Chapter 49 (Learning Outcomes) Flashcards
What are some chronic complications of unmanaged diabetes (7)?
- cardiovascular disease (HTN, heart disease, stroke)
- kidney failure
- blindness
- nervous system disease
- extremity amputations
- dental diseases
- pregnancy complication
What is the prototype of Sulfonylurea?
Glyburide
What is the prototype of Non-sulfonylurea?
Metformin
What are the three body systems that are involved in the regulation and use of glucose in the body?
- Liver
- Pancreas
- Skeletal muscle
What tissue is unable to store glucose for future use?
Brain!
What is the exocrine function of the pancreas?
Produce digestive enzymes
What is the endocrine function of the pancreas?
Synthesize and secrete peptide hormones
What 3 peptide hormones does the pancreas secrete?
- Insulin
- Glucagon
- Somatostatin
What do Beta cells do (in the pancreas)?
Secrete the HYPOglycemic hormone insulin
What do Alpha cells do (in the pancreas)?
Secrete the HYPERglycemic hormone glucagon
What do Delta cells do (in the pancreas)?
Release somatostatin
What is the role of somatostatin?
A hormone that inhibits both glucagon and insulin secretions
What is insulin secretion most commonly triggered by?
High blood glucose levels
What is the main function of insulin?
Regulates carbohydrate metabolism
How does insulin regulate carbohydrate metabolism?
Lowers blood glucose levels by stimulating peripheral glucose uptake (especially by skeletal muscles and fat)
What effect does insulin have on the liver (4)?
- Promotes the uptake and storage of glucose in the form of glucagon
- Promotes the conversion of excess glucose into fat
- Suppresses heptaic gluconeogenesis (production of glucose)
- Suppresses hepatic glycogenolysis (breakdown of glycogen to glucose)
Which tissues do NOT require insulin in order for glucose to enter their cells (7) ?
- Brain
- Nerves
- Intestine
- Liver
- Retina
- Erythrocytes
- Renal tubules
Other than insulin, what other factors can affect blood glucose levels (6) ?
- Stress
- Illness
- Secretion of insulin-antagonistic hormones (cortisol, E, growth hormone, glucagon, and somatostatin)
- number of cellular insulin receptors
- Use of glucose by cells
- Rates of hepatic synthesis of glucose
What happens when blood glucose get too low?
Alpha cells (in the pancreas) release glucagon
- stimulates release of glycogen from hepatic storage sites
- prevents blood glucose from getting too low
How quickly after a meal are hepatic glycogen stores depleted?
Within 6 hours after a meal
If blood glucose levels are low, and the hepatic reserves are empty - where else can the body pull glucose from?
- Muscles release amino acids (converted into glucose)
- Lipolysis occurs in adipose tissue
How are free fatty acids used as energy?
Used for energy by muscle and liver cells
- conserving glucose for use by the brain
What triggers the release of glucagon (5)?
- low blood glucose levels
- sympathetic nerve impulses
- exercise
- infection
- trauma
What are the three types of diabetes?
- Type 1
- Type 2
- Gestational
What is the defining characteristic of Type 1 diabetes?
Destruction of insulin-secreting beta cells
- absolute insulin deficiency
- auto-immune disease
What is hyperglycemia?
Abnormally high blood glucose
What happens if the body’s reserve of insulin is depleted?
Hyperglycemia
Explain how ketoacidosis occurs.
- Type 1 diabetes
- Hyperglycemic state (cells cannot access available glucose)
- Body starts to break down proteins and lipids for energy
- Increase in lipid metabolism leads to an increase in ketoacids - causing ketoacidosis
True or False:
Insulin therapy isn’t always indicated for Type 1 diabetes
False!
- Type 1 diabetes always requires insulin
- Beta cells have been destroyed
What does Type 2 diabetes result from?
Insulin resistance by the tissues
- also usually a decrease in insulin production
Why are plasma levels of insulin in Type 2 diabetes essentially normal (or increased)?
Pancreas tried to overcome the resistance by producing more insulin
- problem is that the insulin does not ENTER the cells but stays in the bloodstream
What is the age of onset of Type 1 diabetes? Type 2?
Type 1 = Usually before 20
Type 2 = Usually after 40
What is the incidence of Type 1 diabetes? Type 2?
Type 1 = 5 - 10%
Type 2 = 90 - 95%
What is the typical body weight of a person with Type 1 diabetes? Type 2?
Type 1 = Thin, underweight
Type 2 = Overweight, obese
What are the clinical S/S of Type 1 diabetes?
- Hyperglycemia
- Polyphagia
- Polydipsia
- Polyuria
- Weight loss
What are the clinical S/S of Type 2 diabetes?
- Hyperglycemia
- Fatigue
- Mild Polyphagia/Polydipsia/Polyuria
- Fungal infections
- Blurred vision
What is the clinical management of Type 1 diabetes?
- Insulin injections
- Dietary controls
- Exercise regimen
What is the clinical management of Type 2 diabetes?
