CSII. Continuous Subcutaneous Insulin Infusion Therapy. An Overview of. A Continuing Education Monograph for Physicians, Pharmacists, and Nurses

Transcription

1 An Overview of Continuous Subcutaneous Insulin Infusion Therapy A Continuing Education Monograph for Physicians, Pharmacists, and Nurses CSII This continuing education activity can also be completed online at This activity is supported by an educational grant from Novo Nordisk Inc. It has been accredited by Postgraduate Institute for Medicine for physicians, pharmacists, and nurses.

2 An Overview of Continuous Subcutaneous Insulin Infusion Therapy A Continuing Education Monograph for Physicians, Pharmacists, and Nurses CSII This continuing education activity can also be completed online at Release date: August 15, 2005 Expiration date: August 30, 2007 Estimated time to complete activity: 1.75 hours Sponsored by Postgraduate Institute for Medicine This activity is supported by an educational grant from Novo Nordisk Inc. i

3 Program Goal This continuing education (CE) monograph is designed to introduce the reader to the concepts of optimal glycemic control in patients with diabetes using continuous subcutaneous insulin infusion (CSII). The principles of CSII therapy and the skills and knowledge needed to fulfill the important role of counseling patients about the benefits and use of CSII are also reviewed. Target Audience This CE monograph is designed for physicians, pharmacists, and registered nurses who treat patients with diabetes and wish to expand their knowledge of insulin therapy and CSII. Purpose Provide clinicians treating diabetic patients with the latest information about Continuous Subcutaneous Insulin Infusion (CSII) including indications, benefits and risks, patient selection and training, types of insulin, basic mechanism of the devices and the signs and symptoms of hypoglycemia and diabetic ketoacidosis. Statement of Need/Program Overview This continuing education (CE) monograph is designed to introduce the reader to the concepts of optimal glycemic control in patients with diabetes using continuous subcutaneous insulin infusion (CSII). The principles of CSII therapy and the skills and knowledge needed to fulfill the important role of counseling patients about the benefits and use of CSII are also reviewed. Educational Objectives After completing this activity, the participant should be better able to: Describe the basic mechanism of CSII therapy Review the intent and indications for CSII therapy Evaluate the benefits and risks associated with CSII therapy Describe the process for selecting, training, and initiating patients to CSII therapy Identify the types of insulin used in CSII therapy Identify the signs and symptoms of hypoglycemia and diabetic ketoacidosis ii

4 Editorial Review Board William V. Tamborlane, MD Professor of Pediatrics and Chief of Pediatric Endocrinology Department of Pediatrics and the General Clinical Research Center Yale University School of Medicine New Haven, CT Thomas S. Sisca, PharmD, FCCP, BCPS Clinical Pharmacist, Antithrombosis Specialist Anticoagulation Clinic/Antithrombosis Services Shore Health System Memorial Hospital Easton, MD Jane Young, RN, BSN, CDE, CPT Diabetes Care Center Genesis Medical Center Davenport, IA Physician Continuing Medical Education Accreditation Statement This activity has been planned and implemented in accordance with the Essential Areas and Policies of the Accreditation Council for Continuing Medical Education (ACCME) through the joint sponsorship of Postgraduate Institute for Medicine (PIM) and Scherer Clinical Communications. PIM is accredited by the ACCME to provide continuing medical education for physicians. Credit Designation Postgraduate Institute for Medicine (PIM) designates this educational activity for a maximum of 1.75 category 1 credits towards the AMA Physician s Recognition Award. Each physician should claim only those credits that he/she actually spent in the activity. Pharmacist Continuing Education Accreditation Statement Postgraduate Institute for Medicine is accredited by the Accreditation Council for Pharmacy Education as a provider of continuing pharmacy education. Credit Designation Postgraduate Institute for Medicine designates this continuing education activity for 1.8 contact hour(s) (0.18 CEUs) of the Accreditation Council for Pharmacy Education. (Universal Program Number H01) iii

