Term | Definition |
Energy Sources | Sugars (glucose)
Fat
Protein |
Glucose | Glucose it the body's primary fuel source.
It is the only fuel source used by the brain. |
Glucose | In addition to oxygen, the brain must have a continuous
supply of glucose.
Use of glucose as a fuel source is an aerobic (with oxygen)
function. The body is well equipped to deal with byproducts
of aerobic metabolism (water, carbon dioxide). |
Fats and Proteins | The brain cannot use these alternate fuel sources, but the
rest of the body can.
These energy sources are used in an anaerobic (without
oxygen) environment. |
Fats and Proteins | Fats and proteins are far less efficient (by about 19 times)
than glucose fuel source.
Byproducts of anaerobic metabolism (ketones) are
dangerous. |
Insulin and Blood Glucose | Sugars enter the body and quickly reach the blood stream.
Blood glucose levels can be checked using a glucometer. |
Insulin (a pancreatic hormone) | is needed to efficiently move
glucose out of the bloodstream and into the cells to provide
energy. |
Insulin | will cause blood glucose levels to drop as glucose
leaves the blood stream and enters the cells. |
Without insulin | glucose cannot enter the cells efficiently
and blood glucose levels will rise. The cells begin to starve
and look for other fuel sources. |
Without insulin | While most cells in the body begin looking for alternate fuel
sources, brain cells cannot.
While the brain can use only glucose as an energy source, it
has the ability to accept glucose with or without insulin. As a
result |
brain cells | brain cells will starve and begin to die if there is no
glucose, regardless of the presence of alternate fuel
sources, such as fat and protein
brain cells will not starve if there is glucose present,
regardless of the presence of insulin |
Glucagon and Blood Glucose Levels | Glucagon (also a pancreatic hormone) works opposite of
insulin.
Glucagon serves to increase blood glucose levels. |
NORMAL GLUCOSE REGULATION | The normal process for regulation of blood glucose is cyclical.
Food is consumed and the blood glucose rises. |
Glucose levels | Insulin is released and glucose is transported into cells.
Blood glucose levels fall and glucagon is released. |
Glucose levels | Glucagon acts to temporarily maintain blood glucose levels.
Food is consumed and the process continues. |
TESTING BLOOD GLUCOSE | A glucometer is used to assess capillary blood glucose levels.
In the United States, glucometers measure blood glucose levels
in milligrams per deciliter (mg/dL). |
TESTING BLOOD GLUCOSE | Normal level is 80 to 120 mg/dL. However, 120 to 140 mg/dL
is not unusual after eating.
Hypoglycemia is a blood glucose of 60 mg/dL or less. |
TESTING BLOOD GLUCOSE | Hyperglycemia is a sustained blood glucose greater than about
120 mg/dL. |
PATHOPHYSIOLOGY OF DIABETES MELLITUS | Diabetes is a disease caused by an inability to metabolize
glucose normally. This is frequently due to a problem with
insulin production. Untreated diabetics typically have elevated
blood glucose levels due to a lack of insulin or ineffective
insulin. |
PATHOPHYSIOLOGY OF DIABETES MELLITUS | As blood glucose levels approach about 200 mg/dL, glucose
begins to spill into the urine. |
PATHOPHYSIOLOGY OF DIABETES MELLITUS | Glucose draws water, so increased urinary output and
dehydration is common. Dehydration leads to thirst, and
cells starving for glucose stimulate hunger. |
Type I Diabetes | Also called insulin-dependent diabetes mellitus (IDDM).
Type I diabetics must take (usually inject) supplemental
insulin. |
Type I Diabetes | Type I diabetes usually develops in pediatric patients.
Type I diabetes appears to be genetically caused in most
cases. |
Type I Diabetes | Untreated type I diabetics will present with the three "P's"
(explained below) and very high blood glucose levels.
Type I diabetics are at high risk for diabetic ketoacidosis
(DKA) if untreated.
Type I diabetics are at high risk for insulin shock due to
insulin overdose. |
Type II Diabetes | Also knows as non-insulin-dependent diabetes mellitus
(NIDDM).
