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Assisting in Endocrinology
Chapter 45
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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Learning Objectives
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Define, spell, and pronounce the terms listed in
the vocabulary.
Apply critical thinking skills in performing patient
assessment and care.
Summarize the anatomy of the endocrine
system.
Explain the mechanism of hormone action.
Differentiate among common endocrine
disorders.
Describe the diagnostic criteria for diabetes
mellitus.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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Learning Objectives
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Outline the treatment plan and management of
diabetes mellitus.
Perform blood glucose screening with a
glucometer.
Identify the characteristics of hyperglycemia and
hypoglycemia.
Compare and contrast prediabetes, type 1, type
2, and gestational diabetes mellitus.
Categorize the complications associated with
diabetes mellitus.
Summarize patient education approaches to
diabetes.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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Endocrine System
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The endocrine system consists of glands located
throughout the body that produce and secrete
hormones that are excreted directly into the
bloodstream where they can be carried to target
tissue.
Hormones are the body’s chemical messengers,
transferring information from one group of cells to
another.
Hormones control growth, mood, system functions,
metabolism, sexual maturity, and reproduction.
Hormone levels vary and can be affected by
outside factors such as illness and stress.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
4
Location of the Endocrine Glands
From Gould B:
Pathophysiology for
the health professions,
ed 3, St Louis, 2006,
Saunders.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
5
Hypothalamus and Pituitary
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The hypothalamus is an area of the brain that
contains the pituitary gland, which produces the
"controlling" hormones. These hormones regulate
body processes such as metabolism and control
the release of hormones from glands such as the
thyroid, the adrenals, and the gonads (testes or
ovaries).
Pituitary gland
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Anterior—regulates thyroid, adrenals, gonads by
producing GH, TSH, ACTH, prolactin, FSH, LH
Posterior—oxytocin and ADH
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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Pituitary Hormones
From Thibodeau GA, Patton KT: The human body in health and disease, ed 4, St Louis, 2005, Mosby.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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Endocrine Glands
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Pineal gland—melatonin helps regulate waking
and sleeping patterns
Thyroid—thyroid hormones regulate
metabolism
Parathyroid—controls level of calcium in blood
Thymus—stimulates production of T cells
Adrenals—cortex produces corticosteroids and
medulla produces adrenaline
Gonads—testes produce testosterone and
ovaries produce eggs
Pancreas—insulin and glucagon to regulate
blood glucose
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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Mechanisms of Hormone Action
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The endocrine system is a network of ductless
glands and other structures that secrete hormones
directly into the bloodstream.
Hormones are chemical transmitters produced by
glands and transported to target tissue or organs by
the bloodstream.
Disorders of the endocrine system are caused by
either hypersecretion or hyposecretion of hormones.
Treatment is designed to control hypersecretion or
replace hormones that are not at therapeutic levels.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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Posterior Pituitary Disorders
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Diabetes insipidus—usually caused by tumor
ADH or vasopressin not produced or released in
sufficient amounts
Without ADH, fluid not reabsorbed in the renal
tubules
Signs and symptoms—polyuria, polydipsia,
nocturia, decreased specific gravity
Can cause fatal dehydration
Treatment: synthetic vasopressin
(desmopressin) nasal spray
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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Anterior Pituitary Disorders
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Panhypopituitarism—deficiency in all
hormones produced by the anterior pituitary
GH abnormalities
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Hyposecretion
• Hypopituitary dwarfism
Hypersecretion
• Gigantism—prepuberty; caused by tumor
• Acromegaly—adults; causes excessive growth of the
bones of the face and extremities, CHF, DM, and other
health problems
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
11
Thyroid Gland
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Although the thyroid gland releases the hormones
that govern growth and metabolism, the brain (the
pituitary and the hypothalamus) manages the
release and the balance of the amount of
hormones circulated.
When stimulated by TSH from the anterior
pituitary, the thyroid gland produces the thyroid
hormones triiodothyronine (T3) and thyroxine (T4),
which control the body’s metabolic rate and are
important factors in bone growth and nervous
system development in children.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
12
Hypothyroidism
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Hypothyroidism is a decreased activity of the
thyroid gland, which may affect all body
functions.
The rate of metabolism slows, causing mental
and physical sluggishness.