5 Nursing Continuing Education CNA/ANCC This educational activity for 2.2 contact hours is provided by Postgraduate Institute for Medicine (PIM). PIM is an approved provider of continuing education by the Colorado Nurses Association, an accredited approver by the American Nurses Credentialing Center s Commission on Accreditation. California Board of Registered Nursing Postgraduate Institute for Medicine is approved by the California Board of Registered Nursing, Provider Number for 2.2 contact hours. Disclosure of Conflicts of Interest Postgraduate Institute for Medicine (PIM) assesses conflict of interest with its instructors, planners, managers, and other individuals who are in a position to control the content of CME activities. All relevant conflicts of interest that are identified are thoroughly vetted by PIM for fair balance, scientific objectivity of studies utilized in this activity, and patient care recommendations. PIM is committed to providing its learners with high-quality CME activities and related materials that promote improvements or quality in healthcare and not a specific proprietary business interest of a commercial interest. The following faculty reported a real or apparent conflict of interest: Name of Faculty or Presenter Reported Areas of Conflict William V. Tamborlane, MD Consulting Fees: Novo Nordisk Speakers Bureau: Novo Nordisk Thomas S. Sisca, PharmD, FCCP, BCPS Consulting Fees: Aventis Pharmaceuticals, Bristol Myers Squibb Co., UPA Jane Young, RN, BSN, CDE, CPT No financial relationships related to this activity The following planners and managers reported a real or apparent conflict of interest: Name of Planner or Manager Peter Macholdt Reported Areas of Conflict No financial relationships related to this activity iv

6 Method of Participation There are no fees for participating and receiving CME credit for this activity. During the period August 2005 through August 31, 2007, participants must 1) read the learning objectives and faculty disclosures; 2) study the educational activity; 3) complete the posttest by recording the best answer to each question in the answer key on the evaluation form; 4) complete the evaluation form; and 5) mail or fax the evaluation form with answer key to the Postgraduate Institute for Medicine. A statement of credit will be issued only upon receipt of a completed activity evaluation form and a completed posttest with a score of 70% or better. Your statement of credit will be mailed to you within three weeks. Media Monograph Disclosure of Unlabeled Use This educational activity may contain discussion of published and/or investigational uses of agents that are not indicated by the FDA. Postgraduate Institute for Medicine (PIM), Scherer Clinical Communications, and Novo Nordisk, Inc do not recommend the use of any agent outside of the labeled indications. The opinions expressed in the educational activity are those of the faculty and do not necessarily represent the views of PIM, Scherer Clinical Communications, and Novo Nordisk, Inc. Please refer to the official prescribing information for each product for discussion of approved indications, contraindications, and warnings. Disclaimer Participants have an implied responsibility to use the newly acquired information to enhance patient outcomes and their own professional development. The information presented in this activity is not meant to serve as a guideline for patient management. Any procedures, medications, or other courses of diagnosis or treatment discussed or suggested in this activity should not be used by clinicians without evaluation of their patient s conditions and possible contraindications on dangers in use, review of any applicable manufacturer s product information, and comparison with recommendations of other authorities. Trademarks Amigo is a trademark of Nipro Diabetes Systems. Animas IR-1000 and Animas IR-1200 are registered trademarks of Animas Corporation. Apidra is a registered trademark of Sanofi-Aventis. Deltec Cozmo is a trademark of Smiths Medical, Inc. ACCU-CHEK, D-TRON, and Dahedi are trademarks of Disetronic Medical Systems. H-TRON plus is a registered trademark of Disetronic Medical Systems. Humulin and Humalog are registered trademarks of Eli Lilly and Company. Novolin and NovoLog are registered trademarks of Novo Nordisk A/S. MiniMed, MiniMed 508, MiniMed Paradigm 512/712, MiniMed Paradigm 515/715, Sof-set, Square Wave, and Dual Wave are registered trademarks of Medtronic MiniMed. DANA Diabecare II is a registered trademark of DanaDiabecare USA. Copyright 2005, Scherer Clinical Communications. All rights reserved. Published by Scherer Clinical Communications 117 West Prospect Street, Hopewell, NJ Printed in USA. v

