Chapter 46 Diabetes Mellitus and Hypoglycemia Elsevier items

Learning Objectives • Describe the role of insulin in the body. • Explain the pathophysiology of diabetes mellitus and hypoglycemia. • Describe the signs and symptoms of diabetes mellitus and hypoglycemia. • Explain tests and procedures used to diagnose diabetes mellitus and hypoglycemia. • Discuss treatment of diabetes mellitus and hypoglycemia. • Explain the difference between type 1 and type 2 diabetes mellitus. Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 2

Learning Objectives • Differentiate between acute hypoglycemia and diabetic ketoacidosis. • Describe the treatment of a patient experiencing acute hypoglycemia or diabetic ketoacidosis. • Describe the complications of diabetes mellitus. • Identify nursing interventions for a patient diagnosed with diabetes mellitus or hypoglycemia. • Identify nursing interventions for a patient diagnosed with ketoacidosis. Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 3

Diabetes Mellitus Elsevier items and derived items © 2007 by Saunders, an imprint of

Pathophysiology • Chronic disorder of impaired metabolism with vascular and neurologic complications • Key feature is elevated blood glucose, called hyperglycemia • Blood glucose level normally regulated by insulin, a hormone produced by beta cells in the islets of Langerhans located in the pancreas Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 5

Type 1 • Absence of endogenous insulin • Formerly called juvenile-onset diabetes because it most commonly occurs in juveniles and young adults • An autoimmune process, possibly triggered by a viral infection, destroys beta cells, the development of insulin antibodies, and the production of islet cell antibodies (ICAs) • Affected people require exogenous insulin for the rest of their lives Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 6

Type 2 • Inadequate endogenous insulin and body’s inability to properly use insulin • Beta cells respond inadequately to hyperglycemia; results in chronically elevated blood glucose • Continuous high glucose level in the blood desensitizes the beta cells; they become less responsive to the elevated glucose • More common in adults; increasing in children • Controlled by diet and exercise; may require oral hypoglycemic agents or exogenous insulin Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 7

Role of Insulin • Glucose • • • Insulin stimulates active transport of glucose into cells If insulin absent, glucose remains in the bloodstream Blood becomes thick, which increases its osmolality Increased osmolality stimulates the thirst center Increased fluid does not pass into body tissues; high serum osmolality retains fluid in the bloodstream • As blood passes through the kidneys, some glucose eliminated • Osmotic force created by glucose draws extra fluid and electrolytes with it, causing abnormally increased urine volume Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 8

Role of Insulin • Fatty acids • Promotes fatty acid synthesis and conversion of fatty acids into fat, which is stored as adipose tissue • Also spares fat by inhibiting breakdown of adipose tissue and mobilization of fat and by inhibiting the conversion of fats to glucose • Without adequate insulin, fat stores break down and increased triglycerides are stored in the liver • Increased fatty acids in the liver can triple the production of lipoproteins; promotes atherosclerosis Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 9

Role of Insulin • Protein • Enhances protein synthesis in tissues and inhibits the conversion of protein into glucose • Amino acids are admitted into cells; enhances rate of protein formation while preventing protein degradation • Without adequate insulin, protein storage halts; large amounts of amino acids dumped into the bloodstream • High levels of plasma amino acids place people with diabetes at risk for development of gout • Changes in protein metabolism lead to extreme weakness and poor organ functioning Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 10

Etiology • An autoimmune malfunction may cause complete destruction of the islets of Langerhans in the pancreas, creating type 1 diabetes • Islet cell antibodies are identified in more than 80% of all people with type 1 diabetes at the time of diagnosis Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 11

Figure 46 -1 Elsevier items and derived items © 2007 by Saunders, an imprint

Risk Factors • • • Obesity Sedentary lifestyle Family history of diabetes Age 40 years and older History of gestational DM History of delivering infant weighing more than 10 lb African American (33% higher risk for type 2 DM) Latin American/Hispanic (>300% higher risk for type 2 DM) American Indians (33%-50% higher risk for type 2 DM) Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 13

