MSEM118.pdf

11/20/23, 5:30 PM Realizeit for Student Pharmacologic Therapy Insulin is secreted by the beta cells of the islets of Langerhans and lowers the blood glucose level after meals by facilitating the uptake and utilization of glucose by muscle, fat, and liver cells. In the absence of adequate insulin,...

11/20/23, 5:30 PM Realizeit for Student Pharmacologic Therapy Insulin is secreted by the beta cells of the islets of Langerhans and lowers the blood glucose level after meals by facilitating the uptake and utilization of glucose by muscle, fat, and liver cells. In the absence of adequate insulin, pharmacologic therapy is essential. Insulin Therapy In type 1 diabetes, exogenous insulin must be given for life because the body loses the ability to produce insulin. In type 2 diabetes, insulin may be necessary on a long-term basis to control glucose levels if meal planning and oral agents are ineffective or when insulin deficiency occurs. In addition, some patients in whom type 2 diabetes is usually controlled by meal planning alone or by meal planning and an oral antidiabetic agent may require insulin temporarily during illness, infection, pregnancy, surgery, or some other stressful event. In many cases, insulin injections are given two or more times daily to control the blood glucose level. Because the insulin dose required by the individual patient is determined by the level of glucose in the blood, accurate monitoring of blood glucose levels is essential; thus, SMBG is a cornerstone of insulin therapy. Preparations A number of insulin preparations are available. They vary according to three main characteristics: time course of action, species (source), and manufacturer (Comerford & Durkin, 2020). Human insulins are produced by recombinant deoxyribonucleic acid (DNA) technology and are the only type of insulin available in the United States. Time Course of Action. Insulins may be grouped into several categories based on the onset, peak, and duration of action (see Table 46-3). Rapid-acting insulins produce a more rapid effect that is of shorter duration than regular insulin. Because of their rapid onset, the patient should be instructed to eat no more than 5 to 15 minutes after injection. Because of the short duration of action of these insulin analogues, patients with type 1 diabetes and some patients with type 2 or gestational diabetes also require a long-acting insulin (basal insulin) to maintain glucose control. Basal insulin is necessary to maintain blood glucose levels irrespective of meals. A constant level of insulin is required at all times. Intermediate-acting insulins function as basal insulins but may have to be split into 2 injections to achieve 24-hour coverage. Short-acting insulins are called regular insulin (marked R on the bottle). Regular insulin is a clear solution and is usually given 15 minutes before a meal, either alone or in combination with a longer-acting insulin. Regular insulin can be administered IV (Comerford & Durkin, 2020). Intermediate-acting insulins are called NPH insulin (neutral protamine Hagedorn), which are similar in their time course of action, appear uniformly milky and cloudy. If an NPH insulin is taken alone, it is not crucial that it be taken before a meal but patients should eat some food around the time of the onset and peak of these insulins. “Peakless” basal or long-acting insulins are used as a basal insulin—that is, the insulin is absorbed very slowly over 24 hours and can be given once a day (Comerford & Durkin, 2020). Because the insulin is in a suspension with a pH of 4, it cannot be mixed with other insulins because this would cause precipitation. It is administered once a day at any time of the day but must be given at the same time each day to prevent overlap of action. Many patients fall asleep, forgetting to take their bedtime insulin, or may be wary of taking insulin before going to sleep. Having these patients take their insulin in the morning ensures that the dose is taken. The nurse should emphasize which meals—and snacks—are being “covered” by which insulin doses. In general, the rapid- and short-acting insulins are expected to cover the increase in glucose levels after meals, immediately after the injection; the intermediate-acting insulins are expected to cover subsequent meals; and the long-acting insulins provide a relatively constant level of insulin and act as a basal insulin. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IX2deLl%2f4FdfKSHmHSZ7peJYyAcbNSqCsVXJC0jIBoV… 1/13 11/20/23, 5:30 PM Realizeit for Student Complications of Insulin Therapy Local Allergic Reactions. A local allergic reaction (redness, swelling, tenderness, and induration or a 2- to 4-cm wheal) may appear at the injection site 1 to 2 hours after the administration of insulin. Reactions usually resolve in a few hours or days. If they do not resolve, another type of insulin can be prescribed (Comerford & Durkin, 2020). Systemic Allergic Reactions. Systemic allergic reactions to insulin are rare. When they do occur, there is an immediate local skin reaction that gradually spreads into generalized urticaria (hives). These rare reactions are occasionally associated with generalized edema or anaphylaxis. The treatment is desensitization, with small doses of insulin given in gradually increasing amounts using a desensitization kit. Insulin Lipodystrophy. Lipodystrophy refers to a localized reaction, in the form of either lipoatrophy or lipohypertrophy, occurring at the site of insulin injections. Lipoatrophy is the loss of subcutaneous fat; it appears as slight dimpling or more serious pitting of subcutaneous fat. The use of human insulin has almost eliminated this disfiguring complication. Lipohypertrophy, the development of fibrofatty masses at the injection site, is caused by the repeated use of an injection site. If insulin is injected into scarred areas, absorption may be delayed. This is one reason that rotation of injection sites is so important. Patients should avoid injecting insulin into these areas until the hypertrophy disappears. Resistance to Injected Insulin. Patients may develop insulin resistance and require large insulin doses to control symptoms of diabetes (Comerford & Durkin, 2020). In most patients with diabetes who take insulin, immune antibodies develop and bind the insulin, thereby decreasing the insulin available for use. All insulins cause some antibody production in humans. Very few patients who are resistant develop high levels of antibodies. Many of these patients have a history of insulin therapy interrupted for several months or longer. Treatment consists of administering a more concentrated insulin preparation, such as U-500, which is available by special order (Comerford & Durkin, 2020). U-500 insulin is never stored with other insulin preparations due to the risk of overdose if accidentally given to the wrong patient (Comerford & Durkin, 2020). Occasionally, corticosteroid therapy is needed to block the production of antibodies. This may be followed by a gradual reduction in the insulin requirement. Therefore, patients must monitor their blood for hypoglycemia. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IX2deLl%2f4FdfKSHmHSZ7peJYyAcbNSqCsVXJC0jIBoV… 2/13 11/20/23, 5:30 PM Realizeit for Student Morning Hyperglycemia. An elevated blood glucose level on arising in the morning is caused by an insufficient level of insulin, which may be caused by several factors: the dawn phenomenon, the Somogyi effect, or insulin waning. The dawn phenomenon is characterized by a relatively normal blood glucose level until approximately 3 AM, when blood glucose levels begin to rise. The phenomenon is thought to result from nocturnal surges in growth hormone secretion, which creates a greater need for insulin in the early morning hours in patients with type 1 diabetes. It must be distinguished from insulin waning (the progressive increase in blood glucose from bedtime to morning) and from the Somogyi effect (nocturnal hypoglycemia followed by rebound hyperglycemia). Insulin waning is frequently seen if the evening NPH dose is given before dinner; it is prevented by moving the evening dose of NPH insulin to bedtime. It may be difficult to tell from a patient’s history what the cause is for morning hyperglycemia. To determine the cause, the patient must be awakened once or twice during the night to test blood glucose levels. Testing at bedtime, at 3 am, and on awakening provides information that can be used to make adjustments in insulin to avoid morning hyperglycemia. Methods of Insulin Delivery Methods of insulin delivery include traditional subcutaneous injections, insulin pens, jet injectors, and insulin pumps. (See later Nursing Management discussion of traditional subcutaneous injections.) Insulin Pens. Insulin pens use small (150- to 300-unit) prefilled insulin cartridges that are loaded into a penlike holder. A disposable needle is attached to the device for insulin injection. Insulin is delivered by dialing in a dose or pushing a button for every 1- or 2-unit increment given. People using these devices still need to insert the needle for each injection (see Fig. 46-3); however, they do not need to carry insulin bottles or draw up insulin before each injection. These devices are most useful for patients who need to inject only one type of insulin at a time (e.g., premeal rapid-acting insulin three times a day, bedtime NPH insulin) or who can use the premixed insulins. These pens are convenient for those who administer insulin before dinner if eating out or traveling. They are also useful for patients with impaired manual dexterity, vision, or cognitive function, which makes the use of traditional syringes difficult. Jet Injectors. As an alternative to needle injections, jet injection devices deliver insulin through the skin under pressure in an extremely fine stream. These devices are more expensive and require thorough training and supervision when first used. In addition, patients should be cautioned that absorption rates, peak insulin activity, and insulin levels may be different when changing to a jet injector. (Insulin given by jet injector is usually absorbed faster.) The use of jet injectors has been associated with bruising in some patients. Insulin Pumps. Continuous subcutaneous insulin infusion involves the use of small, externally worn devices called insulin pumps (ADA, 2020). This technology mimics the functions of a healthy pancreas by providing automated systems that can adjust insulin delivery based on basal (background) insulin every 5 minutes. Insulin pumps contain a 3-mL syringe attached to a long (24- to 42-inch), thin, narrow-lumen tube with a needle or Teflon catheter attached to the end. The patient inserts the needle or catheter into subcutaneous tissue (usually on the abdomen) and secures it with tape or a transparent dressing. The needle or catheter is changed at least every 3 days. The pump is then worn either on the patient’s clothing or in a pocket. Some women keep the pump tucked into the front or side of the bra. Additional accessories, such as belt, clip or pouch can be used to carry an insulin pump. When an insulin pump is used, insulin is delivered by subcutaneous infusion at a basal rate that ranges from 0.25 to 2 units per hour depending on the device. When a meal is consumed, the patient calculates a dose of insulin to metabolize the meal by counting the total amount of carbohydrate for the meal using a predetermined insulin-to-carbohydrate ratio; for example, a ratio of 1 unit of insulin for every 15 g of carbohydrate would require 3 units for a meal with 45 g of carbohydrate. This allows flexibility of meal timing and content. Possible disadvantages of insulin pumps are unexpected disruptions in the flow of insulin from the pump that may occur if the tubing or needle becomes occluded, if the supply of insulin runs out, or if the battery is depleted, increasing the risk of DKA. Effective education to produce knowledgeable patients minimizes this risk. There is the potential for infection at needle insertion sites. Hypoglycemia may occur with insulin pump therapy; however, this is usually related to the lowered blood glucose levels that many patients achieve rather than to a specific problem with the pump itself. The tight diabetes control associated with the use of an insulin pump may increase the incidence of hypoglycemia unawareness because of the very gradual decline in serum glucose level, from more than 70 mg/dL (3.9 mmol/L) to less than 60 mg/dL (3.3 mmol/L). Some patients find that wearing the pump for 24 hours each day is inconvenient. However, the pump can easily be disconnected, per patient preference, for limited periods, such as for showering, exercise, swimming, or sexual activity. Candidates for the insulin pump must be willing to assess their blood glucose level several times daily with either SMBG or CGM (ADA, 2020). In addition, they must be psychologically stable and comfortable about having diabetes, because the insulin pump is often a visible sign to others and a constant reminder to patients that they have diabetes. Most important, patients using insulin pumps must have extensive education in the use of the pump and in self-management of blood