7 Table of Contents Introduction Basics of CSII Therapy The Insulin Infusion Pump Rationale for CSII Potential Advantages of CSII Types of Insulin Used in CSII Selection of Candidates for CSII Clinical Experience with CSII Type 1 Diabetes Type 2 Diabetes Children and Adolescents Pregnancy The Healthcare Team Initiating CSII Therapy Prepump Training Starting to Use the Pump Establishing and Adjusting Initial Insulin Doses Determining the Initial Basal Rate and Bolus Doses Individualizing Insulin Dosing Sick Day Management Record Keeping Meal Planning Various Activities Pump Vacations Risks and Complications Associated with CSII Mechanical Problems Hyperglycemia Hypoglycemia Diabetic Ketoacidosis Skin Infections Weight Gain Long-term Follow-up Other Resources for Healthcare Providers and Patients Cost/Reimbursement Considerations Conclusions Case Studies Case Study Case Study Case Study References Post-Test Evaluation Form vi

8 Introduction This monograph reviews the use of continuous subcutaneous insulin infusion (CSII) therapy for achieving and maintaining glycemic control in patients with diabetes. The basics of insulin pump therapy and patient education, including pump initiation and follow-up care, are covered. The skills and knowledge needed to fulfill the important role of counseling patients about the benefits and use of CSII are also reviewed. Finally, the use of patient and professional support groups and materials as additional resources for counseling patients and helping them to integrate CSII into their daily lives are discussed. Optimal glycemic control is the management of a patient s blood glucose level toward near-normal glycemia.1 The results of 2 landmark clinical studies, the Diabetes Control and Complications Trial (DCCT)2 in type 1 diabetes and the United Kingdom Prospective Diabetes Study (UKPDS)3 in type 2 diabetes have clearly demonstrated the benefits of optimal glycemic control. Basics of CSII Therapy The Insulin Infusion Pump CSII utilizes a small external mechanical pump into which an insulin syringe or reservoir is placed. A computer chip enables the user to program how much insulin is delivered at any time of the day. Pump components are housed in a small plastic case no larger than a beeper. The pump has a lever that pushes down the plunger of the syringe to administer insulin. Thin 24- or 42-inch long plastic tubing known as an infusion set is used to connect the insulin pump to a cannula which is inserted into subcutaneous tissue, usually the abdomen (Figure 1). Connecting the pump to the cannula creates an open-loop insulin delivery system.1 Figure 1. Example of insulin pump and infusion set. The pump can be worn on the belt or discreetly under clothing. Software is available to download information from pumps to personal computers and other handheld devices such as a wireless personal digital assistant (PDA). Although several newer models can be interfaced with blood glucose monitors, the user must program the pump to deliver the appropriate amount of insulin to cover basal and prandial needs as well as correct high or low blood glucose levels. Since the pump delivers insulin immediately to the user, only rapid-acting insulin formulations are used. 1