The most severe form of hypothyroidism is
myxedema, which is a medical emergency.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
13
Hyperthyroidism
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Hyperthyroidism or thyrotoxicosis results from
excess quantities of thyroid hormone in the
body.
Excess may be caused by tumors of the
thyroid or inflammation of the thyroid.
Increased thyroid hormone levels cause heat
intolerance, increased energy, difficulty
sleeping, diarrhea, and anxiety.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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Thyroid Disorders
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Hypothyroidism
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Simple goiter—endemic iodine deficiency; thyroid
enlarges to try to produce enough hormones
 Cretinism—congenital lack of thyroid hormones
 Myxedema—chronic hypothyroidism in older child or adult;
fatigue, weight gain, hair loss, bradycardia, and so on;
treatment is Synthroid or Levothroid daily for rest of life
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Hyperthyroidism (thyrotoxicosis)
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Signs and symptoms—weight loss, tachycardia,
nervousness, exophthalmos, tremor, goiter, palpitations
 Graves’ disease most common type—autoimmune
 Treatment: drugs, radiation, surgery
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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Adrenal Gland Disorders
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Addison’s disease—hyposecretion;
autoimmune disease of adrenal cortex; rare
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Treatment: daily corticosteroids
Cushing’s syndrome—hypersecretion of
adrenal cortex
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Pituitary or adrenal tumor
Excessive levels of cortisol
• Increased adipose tissue, moon face, cervical spine fat
pads, glucose intolerance, muscle wasting, problems with
healing, mental disorders
• Treatment: medication, radiation, surgery
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
16
Pancreas
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The pancreas contains islets of Langerhans,
which produce and secrete the hormones insulin
and glucagon.
When the blood glucose level is too high, beta
islet cells secrete insulin, which is sent through
the bloodstream to the target tissue site to
conduct glucose into the cell.
Glucagon is secreted by the alpha islet cells
when blood glucose levels are low to stimulate
the liver to convert glycogen into circulating
glucose.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
17
Diabetes Mellitus
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If there is resistance to insulin at the target cell
membrane or there is not enough insulin to
help transport glucose from the blood into the
cells, an individual experiences a variety of
symptoms.
Signs and symptoms—glycosuria, polyuria,
polydipsia, polyphagia, rapid weight loss,
drowsiness, visual disturbances, skin itchiness,
and infections.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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Prediabetes
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Diagnosis – FBS between 100 and 125mg/dl;
2-hour OGTT of 140 to 199 mg/dl
Long-term damage to vascular and cardiac
systems may be occurring during prediabetes
Majority of individuals with prediabetes
develop type 2 diabetes within 10 years
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
19
Diagnostic Criteria for Diabetes Mellitus
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NFBS equal or above 200 mg/dl (norm 80
to 120) with symptoms
FBS equal or above 126 mg/dl (norm 70
to 110) more than once
OGTT—2-hour glucose equal or above
200 mg/dl
Urinalysis + glucose and/or ketones
Glycosylated hemoglobin >7% (norm 4%
to 6%)
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
20
Glucose Tests
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Fasting blood sugar (FBS or FPG)—taken after patient has
been without food or drink for 12 hours; more accurately
assesses blood glucose level than random level.
Glucose tolerance test (GTT or OGTT) measures body’s
ability to metabolize concentrated oral glucose load; first draw
an FBS, then measure glucose levels from 1 to 5 hours.
Glycosylated hemoglobin level (HbA1c)—accurate measure
of glucose control for preceding 3 months; measures glucose
levels that are chemically bound to hemoglobin molecule on
the RBC; may be performed without fasting; the higher the
result, the greater the risk for complications. Should be <6.5%
– A1c of 7% = FBS of 70 to 110.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
21
Correlation between A1c Levels
and FPG Levels
A1c (%)
6
7
8
9
10
Plasma Glucose (mgdl)
135
170
205
240
275
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
22
Type 1 Diabetes Mellitus
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In response to high levels of glucose in the
blood, the beta islet cells in the pancreas
secrete the hormone insulin.
Type 1 diabetes occurs when the beta islet
cells are destroyed by autoimmune, genetic, or
environmental factors.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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Type 1 Diabetes Mellitus
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Type 1 or immune-mediated diabetes usually
develops before age 30 years; previously called
juvenile or insulin-dependent diabetes (IDDM).
Insulin is no longer being produced, so insulin
administration is required.
Treatment goal: maintain blood glucose levels as
close to normal as possible.