Risk Factors • Metabolic syndrome • Thought to be a precursor to diabetes • Impaired glucose tolerance, high serum insulin, hypertension, elevated triglycerides, low HDL cholesterol, altered size and density of LDL cholesterol • Believed that metabolic syndrome is a chronic low-grade inflammatory process affecting endothelial tissue • Long-term effects: atherosclerosis, ischemic heart disease, left ventricular hypertrophy, type 2 DM • Research directed at learning how to detect this syndrome early and what interventions might slow or arrest the progress Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 14

Long-Term Complications Elsevier items and derived items © 2007 by Saunders, an imprint of

Microvascular Complications • Retinopathy • Pathological changes in the retina that are associated with DM • Nephropathy • Kidney damage Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 16

Macrovascular Complications • Accelerated atherosclerotic changes in the person with diabetes • Associated with coronary artery disease (CAD), cerebral vascular accidents (CVA or stroke), and peripheral vascular disease (PVD) Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 17

Neuropathic Complications • Neuropathy: pathologic changes in nerve tissue • Mononeuropathy affects a single nerve or group of nerves • Polyneuropathy involves both sensory and autonomic nerves • Autonomic neuropathy affects the sympathetic and parasympathetic nervous systems Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 19

Hypoglycemic Unawareness • The usual symptoms of tachycardia, palpitations, tremor, sweating, and nervousness may be absent • Patient may suddenly have changes in mental status as the first sign of hypoglycemia Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 20

Long-Term Complications • Foot complications of diabetes • May have foot problems associated with neuropathy, inadequate blood supply, or a combination • Mechanical irritation • Thermal injury • Chemical irritation Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 21

Long-Term Complications: Prevention • Diabetes Control and Complications Trial (DCCT): intensive treatment of type 1 DM delayed the onset or slowed the progress of diabetic retinopathy, nephropathy, and neuropathy • Outcome of United Kingdom Prospective Diabetes Study (UKPDS): similar benefits of tight control with type 2 DM Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 22

Long-Term Complications: Prevention • ADA recommends • • • Blood pressure: <130 systolic, <80 diastolic Total cholesterol: <200 mg/d. L LDL: <100 mg/d. L HDL: >45 mg/d. L for men (>55 mg/d. L for women) Triglyceride: <150 mg/d. L Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 23

Acute Emergency Complications Elsevier items and derived items © 2007 by Saunders, an imprint

Acute Hypoglycemia • Dangerous drop in blood glucose • Causes • Taking too much insulin, not eating enough food or not eating at the right time, an inconsistent pattern of exercise • Gastroparesis, renal insufficiency, and certain drugs including aspirin and beta-adrenergic blockers Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 25

Acute Hypoglycemia • Signs and symptoms • Adrenergic: shakiness, nervousness, irritability, tachycardia, anxiety, lightheadedness, hunger, tingling or numbness of the lips or tongue, and diaphoresis • Neuroglucopenia: drowsiness, irritability, impaired judgment, blurred vision, slurred speech, headaches, and mood swings progressing to disorientation, seizures, and unconsciousness Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 26

Acute Hypoglycemia • Treatment • Give patient 10 to 15 g of quick-acting carbohydrates • Repeat every 15 -30 minutes until blood glucose is >70 mg/d. L for adults, 80 to 100 mg/d. L for older adults and children • If patient is unable to swallow, an IM or subcutaneous injection of 1 mg of glucagon or an IV dose of 50 m. L of 50% dextrose should be given as ordered or per protocol Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 27

Diabetic Ketoacidosis (DKA) • Life-threatening emergency caused by a relative or absolute deficiency of insulin • Early signs and symptoms • Anorexia, headache, and fatigue • As condition progresses, classic symptoms of polydipsia, polyuria, and polyphagia develop • If untreated, patient becomes dehydrated, weak, and lethargic with abdominal pain, nausea, vomiting, fruity breath, increased respiratory rate, tachycardia, blurred vision, and hypothermia Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 28