9 Since insulin pumps were first introduced in the 1970s there have been advances in dose adjustment capability, infusion catheters, display screens, programming modes and capabilities, and size. 4 Newer models can monitor and record insulin usage and some even interface with blood glucose monitors to receive blood glucose data, thereby alleviating the need to enter it manually. Insulin to carbohydrate ratios and correction factors can also be programmed into the new models of insulin pumps. Patients can then use the pump software to calculate and adjust the meal bolus or deliver a correction bolus. Square Wave and Dual Wave options allow the bolus dose to be given over a long time period; these features are useful when eating drawn out meals. 4 Implantable insulin pumps are available in Europe and continuous glucose sensors that interface with the pump are currently in development. However, development of a closed-loop system (the artificial pancreas), where an insulin pump can automatically adjust insulin delivery in response to data received from an attached glucose sensor, remains an elusive goal. All changes in insulin delivery via the pump must be programmed by the user. The concepts that are vital for controlling diabetes when using other insulin delivery systems are just as important when using a pump. CSII is simply a different way to deliver insulin. To use a pump, the patient must be willing to check blood glucose frequently and learn how to make adjustments in insulin, food, and physical activity in response to those test results. Five manufacturers marketed or serviced insulin pumps in the United States in Some examples of currently available pumps and their specifications are listed in Figure 2: Animas (Animas IR-1000, IR-1200 ), Disetronic Medical Systems (D-TRON TM, Dahedi TM, and H-TRON plus), Medtronic MiniMed (Paradigm 512/712 and 515/715 insulin pumps; 508 was discontinued but continues to be serviced), DanaDiabecare USA (DANA Diabecare II), and Deltec (Cozmo TM ). Due to manufacturing problems identified by the FDA in June 2003, new pumps manufactured by Disetronic are not currently available in the United States but existing pumps, with the exception of the recalled Dahedi, continue to be serviced. Disetronic is currently developing the ACCU-CHEK TM Spirit insulin pump system. In May 2004, Nipro Diabetes Systems issued a voluntary recall of the Amigo TM insulin pump due to deficiencies related to documentation in their quality systems as identified by the FDA; the pump is scheduled to be available again in September Most insulin pumps are lightweight ( ounces) and small ( inches long). Current models vary according to the number of programmable basal rates of infusion (12 48 profiles), range of infusion rate (0 99 units/hour), and smallest bolus dose ( unit). Today s pumps all have alarms to alert the user to catheter occlusion or high pressure, and when the insulin reservoir is low. Pump runaway is prevented by built-in safeguard systems. Most hold up to 300 units (3 ml) of a rapid-acting insulin analog or short-acting insulin; enough insulin for several days for most patients. Although insulin pumps can last many years, the infusion set and cannula must be changed every 2 to 3 days. The user can disconnect the tube from the set for sports, showering, or any other short-time activity. 5 2

10 The Medtronic MiniMed Paradigm 515 contains an insulin-filled 176-unit plastic reservoir, a battery-operated pump, and computer chip that controls insulin delivery. It is 4.62 cubic inches, smaller than the MiniMed 508, and weighs 3.52 ounces. The Paradigm is programmed to deliver insulin in 0.05-unit increments and programmed bolus delivery from 0.1 to 35.0 units in 0.1-unit increments in normal, Square Wave, and Dual Wave modes. These models contain alarms for occlusion, near-empty, and overdelivery of insulin. The Medtronic MiniMed Paradigm 515 and the Paradigm Link Blood Glucose Meter are available as a set. The pump can receive wireless radio transmissions from the meter which are used in combination with food (carbohydrate) entries to estimate food and correction bolus doses. The Medtronic MiniMed Paradigm 712 has the same features as the 515 model but holds a larger 300-unit reservoir. New Innovations include the Web-based Medtronic CareLink Therapy Management System for Diabetes, which charts A1C, blood glucose, carbohydrates, and other trends. Reprinted with permission from Medtronic MiniMed. The DANA Diabecare II features a 300-unit plastic reservoir, dual microprocessors, and a 24 setting basal profile. The basal delivery interval is 4 minutes with increments adjustable from 0.01 to 16.0 units/hour. Bolus increments are selectable 0.1 unit (up to 10 units) and 1.0 unit (up to 87 units). It is powered by one 3.6 volt DC battery. Its net weight (empty) is 1.8 ounces, and safety settings include maximum bolus, maximum basal, maximum daily total, low reservoir, occlusion, and low battery. Used with permission from DanaDiabecare USA. The features of Deltec Cozmo TM insulin pump from Smith s Medical, Inc., include power by one AAA battery and a large display. The unit features a program lockout that prevents menu entry, a delivery limit alarm to limit insulin delivery within a 60-minute period, a blood glucose test alert, change infusion set reminder, and a missed bolus alarm that alerts users if a meal-bolus dose is not given. The unit utilizes 4 basal patterns with 48 rates in each. The basal range is 0.05 to 35 units/hour whereas the bolus range is 0.05 to 75 units. Insulin doses based on meal carbohydrate as well as correction boluses can be calculated. The CoZmonitor blood glucose module can be attached to the back of the pump. This photo was provided courtesy of Deltec, Inc., St. Paul, Minnesota. The Animas IR-1000 insulin pump from Animas Corporation contains an insulin-filled cartridge and a battery-operated pump motor that delivers insulin every 3 minutes. The pump has four different basal programs and can deliver up to 12 rates per basal program. The basal rates range from 0.05 to 9.9 units/hour in 0.05-unit/hour increments and the bolus ranges from 0.1 to 25 units in increments of 0.1 unit. Safety alarms include low battery, dead battery, occlusion, near-empty cartridge, pump malfunction, and pump delivery error. The IR-1200 pump features a to 25 unit/hour basal rate range and an easy to debubble insulin cartridge. The smallest bolus is 0.05 unit. The programming functions of this unit are menu-driven and it is compatible with any infusion set using Luer lock connections. Functions to calculate insulin to carbohydrate ratios and a correction bolus dose based on the blood glucose reading are included. The new IR-1250 model includes additional software to count calories and carbohydrate content of various foods and make adjustments in insulin dose. Reprinted with permission from Animas Corporation. Figure 2. Examples of insulin pumps. 3