Insulin administered via SQ injections, pump, or
injector pen; inhaler, patch, and tablet being
researched.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
24
Insulin Types
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Patients must receive a combination of insulin
types throughout the day; typically combination
of fast-acting and intermediate insulin before
each meal and long-acting at bedtime.
Fast acting—Lispro and Regular
Intermediate—NPH and Lente
Long-acting—Ultralente
Combinations of NPH and Regular can be
ordered
Refer to Table 45-1
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
25
Treatment
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Complicated combination of insulin therapy,
glucometer screening, diet, and exercise.
Glucometer screening on a regular basis (several
times a day) will help track therapeutic success and
possibly indicate the need for additional insulin.
MA should be prepared to instruct the patient on how
to perform and record accurate glucometer
screenings.
Patient should work with dietician to manage
appropriate diet based on glycemic index of foods.
Patient should be closely monitored if ill, because
insulin changes may be required.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
26
Glucometers
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A person with diabetes constantly manages his
or her blood glucose levels.
After a blood sample is taken and tested, it is
determined whether the glucose levels are low
or high.
If glucose levels are too low, carbohydrates are
ingested. If glucose in the blood is too high, the
appropriate amount of insulin is administered
into the body.
Refer to Procedure 45-1.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
27
Blood Glucose Monitoring Device
Courtesy Home Diagnostics, Fort Lauderdale, Florida.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
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Glucometer Quality Control
Some examples of quality control methods include:
 Correctly follow manufacturer’s instructions.
 Perform instrument maintenance specified by the
manufacturer, including correct cleaning and
storage of the instrument.
 Check expiration dates on test strips and
solutions and store these products correctly.
 Match and correctly enter the test strip code into
the instrument before use.
 Contact the physician if test results do not match
patient symptoms.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
29
Alternative Insulin Administration
Methods
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Insulin pump – computerized device that administers a
constant dose of insulin using a small portable pump;
programmed to deliver a measured dose of insulin by
continuous subcutaneous infusion through a catheter
that is placed in the abdomen or buttocks areas; more
closely resembles the body’s normal surge of insulin
and is designed to maintain blood glucose levels
consistently within normal limits.
Insulin can be administered through an injector pen
that comes in preloaded cartridges for easy use.
Insulin pens are disposable or refillable and easily
portable.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
30
Type 2 Diabetes Mellitus:
Signs and Symptoms
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Increased hunger
Polydipsia
Polyuria
Blurred vision
Fatigue
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Numbness or tingling
in hands and feet
Slow healing
Frequent infections
Impotence
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
31
Type 2 Diabetes Mellitus
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Once called adult-onset diabetes or NIDDM; 90%
to 95% of all people with diabetes
Risk factors: family history, history of gestational
diabetes, sedentary lifestyle, obesity
Caused by decreased insulin production and/or
decreased target cell sensitivity to insulin
Treatment: weight loss, exercise, diet, oral
hypoglycemics (refer to Table 45-2); medications
stimulate pancreas to produce more insulin and
decrease cellular insulin resistance; over time may
require insulin injections
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
32
Injectable Drugs for Management of
Type 1 and Type 2 Diabetes
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Pramlintide (Symlin) – synthetic form of the
hormone amylin that works with insulin and
glucagon to maintain normal blood glucose
levels; injections taken before meals help
improve A1c levels by decreasing the rate of
movement of food through the stomach
thereby preventing a sharp increase in blood
plasma levels after meals.
