Fortunately, during the last three decades, progress in diabetes has enabled patients to take far better care of their diabetes than ever before. Unfortunately, many nurses and physicians have found it difficult to keep up with all of the changes. Many things nurses learned in nursing school are no longer relevant or are counter to current recommendations, like rotation of insulin injection sites among several body areas, urine glucose testing, and drinking fruit juice (even for treatment of hypoglycemia). Because more than 10% of Americans over age 55 have diabetes, every nurse needs to be aware of current diabetes practices. This chapter will provide an update and practical recommendations for improving diabetes-nursing care for both the inpatient and outpatient settings.
Diabetes diagnosis and terminology
Glucose tolerance tests are no longer routinely used to diagnose diabetes. Instead, diabetes in adults is diagnosed based on elevated BG levels: fasting BG equal to or exceeding 126 mg/dl on two occasions, or casual BG levels equal to or exceeding 200 mg/dl accompanied by classic diabetes symptoms.1 The main types of diabetes are Type 1 (formerly called insulin dependent diabetes mellitus or IDDM); Type 2 (formerly called noninsulin-dependent diabetes mellitus or NIDDM); and gestational diabetes. Diabetes can also occur secondary to treatment with steroids or certain other medications, or related to pancreatitis or other conditions (e.g., trauma to the pancreas).
Type 1 diabetes, also formerly called “juvenile (or childhood) onset,” commonly occurs in adolescents but can occur in children at any age. It may have an acute onset, but in some cases develops over a period of years. Type 1 diabetes results from a lack of insulin caused by destruction of the insulin-producing beta cells of the pancreas. Insulin controls BG levels, and the absence of insulin results in severe hyperglycemia, ketoacidosis, coma and death. Type 1 diabetes always requires insulin for treatment in addition to meal planning and exercise. This form of diabetes accounts for only 5-10% of those with diabetes
Type 2 diabetes was also formerly called “mature (or adult) onset” diabetes. Type 2 diabetes is usually diagnosed in people over 40 years old, but it can occur much earlier, even in children. Type 2 diabetes is associated primarily with insulin resistance (impaired sensitivity to the action of insulin) and, to a lesser degree, with impaired insulin production; these problems result in hyperglycemia. Usually, people with Type 2 diabetes are overweight at the time of diagnosis, and meal planning and exercise are important components of the treatment plan for people with Type 2 diabetes. Oral diabetes medications and/or insulin are often used in treatment, either initially or if non-medication-based treatment fails to achieve acceptable BG levels. Patients with Type 2 diabetes often have hypertension, hyperlipidemia, and central (or truncal) obesity. Insulin resistance syndrome, or “syndrome X,” a condition consisting of these symptoms plus insulin resistance and hyperinsulinemia (elevated amounts of insulin in the blood), has been associated with the development of hyperglycemia and the diagnosis of diabetes. Type 2 patients who need insulin to control BG levels are sometimes called “Type 2, insulin requiring”; they are not classified as Type 1 or “insulin dependent” because they still make endogenous insulin (though it does not adequately control their BG levels). This form of diabetes accounts for about 90-95% of those with diabetes.
Pregnancy and diabetes
Gestational diabetes occurs in pregnancy and is associated with pregnancy-induced insulin resistance. Complications can include macrosomia (“big baby”) and hypoglycemia in the newborn, both of which can usually be prevented with strict BG control from the time of the gestational diabetes diagnosis throughout the remainder of the pregnancy. Treatment includes meal planning, BG monitoring, moderate exercise, and sometimes insulin.
Women with Type 1 diabetes who become pregnant have an excellent chance of having a healthy baby with aggressive BG management beginning before conception and continuing throughout pregnancy.
Hyperglycemia and diabetes management
Although Type 1, Type 2, and gestational diabetes have very different etiologies, they share the same basic problem (hyperglycemia) and the same treatment goal: control of BG levels. A target BG range is identified for each patient, and treatment is designed to maintain BG levels in that range. The target range may be based on American Diabetes Association guidelines (90-130 pre-meal, <180 post-meal one to two hours after a meal),2 or modified depending on the patient’s situation.
BG control helps maximize daily health and prevents acute complications; it is also the major factor in preventing long-term complications (including cardiovascular disease, kidney and eye disease, and neuropathy). In June 1993, the National Institutes of Health (NIH) released the results of the largest, most comprehensive diabetes study ever done, the Diabetes Control and Complications Trial (DCCT). This study clearly showed that Type 1 patients who used “intensive” diabetes treatment to control their BG levels were able to markedly prevent complications, compared to patients who used “conventional” diabetes treatment. The intensively treated group took three to four insulin injections per day or used an insulin pump, monitored BG levels three to four times per day, paid close attention to diet and exercise, and had monthly evaluations by a diabetes treatment team. The conventional treatment group took one to two insulin injections per day, checked BG levels once a day, and had a standard program of diet and exercise.
The intensively treated group achieved an average BG of 155 mg/dl, and prevented retinopathy (by 76%), nephropathy (by 54%), and neuropathy (by 60%), compared to the conventional treatment group, whose BG levels averaged 210.3 Although neither group achieved consistently normal BG levels, the study demonstrated that improvement (lowering) of BG levels results in prevention of complications. Given that many diabetes patients neither receive the level of treatment described as “conventional” in the study nor achieve average BG levels of even 210, the correlation between BG control and complications prevention is critical information for nurses and other healthcare professionals. Another major study, the United Kingdom Prospective Diabetes study (UKPDS), demonstrated similar results for Type 2 patients with intensive therapy, including a 25% decrease in the microvascular complications rate, and a 35% reduction in complication rate for every percentage point decrease in hemoglobin A1C (AlC), e.g., from an AlC of 9% to 8%.4 (Note: A1C is a blood test that reflects the level of BG control over the previous two to three months.)