11 Rationale for CSII The programming capabilities of the pump and the flexibility CSII provides allows insulin delivery to more closely mimic the activity of the normal pancreas. Plasma concentrations of glucose and insulin in a nondiabetic individual with normal glycemic control are represented in Figure 3. 6 In individuals without diabetes, the pancreas secretes sufficient insulin during the fasting state and between meals to maintain blood glucose levels in the range of 60 to 120 mg/dl (3 7 mmol/l), allowing the body s tissues to have sufficient glucose available for fuel. After a meal, blood glucose levels rise and the pancreas responds by rapidly increasing the release of insulin to maintain blood glucose levels within the normal range. Basal insulin secretion is the amount of insulin secreted by the pancreas independently of meals; it regulates hepatic glucose output. The rate of basal secretion is not constant and has a natural biorhythm in that it is higher in the morning, somewhat lower in the late afternoon, lower at night during sleep, and begins to rise again in the early morning. 6 Exercise and stress may also cause metabolic changes that affect the rate of basal insulin secretion. In CSII, the patient can administer a variable basal level of insulin throughout the day and night as well as bolus doses of insulin at mealtimes, in an attempt to simulate the responsiveness of the pancreas in an individual without diabetes to the body s insulin requirements. CSII therapy is therefore intended to help patients achieve normal or near-normal blood glucose levels. Figure 3. Plasma concentrations of glucose and insulin in the nondiabetic individual. Adapted from: Pickup J, Williams G, eds. Normal metabolism: The physiology of fuel homeostasis. In: Textbook of Diabetes. London: Blackwell Science Ltd; 1998:11.3. Serum insulin profiles for individuals receiving insulin via CSII over a 24-hour period are illustrated in Figure 4. Basal insulin is delivered at a programmable rate set by the patient. The appropriate bolus dose is administered by pressing a button on the pump. The patient can program incremental changes in basal insulin rate at either 30-minute or 1- or 2-hour intervals, depending on the manufacturer, to simulate a natural biorhythm. The preset basal rate can also be adjusted to accommodate exercise, illness (eg, fever), or other changes to the patient s routine as they occur. At mealtime, the patient is able to deliver a bolus insulin dose to accommodate the increased insulin need after a meal. 4

12 Figure 4. The insulin delivery under continuous subcutaneous insulin infusion. Reprinted with permission from Disetronic Medical Systems, Inc. Potential Advantages of CSII In comparison with other currently available modes of insulin delivery, CSII therapy provides the closest approximation of normal physiological insulin delivery to the patient with diabetes. Therefore, CSII can be a very effective means to improve diabetes control and attain nearnormal blood glucose levels, which has psychological as well as metabolic, macrovascular, and microvascular benefits. 7,8 CSII therapy may improve or stabilize glycemic control for some patients especially if multiple daily injection (MDI) therapy is not effective because of wide glycemic excursions or nocturnal hypoglycemia, or due to the effects of the dawn phenomenon (hyperglycemia due to increasing basal insulin requirements during the early morning hours). 1,9 Optimal glycemic control is often associated with an increased incidence of hypoglycemia and weight gain; however, the results of some studies suggest that compared with MDI in patients who receive proper training and education, CSII may be associated with a decreased risk of hypoglycemia, dawn phenomenon, glycemic variability, and weight gain. 8,10,11 CSII therapy may be able to help certain patients achieve a greater degree of lifestyle flexibility and improved quality of life. Patients undergoing CSII therapy, when properly trained and educated, may experience more freedom and flexibility in eating as well as more freedom to engage in athletic activities. 5,12 The lifestyle demands of some patients may result in ineffective MDI therapy and lack of adherence. Some patients may not have privacy at the workplace to inject insulin using a traditional vial and syringe. These patients may view the pump as a more convenient and discreet way to administer insulin. Insulin pumps allow patients to more easily adjust insulin delivery to accommodate physical strain and changes in working conditions. Only short- and rapid-acting insulin preparations (regular human insulin, rapid-acting insulin analogs) (see Types of Insulin Used in CSII) are currently being used in CSII. The abdomen is the preferred site for CSII, although some patients may use the thigh. Abdominal administration allows for relatively rapid and consistent insulin absorption. 13 5