Diabetic Ketoacidosis (DKA) • Late signs • Air hunger (Kussmaul’s respirations), coma, and shock • Death can result without prompt medical care Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 29

Diabetic Ketoacidosis (DKA) • Treatment aimed at correction of three main problems • Dehydration • Electrolyte imbalance • Acidosis Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 30

Hyperglycemic Hyperosmolar Nonketotic Syndrome • Patient goes into a coma from extremely high glucose levels (>600 mg/d. L) • There is no evidence of elevated ketones • Pancreas produces enough insulin to prevent breakdown of fatty acids and formation of ketones, but not enough to prevent hyperglycemia • Persistent hyperglycemia causes osmotic diuresis, resulting in loss of fluid and electrolytes • Dehydration and hypernatremia develop • May be caused by the same factors that trigger ketoacidosis Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 31

Medical Diagnosis • One or more of the following criteria on two separate occasions is considered DM • Polyuria, polydipsia, polyphagia, unexplained weight loss plus random glucose level >200 mg/d. L • Fasting serum glucose level >126 mg/d. L (after at least an 8 hour fast) • Two-hour postprandial glucose level >200 mg/d. L during oral glucose tolerance test (OGTT) under specific guidelines. Test must use a glucose load of 75 g of anhydrous glucose dissolved in water Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 32

Medical Diagnosis • Prediabetes • Individuals with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) • Individuals should receive education on weight reduction and increasing physical activity Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 33

Medical Diagnosis • Oral glucose tolerance test • • Diet of 150 to 300 g carbohydrate for 3 days before test Night before test, patient fasts after midnight Morning of test, blood drawn for fasting serum glucose Patient then given a drink (Glucola) containing 75 g of carbohydrates and instructed to remain quiet • Blood drawn at 30 minutes and 1 hour after the ingestion of glucose. After these two samples, blood is drawn at hourly intervals until the test is completed Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 34

Medical Treatment • Nutritional management • Medical nutrition therapy (MNT) is an important part of diabetes management; should be included in diabetes self-management education • Because of complexity of nutritional management, a registered dietitian should be part of the diabetes management team, and the individual with diabetes should be included in decision making Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 35

Medical Treatment • Exercise • Effective adjunct for people with diabetes • Aids in weight loss, improves cardiovascular conditioning, improves insulin sensitivity, and promotes a sense of well-being • Exercising muscle uses glucose at 20 times the rate of a muscle at rest and does not require insulin Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 36

Insulin Therapy • All patients with type 1 disease need insulin injections; some patients with type 2 disease may eventually need insulin • Insulins classified by source and course of action • Source: human, pork, or beef (beef is being phased out) • Course of action: rapid acting, short acting, intermediate acting, and long acting • All rapid-acting and short-acting insulins are clear • The other insulins are cloudy Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 37

Figure 46 -2 Elsevier items and derived items © 2007 by Saunders, an imprint

Insulin Therapy • Route • Oral: insulin cannot be given orally because it is rendered useless in the gastrointestinal tract • Subcutaneously: all insulins can be given subcutaneously • Intravenously: ONLY regular insulin can be given intravenously • Inhalation: a form of insulin that can be taken by inhalation has recently been approved, but it is not yet widely used Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 39

Insulin Therapy • Concentrations • U-100 insulin has 100 units/m. L • Most commonly used • U-500 insulin has 500 units/m. L • Used only in emergencies and for patients who are extremely insulin resistant • U-40 insulin has 40 units/m. L • Not available in the United States Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 40

Insulin Therapy • Premixed insulin products • Contain both Regular and NPH insulin • 70% NPH and 30% Regular insulin • 50% NPH and 50% Regular insulin • 75% NPH and 25% Lispro Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 41

