Page 350 - Critical Care Nursing Demystified

Chapter 7 CARE OF THE PATIENT WITH ENDOCRINE DISORDERS 335

use. Glycogen is an excess of glucose, stored in the liver and muscle cells for
use as body fuel when needed. Hyperglycemia will occur if there is an ab-
normal or insufficient amount of insulin hormone available to decrease high
blood glucose levels. Insulin is the only hormone with the ability to directly
lower blood glucose levels. Without insulin, cells are deprived of their energy
source. The body is forced to break down and use stored fats and proteins as
fuel instead of glucose. This process is known as glucogenesis, where ketoac-
ids are converted into glucose.
Glucagon – Has the opposite role of insulin, in that it increases blood sugar
levels to prevent hypoglycemia, especially when stimulated by factors such as
starvation and exercise. Stored glucose will be broken down (glycogenolysis),
and noncarbohydrate molecules will be converted into glucose (glucogenesis).

NURSING ALERT

In a healthy person, insulin is released to decrease high blood glucose levels. When
blood glucose levels are low, glucagon is released to increase blood glucose levels.

Somatostatin – A hormone that prevents the release of both insulin and Downloaded by [ Faculty of Nursing, Chiangmai University 5.62.158.117] at [07/18/16]. Copyright © McGraw-Hill Global Education Holdings, LLC. Not to be redistributed or modified in any way without permission.
glucagon.
Pancreatic polypeptide – Has the effect of creating smooth muscle relaxation
of the gallbladder.

5 Interpreting Test Results

Fasting blood sugar (FBS) – Measures abnormal carbohydrate metabolism
after the patient has been fasting for at least 8 hours (patient may have
water). Normal value is 70 to 110 mg/dL. An FBS greater than 126 mg/dL
on two separate occasions suggests the condition of diabetes mellitus.
Fingerstick glucose test – A convenient, rapid, and economical test that can be
done at the bedside or by the patient. Quick, accurate results make it easier to
keep track of managing diabetes and provide information for insulin coverage.
Glycosylated hemoglobin (HbA1c) – Normal value is 4% to 7%. A recom-
mended test for follow-up care only, not for an initial diagnosis. This study
offers information about the average amount of glucose remaining in the
bloodstream for the 120-day lifespan of the red blood cells. Glucose adheres
to red blood cells through the process of glycosylation, making it possible for
the health care provider to identify if the patient has adhered to diabetic
dietary protocols within the 120-day time span.