13 Types of Insulin Used in CSII As discussed above, regular human insulin (Humulin, Novolin ) and rapid-acting insulin analogs are used in CSII therapy. 14,15 The analogs are stable, effective, and safe in the management of patients with diabetes using CSII therapy Insulin aspart (NovoLog ), insulin lispro (Humalog ), and insulin glulisine (Apidra ) are approved by the US Food and Drug Administration (FDA) for use in external infusion pumps Rapid-acting insulin analogs have become the standard formulation to use in insulin pumps. 22 The use of rapid-acting analogs in CSII has increased because these agents have less variability in onset, peak, and duration of action compared with regular human insulin. The B chain of the insulin molecule has been modified in the rapid-acting analogs to allow for more rapid absorption of the insulin after subcutaneous injection. 19, 21, 23, 24 For example, insulin aspart differs from human insulin at position B28, where proline has been replaced by aspartic acid. The modification allows the analog to dissociate more quickly and be more rapidly absorbed from subcutaneous tissue than regular human insulin. 19 With regular human insulin, the onset of glucose-lowering action occurs about 30 minutes after subcutaneous injection, peaks in 3 to 4 hours, and, in high doses, continues to lower blood glucose for 6 to 8 hours after injection. It is important that the patient knows how to administer bolus doses as instructed. Because of the absorption kinetics of regular human insulin, taking the bolus dose too close to a meal may result in postprandial hyperglycemia, followed by hyperinsulinemia and the risk of hypoglycemia. Administering the bolus dose of regular insulin less than 30 minutes before a meal may also result in hypoglycemia. In comparison, the onset of glucose-lowering action for rapid-acting analogs occurs in approximately 10 to 20 minutes, peak activity occurs in 1 to 3 hours, and the duration of action is less than 5 hours. 19,21 Because the insulin analogs have a rapid onset of action, bolus doses can be administered immediately before, or in some cases, immediately after, eating a meal. This offers greater convenience and flexibility, which may improve adherence to therapy. 25 Because of their rapid action, it is important that the meal is not delayed after a bolus dose of a rapid-acting analog is taken. A recent meta-analysis concluded that compared with regular human insulin, the use of insulin analogs in CSII pumps produces a modest (0.26%) reduction in glycosylated hemoglobin (A1C) and that patients have a greater preference for rapid-acting insulin analogs. 26 Furthermore, some studies report that the incidence of hypoglycemia is lower during CSII with rapid-acting insulin analogs. 26 Selection of Candidates for CSII Successful CSII therapy includes careful patient selection and training on the use of the pump, continuing care by skilled professionals, and a patient support program. The patient s commitment to meticulous self-monitoring of blood glucose (SMBG) and record-keeping of SMBG values, hypo- and hyperglycemic experiences, and pump incidents (eg, clogs, blockages, leaks) contribute to better results with CSII. 1 The inability to achieve normal or near-normal blood glucose levels on MDI is an important reason to consider a switch to the insulin pump. Patients who experience recurrent episodes of hypoglycemia or hypoglycemic unawareness may also consider switching to CSII. Some patients may be motivated to start CSII from the time of initial diagnosis. 6 Good candidates for CSII therapy include those individuals who can adapt to the use and demands of the insulin pump, those who want a higher level of participation in their diabetes

