Even though there have been many advances in the treatment of DKA, the rate of morbidity and mortality remain high.  In one study involving almost 29,000 individuals with diabetes who were under the age of 20 years, the vast majority (94 percent) of individuals had no DKA episodes, 5 percent had only a single episode of DKA, while 1 percent had at least 2 episodes of DKA.  The most common cause of death in DKA patients is cerebral edema.

Although most people with DKA have a preexisting case of diabetes, up to 37 percent of people did not know they had diabetes when they had their first episode of the disorder.  This is especially the case in young children with a new diagnosis of diabetes mellitus type 1.  While type 2 diabetics can suffer from DKA, most patients are diabetes type 1 patients.

Diagnostic Recommendations

When diagnosing DKA, it is acceptable to get a venous pH level rather than getting an arterial blood gas measurement in diabetics who aren’t suffering from respiratory failure.  The serum ketone level usually clinches the diagnosis of DKA but ketones can also be seen in the urine.  If the DKA isn’t terribly complicated, subcutaneous insulin can be used as part of the treatment for the disease.  Bicarbonate therapy is another treatment, although it hasn’t been shown to improve the clinical outcome.

In diagnosing DKA, the serum glucose level needs to be greater than 250 mg/dL, the serum ketone level needs to be elevated, the blood pH should be less than 7.3, and the serum bicarbonate level should be less than 18 mEq/l.  Arterial pH and venous pH are usually the same so the person can have the pH level drawn via a venipuncture rather than having to do an arterial blood gas measurement.

Laboratory testing should include a hemoglobin A1c level, anion gap measurement, pH measurement, arterial blood gases, BUN, creatinine, CBC with differential, EKG, serum bicarbonate level, serum glucose level, serum magnesium level, serum osmolality, serum phosphate level, serum sodium level, urinalysis, chest x-ray, serum amylase, serum lipase, creatine kinase level, troponin level, and both urine and blood cultures (for infection).

Causes of Diabetic Ketoacidosis

The main causes of DKA include the following:

• Antipsychotic medications, such as Clozaril, Risperdal, and Zyprexa
• Illegal drugs such as cocaine
• Alcohol use
• Steroid use
• Other medications, such as the use of interferon, glucagon, thiazide diuretics, and pentamidine
• Infections in the body
• Lack of insulin
• Failure of an insulin drug
• Failing to take one’s insulin

Treatment Guidelines for DKA

The treatment of DKA is different when treating adults versus treating children with the disorder.  The recommendations for treatment come from the American Diabetes Association.  In general, treatment guidelines include the following:

• Replacement of fluids. These patients are generally dehydrated and need IV fluids in the form or normal saline or other fluid replacement that does not contain dextrose in it.
• Insulin. Insulin should first be given by IV about 1-2 hours after starting the IV fluids.  A dose of 0.1 units per kilogram should be given with an infusion of 0.1 mg of insulin per kilogram given as an IV drip.  Glucose levels are expected to decrease by about 50-70 mg/dL per hour.  After the blood sugar is less than 200 mg/dL, the IV insulin rate should be decreased to 0.05-0.1 units per kilogram per hour and sugar should then be added to the IV.  The ideal blood sugar level should be between 150 and 200 mg/dL.  If the DKA is uncomplicated, subcutaneous insulin can be given as it is just as effective as IV insulin. DKA is considered treated when the blood glucose level is less than 200 mg/dL, the blood pH is more than 7.3, and the serum bicarbonate level is 18 mEq/l or more.
• Potassium. While the potassium in the body is usually seriously depleted in DKA; however, decreased levels of insulin, dehydration, and metabolic acidosis cause increases in the potassium level.  The level of potassium should be checked every 2 hours.  Giving fluids will cause the potassium level to be decreased and the kidneys will begin to flush out the potassium.  When insulin is given, the potassium enters the cells so that the end result is a low potassium level.  For this reason, IV potassium should be given to correct the overall decreased bodily amount of potassium.
• Bicarbonate. The use of bicarbonate in managing DKA is controversial. Those who think that bicarbonate should be given state that the metabolic acidosis seen in DKA can cause heart and brain complications.  Even so, it has not been shown that giving bicarbonate actually helps.  It can also lead to low potassium levels.   For this reason, bicarbonate should be given to only those people who have a blood pH level of 6.9 or less and should be stopped when the serum pH level is above 6.9, according to the American Diabetes Association Guidelines.
• Phosphate and Magnesium. The phosphate level is usually normal or increased in DKA but decrease as the problem is treated. Research has not shown that replacing phosphate helps and it can cause low levels of both magnesium and calcium.  Replacement should be considered only if the phosphate level is less than 1.0 mg/dL or when there are complications of low phosphate levels (muscle weakness, hemolysis, respiratory failure, rhabdomyolysis, or heart arrhythmias).  People with DKA often have decreased magnesium levels, which can result in muscle spasms, tremor, seizures, heart arrhythmias, and paresthesia.

References:

1. Diabetic Ketoacidosis: Evaluation and Treatment. http://www.aafp.org/afp/2013/0301/p337.html. Accessed 5/28/16.