glucose and insulin doses. They must work closely with a https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IX2deLl%2f4FdfKSHmHSZ7peJYyAcbNSqCsVXJC0jIBoV… 3/13 11/20/23, 5:30 PM Realizeit for Student team of health care professionals who are experienced in insulin pump therapy—specifically, a diabetologist/endocrinologist, a dietitian, and a diabetes and education specialist or CDE. The most common risk of insulin pump therapy is DKA which can occur if there is an occlusion in the infusion set or tubing. Because only rapid-acting insulin is used in the pump, any interruption in the flow of insulin may rapidly cause the patient to be without insulin. The patient should be taught to administer insulin by manual injection if an insulin interruption is suspected (e.g., no response in blood glucose level after a meal bolus). Many insurance companies cover the cost of pump therapy. If not, the extra expense of the pump and associated supplies may be a deterrent for some patients. Medicare covers insulin pump therapy for patients with type 1 diabetes. Insulin pumps have been used in patients with type 2 diabetes whose beta-cell function has diminished and who require insulin. Patients with a hectic lifestyle often do well with an insulin pump. There is no risk of DKA when there is an interruption of the flow of insulin in people with type 2 diabetes wearing an insulin pump. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IX2deLl%2f4FdfKSHmHSZ7peJYyAcbNSqCsVXJC0jIBoV… 4/13 11/20/23, 5:30 PM Realizeit for Student Storing Insulin Whether insulin is the short- or the long-acting preparation, vials not in use, including spare vials or pens, should be refrigerated. Extremes of temperature should be avoided; insulin should not be allowed to freeze and should not be kept in direct sunlight or in a hot car. The insulin vial in use should be kept at room temperature to reduce local irritation at the injection site, which may occur if cold insulin is injected. If a vial of insulin will be used up within 1 month, it may be kept at room temperature. The patient should be instructed to always have a spare vial of the type or types of insulin used (ADA, 2020). Cloudy insulins should be thoroughly mixed by gently inverting the vial or rolling it between the hands before drawing the solution into a syringe or a pen (Comerford & Durkin, 2020). The patient needs to be educated to pay attention to the expiration date on any type of insulin. Bottles of intermediate-acting insulin should also be inspected for flocculation, which is a frosted, whitish coating inside the bottle. This occurs most commonly with insulins that are exposed to extremes of temperature. If a frosted, adherent coating is present, some of the insulin is bound, inactive, and should not be used. Selecting Syringes Syringes must be matched with the insulin concentration (e.g., U-100). Currently, three sizes of U-100 insulin syringes are available: 1-mL syringe, 100-unit capacity 0.5-mL syringe, 50-unit capacity 0.3-mL syringe, 30-unit capacity The concentration of insulin used in the United States is U-100; that is, there are 100 units per milliliter (or cubic centimeter). Small syringes allow patients who require small amounts of insulin to measure and draw up the amount of insulin accurately. There is a U-500 (500 units/mL) concentration of insulin available by special order for patients who have severe insulin resistance and require massive doses of insulin. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IX2deLl%2f4FdfKSHmHSZ7peJYyAcbNSqCsVXJC0jIBoV… 5/13 11/20/23, 5:30 PM Realizeit for Student Most insulin syringes have a disposable 27- to 29-gauge needle that is approximately 0.5 in long. The smaller syringes are marked in 1-unit increments and may be easier to use for patients with visual deficits and those taking very small doses of insulin. The 1-mL syringes are marked in 1- and 2-unit increments. A small disposable insulin needle (31 gauge, 8 mm long) is available for very thin patients and children. Mixing Insulins When rapid- or short-acting insulins are to be given simultaneously with longer-acting insulins, they are usually mixed together in the same syringe; the longer-acting insulins must be mixed thoroughly before drawing into the syringe. It is important that patients prepare their insulin injections consistently from day to day. There are varying opinions regarding which type of insulin (short- or longer-acting) should be drawn up into the syringe first when they are going to be mixed, but the ADA recommends that the regular insulin be drawn up first. The most important issues are that patients are consistent in technique, so as not to draw up the wrong dose in error or the wrong type of insulin, and that patients not inject one type of insulin into the bottle containing a different type of insulin. Injecting cloudy insulin into a vial of clear insulin contaminates the entire vial of clear insulin and alters its action. For patients who have difficulty mixing insulins, several options are available. They may use a premixed insulin, they may have prefilled syringes prepared, or they may take 2 injections. Premixed insulins are available in many different ratios of NPH insulin to regular insulin (Comerford & Durkin, 2020). The ratio of 70/30 (70% NPH and 30% regular insulin in one bottle) is most common. Combinations with a ratio of 75% NPL (neutral protamine lispro) and 25% insulin lispro are also available. The appropriate initial dosage of premixed insulin must be calculated so that the ratio of NPH to regular insulin most closely approximates the separate doses needed. For patients who can inject insulin but who have difficulty drawing up a single or mixed dose, syringes may be prefilled with the help of home health nurses or family and friends. A 3-week supply of insulin syringes may be prepared and kept in the refrigerator but warmed to room temperature before administration. The prefilled syringes should be stored with the needle in an upright position to avoid clogging of the needle; they should be mixed thoroughly by inverting syringe several times before the insulin is injected. Withdrawing Insulin Most (if not all) of the printed materials available on insulin dose preparation instruct patients to inject air into the bottle of insulin equivalent to the number of units of insulin to be withdrawn. The rationale for this is to prevent the formation of a vacuum inside the bottle, which would make it difficult to withdraw the proper amount of insulin. Selecting and Rotating the Injection Site The four main areas for injection are the abdomen, upper arms (posterior surface), thighs (anterior surface), and hips. Insulin is absorbed faster in some areas of the body than others. The speed of absorption is greatest in the abdomen and decreases progressively in the arm, thigh, and hip, respectively. Systematic rotation of injection sites within an anatomic area is recommended to prevent lipodystrophy (localized changes in fatty tissue). In addition, to promote consistency in insulin absorption, the patient should be encouraged to use all available injection sites within one area rather than randomly rotating sites from area to area. For example, some patients almost exclusively use the abdominal area, administering each injection 0.5 to 1 inch away from the previous injection. Another approach to rotation is always to use the same area at the same time of day. For example, patients may inject morning doses into the abdomen and evening doses into the arms or legs. A few general principles apply to all rotation patterns. First, the patient should try not to use the exact same site more than once in 2 to 3 weeks. In addition, if the patient is planning to exercise, insulin should not be injected into the limb that will be exercised because this will cause the drug to be absorbed faster, which may result in hypoglycemia. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IX2deLl%2f4FdfKSHmHSZ7peJYyAcbNSqCsVXJC0jIBoV… 6/13 11/20/23, 5:30 PM Realizeit for Student Insulins Insulin in its various forms is the only effective drug treatment for type 1 diabetes, where pancreatic beta cells are unable to secrete endogenous insulin and metabolism is severely impaired. Regular insulin (HumuLIN R U-500, HumuLIN R U-500 KwikPen) is the prototype. Over-the-counter (OTC) preparations include HumuLIN R, NovoLIN R, and NovoLIN R ReliON. Insulin is also necessary in patients with type 2 diabetes who cannot control their disease with diet, weight control, and oral agents. Any person with diabetes may need insulin during times of stress, such as illness, infection, or surgery. Other uses of insulin include control of diabetes induced by chronic pancreatitis, surgical excision of pancreatic tissue, hormones and other drugs, and pregnancy (gestational diabetes). In patients who do not have diabetes, health care providers use insulin to prevent or treat hyperglycemia induced by IV parenteral nutrition and to treat hyperkalemia. In hyperkalemia, an IV infusion of insulin and dextrose solution causes potassium to move from the blood into the cells; it does not eliminate potassium from the body. All insulin in the United States is human insulin. Pork and bovine insulins, which were more antigenic, are no longer manufactured in the United States. The name human insulin means that the synthetic product is identical to endogenous insulin (i.e., has the same number and sequence of amino acids). Types of Insulin Insulins differ in onset and duration of action. They are usually categorized as short, intermediate, or long acting. The synthesis of insulin analogs involves altering the type or sequence of amino acids in insulin molecules. Rapid-acting insulins have a rapid onset (15 minutes or less) and a short duration of action (4–8 hours). Rapid-acting products include insulin lispro (HumaLOG, Admelog, HumaLOG KwikPen), insulin aspart (NovoLOG, Fiasp, NovoLOG FlexPen), and insulin glulisine (Apidra, Apidra SoloStar). Lispro, the first insulin analog to be marketed, is identical to human insulin except for the reversal of two amino acids (lysine and Proline). It is absorbed more rapidly and has a shorter half-life after subcutaneous injection than regular (short-acting) human insulin. As a result, it is similar to physiologic insulin secretion after a meal, more effective at decreasing postprandial hyperglycemia, and less likely to cause hypoglycemia before the next meal. Injection just before a meal produces hypoglycemic effects similar to those of an injection of conventional regular insulin given 30 minutes before a meal. Aspart has an even more rapid onset and shorter duration of action. Glulisine has the shortest onset of action (5–10 minutes). https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IX2deLl%2f4FdfKSHmHSZ7peJYyAcbNSqCsVXJC0jIBoV… 7/13 11/20/23, 5:30 PM Realizeit for Student Afrezza is an inhaled regular insulin analog. The U.S. Food and Drug Administration has issued a BLACK BOX WARNING for this insulin, stating that patients with diabetes and chronic lung disease who take it are at risk for acute bronchospasm. Acute bronchospasm has been reported in patients with asthma and chronic obstructive pulmonary disease, and Afrezza is contraindicated in these patients who need insulin. The Institute for Safe Medication Practices also lists Afrezza as a drug with heightened risk for significant patient harm. Before ordering Afrezza, prescribers should collect a detailed medical history, perform a physical examination, and evaluate the patient’s spirometry. The insulin requirements can vary with the use of Afrezza; thus, careful blood glucose monitoring is necessary. Afrezza is administered at the beginning of every meal. The cartridges should be stored at room temperature. Intermediate-acting insulin preparations such as isophane (NPH) suspension possess zinc insulin crystals that have been modified by protamine in a neural buffer. The addition of zinc assists in slowing the absorption and thus prolongs the duration of action. Long-acting insulin preparations include insulin glargine and insulin detemir. Health care providers use them to provide a basal amount of insulin through 24 hours, similar to normal, endogenous insulin secretion. Several mixtures of an intermediate- and a short-acting insulin are available and in common use. U-100, the main insulin concentration in the United States, contains 100 units of insulin per milliliter of solution. Accurate measurement requires an orange-tipped syringe designed for use only with U-100 insulin. After subcutaneous injection, insulin is absorbed most rapidly from the abdomen, followed by the upper arm, thigh, and buttocks. Absorption is delayed or decreased by injection into subcutaneous tissue with lipodystrophy or other lesions, by circulatory problems such as edema or hypotension, by insulin-binding antibodies (which develop after 2 or 3 months of insulin administration), and by injecting cold (i.e., refrigerated) insulin. Absorption may also be increased when administered in an extremity before the patient engages in a sport that requires use of the specific extremity (i.e., swimming, tennis, or jogging). Choice of Insulin When insulin therapy is indicated, the physician