- Weight reduction
- Dietary controls
- Exercise regimen
- Oral drug therapy
- Insulin
What are the classic signs of hyperglycemia (6)?
- Excessive urination (polyuria)
- Excessive thirst (polydipsia)
- Fatigue
- Dry or itchy skin
- Poor wound healing
- Vision changes
What happens during the dawn phenomenon?
Blood glucose levels are at their highest between 5am and 6am
What is the believed to be the cause behind dawn phenomenon?
The release of growth hormone overnight
- increases blood glucose levels
How is dawn phenomenon treated?
By providing larger doses of intermediate-acting insulin at bedtime
- to prevent early morning elevations of glucose
What is the Somogyi effect?
Produces early morning hyperglycemia
- but precipitating factor is actually a HYPOglycemic event after midnight
- body compensates
What are the two main classifications of chronic complications of diabetes?
- Microvascular
2. Macrovascular
What are some examples of macrovascular complications (3)?
- Atherosclerotic vascular disease
- Myocardial infarction
- Cerebrovascular accident
What are some example of microvascular complications (6)?
- Cataracts
- Glaucoma
- Blindness from retinopathy
- Lower extremity infections and gangrene
- Foot ulcers
- Renal failure
What is the lab value that measures chronic glucose levels?
Hemoglobin A1C
What happens if you lower Hemoglobin A1C levels?
Reduction of microvascular and neuropathic complications of diabetes
- may also lower macrovascular complications
What is the danger of keeping a tight control of blood glucose levels?
Hypoglycemia
What can severe hypoglycemia result in?
Altered consciousness or coma
What are the two regimens that are used for the treatment of Type 1 diabetes?
- Non-physiologic regimen
2. Physiologic regimen
Describe the non-physiologic regimen. When is it useful?
1-2 daily injections of long-acting insulin
- Ideal for those newly diagnosed (those who can still produce SOME endogenous insulin and have not progressed to complete beta cell failure)
Describe the physiologic regimen. When is it useful?
Consists of BASAL and PRANDIAL insulin
- for patients in complete beta cell failure
Define Basal Insulin
The continuous secretion that maintains glucose homeostasis
- the body’s baseline of insulin
Define Prandial Insulin
Insulin secretion stimulated in response to meals
What is the main goal of Type 1 insulin therapy?
Avoid hypoglycemic episodes
- improve hemoglobin A1C levels yet maintain a simple regimen to which the patient can adhere
How can a hospitalized Type 1 diabetic patient, that is not eating regularly receive nutrition?
- IV fluids with dextrose
- Total parenteral nutrition
- Partial parenteral nutrition
- Tube feedings
Define Correctional (or supplemental) insulin dose.
Dose to correct any elevations in blood glucose
- goal is to keep blood glucose as close to normal as possible
What kind of insulin are given with correctional (or supplemental) insulin doses?
Short-acting or long-acting in addition to their prandial dose
What is the first line of treatment for patients diagnosed with Type 2 diabetes?
Oral antidiabetic agents
What kind of insulin is typically used for Type 2 diabetes (if it is used)?
Bedtime long-acting basal insulin
- while continuing with 1 or 2 daytime oral antidiabetic medications
What are the names of the rapid acting insulin?
- Aspart
- Lispro
- Glulisine
What speeds are insulin available at?
- Rapid
- Short
- Intermediate
- Long
What is the prototype for short-acting regular insulin?
Insulin
When is regular insulin used?
Used only to correct a current glucose elevation or an expected rise after eating
- not used to correct all day levels
Why is regular insulin indicated for patients with hyperkalemia?
An infusion of glucose and insulin produces a shift of potassium into cells and lowers serum potassium levels
What is the onset and duration of Regular insulin (Humulin R, Novolin R)?
Onset: 30 min - 1 hour
Dur: 8 - 12 hours
What is the onset and duration of Lispro (Humalog)?
Onset = 15 mins
Dur: 6 - 8 hours
What is the onset and duration of Aspart (Novolog)?
Onset = 5 - 10 mins
Dur: 3 - 5 hours
What is the onset and duration of Isophane insulin suspension (Humulin N, NPH)
Onset = 1 - 1.5 hours Dur = 18 - 24 hours
What is the onset and duration of Glargine (Lantus)?
Onset = 1 hour Dur = 24 hours
What is the onset and duration of Glyburide?
Onset = 1 - 2 hours
Dur: 16 - 24 hours
What is the onset and duration of Metformin?
Onset = 2 - 2.5 hours
Dur: 10 - 16 hours
What is the fastest site of absorption of insulin subcutaneously?
Abdominal SC layer
- then back of arm
- then thigh
- lastly, buttocks
What happens when insulin is delivered by IV infusion?
Between 20 - 30% is absorbed by the plastic tubing
How long is insulin stable for at room temperature?
1 month (for longer storage, place in the fridge)
Where in the body is insulin filtered and reabsorbed?
- Filtered in glomerulus
- Reabsorbed in proximal renal tubule
What is the most common adverse effect of insulin therapy?
