Diabetic Coma Menu

Balance Between Insulin and Glucagon

Diabetic ComaBoth insulin and glucagon are made and released from the pancreas, an organ associated with the intestines that also makes digestive enzymes to break down food that is eaten.

Insulin: Diabetes interferes with the entrance of glucose into the cells. Normally, glucose entering from the blood into the cells (which use it for energy) is controlled by a hormone called insulin. If someone doesn’t have enough insulin, this is called diabetes mellitus, which results in a build-up of glucose in the blood that normally would have entered the cells. This increased level of glucose is called “hyperglycemia” (meaning, high glucose in the blood). With diabetes, this hyperglycemia can damage blood vessels and organs as well as mean too little getting into the cells, affecting the way they work.

Glucagon: A second hormone, glucagon, affects the liver such that it manufactures more glucose when needed. Normally, the two hormones (insulin and glucagon) are in a balance, but in diabetes, that balance is thrown off because insulin normally suppresses the release of glucagon and when there is too little insulin, glucagon is overproduced. Too little insulin makes the glucose in the blood accumulate, since it’s not getting into the cells; more glucagon makes the liver produce extra glucose. Thus, too little insulin raises the blood sugar by both mechanisms.

Another type of diabetes is “insulin-resistant” or Type II diabetes, in which—instead of not enough insulin—the cells resist the insulin’s normal functioning with the same result: not enough glucose enters cells and too much of it builds up in the blood.

Ketones: Untreated, runaway hyperglycemia can cause the acidity of the blood to increase, measured by a value called pH (how acid the blood is). Also, if the cells resort to a secondary method—a back-up method—of making their own glucose for energy, it can cause a build-up of ketones (by-products of this method). Therefore, there are two distinct types of hyperglycemia:

  • Non-ketotic hyperglycemia: Also called Hyperosmolar Hyperglycemic State (HHS)
  • Ketotic hyperglycemia: Also called Diabetic Ketoacidosis (DKA)

Hyperosmolar Hyperglycemic State and Diabetic Ketoacidosis (HHS and DKA)

Both HHS and DKA are endpoints in the abnormal metabolism initiated with hyperglycemia and are the most serious acute complications seen in DM. As glucose builds in the blood, its concentrations rise, making the blood “hyperosmolar” (over-concentrated). This stimulates the kidneys to compensate with excess urinary excretion of electrolytes (sodium, potassium, etc.) which causes an imbalance in them, as well.

In normal circumstances, blood sugar concentration is < 100 mg/dL. In DKA, however, the glucose concentration can be 350-400, and in HSS it can reach 1,000. DKA is a rapid sequence of events, causing nausea, vomiting, and abdominal pain, but HSS begins more slowly.

Diabetic Coma

In both HSS and DKA there is a hyperosmolality (overconcentration of glucose within the blood) that causes neurologic changes, beginning as focal neurologic weakness, lethargy, and mental changes that progresses to seizures, stupor, and coma.

Diabetic coma results from these over-concentrated conditions, with neurological changes in the brain beginning with levels > 320-330 mg/dL. The coma can occur due to either a hyperosmolar hyperglycemic state (HHS) or being in diabetic ketoacidosis (DKA). Both involve a hyperglycemia state, but in HHS, glucose levels can exceed 1,000. In DKA, they are usually lower.

Identifying HHS vs. DKA as the Cause of Diabetic Coma: Blood pH

pH—a measure of the acid nature of blood, is determined by an arterial blood gas (which has the pH as one of its measurements. This measure of acidity can help distinguish between HHS vs. DKA, as DKA is an acidosis (acid-like, with a low pH) due to excess ketoacids (ketones) in the blood.

HHS, Alternately, Is a Non-Ketotic Hyperosmolar State

Determination of electrolytes levels (sodium, potassium, etc.) is important to identify life-threatening conditions that the overconcentration in the blood produces in HHS and DKA. Then when there is additional excretion by the kidneys to compensate, the lost water makes the concentration of some solutes (sugar, electrolytes, and other substances found in the blood) even higher. Therefore, testing of the following are indicated:

  • Serum and urine ketones (present or absent)
  • Serum sodium, potassium, chloride, bicarbonate, and other electrolytes
  • ECG/EKG: Acidosis/overconcentrated states resulting in electrolyte  abnormalities (too little or too much of one of them) severely impact cardiovascular status, necessitating an electrocardiogram to determine whether support for cardiac issues is warranted
  • Infection can convert a well-controlled diabetic into an hyperglycemic state, so diagnostic tests for infection, such as bacterial cultures, blood counts, and chest X-rays, are indicated

Telling the difference between HHS and DKA as the cause of coma and diagnosing the types of electrolyte problems that occur allow for a rational approach to rapid treatment, which is necessary to avoid death.