Insulin Therapy • Dosing schedules • Conventional therapy • Typically uses a combination of a short-acting and an intermediate- or long-acting insulin • Intensive therapy • To achieve tight control; may require 3 or 4 injections daily • Continuous subcutaneous insulin infusion • Patient has indwelling subcutaneous catheter connected to an external portable infusion pump; pump delivers Regular insulin continuously Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 42

Insulin Therapy • Insulin mixing • Two types can be mixed in one syringe to avoid two injections • Insulin injection • Site rotation helps prevent lipohypertrophy or lipoatrophy • Absorption rate varies with different body sites • American Diabetes Association recommends rotating sites within one anatomic area rather than moving among all areas • See Figure 46 -3 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 43

Figure 46 -3 Elsevier items and derived items © 2007 by Saunders, an imprint

Insulin Therapy • Insulin pump • Needle is inserted subcutaneously in an appropriate part of the anatomy • Pump is programmed to deliver a steady trickle of insulin throughout the day and can provide a bolus of insulin at mealtimes Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 45

Figure 46 -4 Elsevier items and derived items © 2007 by Saunders, an imprint

Insulin Therapy • Intranasal route • Only 10% of the drug is absorbed through the nasal mucosa, making it relatively expensive to use • Nasal irritation is a frequent side effect • Only Regular insulin is given intranasally • Insulin catheter • Indwelling subcutaneous catheters may be placed in the abdomen to permit repeated insulin injections without repeated needlesticks Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 47

Oral Hypoglycemic Agents • If patients with type 2 DM unable to control blood glucose with nutrition and exercise, physician may prescribe oral hypoglycemics • Sulfonylureas (three generations), alpha-glucosidase inhibitors, biguanides, thiazolidinediones, Dphenylalanines, meglitinides • Combination oral medications • ACTOplus met (pioglitazone and metformin), Avandamet (rosiglitazone and metformin), Avandaryl (rosiglitazone and glimepiride), Glucovance (glyburide and metformin), Metaglip (glipizide and metformin) Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 48

Self-Monitoring of Blood Glucose • Allows patients to monitor blood glucose levels to regulate their diet, exercise, and medication regimens to remain euglycemic • Portable electronic glucose meters have largely replaced other methods of self-monitoring Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 49

Glycosylated Glucose Levels • Glycosylated hemoglobin (Hb. A 1 c) reflects glucose levels over the past few months • Fructosamine levels reflect those over several weeks Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 50

Complications of Therapy • Hypoglycemia • A person injects too much insulin, does not eat enough, eats at the wrong time, or exercises inconsistently: glucose levels may suddenly drop • Somogyi phenomenon • Rebound hyperglycemia in response to hypoglycemia • Dawn phenomenon • An increase in fasting blood glucose levels between 5 and 9 AM that is not related to hypoglycemia Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 51

Assessment • Ketoacidosis: ketonuria, Kussmaul’s respirations, orthostatic hypotension, hypertension, nausea, vomiting, lethargy, or change in level of consciousness • Hypoglycemic patient: expect to find tachycardia, anxiety, trembling, and decreasing level of consciousness • Be alert for indications of hyperosmolar nonketotic coma Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 52

Assessment • Attempt to determine the following • Type of diabetes • Hypoglycemic agents: name, dosage, when last dose was taken • Food and fluid intake for the past 3 days • Relevant laboratory values: blood glucose, blood p. H, bicarbonate levels, electrolytes, and osmolality and urine osmolality Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 53

Health History • Chief complaint and history of present illness • Signs/symptoms that prompted patient to seek medical care • Past medical history • Type and duration of DM • Name and dosage of prescribed medications and when they were last taken • If patient monitors blood glucose, record type of equipment used, testing schedule, recent test results • Family history • Diabetes, heart disease, stroke, hypertension, hyperlipidemia Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 54

Health History • Review of systems • Description of the patient’s general health • Changes in skin moisture or turgor • Inquire whether the patient has had floaters, diplopia (double vision), or blurred vision, or has seen white halos around objects • Abdominal symptoms: diarrhea, abdominal bloating, and gas • Problems passing or holding urine • If any pain in the legs, note when it occurs • Numbness, tingling, or burning in the extremities • Changes in mental alertness or seizures Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 55