The patient’s daily management of the many factors that affect BG levels is the key to controlling hyperglycemia (“BG control”). Nurses play an important role in diabetes control by providing direct care, by giving patients education and support for self-care, and by recognizing undiagnosed diabetes (over 6 million Americans have undiagnosed Type 2 diabetes). Nurses should be alert for the following diabetes risk factors: The patient is over 40 years old, is overweight, has a family history of diabetes, or is experiencing symptoms of hyperglycemia: fatigue, thirst, hunger, frequent urination, blurred vision, or numbness or tingling in the extremities.
Hypoglycemia (formerly called “insulin reaction” or “insulin shock”) occurs when blood glucose levels fall too low in diabetes patients taking oral hypoglycemic medications and/or insulin. Early signs and symptoms of hypoglycemia (adrenergic symptoms) include trembling, perspiration, pallor, hunger, palpitations, nervousness, and headache. If the episode is promptly treated, these symptoms should resolve within five to 15 minutes and pose virtually no problem for the patient. However, if left untreated, hypoglycemia can become severe and progress to neuroglycopenia: symptoms include confusion, irritability, loss of coordination, and lethargy, followed by loss of consciousness (may be accompanied by seizures) and coma. Death can occur in extreme hypoglycemia. Some patients have lost the early, adrenergic symptoms of hypoglycemia, a condition called “hypoglycemic unawareness.” These patients need to be especially careful to prevent hypoglycemic episodes and may need slightly higher target BG ranges than patients whose adrenergic response is intact.5
Preventing hypoglycemia involves learning the factors that affect BG levels (Table 1), especially those that lower BG. High-risk situations for hypoglycemia include eating less than or later than usual, exercising more than usual, or drinking alcohol. Alcohol can also diminish awareness of hypoglycemia and impair the body’s attempts to correct it. Patients should be cautioned to have a maximum of one to two drinks daily and to always eat when drinking.6 Prevention of hypoglycemia also requires that patients eat adequate amounts, eat on time, take appropriate doses of medications, and compensate (with increased food or decreased insulin) for increased exercise.
|Factors affecting blood glucose levels in diabetes|
|BG is raised by:||BG is lowered by:|
Acute illness or trauma
Some medications (such as steroids)
Some oral diabetes medications
Some medications (such as pentamidine)
|*Note: Exercise usually lowers BG levels, but can raise BG if insulin is insufficient or if BG is already elevated.|
It is important to check the patient’s blood glucose level whenever hypoglycemia is suspected. The clinical signs and symptoms of hypoglycemia may vary, and some patients lose the adrenegic response, resulting in hypoglycemia unawareness. In the acute care setting, nurses should always follow the institution’s protocol for treating hypoglycemia. In conscious patients who have no trouble swallowing, giving 15-30 grams of rapidly absorbed carbohydrate (such as glucose tablets or gel) is generally recommended, depending on symptoms and the BG level, retesting the BG after 15 minutes, and repeating the carbohydrate dose if needed. When the BG has reached an adequate level, follow the treatment with a snack of complex carbohydrate and protein (for example, half a sandwich), unless a meal will be eaten within the hour.
In unconscious patients who have an accessible IV line, you can give 50% dextrose IV; glucagon IM can be given if there is not an established intravenous line.7 Follow hospital protocol for dosages, testing, and timing.
Glucose tablets and gel are available for treating hypoglycemia, and although they are more expensive than candy or juice, they are recommended because they provide measured amounts of a medical treatment (quick-acting glucose) for a medical condition (hypoglycemia). It can be confusing to patients to be told to limit juice, or regular soda, and candy, but with regard to hypoglycemia to hear, “You must drink juice or regular soda or eat candy!” Candy bars are an especially poor choice for hypoglycemia treatment. They can contain many times the needed calories and have fats and proteins that can slow glucose absorption.
Patients with hypoglycemic unawareness need special nursing care related to hypoglycemia. They may lose consciousness without warning, and great care must be taken to prevent hypoglycemic episodes. You must monitor these patients closely, especially if meals are delayed or the patient is not to have anything by mouth (NPO). Your care may include frequent BG monitoring as well as teaching regarding prevention of hypoglycemia and use of a glucagon emergency kit.
Insulin and oral diabetes medications
Insulin is necessary for normal carbohydrate, fat, and protein metabolism. Patients with Type 1 diabetes do not produce enough insulin to sustain life, so they must depend on exogenous insulin to live. On the other hand, patients with Type 2 diabetes do not solely depend on exogenous insulin to live. In gestational diabetes, insulin is often required as a part of treatment.
Insulin utilization must be individualized and balanced with diet and exercise. A primary goal of insulin therapy is to match insulin action with the rise in BG that occurs after eating. There are a variety of insulin products and several possible regimens that can achieve this goal in most patients. However, the often used regimen of one injection of NPH insulin each morning almost always falls short of the goal. (See Chapter Three for more insulin information.)
Insulin is available in rapid, short, intermediate, and long-acting types that may be injected separately or as mixtures. Regimens of mixed insulin before breakfast and before supper or of short/rapid insulin analogs before meals and intermediate/long-acting at bedtime are usually more effective in controlling BG. Patients who have difficulty mixing two types of insulin may benefit from pre-mixed insulin preparations with specific proportions of insulin types, such as intermediate-acting insulin mixed with short- or rapid-acting insulin (e.g., 70% NPH/30% regular, 50% NPH/50% regular, 75% Neutral Protamine Lispro (NPL)/25% Lispro).
