Diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) are two of the most serious complications of diabetes. These hyperglycemic emergencies continue to be important causes of morbid mortality among persons with diabetes in spite of all of the advances in understanding diabetes.
The annual incidence rate of DKA estimated from population-based studies ranges from 4.8.to 8 episodes per 1,000 patients with diabetes. Unfortunately, in the US incidents of hospitalization due to DKA have increased. Currently 4-9% of all hospital discharge summaries among patients with diabetes include DKA.
The incidence of HHS is more difficult to determine because of lack of population studies but it is still high at ~15%. The prognosis of both conditions is substantially worsened at the extremes of age, and in the presence of coma and hypertension.
Why and How?
The pathogenesis of DKA is more understood than HHS but both relate to the basic underlying reduction in the net effective action of circulating insulin coupled with a concomitant elevation of counter regulatory hormones such as glucagons, catecholamines, cortisol, and growth hormone.
These hormonal alterations in both DKA and HHS lead to increased hepatic and renal glucose production and impaired use of glucose in peripheral tissues, which results in hyperglycemia and parallel changes in osmolality in extracellular space. This same combination also leads to release of free fatty acids into the circulation from adipose tissue and to unrestrained hepatic fatty acid oxidation to ketone bodies.
Some drugs can affect these processes. Drugs that affect carbohydrate metabolism such as corticosteroids, thiazides, and sympathomimetic agents may precipitate the development of both DKA and HHS.
Sometimes ketones are present in urine when blood sugar falls too low and the body has to use body fat to get energy. In young diabetic persons, psychological problems complicated by eating disorders (see our article on eating disorders and diabetes) may be a contributing factor in 20% of recurrent ketoacidosis.
Factors that may lead to insulin omission in younger patients include fear of weight gain with improved metabolic control, fear of hypoglycemia, rebellion from authority, and stress stemming from having a chronic disease.
The most common precipitating factor in the development of DKA or HHS is infection. Other factors are cerebrovascular accident, alcohol abuse, pancreatitus, myocardial infarction, trauma, and drugs. Both the youngest and eldest are most at risk. A rule of thumb to understand DKA is that dehydration plus blood ketones equals DKA.
How are these conditions diagnosed?
The process of HHS usually evolves over several days to weeks, whereas the evolution of acute DKA in both type 1 and type 2 diabetes tends to be much shorter (<24h). Occasionally, a patient may develop DKA with no prior clues or symptoms. What are the symptoms?
The first symptoms appear within the first few hours:
- Thirst or a very dry mouth
- Frequent urination
- High blood-glucose levels
- High levels of ketones in the urine
The next symptoms which appear:
- Constant tiredness
- Dry or flushed skin
- Nausea, vomiting, or abdominal pain (vomiting can be caused by many illnesses, not just ketoacidosis. If you continue to vomit for more than 2 hours, contact your physician)
- Difficulty breathing (short, deep breaths)
- Fruity odor on breath
- Difficulty paying attention, or confusion
Differential diagnosis needs to rule out starvation and alcoholism as well as the other precipitation factors stated above. Your physician should have prescribed urine test strips which will test for ketones. It is suggested that if your blood glucose levels reads above 249mg/dl that you test for ketones. When you are ill with the flu or a cold, test for ketones every 4 to 6 hours. Also, make sure you test for ketones if you have the symptoms outlined above.
When you arrive at the hospital laboratory work to determine plasma glucose levels, blood urea nitrogen/creatinine, serum ketone, electrolytes, osmolality, urinalysis, urine ketones as well as arterial blood gas, complete blood count and throat, etc. if infection is suspected as well as HbA1c to help decide if poor control may be involved. If low potassium is noted this must be addressed, as it can provoke cardiac dysrhythmia.
Successful treatment of DKA and HHS requires correction of dehydration, hyperglycemia, and electrolyte imbalances as well as identification of comorbid events and, above all, patients monitoring.
Many cases of DKA and HHS can be prevented by better access to medical care, proper education and better communication with health care providers during any illness. It is well known documented that poor inner city diabetics stop taking their insulin for economic reasons. This is a problem that we as a society need to address. Sick day management should be taught to all diabetic patients.
This should include specific information on
- When to contact the health care provider
- How to supplement with short-acting insulin during an illness when blood glucose levels rise
- Methods of controlling fever and infections
- How to eat during an illness including an easily digestible diet containing carbohydrates and salt.
- All patients need to know that they should NEVER discontinue taking insulin and to seek professional advice early in an illness
Since we all get sick with colds and the flu at some time, we end this article with sick day rules and regulations. After reading this article, you are aware that controlling blood glucose levels when you have an infection can be difficult. In January, I came down with walking pneumonia and wound up taking my blood glucose levels every few hours and worked very hard to keep my levels anywhere near normal. So, plan ahead and do the following:
- Have Ketostix in the house. You don’t want to have to get to the drug store after the fact.
- Have the proper foods in the pantry. You’ll need Jell-O and Gatorade.
- Report your illness to the doctor when it causes your blood glucose levels to rise and causes urine ketones. This is not the time to do a scientific experiment. Get good advice. Get in to see the doctor if you do not improve within 6 hours.
- Test blood glucose levels and ketones frequently, about every 2-4 hours, until they are normal again.
- Get advice from your health care team if your blood glucose levels is above 250mg/dl for more than 6 hours, if you are unable to take fluids or food for more than 4 ours, if you have a fever (101.5° F.), if you are ill for more that 24 hours, or if you have these symptoms we spoke of like dehydration, severe abdominal pain, or other unexplained symptoms.
- When you call the doctor, have your ketone and blood glucose levels handy as well as temperature and symptoms.
- Continue to take your insulin even if you can’t eat solid foods. Your insulin needs will probably increase with illness. If you take oral agents, continue to take them too. If you cannot keep the pills down, call your physician. If your blood glucose level are below 70mg/dl and you take pills, call your doctor.
- Continue to eat and drink even if your blood glucose levels are high, if you are vomiting or if you have diarrhea. Take at least 45-50 g of carbohydrate every 3-4 hours to prevent low blood glucose while the insulin clears the ketones. If you can’t eat, try carbohydrate containing liquids or soft foods. These include 1/2 cup regular soft drinks, 1 double Popsicle, 1/2 cup regular Jell-O, 1 cup Gatorade, 1 cup soup, 1/2 cup fruit juice, 1 slice toast or 6 soda crackers.
- To prevent dehydration, drink at least 8 ounces of fluid every hour. If you are vomiting, limit fluid to 1-2 tablespoons every 20 minutes, or suck on a Popsicle. Fluids with mineral, like Gatorade, can help prevent dehydration.
- Limit your activity if your blood glucose levels are above 259 mg/dl and ketones are moderate to large.
So, that’s the story about ketones. They can be dangerous, but if you are educated, you can control your blood glucose levels or know where to go to get the information to do so. Take care and keep remembering the D.C.C.T.