Health History • Functional assessment • Explore factors that can affect patient’s ability to perform self-care, including literacy, financial resources such as health insurance, and family support Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 56

Health History • Physical examination • Level of consciousness, posture and gait, and apparent wellbeing • Vital signs, height, and weight • Skin color, warmth, turgor, and lesions noted • Inspect eye grounds for evidence of diabetic retinopathy or cataracts • Be alert for a sweet, fruity odor to the patient’s breath that is common with ketoacidosis • Carefully assess the feet • Test gait, balance, and motor coordination Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 57

Interventions • • Ineffective Health Maintenance Ineffective Therapeutic Regimen Management Risk for Deficient Fluid Volume Risk for Injury Activity Intolerance Chronic Pain Disturbed Sensory Perception or Impaired Skin Integrity • Disturbed Thought Processes • Ineffective Coping Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 58

Hypoglycemia Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier,

Pathophysiology • Develops when the blood glucose level falls to less than 45 to 50 mg/d. L • Symptoms occur at different blood levels according to individual tolerances and how rapidly the level falls Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 60

Causes • Exogenous hypoglycemia • Results from outside factors acting on the body to produce a low blood glucose • Include insulin, oral hypoglycemic agents, alcohol, or exercise Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 61

Causes • Endogenous hypoglycemia • Occurs when internal factors cause an excessive secretion of insulin or an increase in glucose metabolism • These conditions may be related to tumors or genetics Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 62

Causes • Functional hypoglycemia • From a variety of causes, including gastric surgery, fasting,

Signs and Symptoms • Glucose level falls rapidly, causes epinephrine, cortisol, glucagon, and growth hormone to be secreted in an attempt to increase glucose levels • Symptoms: weakness, hunger, diaphoresis, tremors, anxiety, irritability, headache, pallor, and tachycardia • A blood glucose level that falls over several hours: symptoms attributed to lack of essential glucose to brain tissue • Symptoms: confusion, weakness, dizziness, blurred or double vision, seizure, and in severe cases, coma Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 64

Medical Diagnosis • The diagnosis of hypoglycemia not associated with diabetes can be based on fasting blood glucose, OGTT, intravenous glucose tolerance test, and 72 -hour inpatient fasting • Whipple’s triad • The presence of symptoms • Documentation of low blood glucose when symptoms occur • Improvement of symptoms when blood glucose rises Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 65

Medical Treatment • In an unconscious patient who has diabetes, hypoglycemia should be suspected until it is ruled out • 50 m. L of 50% glucose solution should be administered immediately • The patient with a milder form of hypoglycemia • Treated with 15 g carbohydrate • If the patient’s condition does not improve, another 15 g of carbohydrate should be given after 10 minutes Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 66

Medical Treatment • Prevention of hypoglycemia by proper food intake • The diet is directed by the underlying cause • If overproduction of insulin after carbohydrate ingestion, a lowcarbohydrate, high-protein diet • Restriction of carbohydrates to no more than 100 g/day is recommended • Simple sugars avoided; complex carbohydrates encouraged • Patients may tolerate smaller, more frequent meals. Alcohol should be avoided Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 67

Assessment • Present illness: shakiness, nervousness, irritability, tachycardia, anxiety, lightheadedness, hunger, tingling or numbness of the lips or tongue, nightmares, and crying out during sleep • Note when episodes occur in relation to meals and particular food intake • The past medical history documents diabetes, previous gastric surgery, abdominal cancer, or adrenal insufficiency • Medications, paying particular attention to hypoglycemic agents Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 68

Assessment • Note hypoglycemic agents, prescribed dose, and the time last dose taken • Functional assessment: information about current diet, exercise, alcohol intake, and the effects of symptoms on daily activities • Important aspects of the physical examination include general behavior, appearance, pulse, and blood pressure Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 69