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Explore the pathophysiology of diabetes mellitus, its regulation by insulin, symptoms, classification, complications, and treatment options. Learn about the impact of hyperglycemia, neuropathic, microvascular, and macrovascular complications.
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Diabetes Mellitus2013, MC Disorder of metabolism Regulated by insulin
Pathophysiology & Key Words • Pg. 1047 • Endogenous • Exogenous • Glycosuria • Hyperglycemia & Hypoglycemia
Effect of Foods • Food is broken down into chemicals which include glucose • Percent of glucose conversion: • Carbohydrates– 100% • Protein– 58% • Fat– 10%
Role of Insulin • Regulates the rate of glucose metabolism • Moves glucose into cells • Reduces blood sugar by ^ utilization of carbohydrates • Synthesis of fatty acids and proteins
Role of Insulin (cont’d) • Moves glucose into cells • Helps carry glucose into resting muscle cells • Helps convert fatty acids into fat
Insulin • Without adequate insulin, fat stores breakdown which increases tryglyceride levels. This increases fatty acid production of the liver, thus increasing the production of lipoproteins, which promotes the development of atherosclerosis.
Classifications… • Type 1 (previously known as IDDM or Insulin Dependent Diabetes Mellitus) • Type 2 ( previously known as NIDDM or non-insulin-dependent Diabetes Mellitus) • Gestational
Type I ( IDDM) • Absence of endogenous insulin • Most commonly caused by autoimmune disorder • Complete destruction of beta cells • Totally insulin dependent
Type II ( NIDDM ) • Usually adult onset • Showing up in children • Inadequate supply endogenous insulin • Cells become resistant to insulin • Pills are given to increase the sensitivity • Symptoms develop gradually and therefore often go un-noticed
Risk Factors for type 2 DM • Review page 1049 • Learn the Risk Factors !
Symptoms of DM • Hyperglycemia key feature • FBS @ NCH = 70-99 or 70-110 • FBS @ ADA = 70-80-130 • There is NO NATIONAL STANDARD • Polydipsia • Polyuria • Polyphagia (hunger)
Criteria for Medical Diagnosis • Symptoms of Diabetes (3 P’s) • Fasting serum glucose level of 126mg/dl or greater • Two-hour postprandial glucose above 200mg/dl during OGTT (Oral Glucose Tolerance Test) • What is “Prediabetes”
DM Complications are influenced by: • Duration of DM • Poor glycemic control • Every organ is affected • Classified as: • Microvascular • Macrovascular • Neuropathic
Microvascular Complications • Basement membrane of capillaries thickens • Exchange of nutrients, gases and waste is impaired • Related to persistent hyperglycemia and aggravated by hypertension & smoking • Eyes and kidneys most vulnerable
Diabetic Retinopathy • Pathological changes in the retina due to DM • Nonproliferative and proliferative • Macula edema ( floaters or spots ) • Causes loss of central vision • Eye exams should be yearly
Nephropathy • Kidney disease • Caused by high concentrations of glucose in urine, along w/ HTN, destroy capillaries supplying the renal glomeruli. • S/S persistent proteinuria, ^BP & serum creatinine, hematuria, oliguria and anuria • How to reduce the risk of damage……
Macrovascular Complications • Causes the development of atherosclerosis • Coronary, cerebral, carotid and peripheral blood vessels are affected • Leading to CAD, CVA and PVD • Trmt is directed at weight loss,exercise and quitting smoking • Increased complications post surgery d/t poor circulation
Neuropathic Complications • Neuropathypathological changes in nerve tissue • May not feel or recognize injury • Related to poor glucose control and ischemic lesions of nerves • Affects 13% of people w/ diabetes • 50% chance of having neuropathies if diabetic for over 25 yrs • Classified as: Mono, Poly or Autonomic
Foot complications • Related to neuropathy or inadequate blood supply (PVD) • Ulcers, burns or abscess may easily develop and go unnoticed • Best treatment is prevention • “Do’s & Don’ts” of foot care ???