14 self-care, and those who understand the potential benefits and risks of CSII. 27 These individuals are usually highly self-motivated and are ready to take a very active role in the management of their diabetes. 28,29 The most common reason patients give in choosing CSII over MDI therapy is the wish to increase flexibility with regard to daily activities. 28,30 CSII can make it easier for patients to occasionally skip or delay meals, sleep late on weekends, exercise for prolonged periods, or adjust more easily to time zone changes. 12 However, candidates for CSII must understand that any increased flexibility in lifestyle associated with CSII only comes with thorough training, knowledge of how to properly utilize CSII, and a willingness to accept responsibility for day-to-day self-care. 27 A supportive home environment is another important consideration. A program of intensive glycemic management requires a commitment by the patient and a sharing of responsibility with the patient s family and healthcare professional team. Positive characteristics for selection of CSII candidates are listed in Table 1. Table 1. Positive Characteristics of Potential Continuous Subcutaneous Insulin Infusion (CSII) Candidates Motivation and Self-reliance Strongly self-motivated to improve glycemic control Ability to adjust insulin doses based on blood glucose levels and carbohydrate content of meals Technical skills to operate the insulin infusion pump and infusion set and troubleshoot the pump Willing and able to accept responsibility for daily self-care Acceptance Can establish realistic goals for pump therapy, understands that CSII is not a cure for diabetes Feels comfortable relying on the insulin pump and is not self-conscious about wearing the pump Follows the healthcare provider s schedule for office visits and phone conversations Family Support Has support of family members, significant others, and employers (when applicable) Monitoring Able and willing to self-monitor blood glucose at least 4 times a day Willing to maintain rigorous and thorough record keeping Willing to test blood or urine ketones when plasma glucose levels are greater than 250 mg/dl and to follow up in the appropriate manner when ketones are present Adopted from Fredrickson L, ed. The Insulin Pump Therapy Book: Insights from the Experts. Sylmar, Ca: MiniMed Technologies; Characteristics that may prevent or adversely affect a patient s ability to adapt successfully to CSII therapy are listed in Table 2. Potential CSII candidates must have access to a well-trained diabetes-care team to make an optimal transition from their previous therapy. 7

15 Table 2. Undesirable Characteristics of Potential Continuous Subcutaneous Insulin Infusion (CSII) Candidates Fear of needles, catheters, or pain Reluctance to tell others about their diabetes history or current therapy Continually miss healthcare appointments Cannot or will not follow treatment plans Psychiatric history, including depression, history of suicidal thoughts or attempts, personality disorders, passive-aggressive behavior, other psychiatric disorders, substance abuse Severe physical disability affecting the ability to use the pump Inadequate financial resources Lack of commitment to strict treatment goals or to frequent self-monitoring of blood glucose Farkas-Hirsch R, Hirsch IB. Continuous subcutaneous insulin infusion: A review of the past and implementation for the future. Diabetes Spectrum. 1994;7: Gentili P, Maldonato A, Bloise D, et al. Personality variables and compliance with insulin therapy in type 2 diabetic subjects. Diabetes Nutr Metab. 2000;13:1 6. Tannenberg RJ. Candidate selection. In: Fredrickson L, ed. The Insulin Pump Therapy Book: Insights from the Experts. Sylmar, Ca: MiniMed Technologies; 1995; Clinical Experience with CSII Type 1 Diabetes The earlier trials on CSII involved the use of regular human insulin in patients with type 1 diabetes participating in mostly nonrandomized and poorly controlled studies. 31 Studies varied considerably in the outcome variables measured, number of patients, and length of the trial In a meta-analysis of 12 randomized controlled trials, most of which were conducted before 1990 with low numbers of patients, CSII therapy provided a small advantage in glycemic control (~0.5% lower A1C) compared with MDI therapy; however, blood glucose levels were less variable in patients receiving CSII and 14% less insulin was used. 32,33 These conclusions were supported by an independent meta-analysis of 52 (randomized and nonrandomized) studies 31 ; the risk of developing mild or severe hypoglycemia was also lower with CSII. In general, CSII either improved or did not change the levels of anxiety, quality of life, and compliance. 31 A recent meta-analysis comparing the use of rapid-acting insulin analogs in CSII versus MDI showed that insulin pump therapy tended to produce better glycemic control, particularly in patients with high A1C values at baseline. 34 The number of patients using CSII has increased exponentially since 1990 in the United States. 35 In 2001, 160,000 patients were estimated to be using an insulin pump; the greatest recent increase in use has been noted among children and adolescents. Several recent trials in patients with long-standing uncontrolled hyperglycemia have shown that CSII does produce greater reductions in A1C (0.35% to 0.84% lower) and improvements in general well-being compared with MDI. 36,37 The importance of postprandial hyperglycemia in overall glycemic control is now well recognized. 38 In 100 patients with type 1 diabetes who previously used an insulin pump, CSII therapy with insulin aspart reduced the number of postprandial glucose excursions and episodes of nocturnal hypoglycemia compared with MDI therapy with insulin glargine and insulin aspart. 39 8