may choose from several preparations that vary in composition, onset, duration of action, and other characteristics. Some factors to be considered include the following: Regular insulin (insulin injection) has a rapid onset of action and can be given intravenously. Therefore, it is the insulin of choice during acute situations, such as DKA, severe infection or other illness, and surgical procedures. Isophane insulin (NPH) is often used for long-term insulin therapy. For many patients, a combination of NPH and short-acting insulin provides more consistent control of blood glucose levels. Although several regimens are used, a common one is a mixture of regular and NPH insulins administered before the morning and evening meals. A commercial mixture is more convenient and probably more accurate than a mixture prepared by a patient or caregiver, if the proportions of insulins are appropriate for the patient. Insulin lispro, aspart, or glulisine may be used instead of regular subcutaneous insulin in most situations, but safe use requires both health care providers and patients to be aware of differences. All rapid-acting insulins are approved for use in external insulin pumps that administer a continuous subcutaneous infusion. Insulin glargine or insulin detemir may be used to provide a basal amount of insulin over 24 hours, with a short-acting or rapid-acting insulin at meal times. Short-acting insulin, such as regular, will act in 15 to 30 minutes, whereas rapid-acting insulin begins to act immediately upon administration. Pharmacokinetics Regular insulin is rapidly absorbed after IV, intramuscular (IM), and subcutaneous administration. Afrezza is the newest rapid-acting insulin on the market. It is inhaled and rapidly absorbed. All of these forms of regular insulin are considered to be of short duration with a slow action. It is primarily metabolized in the liver, and a small amount is metabolized in the kidneys. Less than 2% of the drug is excreted in the urine. Action Insulin and its analogs (structurally similar chemicals) replace endogenous insulin, and this exogenous insulin has the same effects as the pancreatic hormone. The insulins lower blood glucose levels by increasing glucose uptake by body cells, especially skeletal muscle and fat cells, and by decreasing glucose production in the liver. Use Insulin is used to lower blood glucose, and the dosage must be individualized according to blood glucose levels. Blood glucose meters are devices that measure how much glucose is in the blood. A specially coated test strip containing a fresh sample of blood (obtained by pricking the skin, usually the finger or forearm, with a lancet ) is inserted in the meter, which then measures the amount of glucose in the blood. The goal is to administer enough insulin to alleviate symptoms of hyperglycemia and to reestablish metabolic balance without causing hypoglycemia. An initial dose of 0.4 to 1 units/kg/d may be started and then adjusted to maintain blood glucose levels (tested before meals and at bedtime) of 80 to 130 mg/dL in adults. For children and adolescents, insulin is used to maintain glucose levels (tested before meals and at bedtime) of 90 to 150 mg/dL. However, many factors influence blood glucose response to exogenous insulin and therefore influence insulin requirements. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IX2deLl%2f4FdfKSHmHSZ7peJYyAcbNSqCsVXJC0jIBoV… 8/13 11/20/23, 5:30 PM Realizeit for Student BOX 41.4 Hypoglycemia: Characteristics and Management Hypoglycemia may occur with insulin, meglitinides, oral sulfonylureas, amylin analogs (pramlintide [Symlin]), and incretin mimetics (exenatide [Byett blood glucose level should be measured if possible, although signs and symptoms and the plasma glucose level at which they occur vary from pers glucose below 60 to 70 mg/dL and is especially dangerous at approximately 40 mg/dL or below. Central nervous system effects may lead to accide cardiovascular effects may lead to cardiac dysrhythmias or myocardial infarction. Causes of hypoglycemia include: Intensive insulin therapy (i.e., continuous subcutaneous [sub-Q] infusion or three or more injections daily) Omitting or delaying meals An excessive or incorrect dose of insulin or an oral agent that causes hypoglycemia Altered sensitivity to insulin Decreased clearance of insulin or an oral agent (e.g., with renal insufficiency) Decreased glucose intake Decreased production of glucose in the liver Giving an insulin injection via the intramuscular (IM) rather than the sub-Q route Drug interactions that decrease blood glucose levels Increased physical exertion Ethanol ingestion Hormones That Raise Blood Sugar Normally, when hypoglycemia occurs, several hormones (glucagon, epinephrine, growth hormone, and cortisol) work to restore and maintain blood epinephrine, the dominant counterregulatory hormones, act rapidly because they are activated as soon as blood glucose levels start declining. Gro about 2 hours after hypoglycemia occurs. People with diabetes who develop hypoglycemia may have impaired secretion of these hormones, especially those patients with type 1 diabetes. D evident in patients who have had diabetes for 5 years or longer. Decreased secretion of epinephrine also occurs in people who have been treated w epinephrine decreases tachycardia, a common sign of hypoglycemia, and may delay recognition and treatment. The Conscious Patient Treatment of hypoglycemic reactions consists of immediate administration of a rapidly absorbed carbohydrate. For the conscious patient who is ab orally. Foods and fluids that provide approximately 15 g of carbohydrate include: Liquids or fruit juices. Teaspoons of sugar. Commercial glucose products (e.g., Glutose, B-D Glucose). These products must be swallowed to be effective. Symptoms usually subside within 15 to 20 minutes. If they do not subside, the patient should take another 10 to 15 g of oral carbohydrate. If acarbose or miglitol has been taken with insulin or a sulfonylurea and a hypoglycemic reaction occurs, glucose (oral or intravenous [IV]) or gluc (table sugar) and other oral carbohydrates do not relieve hypoglycemia because the presence of acarbose or miglitol prevents their digestion and The Unconscious Patient Carbohydrate cannot be given orally. Therefore, the choices are parenteral glucose or glucagon. In the health care facility, administer 25% to 50% dextrose solution. In home or elsewhere, give sub-Q or IM glucagon 0.5 to 1 mg if available, and there is someone to inject it. Glucagon is a pancreatic hormone that increases blood sugar by converting liver glycogen to glucose. It