Hypoglycemia
What are the signs of hypoglycemia?
- Fatigue and malaise
- Trembling
- Irritability
- Headache
- Nausea
- Numbness
- Paresthesias
- Muscle weakness
How can hypoglycemia manifest?
Hunger, tachycardia, sweating, and nervousness
What is lipodystrophy?
An adverse effect from repetitive SC injections into the same INJECTION site
- cause disturbances in fat metabolism
How can lipodystrophy present?
- Lipoatrophy - SC fat breaks down
2. Lipohypertrophy - additional lipid deposits at a particular site
How does alcohol affect the impact of insulin?
Alcohol potentiates the hypoglycemic effect of insulin
Why is INTRA-SITE rotation used with insulin therapy?
Promotes regular absorption
- different sites have different absorption speeds
What can result in a falsely higher glucose reading than it should be (4)?
- Low hematocrit
- Hypoxia
- Hyperbilirubinemia
- Tylenol overdose
What can result in a falsely lower glucose reading than it should be (5)?
- High hematocrit
- Shock and dehydration
- Hypoxia
- Sodium fluriode
- Tylenol overdose
How can we (as nurses) minimize adverse effects when administering insulin?
- avoid administering cold insulin (lipodystrophy)
- assess blood glucose levels
What are 4 ways we can treat hypoglycemic episodes?
- 4 oz of juice (or soda)
- 4 oz of water with 4 sugar packets
- 8 oz low fat milk
- 50% IV dextrose or glucagon if patient is not able to swallow
When drawing up insulin, what do you always have to do?
Have another nurse check the dose - to prevent accidental overdose
When referring to insulins, do we use generic names or trade names?
GENERIC!
What 4 things do people with diabetes need to understand?
- What diabetes is and what treatment is necessary
- How to administer and store insulin
- How and when to test their blood glucose
- How and when to take oral medications if they have type 2 diabetes
What are the two types of insulin that cannot be mixed with any other types of insulin?
- Glargine
2. Detemir
What are the three rapid-acting drug related to Regular Insulin?
- Aspart (Novolog)
- Lispro (Humalog)
- Glulisine (Apidra)
When can rapid-acting insulin be used?
Type 1 or Type 2 diabetes
What happens when Protamine is added to Aspart or Lispro?
Provides some rapid action as well as prolonged action
- longer component is always listed FIRST
- Ex: NovoLog Mix 70/30
Is NPH cloudy or clear?
Cloudy!
- only insulin that is NOT clear
What is the most widely used intermediate acting insulin?
NPH
What is the name of a long-acting insulin?
When is it used?
Detemir
- used in Type 1 and Type 2
What are the two groups of oral antidiabetic medications used?
- Sulfonylureas
2. Non-sulfonylureas
What is the prototype of sulfonylurea drugs?
Glyburide
When is Glyburide used?
Type 2 patients that cannot control hyperglycemia with diet and exercise alone
What is the BIDS system?
Bedtime Insulin = NPH Daytime Sulfonylurea (morning) ... BIDS
How is Glyburide administered?
Orally
Describe the hypoglycemic action of Glycuride.
Results from the stimulation of pancreatic beta cells, leading to increased insulin secretion
- reduces the glucose output from the liver (decreasing liver glycogenolysis and gluconeogenesis)
Why is Glycuride ineffective on Type 1 diabetes?
B/c endogenous release of insulin is not possible from beta cells (they are destroyed)
When is Glycuride contraindicated?
Sulfa allergy
- or hepatic or renal failure
What are the most common adverse effects of Glyburide?
- Nausea
- Epigastric fullness
- Heartburn
What are the three different classes of non-sulfonylurea antidiabetics?
- Biguanides
- Thiazolidinediones
- Alpha-glucosidase inhibitors
What class does Metformin fit into?
Biguanide (Non-sulfonylureas)
When is Metformin used?
Type 2 diabetes
- does not stimulate insulin secretion
- rather it is an antihyperglycemic or “insulin sensitizer” agent
What is the main action of Metformin?
Reduced insulin resistance
- suppresses hepatic glucose production and enhances insulin sensitivity
Why does Metformin rarely cause hypoglycemia (by itself)?
Because it does not stimulate the release of insulin
What are some adverse effects of Metformin?
- Gi disturbances (anorexia, N/V, weight loss, abdominal discomfort, dyspepsia, flatulence, diarrhea)
What are the two major contraindications for Metformin?
Serious renal or hepatic function impairment
What are the drugs closely related to Metformin?
Thiazolidinediones (Rosiglitazone and Pioglitazone)
What does glucagon do?
Opposite effect of insulin
- body’s mechanism to protect against hypoglycemia
When is glucagon typically used?
On unconscious patients with diabetes ti reverse severe hypoglycemia
- RESULTING FROM INSULIN OVERDOSAGE
When is glucagon ONLY effective?
Only when liver glycogen is available
How do you minimize adverse effects when using Glucagon?
Administer supplemental carbohydrates as soon as possible (pt is awake) to restore liver glycogen
