By Robert S. Dinsmoor | July 24, 2006 12:00 am
One type results in about 100,000 hospitalizations a year with a mortality rate of under 5%. The other is thought to cause fewer hospitalizations, yet the mortality rate is about 15%. Severe hyperglycemic conditions, known as diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS), involve very serious imbalances in blood chemistry and usually require that a person be hospitalized until normal blood chemistry is restored. Because they can occur in anyone with diabetes, everyone should know what causes them, how to prevent them, how they are treated, and when to seek medical attention.
Glucose metabolism is a complex balancing act. In people who don’t have diabetes, a number of interconnected processes help the body to use glucose and keep blood glucose levels in the normal range. The body constantly balances glucose extracted from foods and produced by the liver with glucose utilization by the body’s tissues. When there is ample glucose in the bloodstream, the liver converts some of it into glycogen for storage. When the body needs more energy, such as during a prolonged period of fasting or activity, the liver converts stored glycogen back into glucose so that it can be used by the body’s tissues. The liver also can create glucose from amino acids and fats.
Insulin lowers blood glucose levels both by slowing down the liver’s glucose production and by helping the body’s tissues to use glucose for energy. If the blood glucose level goes too low, other hormones, called counterregulatory hormones, work against the action of insulin to raise blood glucose levels. These hormones include glucagon, epinephrine, growth hormone, and cortisol. All work by prodding the liver to release glucose and by limiting glucose utilization by the body’s tissues.
In diabetes, this delicate balance is disrupted. People with Type 1 diabetes do not produce insulin, so they must inject it. They may have deficient or altered counterregulatory responses as well. People with Type 2 diabetes either do not produce enough insulin or do not respond properly to insulin, or both. They, too, must take steps to control their blood glucose with diet, exercise, or diabetes pills or insulin. If blood glucose control measures don’t work, high blood glucose is one of the possible, undesired results.
What sets the stage for diabetic ketoacidosis (DKA) is hyperglycemia (high blood glucose), especially when there is not enough insulin to handle it. In the absence of insulin, at least two things happen: The liver begins to produce more glucose, and the body’s fat and muscle cells are unable to use glucose for energy and begin to starve. The body reacts to starvation by releasing counterregulatory hormones, which signal the liver to break down fat cells for energy. But because the liver and fat cells are unable to use the glucose in the bloodstream, they are unable to properly and completely break down the fat. Instead, they stop at a chemical “halfway point,” producing chemical by-products called ketones.
Soon, the bloodstream gets flooded with excessive amounts of these ketones, rendering it more and more acidic. At the same time, the kidneys begin filtering large amounts of glucose from the blood and producing large amounts of urine. As the person urinates more frequently, the body becomes dehydrated and loses important minerals called electrolytes, which include sodium, potassium, and calcium. Having the proper amount of electrolytes is critical to many body functions, including the contraction and relaxation of the heart muscle. If not treated, all of these serious imbalances can eventually lead to coma and death.
Hyperosmolar hyperglycemic state (HHS) most commonly affects elderly people. Like DKA, HHS starts with hyperglycemia and insulin deficiency. As in DKA, people with HHS urinate frequently and become dehydrated. However, unlike in DKA, HHS impairs the ability of the kidneys to filter glucose from the bloodstream, so the hyperglycemia worsens.
Individuals developing HHS don’t experience the same buildup of ketones in the blood as do those with DKA. Diabetes experts believe that this is probably because most people with HHS have Type 2 rather than Type 1 diabetes, so they probably have enough insulin secretion left to prevent the breakdown of fats. Even so, because of the extreme dehydration, HHS can be life-threatening and even more difficult to treat than DKA.
Either of these conditions can occur in anyone with diabetes, whether he has Type 1 or Type 2 diabetes. However, DKA more commonly affects people with Type 1 diabetes and HHS more commonly affects those with Type 2. Both DKA and HHS may be triggered by insulin deficiency or by any major stress to the body, which can cause the counterregulatory hormones to surge and elevate blood glucose levels.
The most common trigger for a hyperglycemic crisis is an infection, such as strep throat, pneumonia, an infected foot ulcer, an intestinal virus, or a urinary tract infection. Other triggers include stroke, heart attack, trauma, alcohol abuse, certain drugs (such as corticosteroids and certain blood pressure medicines), and the skipping or lowering of one’s insulin dose.
In rare instances, mechanical problems with insulin pumps, such as blocking or kinking of the tubing, can stop insulin delivery and result in extreme hyperglycemia. People who use the rapid-acting insulin analog lispro (brand name Humalog), aspart (NovoLog), or glulisine (Apidra) in an insulin pump need to be particularly alert to pump malfunctions. Since lispro, aspart, and glulisine stop working more quickly than Regular insulin does, hyperglycemia can occur more quickly.
DKA and HHS can be prevented by keeping hyperglycemia from happening in the first place. Prevention involves carrying out all parts of your diabetes regimen, monitoring your blood glucose level regularly, and learning to adjust your insulin dose properly, if you use insulin.
Because infection is a common trigger, it’s important to be aware of signs of infection (such as high blood glucose) and to seek treatment promptly. In addition, when you’re sick, it’s important to take your usual doses of insulin or diabetes pills, monitor your blood glucose frequently, and test your urine for ketones. (For more specifics, see “Sick-Day Management.”)