Exenatide (Byetta) lowers blood glucose
levels by increasing insulin secretion; injected
60 minutes before breakfast and dinner;
helps patients achieve modest weight loss
and improved glycemic control. Not for use in
patients with Type 1 diabetes.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
33
Hypoglycemia
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Low blood glucose
(<70 mg/dl),
sudden onset of
symptoms
Poor coordination
Angry, moody
Pale skin
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Confusion and
disorientation
Sudden hunger
Diaphoresis
Tremor
May result in insulin
shock
Elevated insulin
levels
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
34
Hyperglycemia
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High blood glucose
(>126 mg/dl)
Gradual onset of
symptoms
Sleepiness
Excessive thirst
Polyuria
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Flushed skin color
Nausea and vomiting
Acetone breath
(fruity smelling)
Heavy breathing
May result in diabetic
coma
Low insulin levels
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
35
Treating Hypoglycemia: Rule of 15
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15 g of CHO every 15 minutes until blood
glucose level is above 80 mg/dl
Treat if blood glucose level is below 70
15 g of CHO =
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4–5 lifesavers
4 oz orange juice
8 oz skim milk
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
36
Hyperglycemia and Hypoglycemia
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Hyperglycemia—rapid
onset; causes “fruity” breath;
can cause ketoacidosis
(diabetic coma)
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Too little insulin
 Too many calories
 Decreased exercise
 Illness
 Stress
Treatment
 Exercise if possible
 Decrease caloric intake
 Increase insulin dose or time
doses differently
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Hypoglycemia—slow
onset; may cause insulin
shock
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Too much insulin
 Not enough calories
 Overexercise
Treatment
 Ingest glucose tablets
 Glucometer check in 15 to
20 minutes
 If still low, another glucose
tablet
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
37
Gestational Diabetes
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Diagnosed in pregnant woman if she has either:
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FBS >105 mg/dl
OGTT abnormality
Risk factors—older age, obesity, history of large
infants, family history, previous birth complications
(fetal death, anomalies), smokers, certain ethnic
groups
May be asymptomatic; all women screened
between twenty-fourth and twenty-eighth weeks of
pregnancy
Treatment: exercise, calorie reduction, insulin;
most return to normal postpartum; are at increased
risk for developing type 2 diabetes later in life
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
38
Complications of Diabetes
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Acute—hypoglycemia resulting in insulin shock or
hyperglycemia causing ketoacidosis (diabetic
coma)
Chronic—can appear many years after diagnosis
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Microvascular—retinopathy, nephropathy
 Macrovascular—atherosclerosis, CAD, hypertension,
CVA, PVD
 Diabetic neuropathy
 Infection—combination of increased risk of injury,
decreased blood supply resulting from atherosclerosis,
decreased phagocytosis. Prevention of skin trauma
important.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
39
Questions to Ask When Screening for
Diabetic Neuropathy
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Can you feel your feet when walking?
Have you noticed weakness in the muscles of your feet and
legs?
Do you have problems with balance when standing or walking?
Do you have trouble feeling heat or cold in your feet or hands?
Do you have open sores on your feet and legs that heal
slowly?
Have you noticed that your feet have changed shape?
Do your feet tingle or feel like “pins and needles,” or do you
have burning or shooting pains in your feet? Do they hurt at
night? Are they numb?
Are your feet very sensitive to touch?
Do your feet and hands get very cold or very hot?
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
40
Diabetic Foot Problems
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People with diabetes are at risk for blood
vessel injury, which may be severe enough to
cause tissue damage in the legs and feet.
Basic foot care is important for diabetic
patients because of potential problems with
their circulation.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
41
Diabetic Foot Problems
From Levin ME: Pathogenesis
and general management of
foot lesions in the diabetic
patient. In Bowker JH, Pfeifer
MA, editors: Levin and
O’Neal’s the diabetic foot, ed
6, St Louis, 2001, Mosby.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
42
Foot Care
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Basic foot care is important for diabetic patients
because of potential problems with their circulation.
Even a minor undetected injury can lead to serious
problems.
Feet should be inspected at each visit.
Education guidelines—wash every day with warm
water, cut nails straight across, apply lotion to
prevent cracking, check feet every day, call
physician at first signs of redness, do not go
barefoot, check shoes for rough areas, wear
well-fitting shoes, stop smoking (causes
vasoconstriction).
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
43
Developing Diabetic Patient Education
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Many factors affect glucose levels—activity, stress,
illness, medications, diet.
Diet plan—maintain desirable body weight, help
maintain homeostatic blood glucose level.
Medication management with insulin or oral
hypoglycemics must be strictly followed.
Patient must understand how to perform glucometer
readings and administer insulin.
Involve family members to achieve success with diet,
weight control, exercise, foot screening, medication
administration, and prevention of complications.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
44
Legal and Ethical Issues
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Document all patient teaching
Advise patients to wear medic alert bracelet
Patients must take medications as prescribed
Newly diagnosed diabetic persons should avoid driving
until glycemic control is stabilized and should be warned
about possible visual impairment from the disease
Remember that you are always representing your
profession and employer, and respond to each situation
accordingly
Ask for assistance or further information if you feel
unprepared to perform a procedure or to give accurate
information
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45