Insulin administration requires a subcutaneous injection with a syringe. There are a variety of syringe sizes (e.g., 0.3 cc, 0.5 cc, 1.0 cc) and several needle sizes available. Regulations governing the purchase of syringes vary from state to state. There are also a number of measurement aids and injection devices available (e.g., injection pens, insulin pumps) that can benefit patients taking insulin.
Rotating injection sites from one area of the body to another (e.g., thigh, arm, buttock) is no longer recommended due to variability (up to 40%) in absorption rates from different areas results in variable BG levels.8 Patients should use only one injection area (preferably the abdomen, since absorption from abdominal sites is fastest and least variable.) Tissue damage can be prevented by moving the injection site one inch from the last site used; each site should be used only once every 30 days. Thigh, arm, and buttock areas are acceptable, but slower absorption rates must be anticipated with use of these areas. If areas are rotated, their use must be kept consistent (for example, give every pre-breakfast injection in the abdomen, every pre-lunch injection in the thigh). Exercising an area after giving an insulin injection can lead to more rapid absorption, so patients may be advised to avoid exercising the area for 30-60 minutes following the injection (for example, avoid sit-ups for 30-60 minutes following an abdominal injection) or to be aware that absorption can occur more rapidly than usual.
Patients do not need to use alcohol on their skin (for injections or BG monitoring) and can even inject through clothing,9 though infection control guidelines may still require alcohol in the hospital. There have been many different devices developed to dispose of and reduce the risk of needle sticks and exposure. Syringes, lancets, and pen needles should be disposed of according to local regulations. It is recommended that these sharps be disposed of in a puncture-resistant container if there are no community disposal programs available. Furthermore, manufacturers of insulin syringes and needles recommend that they only be used once and disposed of properly.
A variety of oral diabetes medications are available for use in Type 2 diabetes. (See Chapter Three.) Most are classed as sulfonylurea drugs, also known as oral hypoglycemic agents (OHAs), which stimulate the pancreas to produce more insulin and may enhance tissue sensitivity for insulin.10 Repaglinide (Prandin-1998) and Nateglinide (Starlix -2001) are oral hypoglycemic agents classified as meglitinides. These medications stimulate insulin release to control post-prandial blood glucose levels and should be taken before the main meal each day. Another type of oral diabetes medication is metformin (Glucophage); it is classed as a biguanide, decreases hepatic glucose production, and may enhance insulin sensitivity at the tissue level. Metformin is known as an anti-hyperglycemia agent (not hypoglycemic) since it does not cause an increased production of insulin. Acarbose (Precose) and miglitol (Glyset) are alpha-glucosidase inhibitors, which slow the rate of absorption of glucose from the bowel. The thiazolidinediones are a different class of anti-hyperglycemic agents that reduce insulin resistance at the tissue level. These include rosiglitazone (Avandia) and pioglitazone (Actos). (The FDA removed troglitazone [Rezulin], another thiazolidinedione, from the market in 2000 because of reports of liver toxicity, including death.) Recommendations for rosiglitazone and pioglitazone include baseline liver enzyme monitoring for increased plasma volume; see product literature for specific testing recommendations and precautions. Although they result in lower BG levels, neither the alpha-glucosidase inhibitors nor the thiazolidinediones are considered hypoglycemic agents, because they do not stimulate increased insulin production.
Patients taking sulfonylurea drugs (OHAs), alone or combined with other oral diabetes medications or insulin, are at risk for having hypoglycemia, especially if their BG levels are close to the normal range. Hypoglycemic episodes in patients taking OHAs can be severe and prolonged, because the duration of OHA action can be as long as 24 to 60 hours. The risk of hypoglycemia is increased for older patients and those with impaired kidney function; therefore, OHAs with shorter durations may be safer for these patients.11,12 Chlorpropamide (Diabinese) has a very long duration and is not recommended for patients over age 60, because of the risk of protracted hypoglycemia and hyponatremia.13 There are gastrointestinal and other side effects that can occur with other oral diabetes medications; be sure to read the package insert precautions and other information when administering these medications to patients.
Self-monitoring of BG (SMBG) is recommended for patients with diabetes, especially those taking insulin or sulfonylureas.14 SMBG allows patients to evaluate the response to their individual treatment plan. Results are often used to make appropriate adjustments to current treatment plans. Testing frequency and timing are based on individual needs, including the financial impact of the cost of testing supplies. It is also important to remember that the accuracy of results is based on the instrument and user technique. Therefore, the nurse should periodically evaluate the patient’s technique.13
BG meters for self-monitoring are easy to use, have little potential for error, and are relatively low in cost or can be obtained at a discount or with a rebate. Newer BG meters allow for obtaining blood samples from alternative sites (such as the forearm); however, the blood glucose concentration from alternative site testing is not always identical to that of the finger.15
Urine glucose monitoring is not generally recommended: it is highly unreliable and cannot measure hypoglycemia. In Type 1 patients, however, urine ketones should be monitored in addition to SMBG when ketosis is likely (such as when the following conditions are present: illness or infection, BG over 300, or dehydration).
The goals of medical nutrition therapy (MNT) are key components of the diabetes management plan. The goals of MNT that apply to all patients with diabetes according to the American Diabetes Association are:
- Attain and maintain the following levels: Glucose (90-130 pre-meal and <180 post-meal), A1C (<7.0), LDL (<100), HDL (>40), triglycerides (<150).
- Blood pressure (<130/80) and body weight targets.
- Prevent and treat chronic complications of diabetes, modify nutritional intake and lifestyle as appropriate for prevention and treatment of obesity, hypertension, and cardiovascular disease.
- Improve overall health through healthy food choices and physical activity.
- Address individual needs, taking into consideration age and personal and cultural needs and respecting individual wishes.