is effective only when liver glycogen is p glucagon because glycogen stores are depleted by conditions such as starvation, adrenal insufficiency, or chronic hypoglycemia. The hyperglyce slowly than that of IV glucose and is of relatively brief duration. If the patient does not respond to one or two doses of glucagon within 20 minute Avoid Overtreatment Caution is necessary in the treatment of hypoglycemia. Although the main goal of treatment is to relieve hypoglycemia and restore the brain's supp overtreatment and excessive hyperglycemia. Factors that increase insulin requirements include weight gain, increased caloric intake, pregnancy, decreased activity, acute infections, hyperad hyperparathyroidism, acromegaly, hypokalemia, and drugs such as corticosteroids, epinephrine, levothyroxine, and thiazide diuretics. Patients w because of resistance to insulin in peripheral tissues. Factors that decrease insulin requirements include weight reduction; decreased caloric intake; increased physical activity; development of renal i corticosteroids, epinephrine, levothyroxine, and diuretics; hypothyroidism; hypopituitarism; recovery from hyperthyroidism; recovery from acute i which may occur with type 1 diabetes. People who need less than 0.5 units/kg/d may produce some endogenous insulin, or their tissues may be more responsive to insulin because of In acute situations, dosage of regular insulin needs frequent adjustments based on measurements of blood glucose. When insulin is given intrave 30% binds to the IV fluid container and the infusion tubing. Dosage of insulin for long-term therapy is determined by blood glucose levels at various times of the day and is adjusted when indicated (e.g., be activity). Titrating insulin dosage may be difficult and time consuming; it requires cooperation and collaboration between patients and health care Insulin has been used successfully with all currently available types of oral agents (alpha-glucosidase inhibitors, biguanide, thiazolidinediones, m Use in Older Adults https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IX2deLl%2f4FdfKSHmHSZ7peJYyAcbNSqCsVXJC0jIBoV… 9/13 11/20/23, 5:30 PM Realizeit for Student It is estimated that at least 20% of people older than 65 years of age have diabetes. General precautions for safe and effective use of oral hypoglycemic drugs apply to older adults, including close monitoring of blood glucose levels; however, control of cardiovascular risk factors may play a greater role in reducing morbidity and mortality in this population. In addition, older adults may have impaired vision, poor manual dexterity, or other problems that decrease their ability to perform needed tasks (e.g., self-administration of insulin, monitoring blood glucose levels, managing diet, and exercise). Use in Patients With Renal Impairment Frequent monitoring of blood glucose levels and dosage adjustments may be necessary. It is difficult to predict dosage needs because, on the one hand, less insulin is degraded by the kidneys (normally about 25%), and this may lead to higher blood levels of insulin if dosage is not reduced. On the other hand, muscles and possibly other tissues are less sensitive to insulin, and this insulin resistance may result in an increased blood glucose level if dosage is not increased. Overall, vigilance is required to prevent dangerous hypoglycemia, especially in patients whose renal function is unstable or worsening. Use in Patients With Hepatic Impairment Higher blood levels of insulin may occur in patients with hepatic impairment because less insulin may be degraded. Careful monitoring of blood glucose levels and insulin dosage reductions may be needed to prevent hypoglycemia. Use in Patients With Critical Illness Critically ill patients, with and without diabetes mellitus, often experience hyperglycemia associated with insulin resistance. Hyperglycemia may complicate the progress of critically ill patients, resulting in increased complications such as postoperative infections, poor recovery, and increased mortality. Tight glycemic control is a key factor in preventing complications and improving mortality in the patient in an intensive care unit. Insulin is more likely to be used in critical illness than any of the oral agents. Reasons include the greater ability to titrate dosage needs in patients who are often debilitated and unstable, with varying degrees of cardiovascular, liver, and kidney impairment. One important consideration with IV insulin therapy is that 30% or more of a dose may adsorb into containers of IV fluid or infusion sets. In addition, many critically ill patients are unable to take oral drugs. Surgery may require use of insulin. Box 41.5 provides information about perioperative insulin therapy. Some critically ill patients are also at risk for serious hypoglycemia, especially if they are debilitated, sedated, or unable to recognize and communicate symptoms. Vigilant monitoring is essential for any patient who has diabetes and a critical illness. Use in Patients Receiving Home Care Most insulins are taken at home, and the home care nurse shares the responsibility for teaching patients how to use the drug effectively and how to recognize medication responses that should be reported to the health care provider. Accurate dosing is extremely important so that blood glucose levels can be maintained at a normal level. Hyperglycemia and hypoglycemia are both unwanted effects of poor glycemic control. The nurse instructs the patient and any caregivers that if symptoms of hypoglycemia develop, it is essential to take corrective steps immediately. The home care nurse also monitors the patient’s response to insulin and changes in the patient’s condition or drug therapy that increases the patient’s risk for hypoglycemic episodes. When a patient is receiving a combination of insulins for management of diabetes, the nurse assists the patient in understanding that the different types of insulins have different onsets and therapeutic ranges. As a result, the medications work together to be more effective and maintain a more stable glycemic control. Changing medications or dosages can upset the balance and lead to hyperglycemia or hypoglycemia. If the patient is unable to take the medications for any reason, it is essential to notify the health care provider. Contraindications The only clear-cut contraindication to the use of insulin is hypoglycemia because of the risk of brain damage (see Box 41.4). Nursing Implications Preventing Interactions Patients who take insulin may have other diseases that require therapeutic drugs. Certain medications can interfere with insulin, increasing or decreasing the effects, thus causing hypoglycemia or hyperglycemia. Some herbs increase the risk of hypoglycemia. Administering the Medication Oral administration of insulins is not effective because the proteins are destroyed by proteolytic enzymes in the GI tract. Sub-Q administration is fine, and for regular insulin, the IV route may be appropriate. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IX2deLl%2f4FdfKSHmHSZ7peJYyAcbNSqCsVXJC0jIBo… 10/13 11/20/23, 5:30 PM Realizeit for Student QSEN Alert: Safety Before administering insulin, patient safety requires that two nurses always check the dosage. Timing Patients with type 1 diabetes administer rapid-acting or short-acting insulin prior to meals. Patients with type 2 diabetes may take at least two insulin injections daily, with one half to two thirds of the total daily dose in the morning before breakfast and the remaining one half or one third before the evening meal or at bedtime. With regular insulin before meals, it is very important that the medication be injected 30 to 45 minutes before meals so that the insulin is available when blood sugar increases after meals. With insulin lispro, aspart, or glulisine before meals, it is important to inject the medication about 15 minutes before eating. Insulin glargine or detemir is most commonly given at bedtime. However, it may be administered in the morning or in split doses as needed. For the patient who uses an external insulin pump, it is important for the patient to understand the pharmacokinetics of the insulin used in the pump. The health care provider overseeing the patient’s insulin pump sets the basal insulin settings that provide the continuous insulin needed throughout the day. However, the patient needs to have an understanding of how much and when to administer the insulin for meals. Figure 41.3 presents information concerning the insulin pump. Figure 41.3. Continuous subcutaneous (sub-Q) insulin infusion pump. The insulin dosage is programmed into the pump's computer, and the appropriate amount of insulin is injected into the adipose tissue through a needle inserted into the sub-Q area. Insulin pumps are being increasingly used, especially by adolescents and young adults who want flexibility in diet and exercise. These devices allow continuous subcutaneous administration of regular insulin, insulin aspart, or insulin glulisine. A basal amount of insulin is injected (e.g., 1 unit/h or a calculated fraction of the dose used previously) continuously, with bolus injections before meals. This method of insulin administration maintains more normal blood glucose levels and avoids wide fluctuations. Candidates for insulin pumps include patients with diabetes that is poorly controlled with other methods and those who are able and willing to care for the devices properly. The MiniMed Paradigm Realhttps://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IX2deLl%2f4FdfKSHmHSZ7peJYyAcbNSqCsVXJC0jIBo… 11/13 11/20/23, 5:30 PM Realizeit for Student Time System (Medtronic), the world's first integrated insulin pump and continuous glucose monitoring system, is now available in the United States. The Guardian RT System is an insulin pump and displays glucose readings every 5 minutes. It sounds an alarm when glucose levels reach high or low glucose limits preset by the clinical professional. The study completed on the RT System demonstrated that patients using the RT continuous glucose monitoring technology had better control of their blood glucose than patients using fingersticks only. Selection of Subcutaneous Sites for Injections and Pumps Several factors affect insulin absorption from injection sites, including the site location, environmental temperature, and exercise or massage. Studies indicate that insulin is absorbed fastest from the abdomen, followed by the deltoid, thigh, and hip. Because of these differences, many clinicians recommend rotating injection sites within areas. This technique decreases rotations between areas and promotes more consistent blood glucose levels. With regard to temperature, insulin is absorbed more rapidly in warmer sites and environments. In relation to exercise, people who exercise should avoid injecting insulin into subcutaneous tissue near the muscles to be used. The increased blood flow that accompanies exercise promotes rapid absorption and may lead to hypoglycemia. For the patient with an insulin pump, the most commonly recommended sites are the abdomen and lower back so that absorption rates remain consistent (see Fig. 41.3 ). It is extremely important that the patient rotate sites and avoid placing a site into scar tissue, which also affects insulin absorption. Timing of Food Intake Patients receiving insulin need food at the peak action time of the insulin and at bedtime. They usually take the food as a between-meal and a bedtime snack. These snacks help prevent hypoglycemic reactions between meals and at night. When hypoglycemia occurs during sleep, there may be a delay in recognition and treatment, which may allow the reaction to become more severe. Assessing for Therapeutic Effects Patients with type 1 diabetes self-monitor their blood glucose by testing 6 to 10 times daily. Patients with type 2 diabetes and using basal insulin may test their blood glucose up to four times a day. In patients with type 2 diabetes not using insulin, routine glucose monitoring has limited clinical benefit. The more often the patient can check blood glucose levels, the greater possibility of tighter glucose control. The goal of the patient taking insulin is to maintain blood glucose levels within normal range. Health care providers also look at the glycosylated hemoglobin (hemoglobin A1C) levels to assess the effectiveness of treatment. Because glucose stays attached to hemoglobin for the life of the red blood cell, which is about 120 days, the hemoglobin A1C level reflects the average blood glucose level over the past 3 months. The normal hemoglobin A1C level is less than 7%. Assessing for Adverse Effects QSEN Alert: Patient-Centered Care Patients who work outdoors in hot weather and have insulin pumps are at risk for not receiving the insulin because of its inactivation with increased Patient Teaching It is important to teach the patient and family about all aspects of diabetes care. It is also essential to teach them about the insulins and their administration Wear or carry diabetic identification (e.g., a MedicAlert necklace or bracelet) at all times to aid treatment if needed. Take antidiabetic medication as prescribed. If unable to take a medication, notify a health care provider. To