Type II diabetics do not typically require supplemental
insulin. |
Type II Diabetes | Type II diabetes is caused by a combination of lifestyle and
genetics. It can be largely controlled through diet, exercise,
and oral medications.
Type II is more common than type I diabetes. |
Type II Diabetes | Incidence of type II diabetes is growing rapidly in the United
States, largely due to obesity. |
The three "P's" are the triad of classic symptoms for untreated
diabetic emergencies related to hyperglycemia. | Polyuria: excessive urination due to excess glucose in the
urine
Polydipsia: excessive thirst due to dehydration
Polyphagia: excessive hunger due to cell starvation |
Risks of Diabetes | Fatty deposits in blood vessels increase risk of stroke and
heart attack.
Chronically high blood glucose levels can damage arteries,
compromising circulation and leading to blindness and
amputation of lower extremities.
Poor circulation can lead to ulcers and difficulty healing. |
Hypoglycemia | A blood glucose level below 60 mg/dL with signs and
symptoms or a blood glucose level below 50 mg/dL
regardless of the presence of signs or symptoms. |
Hypoglycemia | Occurs more often in type I diabetes than type II
diabetes.
Hypoglycemia can very quickly lead to an altered level of
consciousness (LOC), seizures, coma, and brain death. |
Insulin shock | Insulin shock" is a term commonly used to refer to
severe hypoglycemia with signs and symptoms. |
Insulin shock | Diabetics can suddenly become confused, violent, or
unresponsive due to severe hypoglycemia. |
Insulin shock | Commonly caused by a sudden unexpected drop in
blood glucose due to
> taking a regular insulin dose but not eating
>extreme physical activity without adjusting insulin
level or food intake
> insulin overdose |
Signs and symptoms of hypoglycemia/insulin shock | Onset of signs and symptoms is typically rapid. Brain
damage can occur rapidly. Treatment must be provided
rapidly.
Low blood glucose level.
Signs and symptoms caused by brain cell starvation
~ Altered LOC, such as confusion or irritability
~ Seizures or coma |
Signs and symptoms caused by an increase in
epinephrine release | (this shuts down release of insulin
and stimulates release of glucagon) |
Signs and symptoms caused by an increase in
epinephrine release | ~ Possible restlessness, anxiousness, irritability
~ Diaphoresis, tachycardia
Pale, cool skin, tremors
Patients with hypoglycemia are often misdiagnosed as
being intoxicated or a behavioral emergency. |
Hyperglycemia | A sustained blood glucose over 120 mg/dL.
Hyperglycemia typically develops slowly and requires a
slower recovery process. . Hyperglycemic patients can experience seizures, coma, and permanent injury; however, they do not typically develop signs and symptoms rapidly as do
hypoglycemic patients. |
Diabetic ketoacidosis (DKA) | Occurs more frequently with type I diabetes.
With DKA, the blood glucose is frequently above 350
mg/dL. |
Diabetic Emergencies | Brain cells are able to utilize glucose, but the rest of the
body's cells are starving and begin using alternate fuel
sources.
The body spills large amounts of glucose into the
urine, which increases urinary output and leads to
dehydration. |
Diabetic Emergencies | The use-of alternate fuel sources (anaerobic metabolism)
leads to the production of ketones and acidosis.
It is the acidosis that threatens the brain during DKA,
not a lack of glucose. |
Signs and symptoms of DKA | High blood glucose, typically above 350 mg/dL
Kussmaul respirations: deep, rapid breaths
The three "P's"
~ Polydipsia: excessive thirst
~ Polyphagia: excessive hunger
~ Polyuria: excessive urination |
Signs and symptoms of DKA | Unusual odor on breath: fruity or acetone-like
Incontinence
Tachycardia
Coma |
Hyperglycemic hyperosmolar non ketotic syndrome | Similar to DKA, without the buildup of ketones
Occurs more frequently with type" 2 diabetes |
MANAGEMENT OF DIABETIC EMERGENCY | Consider oral glucose if the patient is hypoglycemic and able to
swallow.
Consult medical direction and follow local protocols for blood
glucose testing and administration of oral glucose. |