Current recommendations state that MNT needs to be individualized and that a registered dietitian (RD) should provide nutrition assessment, care, and education. Nurses and dietitians can also provide information and support to patients about BP and lipid levels and obesity. While weight reduction can be a complex issue, it is important for nurses and patients to understand the benefits of even modest weight loss, which include decreased insulin resistance, improved BG and lipid levels, and decreased BP.15,16,17,18
Current guidelines allow for the inclusion of some simple sugars (such as sucrose) in a diabetes meal plan as part of the total carbohydrate content.19 However, concentrated sweets, including fruit juice, may contain a high concentration of carbohydrates and may contribute to hyperglycemia.20 Patients should be advised to check their blood sugar after consuming concentrated sweets or large portions of carbohydrates to find out the effect on their BG. Instead of juice, patients should be given whole fruit (one serving equals a small apple or half a banana). Nutritional/enteral supplements may also contain concentrated sugars; products with lower sugar content, such as Glucerna or CHOICEdm, may be the best for diabetes patients.21 Again, an RD evaluation is recommended to determine the best nutrition therapy.
The exchange system is used by many patients for meal planning and can be useful to nurses, especially regarding serving sizes and food substitutions. There are also other systems for meal planning, including portion size control and carbohydrate counting. You can obtain more information from your facility’s dietitian or diabetes educator, the American Diabetes Association, or the American Dietetic Association (see Diabetes Resources, page 34).
Regular exercise has been shown to improve blood glucose levels, reduce the cardiovascular risk factors, and contribute to weight loss, as well as improve the overall well-being of an individual. It is recommended that all patients who have diabetes and are capable of participating have a regular physical activity program.
However, before beginning a physical activity program, all patients with diabetes should have a detailed medical examination to screen for any complications that may be worsened by physical activity. Identification of these complications will allow the design of an activity program that will minimize risks.22
Acute care situations are windows of opportunity for you to positively affect the lives of patients with diabetes. Your recommendations on self-care can strongly influence patients’ behaviors and must be based on current diabetes knowledge. You are in a unique position to support patients in virtually every nurse-patient interaction by encouraging them to take diabetes seriously, by validating their self-care efforts, and by offering explanations while giving care. Through giving up-to-date diabetes care, you can help patients maximize their health today and in the future.
Chapter 2: Inpatient Diabetes Care
Janet, a 31-year-old patient with Type 1 diabetes, was in the hospital for chemotherapy. Since she was vomiting and could not tolerate oral foods, her insulin was held (not given) in the morning. By the time the nurse received Janet’s a.m. lab results, which showed a blood glucose of 672, Janet was already in ketoacidosis. A repeat, stat BG was 758, and Janet was transferred to the ICU.
Although she recovered, Janet’s hospital stay was twice as long and three times as expensive as it might have been if Janet’s BG level had been controlled more closely. People with diabetes are often admitted to the hospital for problems other than diabetes, and too often their diabetes is poorly controlled during the hospitalization, especially early in the admission. Patients with diabetes typically comprise 10% to 20% of a hospital’s inpatient population, and poorly controlled BG levels in these patients can contribute to acute complications and longer, more costly hospital stays. Many conditions for which patients require hospitalization increase BG levels due to physiologic stress (e.g., surgery, infection), and therefore require more intensive management than the patient’s home treatment regimen. For example, many patients controlled on oral agents at home require insulin for BG control in the hospital. Virtually all diabetes patients need BG monitoring in the hospital so that physicians and nurses can ensure adequate BG control and prevent and treat both hyperglycemia and hypoglycemia.
Hyperglycemia in hospitalized patients is costly and serious. Several studies confirm that hospitalized patients with hyperglycemia have increased mortality and morbidity rates. Although there is not a specific target level of BG control identified for all hospitalized patients, The American College of Endocrinology strongly supports the need for early detection of hyperglycemia in the hospital and an aggressive management approach to improve outcomes.1
Proper medication management is a key element in controlling BG levels in the hospital. Remember that patients with Type 1 diabetes need a certain amount of (basal) insulin for metabolic function, even when they are NPO for surgery, tests, or other reasons. Also, many physicians write “sliding scale” or “rainbow coverage” orders for both Type 1 and Type 2 patients, but when used without any routine insulin or other diabetes medications orders, this can exacerbate problems with both high and low BG levels. Instead, it is recommended that such orders be used only as a supplement to routine insulin (e.g., NPH and Regular BID) or oral diabetes medication orders.1
The timing of insulin and oral diabetes medications is also very important in caring for hospitalized diabetes patients. All oral diabetes agents and most insulins (all except Lantus/glargine insulin) are to be given either before or with meals, depending on the medication or type of insulin (be sure to note specific recommendations for each medication). Giving these medications at incorrect times (for example, after meals) impairs their effectiveness and worsens the patient’s clinical condition.
Appropriate treatment of hypoglycemic episodes is especially important in hospitalized patients. Be sure to be aware of your hospital’s protocol for treating hypoglycemia (see Chapter One for general treatment recommendations), and be sure to be accurate in both the dose and the timing of glucose administration. Overtreating hypoglycemia not only results in hyperglycemia, but also gives the patient incorrect information regarding self-treatment. Finally, it is important to look for the cause of the hypoglycemic episode and discuss interventions with the physician who is managing the patient’s diabetes care. Don’t automatically withhold the patient’s insulin (or other diabetes medications) after successful treatment of hypoglycemia. Withholding medication is likely to cause hyperglycemia, and should always be discussed with the physician.
Bedside blood glucose monitoring: a nursing tool
According to the American Diabetes Association, “The modern management of hospitalized patients with diabetes is often enhanced by capillary glucose determinations at the bedside … BBGM [bedside blood glucose monitoring] can improve management and conceivably can shorten hospital stays.”3 By using BBGM, nurses can quickly ascertain the level of glucose in a patient with diabetes in both routine and emergency situations. Non-diabetic patients, such as patients receiving pentamidine, steroids or hyperalimentation, can also be monitored for abnormal glucose levels using BBGM.