control blood sugar most effectively, medications are balanced with diet and exercise. If you take insulin, you need to know what type(s) you are taking, how to obtain more, and how to store it. Unopened vials of insulin should be refrigerated. An opened vial may be stored at room temperature for 28 days. DO NOT freeze insulin. Regular and isophane (NPH) insulins and mixtures (e.g., Humulin) are available over the counter; lispro (Humalog), aspart (NovoLog), glargine (Lantus), glulisine (Apidra), and detemir (Levemir) require a prescription. Keep several days’ supply of insulin and syringes on hand to allow for weather or other conditions that might prevent replacement of insulin or other supplies when needed. If you take Byetta, you should store it in the original package in the refrigerator and discard unused portion after 30 days. Alert your health care provider if you experience acute abdominal discomfort while taking Byetta. If you take Symlin, opened vials can be kept in the refrigerator or at room temperature for up to 28 days. You need to know the signs and symptoms of high blood sugar (hyperglycemia): increased blood glucose and excessive thirst, hunger, and urine output. Persistent hyperglycemia may indicate a need to change some aspect of the treatment program, such as diet or medication. You need to know the symptoms of low blood sugar (hypoglycemia): sweating, nervousness, hunger, weakness, tremors, and mental confusion. Hypoglycemia may indicate too much medication or exercise or too little food. Treatment is a rapidly absorbed source of sugar, which usually reverses symptoms within 10 to 20 minutes. If you are alert and able to swallow, take 4 ounces of fruit juice, 4 to 6 ounces of a sugar-containing soft drink, a piece of fruit or 1/3 cup of raisins, two to three glucose tablets (5 g each), a tube of glucose gel, 1 cup of skim milk, tea, or coffee with two teaspoons of sugar, or eight Lifesaver candies. Avoid taking so much sugar that hyperglycemia occurs. You need to have a family member or another person who is able to recognize and manage hypoglycemia in case you are unable to obtain or swallow a source of glucose. If you take insulin, glucagon should be available in the home, and a caregiver should know how to give it. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IX2deLl%2f4FdfKSHmHSZ7peJYyAcbNSqCsVXJC0jIBo… 12/13 11/20/23, 5:30 PM Realizeit for Student The best way to prevent, delay, or decrease the severity of diabetes complications is to maintain blood sugar at a normal or near-normal level. Other measures include regular visits to health care providers, preferably a team of specialists in diabetes care; regular vision and glaucoma testing; and special foot care. In addition, if you have hypertension or elevated lipid levels, treatment can help prevent heart attacks and strokes. Take only drugs prescribed by a physician who knows you have diabetes. Avoid other prescriptions and over-the-counter drugs unless these are discussed with the physician treating the diabetes because adverse reactions and interactions may occur. For example, nasal decongestants (alone or in cold remedies) and asthma medications may cause tachycardia and nervousness, which may be interpreted as hypoglycemia. In addition, liquid cold remedies and cough syrups may contain sugar and raise blood glucose levels. If you wish to take any kind of herbal or dietary supplement, you should discuss this with the health care provider who is managing your diabetes. There has been little study of these preparations in relation to diabetes; many can increase or decrease blood sugar and alter diabetes control. If you start a supplement, you need to check your blood sugar frequently to see how it affects your blood glucose level. Test blood regularly for glucose. A schedule individualized to your needs is best. Testing should be done more often when medication dosages are changed or when you are ill. Current blood glucose technology allows the selection of the fingertip or other location such as the forearm to obtain the blood sample. Glucose concentrations measured at different sites may vary. The fingertips are the most accurate site and should be the preferred test site if hypoglycemia is suspected. Reduce insulin dosage or eat extra food if you expect to exercise more than usual. Specific recommendations should be individualized and worked out with health care providers in relation to the type of exercise. Ask for written instructions about managing “sick days” and call your physician if unsure about what you need to do. Although each person needs individualized instructions, some general guidelines include the following: Continue your antidiabetic medications unless instructed otherwise. Additional insulin also may be needed, especially if ketosis develops. Ketones (acetone) in the urine indicate insulin deficiency or insulin resistance. Check blood glucose levels at least four times daily; test urine for ketones when the blood glucose level exceeds 250 mg/dL or with each urination. If unable to test urine, have someone else do it. If unable to eat solid food, take easily digested liquids or semiliquid foods. About 15 g of carbohydrate every 1 to 2 hours is usually enough and can be provided by half cup of apple juice, applesauce, cola, cranberry juice, eggnog, cream of wheat cereal, custard, vanilla ice cream, regular gelatin, or frozen yogurt. Drink 2 to 3 quarts of fluids daily, especially if you have a fever. Water, tea, broths, clear soups, diet soda, or carbohydrate-containing fluids are acceptable. Record the amount of fluid intake as well as the number of times you urinate, vomit, or have loose stools. Seek medical attention if a premeal blood glucose level is more than 250 mg/dL, if urine acetone is present, if you have fever above 100°F, if you have several episodes of vomiting or diarrhea, or if you have difficulty in breathing, chest pain, severe abdominal pain, or severe dehydration. Understand that an illness is a stress response and can increase or decrease your blood glucose. The body will have increased secretions of glucagon, epinephrine, growth hormone, cortisol, and hormones that raise blood glucose levels, and this will require an increase in medication to lower blood sugar. If you are unable to eat, hypoglycemia will result. Illnesses that lower blood sugar include viral infections, nausea, and vomiting. These conditions can result in dehydration and changes in fluids and electrolytes, leading to diabetic ketoacidosis. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IX2deLl%2f4FdfKSHmHSZ7peJYyAcbNSqCsVXJC0jIBo… 13/13