Diabetic coma

High blood sugar (hyperglycemia)

If your blood sugar level is too high, you may experience:

• Increased thirst
• Frequent urination
• Fatigue
• Nausea and vomiting
• Shortness of breath
• Stomach pain
• Fruity breath odor
• Fast heartbeat

Low blood sugar (hypoglycemia)

If your blood sugar level is too low, you may feel:

• Shaky or nervous
• Tired
• Sweaty
• Hungry
• Nauseated
• Irritable
• An irregular or racing heartbeat
• Hostile or aggressive
• Confused

Some people develop a condition known as hypoglycemia unawareness and won't have the warning signs that signal a drop in blood sugar.

If you experience any symptoms of high or low blood sugar, test your blood sugar and follow your diabetes treatment plan based on the test results. If you don't start to feel better quickly, or you start to feel worse, call for emergency help.

Risk factors

Anyone who has diabetes is at risk of a diabetic coma.

If you have type 1 diabetes you're more at risk of a diabetic coma caused by:

• Low blood sugar (hypoglycemia)
• Diabetic ketoacidosis

If you have type 2 diabetes, you're generally more at risk of a diabetic coma caused by:

• Diabetic hyperosmolar syndrome, especially if you're middle-aged or older

Certain factors can increase the risk of diabetic coma no matter what type of diabetes you have, including:

• Insulin delivery problems. If you're on an insulin pump, you have to check your blood sugar frequently, and one of the reasons for this is that a kink in the insulin pump tubing may stop all insulin delivery. Even tubeless pumps can sometimes have problems that cause insulin delivery to stop. A lack of insulin can quickly lead to diabetic ketoacidosis if you have type 1 diabetes.
• An illness, trauma or surgery. When you're sick or injured, blood sugar levels tend to rise, sometimes dramatically. This may cause diabetic ketoacidosis if you have type 1 diabetes and don't increase your insulin intake to compensate. Other medical conditions, such as congestive heart failure or kidney disease, may increase your risk of diabetic hyperosmolar syndrome.
• Poorly managed diabetes. If you don't monitor your blood sugar properly, or take your medications as directed, you'll not only have a higher risk of developing long-term complications, but also have a higher risk of diabetic coma.
• Deliberately skipping insulin. Sometimes, people with diabetes who also have an eating disorder choose not to use their insulin as directed with the hope of losing weight. This is a dangerous, life-threatening practice that increases the risk of diabetic coma.
• Drinking alcohol. Alcohol can have unpredictable effects on your blood sugar, sometimes dropping blood sugar levels as long as a day or two after the alcohol was consumed. This can increase your risk of a diabetic coma caused by hypoglycemia.
• Illegal drug use. Illegal drugs, such as cocaine and Ecstasy, can increase your risk of severe high blood sugar levels, as well as your risk of diabetic coma.

Complications

Left untreated, a diabetic coma can lead to:

• Permanent brain damage
• Death

Diagnosis

If you experience a diabetic coma, prompt diagnosis is essential. The emergency medical team will do a physical exam and may ask those who are with you about your medical history.

Lab tests

You may need various lab tests to measure:

• Your blood sugar level
• Your ketone level
• The amount of nitrogen or creatinine — a breakdown product of creatine, an important part of muscle — in your blood
• The amount of potassium, phosphate and sodium in your blood 

Treatments and drugs

Emergency treatment for a diabetic coma depends on whether your blood sugar level is too high or too low.

High blood sugar

If your blood sugar level is too high, you may need:

• Intravenous fluids to restore water to your tissues
• Potassium, sodium or phosphate supplements to help your cells function correctly
• Insulin to help your tissues absorb glucose again
• Treatment for any underlying infections

Low blood sugar

If your blood sugar level is too low, you may be given a:

• Glucagon injection, which will cause your blood sugar level to quickly rise
• Consciousness typically returns when blood sugar reaches a normal level. 

Prevention

Good day-to-day control of your diabetes can help you prevent a diabetic coma. Keep these tips in mind:

• Follow your meal plan. Consistent snacks and meals can help you control your blood sugar level.
• Keep an eye on your blood sugar level. Frequent blood sugar tests can tell you whether you're keeping your blood sugar level in your target range — and alert you to dangerous highs or lows. Check more frequently if you've exercised because exercise can cause blood sugar levels to drop, especially if you don't exercise regularly.
• Take your medication as directed. If you have frequent episodes of high or low blood sugar, let your doctor know. He or she may need to adjust the dose or timing of your medication.
• Have a sick-day plan. Illness can elevate blood sugar unexpectedly. Before you get sick, talk with your doctor about how to best manage this increase in your blood sugar.
• Check for ketones when your blood sugar is high. Check your urine for ketones when your blood sugar level is over 240 mg/dL (13 mmol/L). If you have a large amount of ketones or they persist, call your doctor for advice. Call your doctor immediately if you have any level of ketones and are vomiting.
• Have glucagon and fast-acting sources of sugar available. If you take insulin for your diabetes, make sure you have an up-to-date glucagon kit and fast-acting sources of sugar, such as glucose tablets or orange juice, readily available to treat low blood sugar levels.
• Consider a continuous glucose monitor (CGM), especially if you have trouble maintaining stable blood sugar levels or you don't feel symptoms of low blood sugar (hypoglycemia unawareness). CGMs are devices that use a small sensor inserted underneath the skin to track trends in your blood sugar levels. These devices can alert you when your blood sugar is dangerously low. However, you still need to test your blood sugar levels using a blood glucose meter even if you're using a CGM, and because these devices are still being studied, not all insurance companies will cover them.
• Drink alcohol with caution. Because alcohol can have an unpredictable effect on your blood sugar, be sure to have a snack when you drink, if you choose to drink at all.
• Educate your loved ones, friends and co-workers. Teach loved ones and other close contacts how to recognize early signs and symptoms of blood sugar extremes — and how to summon emergency help should you pass out.
• Wear a medical ID bracelet or necklace. If you're unconscious, the ID can provide valuable information to your loved ones, co-workers and others — including emergency personnel.

References:

http://www.news-medical.net/health/What-is-a-Diabetic-Coma.aspx

https://en.wikipedia.org/wiki/Diabetic_coma

http://www.healthline.com/health/understanding-and-preventing-diabetic-coma

http://www.news-medical.net/health/Diabetic-Coma-Treatments.aspx