The development of self-monitoring blood glucose strips and meters in the 1970s revolutionized the care of diabetes. For the first time, patients were able to measure their actual BG levels instead of guessing at levels suggested by inherently inaccurate urine glucose testing. Also for the first time, patients were able to verify hypoglycemic states. With frequent, accurate BG readings in their hands, patients and caregivers can make informed decisions about treatment regimens and achieve nearly normal BG results. Over the years, meter technology has improved in accuracy and operation; reliable levels can now be obtained in less than a minute.
Just as monitoring a patient’s blood pressure has long been accepted as a nursing function, BBGM is within nursing’s realm. BG levels in patients are vital signs of the patient’s physical state. BG levels change from minute to minute and are affected by a myriad of factors, including: food, insulin, oral diabetes medications, activity, stress hormones, infection, other medications (such as steroids), vomiting, and surgery. Even if a patient’s BG is within reference values before admission, his or her BG levels will change during hospitalization.
Too often, BG control is viewed only as a way to prevent long-term complications. In the acute care setting, however, prevention of hyperglycemia and hypoglycemia by controlling BG is a major factor in successful patient management. Hyperglycemia interferes with wound healing, increases chances of infection and can cause metabolic changes that can result in dehydration, electrolyte imbalance, diabetic ketoacidosis or hyperosmolar coma. In addition, high BG levels can cause hunger, fatigue, frequent urination and increased risk of skin breakdown. If nurses routinely monitor BG levels in all diabetes patients, these problems can be minimized.
BBGM allows nurses to quickly assess hypoglycemic episodes. Hypoglycemia is an emergency situation to which a nurse must respond immediately and appropriately. If BBGM is not immediately available, delays in response due to lab turnaround time can lead to more severe hypoglycemia, with neuroglycopenia (low levels of glucose in the brain), seizures and coma. BBGM can also be used to confirm hypoglycemia when patients complain of symptoms such as trembling and perspiration that are often, but not always, related to hypoglycemia.
The information BBGM provides is used by nurses to evaluate a patient’s response to his or her insulin dose or infusion rate, parenteral nutrition, oral diabetes medication or overall diabetes treatment regimen. Other appropriate uses of BBGM include emergency room evaluation of patient status, perioperative BG management and strict BG control in hospitalized pregnant women.4
Spring-loaded lancing devices provide a measured depth of lancet penetration for finger puncture. When used correctly, they yield an adequate blood drop without undue discomfort. Some manufacturers offer interchangeable end pieces to provide different puncture depths. In order to avoid spreading infection, the end piece or puncturing surface of the device should not be used on more than one patient. Interchangeable end pieces can be given to each patient, or disposable combined lancet/end pieces can be used. As in all nursing procedures involving blood or body fluids, it is essential to follow standard precautions as set forth by the national Centers for Disease Control and Prevention.5
Blood glucose meters
There are many BG meters on the market, a number of which are suitable for BBGM (see following list); some manufacturers have products specifically designed for hospital use. Most brands of meters use a brand-specific plastic strip with a specific area that is treated with a reagent or has electrodes in it. When blood is applied to this area, the glucose in the blood reacts with the reagent to cause a color change or an electrical signal, which is read by the meter as the concentration of glucose in the blood.
In choosing a meter, important considerations include accuracy, ease of learning and operation, infection control, quality assurance factors, cost, manufacturer support, and availability of meters and strips. New meters are regularly introduced to the market, but should be evaluated carefully before adoption.
Performing routine and prn BBGM
Obtaining orders: Obtain a physician’s order or incorporate guidelines regarding BBGM into unit protocols or standard orders. Orders should include frequency of BBGM, values above and below which to notify the physician, prn testing for suspected hyper/hypoglycemia, and routine treatment of hyper/hypoglycemic episodes. Frequent monitoring, such as before meals and at bedtime, is generally recommended for hospitalized patients; perioperative patients or others who need close monitoring may require BBGM every two hours or more often. Pre-meal readings should be done with sufficient time to determine the appropriate insulin dose, to contact the physician if necessary, and to give insulin 30 minutes before the meal.
Lancing technique: Remember that lancing the finger should cause little discomfort; positive experiences with punctures performed by nurses can make the patient more willing to do self-monitoring. If the patient is able to lance his or her own finger for the test, so much the better.
Performing painless punctures
1. Load sterile lancet in device, set spring if necessary.
2. Wear gloves.
3. Choose patient’s finger (never use feet or toes and avoid side of body with hemodialysis shunt); rotate among fingers used for subsequent punctures. If the patient’s fingers cannot be used (e.g., a patient with Raynaud’s syndrome), the earlobe may be used.
4. Ask patient to wash hands with warm water and soap, or use alcohol swab per hospital policy (if alcohol is used, wipe or let dry before puncture).
5. Wrap your fingers around patient’s finger, hold finger in a dependent position, and gently squeeze to collect blood in fingertip.
6. Place device on side of fingertip, not center of finger pad.
7. Lightly rest device evenly on skin.
8. Perform puncture.
9. Again, wrap your fingers around patient’s finger as above, squeeze, and wait patiently for blood drop to appear (if puncture was made, blood drop will almost always be adequate; if not, repuncture with more pressure or use deeper penetration endpiece for thick or calloused skin).
10. Apply blood to reagent strip and start timing sequence if necessary (follow manufacturer’s instructions).
11. Apply pressure to puncture site to stop bleeding (discourage patient from placing fingertip in mouth to stop bleeding-infection may result).