Can a Diabetic Coma Be Diagnosed?

Diabetic coma results from hyperosmolar conditions. Neurological changes begin above levels of 320-330 mg/dL.

Diabetic coma can occur due to either a hyperosmolar hyperglycemic state (HHS) or being in diabetic ketoacidosis (DKA). Both involve a hyperosmolar state, but in HHS, glucose levels can exceed 1,000. In DKA, they are usually lower.

Identifying HHS vs. DKA as the Cause of Diabetic Coma: Blood pH

pH via arterial blood gas assessment will distinguish between HHS vs. DKA, as DKA is an acidosis due to excess ketoacids (ketones) in the blood. Blood gases from an arterial blood sample is used to determine the pH.

The diabetic lack of insulin prevents glucose from entering cells, invoking a compensatory, alternate method for manufacturing  glucose for energy that produces ketones as a by-product.

HHS, Alternately, Is a Non-Ketotic Hyperosmolar State

Determination of electrolytes levels is important to identify life-threatening conditions that the hyperosmolar state produces in HHS and DKA. Excess excretion by the kidneys loses water in compensation to correct it. This makes the concentration of some solutes in the blood even higher at the expense of others. Testing of the following are indicated:

● Serum and urine ketones (present or absent)

● Serum sodium, potassium, chloride, bicarbonate, and other electrolytes

ECG/EKG: acidosis or hyperosmolar states resulting in electrolyte abnormalities severely impact cardiovascular status, necessitating an electrocardiogram to determine whether cardiac support is indicated.

Since infection can convert a well-controlled diabetic into an hyperglycemic state, so diagnostic tests for infection, such as bacterial cultures, blood counts, and chest X-rays, are indicated.

Identifying between HHS and DKA as the cause of coma and diagnosing the types of electrolyte disturbances allow for a rational approach to rapid treatment, which is necessary to avoid death.

How Can a Diabetic Coma Be Managed?

The two causes of diabetic coma, hyperosmolar hyperglycemic state (HHS) and diabetic ketoacidosis (DKA), differ in whether or not there is ketoacidosis. Although both have severe hyperglycemia, that of HHS is more severe.

The results of metabolic changes in both lead to abnormalities in electrolyte concentrations, which can be life-threatening. Identifying the cause of the diabetic coma and determining the severity of the electrolyte abnormalities can then guide treatment.

The approach to treating either cause is similar and includes the following:

  • Infusion of fluids to dilute the over-concentration in the blood from the hyperglycemia, replenish the volume of fluids lost, and improve blood pressure and perfusion of organs to stabilize the cardiovascular status.
  • Correct the potassium deficiency, which will recur after giving insulin
  • Insulin administration in low IV doses so that any hypokalemia can be anticipated and corrected
  • Monitor serum glucose, sodium, potassium, and vital signs frequently
  • Determine cardiac status via EKG

When the cause is ketoacidosis, treatment includes:

  • IV sodium bicarbonate to counteract a pH <6.9.  Frequent monitoring of the arterial blood gases is necessary for status of the pH and bicarbonate levels 

Prevention of a Diabetic Coma

Prevention of serious complications of diabetes, including diabetic coma, requires keeping the diabetes in strict glycemic control by vigilant and aggressive blood glucose management. Even then some things can induce a hyperglycemic state that is unavoidable.

Beginning a regimen of steroids due to a flare of an arthritic condition can raise blood sugars as a side effect of this medication. Infections affect the body’s metabolism in ways that promote hyperglycemia. When an well-controlled diabetic patient begins to develop hyperglycemia without explanation, hidden causes should be sought and identified, including infection, drugs, or drug-drug interactions.

Recognizing Warning Signals

Diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS), life-threatening complications of diabetes, give warning signals. Since either hyperglycemic state–ketotic (DKA) or non-ketotic (HHS)–can create neurological changes that lead to coma and death, recognizing warning signals is the best way to avoid untoward outcomes. Patient self-testing plays an important part of recognizing warnings of hyperglycemia.

Since DKA progresses more rapidly, it may be more difficult to identify its warning signals in a timely way compared with the slower onset of changes in HHS. In either, the warning signals of a worsening hyperglycemic state include the following:

  • Frequent urination–much more than usual
  • Unusual thirst and drinking much more than usual
  • Weight loss
  • Concentrated urine that appears very dark or brown
  • Any of the above occurring with infections or the use of medications that can augment a hyperglycemia tendency

While it is true that the above are seen in diabetes itself, without HHS or DKA, the distinguishing feature is “more than usual.” A patient is his or her own best expert as to when extraordinary changes occur, and a prompt response is the best prevention strategy.

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This information is provided by Vascular Health Clinics and is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition.

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