It’s also important to be aware of symptoms of hyperglycemia, which include thirst, increased appetite, frequent urination, weight loss, and dehydration, since both DKA and HHS typically start with hyperglycemia. These symptoms may be present for several days before either condition develops. Signs of dehydration include dryness of the mouth, cracked lips, sunken eyes, weight loss, and flushed, dry skin. As the situation worsens, vomiting, weakness, confusion, and coma may occur. People with DKA may experience abdominal pain and a “fruity” odor on the breath, due to the presence of ketones.
Children and adolescents. DKA is the most common diabetes-related cause of hospitalization and death in children with diabetes. Unfortunately, hospitalization for DKA is often the way a child is first diagnosed with diabetes. To prevent DKA in children and adolescents, parents need to find a balance between giving children responsibility for their diabetes care and taking a supportive and active role in helping them maintain good monitoring and medicine habits. (Although some children are mature for their age, responsibility and good judgment are not hallmarks of childhood and adolescence.) Parents should also anticipate when high levels of blood glucose may occur, such as when a child is sick, and be ready to take a more active role in such situations to avoid problems.
A common cause of DKA in children is failing to take insulin. This can happen for any number of reasons, including having poor organizational skills, not understanding the consequences of skipping injections, or disliking or resenting the unrelenting regimen, the sense of being different from other children, or the discomfort of sticking oneself with needles. Children and adolescents may also skip injections because they seek to lose weight or gain attention. A parent’s support and understanding can help a lot in these situations. Consulting a mental health professional who specializes in children with diabetes or other chronic diseases can also be a big help, for both the child and the whole family.
Weight issues. When people start taking insulin, many notice some weight gain, and typically they blame it on the insulin. The fact that skipping some insulin doses causes weight loss seems to prove the theory, and some people take to habitually skipping insulin to control their weight. This is a risky practice that can lead to short-term, acute complications such as DKA, and long-term complications of the eyes, nerves, and kidneys.
The weight-gain culprit when starting insulin therapy is not the insulin alone. When blood glucose levels are high, excess glucose is lost in the urine. When insulin therapy is started, the glucose is used or stored by the body instead of being dumped into the urine. The storage of glucose as fat is what causes the weight gain.
A person who uses insulin can safely lose weight without skipping insulin doses. This is best done with the help of a registered dietitian, who can design a healthy, reduced-calorie diet that doesn’t compromise blood glucose control. Since exercise is key to maintaining weight loss, a person wishing to lose weight should ask his physician for advice on starting an exercise regime or ask for a referral to an exercise physiologist.
When a child or adolescent desires to lose weight, parents should not hesitate to consult the diabetes care team. Even in a child who is overweight, weight maintenance, not weight loss, is often the preferred approach. But often, body image is the real problem, not body weight, and it’s a problem that should be taken seriously since it can lead to eating disorders and to both acute and long-term diabetes complications.
Safe alcohol use. Alcohol can cause dehydration, which can contribute to DKA and HHS. However, alcohol can be consumed safely in moderation by many people with well-controlled diabetes. In most cases, “moderation” is defined as no more than two servings of alcohol a day for men and no more than one serving of alcohol a day for women.
To prevent hypoglycemia, do not drink after exercise or on an empty stomach. To prevent weight gain, remember to include the calories in your drink in your meal plan. People who take certain medicines, including metformin (brand name Glucophage and others), may need to limit their alcohol intake to prevent liver problems.
HHS. HHS typically takes much longer to develop than DKA. Studies have shown that HHS most commonly affects older people who either live alone or live in a nursing home, where their confusion may go unnoticed. Unfortunately, decline in mental status in an older person may be mistakenly attributed to “senile dementia.” Once considered an inevitable consequence of growing old, dementia is now known to be a pathological condition. Therefore, any impairment in memory, thought processes, reasoning, or language or any personality changes in an older person should be brought to the attention of that person’s medical provider. It is also important to take note of any symptoms of hyperglycemia or dehydration in an older person with diabetes.
Lactic acidosis. Although it is not a hyperglycemic crisis, lactic acidosis is another diabetes-related crisis worth knowing about, particularly if you take any drug containing metformin. Lactic acidosis is a potentially deadly condition caused by a buildup of lactic acid in the tissues. Such a buildup can be due to dehydration, lack of oxygen, prolonged exercise, hyperventilation, diarrhea, vomiting, kidney disease, or liver disease. If you take metformin and notice symptoms of lactic acidosis, such as lightheadedness, tiredness, weakness, muscle pain, slowed or irregular heartbeat, feeling cold, or unusual stomach pain, call your physician.
Throughout this treatment, doctors and nurses may check the person’s pulse, blood pressure, mental status, temperature, blood glucose level, acid levels, and serum potassium and phosphate levels to make sure the treatment is working properly. Sometimes electrocardiograms are performed to make sure that the heart is beating properly.
Diabetic ketoacidosis and hyperosmolar hyperglycemic state are both serious and life-threatening conditions. Even though they can be treated successfully in many cases, especially if caught early, they’re both worth skipping in the first place. The best way to prevent them is to keep close tabs on your blood glucose levels, to observe the “sick-day management” rules when you become ill, and to seek medical help if you cannot control your blood glucose level with self-care efforts.
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