12. Discard lancet in sharps container.
13. Change lancet and endpiece before using with another patient.
Testing technique: Follow manufacturer’s instructions precisely. There are specific operating instructions for each meter; errors can cause an inaccurate reading. Note that some meters are designed for use with capillary (whole) blood only; use of venous blood or serum will cause an inaccurate reading in some meters. Check the manufacturer’s instructions to ensure accuracy.
Recording/reporting: Record the BG result immediately on the diabetes flow sheet and/or nurses’ notes. Protocols for interventions or for calling the physician should specify certain values above or below which action must be taken.
Interventions: The nursing care plan should address BG-related situations such as hypoglycemic episodes and hyperglycemia, as well as special skin care, hydration, mouth care, wound care, referral to a dietitian or to a diabetes educator and patient teaching.
Concurrent teaching: Every nursing encounter with a patient with diabetes is an opportunity for teaching and for offering reinforcement, motivation and support. Explanations of actions, technique, rationale, and meaning of results can be integrated into the procedure with little or no extra time required, but with immense benefit to the patient.
Considerations and precautions
Take meters seriously! Because BG meters are primarily manufactured for patient use and appeal, they don’t look like laboratory instruments: They are small, portable, and seemingly easy to operate. These factors can create the illusion that training or technique is not important.
Meters on the market today are fairly accurate. However, all meters have limitations and can fail. Blood glucose measured by a meter uses capillary blood and blood glucose drawn from the vein by the lab is plasma. The glucose is more concentrated in the plasma and can be 15% higher. Most meters today yield a plasma glucose value. Highly inaccurate readings also occur, most often due to operator error. Inaccuracies are most commonly due to errors in timing the test, the size of the blood drop, and calibration of the meter. Other possible causes of inaccurate readings include high or low hematocrit (see strip package insert for values), ascorbic acid blood level, a dirty meter, an outdated strip and/or high altitude.6 If BG readings do not match other assessment data, or if the BG result will make a critical difference in a treatment decision, always obtain a laboratory glucose level.
Protect your patients and yourself from infection. Even one drop of blood can carry infectious agents. Always observe universal precautions. Check your institution’s policy for infection control guidelines specific to the use of bedside blood glucose meters.
Quality control is a key element of any BBGM system. Quality assurance areas include training and periodic retraining of nurses in meter technique; daily meter accuracy checks; periodic laboratory/meter accuracy verification; and meter cleaning and maintenance. Identifying one person as responsible for coordinating a hospital’s BBGM program, and using only one brand of meter throughout the hospital, can maximize consistency and efficiency. Agencies that perform hospital accreditation, such as the Joint Commission for Accreditation of Healthcare Organizations, have regulations and guidelines for BBGM quality assurance and point-of-care testing. Several meter manufacturers offer quality control materials for their instrument systems, as well as nurse training, videotaped instructions, patient education materials and hospital-oriented supplies.
Chapter 3: Advances in Insulin Therapy
A new physician on staff wrote the following insulin order this morning: “70/30 insulin by Novo Pen before breakfast and before supper.” She insists that injection areas not be rotated and that only abdominal injection sites be used.
This situation illustrates only a few of the recent developments in insulin therapy that you, as a nurse, face today in diabetes care. Others include changes in recommendations for insulin storage and injection technique, new insulin pumps and other injection devices, and patient self-adjustment of insulin dose. Because you care for so many diabetes patients, you need to understand current recommendations and be able to explain them to patients and physicians. The purpose of this chapter is to review the current practice and rationale of insulin therapy.
Insulin, a hormone manufactured by pancreatic beta cells, lowers blood glucose (BG) levels primarily by transporting glucose from blood into cells. In addition, insulin acts to store and inhibit the release of glucose, and it affects the metabolism of fat and protein in similar ways. Insulin is used in all Type 1 diabetes patients and in many Type 2 patients. Insulin may also be used temporarily in gestational diabetes or in Type 2 patients whose BG levels are acutely elevated (due to infection or trauma, for example), who become pregnant, or who need insulin only until weight loss and the use of oral diabetes medications are sufficient to discontinue its use.
Types of insulin
Names of insulins can be confusing. Names like Humulin, Humalog, and Novolin are manufacturers’ brand names for various products. The main insulin “type” (for example, lispro, aspart, glargine, Regular, NPH, Lente) denotes the duration of the insulin’s action; it is the important designation and can always be found on the bottle. Insulin types differ in timing of action (see Table 2), not in mode of action. Regular insulin is a solution of insulin with no binding agents added. Most other types of insulin are made by adding zinc, protamine, or both to bind insulin in suspension and extend its action (e.g., NPH, Lente). Lispro (Humalog) and aspart (Novolog) are insulin analogs, which are more rapidly absorbed, have an earlier peak of activity, and have a shorter duration of action than Regular insulin. (Lispro is available by prescription only; patient teaching regarding its characteristics is essential.) It is important to note that regular insulin, lispro and aspart, and glargine are clear insulins or solutions of insulin; all others are cloudy or suspensions. Regular insulin is the only insulin used routinely for intravenous administration.
|Types of insulin currently available in the United States|
|Humalog (lispro) (rapid-acting)||<15 min||1-2 hrs.||3-4 hrs.|
|Novolog (aspart )(rapid-acting)||<15 min||1-2 hrs.||3-4 hrs.|
|Regular (short-acting)||0.5-1 hr.||2-3 hrs.||3-6 hrs.|
|NPH (intermediate-acting)||2-4 hrs.||4-10 hrs.||10-16 hrs.|
|Lente (intermediate-acting)||3-4 hrs.||6-12 hrs.||16-20 hrs.|
|Ultralente (long-acting)||6-10 hrs.||10-16 hrs.||20-24 hrs.|
|Lantus (glargine)(long-acting)||2-4 hrs.||Peakless||20-24 hrs.|
|70/30: mixture of NPH (70%) & Regular (30%), see timing for each above
50/50: mixture of NPH (50%) & Regular (50%)
75/25: mixture of (75%) neutral protamine lispro (NPL) & (25%) lispro
*Note: Approximate ranges only—see text
Sources for insulin
Insulin is a protein molecule composed of a chain of 51 amino acids. Most insulins currently used in the United States are “human” insulins (made from baker’s yeast or from E. coli bacteria) and are structurally identical to endogenous human insulin.