Acute Emergency Complications 1) Acute Hypoglycemia 2) Diabetic Ketoacidosis ( DKA) 3) Hyperglycemic Hyperosmolar Nonketotic Syndrome (HHNKS)
Acute Hypoglycemia • S/S shakiness, nervouseness, irritability, tachycardia, anxiety, lightheadedness, hunger, tingling or numbness of lips or tongue, diaphoresis, confusion, dizziness • Caused by: too much insulin, not eating enough food, not eating at right time, or inconsistent pattern of exercise • Glucose betw. 50-70 are moderately low • Insulin Shock • Can happen very fast
Hypoglycemia treatment • Conscious patient 10-15gms of quick acting carbohydrates EX: 4-6 oz of orange or apple juice, skim milk, 3-4 tbsp. Table sugar or corn syrup, 2-3 glucose tablets. Repeat every 15-30 min until glucose is above 70. Injectable glucagon should be avail if insulin dependent
Diabetic Ketoacidosis (DKA) • Caused by insulin deficiency resulting in the inability of carbohydrates, proteins and fats to be metabolized. • Pt exhibits hyperglycemia of 300mg/dl, ketonuria and acidosis • Treatment aimed at correcting the 3 main problems: dehydration, electrolyte imbalance and acidosis
DKA and Stress • Sympathetic response detects need for cell fuel • Converts stored glycogen to glucose • Elevates BS even more • Body is depleted of glycogen and starts to burn fats and proteins • Leads to DKA and metabolic acidosis
Patient becomes dehydrated • What do you treat it with • IV fluids • Patient is hemo-concentrated and is now at risk for what? • Blood clots
S/S of DKA • Early SxAnorexia, headache, and fatigue, f/b polydipsia, polyuria and polyphagia. • If untreated, dehydration, weakness, lethargy, abd. Pain, N,V, tachycardia, blurred vision, fruity breath. • Late Sx Kussmaul’s respirations, coma & shock • Rapid and deep respirations
Hyperglycemic Hyperosmolar Nonketotic Syndrome ( HHNKS) • Extremely high glucose levels (>600mg/dl) • Basic defect is lack of effective insulin or inability to use available insulin • Dehydration and hypernatremia develop • Caused by hyperglycemia, increased osmotic pressure • Kussmaul resp and GI symptoms are absent • May be caused by IV solutions w/ high concentrations of glucose (TPN or dialysis)
Medical Treatment for Diabetes Mellitus • Nutritional Management • Exercise • Insulin Therapy • Oral Hypoglycemic Drugs
Nutritional Management • Weight control important component • Emphasis is on a well-balanced diet • Carbohydrate counting is useful with use of insulin therapy or pumps • Considerable education and support to learn guidelines; employ a dietitian to help teach. • Always consider personal & ethnic choices • Emphasis on total carbs not type
Exercise • Combine aerobic & anaerobic exercise • Type 1 hyperglycemia may occur w/ exercise if insulin is inadequate • Type 2 exercise makes receptor sites more sensitive to insulin & lowers glucose levels • Avoid exercise if glucose are elevated • Regular exercise helps to control glucose • Insulin is absorbed quickly when injected into abdomen
Insulin Therapy • Time Course of Action Table 46-1 pg. 1059 • Novolog is the most rapid acting • Route (No oral forms yet) • Concentrations • ( U-100 ) has a concentration of 100 units/ml & is most commonly used • Premixed easier to prepare and less risk of error when mixing 2 insulins in 1 syringe
Common Therapy Types • Conventional Therapy • Intensive Therapy • Basal Bolus Therapy QBrittle Diabetes would require what type of therapy ??
Subcutaneous Insulin Infusion • Continuous subcutaneous insulin infusion • Delivers regular insulin continuously and a bolus of insulin at mealtimes • Contains 2-3 day supply of insulin • Advantages no need to use intermediate or long acting insulin and more flexibility regarding travel and exercise
Sliding Scale Dosage Blood Sugar: >150 3 units 200-299 6 units 300-400 9 units >400 12 units
Pre-Operative Dosing • Pts instructed to give just ½ dose at regular time • BS value on admission and serial BS as needed • May run background D5W as needed
PostOp • Stress of surgery may cause ^ in BS • Type II patients may need insulin
Insulin Mixing • Remember “clear to cloudy” • When mixing short-acting “clear” and longer-acting (cloudy) insulin, draw the “clear” (short-acting) insulin into the syringe first • NPH (Neutral Protamine Hagedorn) is cloudy, needs warming • Regular is given prior to meals
Insulin Injection • See Figure 46-3 pg. 1061 • Site rotation helps prevent lipohypertrophy or lipoatrophy • Abdomen absorption is 50% faster • ADA recommends rotating sites within one anatomic area
Oral Hypoglycemic Agents • See Table 46-2 & 46-3 • Not insulin substitutes • Some patients may need one dose of insulin at night and then are able to control serum glucose during the day with oral agents • Euglycemia • Metformin
Class Activity • Acute Hypoglycemia • Diabetic Ketoacidosis
Self Monitoring of Blood Glucose (SMBG) • Reduces complications of long term diabetes • Helps normalize blood glucose levels • Glycosylated Glucose Levels drawn every 2-3 mos. Helps MD and patients determine how well blood glucose levels are regulated*
Complications of Therapy • Hypoglycemia • Somogyi Phenomenon • Dawn’s Phenomenon
Dawn Phenomenon • FBS to >180 between 5-9 am • Treat with bedtime snack and delay evening insulin intermediate insulin until 10pm so it will peak around 5-9 am
Assessment of the patient with Diabetes • See Box 46-2 pg. 1068 • Health History ??? • PMHx ??? • Review of Systems?? • Functional Assessment?? • Interventions are ???
Class Activity • A 44-year-old obese man is admitted with a blood glucose level of 400 mg/dl and a blood pH of 7.28. The patient experienced increasing fatigue, headaches, and weakness. He is diagnosed with diabetes mellitus type 2 and DKA. The patient works part-time at night as a security guard. He tells the nurse that he had no idea he had diabetes and says that he loves to eat while at work. He also says that he sleeps all day and doesn’t exercise. The patient is very concerned about how his new diagnosis will affect his life.
Hypoglycemia • Syndrome that develops when blood glucose levels drop below 45-50mg/dl • Symptoms can occur at different blood levels based on individual tolerances • Divided into 3 categories: 1)Exogenous 2) Endogenous 3) Functional
Exogenous hypoglycemia Caused by outside factors that act on body to produce low blood glucose • Insulin • Oral hypoglycemic agents • Alcohol • exercise
Endogenous hypoglycemia Caused by excessive secretion of insulin or an increase in glucose metabolism Usually the result of a tumor or genetics
Functional hypoglycemia • Has a variety of causes 1) gastric surgery (post gastrectomy) 2) fasting 3) malnutrition
Signs and Symptoms • weakness • hunger, diaphoresis, • tremors, anxiety • irritability,headache • pallor • tachycardia • Confusion, dizziness