The most common concentration of insulin in the United States is U-100 (100 units of insulin/ml); however, U-40 and U-500 are also available. Syringes are scaled for specific concentrations: U-40 syringes must be used for U-40 insulin, and U-100 syringes for U-100 insulin. However, several sizes of syringes scaled for U-100 insulin are available (30-, 50-, and 100-unit).
While the desired effect of insulin treatment is a reduction in BG levels, hypoglycemia results when BG levels are excessively reduced. Hypoglycemia occurs when the effects of BG-lowering factors (such as insulin, exercise, alcohol consumption) exceed the effects of BG-raising factors (such as food, illness, stress). Risk of hypoglycemia increases during insulin peak action times and when patients eat less than or later than usual or exercise more than usual. All patients taking insulin and their significant others must be taught about the causes, symptoms, treatment, and prevention of hypoglycemia.
The goal of insulin therapy is to mimic the body’s normal insulin profile, in which a small amount of insulin is released continuously, while larger amounts are released in response to rises in BG (as occur after a meal). Therefore, insulin regimens are designed to maintain a baseline blood level and to match the timing of insulin action with BG increases from food absorption so that the insulin compensates for or “covers” the rises in BG following meals. In any regimen, the timing of the insulin dose relative to a meal must be based on the type of insulin given and its onset of action (otherwise, glucose from the meal will begin to raise BG before the insulin is active, or the insulin’s action can lower BG before the meal glucose is absorbed). Generally, Regular insulin and mixtures of Regular and intermediate or longer-acting insulins should be given 30 minutes before a meal; lispro and aspart insulins should be given within 15 minutes before a meal (it is important that the patient eat within 15 minutes of taking lispro or aspart insulin). Insulin glargine (Lantus) is a peakless long-acting insulin analogue most often given at bedtime. It provides insulin in a basal pattern for 24 hours and cannot be mixed with any other insulin.
Insulin regimens are designed to match patients’ physiologic and lifestyle needs. BG levels are used to evaluate a given regimen’s effectiveness; if necessary, adjustments are then made by physicians and patients. Patients who are willing to check their BGs frequently can have more flexible regimens because they can make and monitor changes themselves (in cooperation with their physicians). Patient self-adjustments can be made according to an algorithm for a given dose (for example, “when BG exceeds 160mg/dl, take 1 extra unit of Regular”), and based on patterns observed in BG levels. For example, if pre-lunch BGs are consistently too high, the pre-breakfast regular dose is increased by 1 to 3 units. If BGs remain high after two or three days, the dose is increased again by 1 to 3 units, and so on, until levels are in the desirable range. Patients may also learn to calculate insulin doses based on carbohydrate counting or other nutrition-based systems for meals.1
The “split-mixed” insulin regimen is a combination of Regular and NPH or a mixture of other short- and intermediate-acting insulins taken before breakfast and before supper. The Regular doses cover the BG rises following breakfast and supper; the NPH doses provide coverage for lunch and through the night. A variation of this regimen uses a mixed regular and NPH dose before breakfast, but uses Regular alone before supper and NPH alone at bedtime. For patients whose mealtimes are inconsistent or who desire flexibility and good control, injecting Regular or rapid-acting insulin before each meal and NPH or long-acting insulin at bedtime is useful. Occasionally, a single pre-breakfast injection of NPH insulin daily or NPH only pre-breakfast and pre-supper is prescribed. However, this regimen often provides inadequate coverage for breakfast and nighttime, and carries a significant risk for hypoglycemia during the peak insulin action time (usually late afternoon). Insulin is also used as an adjunct to treatment with oral diabetes medications. In this case, patients may take an intermediate-acting insulin at bedtime, mixed insulin before supper, or another regimen to supplement the effect of their oral medication(s).2
During hospitalization, insulin is often given intravenously (IV) or according to sliding scales. The onset of IV insulin is about 10 minutes, with peak action in about 20 minutes. Since insulin adheres to IV tubing, the first 30 ml. of solution should be flushed and discarded before administration.3 When sliding scales are used, it is crucial to obtain accurate BG levels to accurately measure the effect of the prior dose and to determine the dose to be given.
Insulin absorption and timing can vary for an individual patient, but you can minimize this variability by controlling factors that affect absorption. Insulin is absorbed at different rates from different injection areas; the timing of insulin injected in the abdomen can vary as much as 40% from the same dose given in the thigh.4 Therefore, rotating injection areas can result in variable insulin action and is no longer recommended. Moving the site about one inch from the last-used site within the same area prevents tissue damage (each individual site should not be used more than once every 30 days) and increases the predictability of insulin action.
Other insulin absorption factors include the angle and depth of injection, vascularity of the injection site, physical activity and temperature (such as jogging after a thigh injection or taking a hot bath). Abdominal injection sites are preferred for most patients because they have the fastest and least variable rate of absorption, are numerous, are easy to see and access, and are less affected by exercise than limb sites.4 Patients are sometimes reluctant to try abdominal sites but are often surprised to find them more comfortable than those in other areas. After the abdomen, the arms afford the fastest absorption, followed by the thighs and buttocks.4 When patients take more than two injections per day and want to access more sites than are available in one area, consistent use of one area for each injection time (for example, pre-breakfast injections in the abdomen, and pre-lunch injections in the arm) is important.
Patients no longer need to use alcohol for site preparation and can even inject through clothing. However, alcohol should be used to wipe the top of the insulin bottle2 and may be required for skin preparation in hospitals. Quick needle insertion minimizes discomfort, but after insertion, insulin should be injected slowly (over two to four seconds) and the needle left in place for 20 to 30 seconds, then withdrawn quickly. This allows tissue expansion and minimizes insulin leakage.5 Aspiration is no longer generally recommended for patients’ self-injections, but nurses may still want to aspirate in thin or obese patients. Patients may re-use their own syringes, but syringes should never be shared, and re-use should be discouraged in those with an increased risk of infection (AIDS/HIV patients, for example).6 See Table 3 for other tips.
|Dos and don’ts of insulin injections|
|Do inject at a 90-degree angle unless the patient is very thin, then use a 45-degree angle.||Don’t rotate injection areas.|
|Do move the injection site 1 inch from the last site used.||Don’t use the same injection site within an area more than once every 30 days.|
|Do give insulin at the correct time relative to a meal.|
|Do use the smallest size insulin syringe that will accommodate the dose.|
|Do allow alcohol (if used) to dry (or wipe site with a cotton ball) before inserting the needle.|
|Do insert the needle quickly.|
|Do inject insulin slowly after quick needle insertion.|
|Do leave needle in place for 20 to 30 seconds, then withdraw quickly.||Don’t cover site with alcohol swab after withdrawing the needle (swab will mask insulin leakage, if any).|
|Do document: injection area, site, angle, and syringe size to ensure consistent nursing practice.||Don’t rub the site after withdrawing needle (rubbing can vary insulin absorption).|
Insulin storage and mixing
Insulin should be stored in a refrigerator, but bottles currently in use can be kept at room temperature, out of direct sunlight, for a month if maintained at a controlled room temperature of 59 F – 86 F (15 C to 30 C). All insulin should be visually inspected before measurement. Regular, lispro, aspart, and glargine insulins should be clear; all other types should be uniformly cloudy when rolled between the hands. Always roll the insulin bottle between your hands to evenly suspend insulin particles before drawing up all cloudy insulins. If insulin looks clumpy or frosted, or stays in precipitation when rolled, it should be exchanged at the pharmacy or thrown away.
Some considerations for insulin mixing and storage are:
- Some types of insulin can be mixed together in the same syringe, and pre-filled syringes can be stored in the refrigerator for up to two to three weeks.13
- Pre-filled syringes should be stored with needle pointed up or flat (insulin particles can settle and clog the needle if needle pointed down).
- Pre-filled syringes should be rolled between the hands to re-suspend the insulin before injection.
- Mixing Regular with NPH or mixing Lente with Ultralente insulins results in stable mixtures. If possible, these mixtures are recommended for patients whose syringes must be pre-filled (for example, in home health care).
- Mixing Regular with Lente or Ultralente insulins results in alteration of the Regular dose (blunting or delayed action) beginning immediately after mixing and stabilizing after about 24 hours. If such mixtures are pre-filled, they should be used only after 24 hours and with the understanding that the Regular dose will be altered.7
- Glargine insulin (Lantus) cannot be mixed with any other type of insulin.
- Mixing lispro with NPH can also result in slightly delayed onset and blunting of peak time. This mixture, if used, should be injected within 15 minutes of mixing.
- Pre-mixed 75/25, 70/30, or 50/50 insulins (75% NPL, 25% lispro; 70% NPH, 30% regular; or 50% NPH, 50% regular, respectively) may be beneficial for patients whose insulin requirements are close to these ratios because they eliminate the need to learn to mix insulins and are stable mixtures.
A number of the insulin measurement and delivery devices are available that are helpful to patients and nurses. Accurate insulin measurement is easier with 30- and 50-unit syringes, because their scales are easier to see. Magnifiers and other aids help visually impaired patients maintain independence in measuring insulin. One product, the “Count-a-Dose,” enables even totally blind patients to accurately measure one or two (mixed) insulins. Injection pens look like large pens and contain a cartridge of Regular, lispro, NPH or 70/30 insulin. They eliminate the need to carry syringes and insulin bottles and allow patients to take insulin more quickly and discreetly in public.
External insulin pumps administer insulin subcutaneously in small, virtually continuous doses (basal rate), and allow patients to give larger doses (boluses) before meals. The effective use of external insulin pump therapy to achieve intensive diabetes treatment can result in patients enjoying excellent BG control while also being able to have optimum flexibility in meal times and composition and in exercise type, duration, and intensity.8,9 An internal pump is now being tested in the United States that delivers insulin to the peritoneal space from a reservoir implanted in the abdomen. The pump is controlled by a telemetry device, and the insulin absorption rate is similar to IV administration.
Jet injectors, which inject by means of a pressurized jet of air instead of a needle, may be preferred by patients who have an aversion to needles. Other patients find injection aids (such as “Inject-Ease”) helpful if they have problems with dexterity or simply do not want to insert a needle without a device.
The variety of diabetes products, while valuable for patients, can be confusing for nurses. Compiling a “diabetes equipment” reference notebook with manufacturers’ instructions is an effective way to have up-to-date information available for both staff and patients.
Using awareness of insulin characteristics, regimens and absorption factors, you can increase the effectiveness of insulin therapy and monitor patients’ response to treatment. In addition, you can help patients understand treatment regimens by incorporating information from this article into normal care routines, explaining reasons for procedures as they are being done, providing education materials, and referring patients to diabetes education programs.