16 Type 2 Diabetes In contrast with type 1 diabetes, there are few published randomized trials of CSII therapy in patients with type 2 diabetes. 40 In 20 patients with poorly controlled type 2 diabetes who were randomized to either MDI or CSII therapy with regular human insulin for 4 months, the number of patients achieving satisfactory reductions in A1C (ie, A1C <50 mmol hydroxymethylfurfural/mol hemoglobin) was higher in the CSII group (80% vs 30%). 41 In 132 patients with type 2 diabetes, CSII with insulin aspart was equivalent to MDI therapy with insulin aspart and neutral protamine Hagedorn (NPH) insulin for glycemic control after 42 weeks; however, the majority of patients preferred CSII and they had a significantly greater improvement in overall treatment satisfaction. 15 The incidence of nocturnal hypoglycemia tended to be lower with CSII (16%) compared with MDI (22%), whereas the overall incidence of hypoglycemia was similar between both groups. 15 Children and Adolescents Optimal glycemic control is critical in preventing growth and related disorders in children and adolescents. 42 Boland and colleagues 7 found that adolescents could achieve optimal glycemic control with the insulin pump and maintain their quality of life. Numerous observational trials and several randomized studies have shown that CSII therapy is safe and effective in pediatric populations including preschoolers and toddlers with uncontrolled type 1 diabetes Because newer insulin pumps are smaller, safer, and easier to use, the number of patients aged <20 years using insulin pumps has increased by 20-fold since the late 1990s. 4 In general, CSII therapy can reduce A1C and hypoglycemic episodes in children and adolescents with type 1 diabetes without causing abnormal increases in body weight. 4 In 75 patients between 12 and 20 years of age who chose either CSII or MDI therapy, reductions in A1C were 0.4% to 0.8% lower and the rates of severe hypoglycemia were 30% to 50% lower with CSII compared with MDI therapy; patients using CSII also found it easier to cope with insulin therapy. 7 In 32 patients between 8 and 21 years of age randomized to either MDI therapy with insulin glargine and insulin aspart, or CSII with insulin aspart, A1C decreased by 0.9% with CSII whereas no change occurred with MDI; mean blood glucose levels were also significantly lower at lunch, dinner, and bedtime in the CSII group. 45 Reductions in A1C and severe episodes of hypoglycemia during CSII therapy in patients who transitioned from MDI therapy have been found in various observational trials. 43,46,48,51,52 Parental supervision and involvement in diabetes care are key considerations for determining whether CSII therapy is appropriate for younger patients. Children and adolescents have not always been considered as good candidates for CSII because of the large size and technical limitations of early insulin pump models, psychosocial issues regarding pump use, and potential lack of commitment by patients, families, and clinicians in achieving the goals of intensive glycemic control. Furthermore, many schools do not have trained personnel who can help the child with diabetes management. Therefore, a child using an insulin pump and his or her family must have sufficient knowledge, skills, and attitudes to independently manage the essentials of CSII therapy. This includes managing potential problems including hypoglycemia and pump failure. These skills should be determined by the diabetes-care team along with parents. When glycemic control is suboptimal with CSII, missed boluses are the most likely cause. 53 Therefore, healthcare providers and parents need to be vigilant in monitoring children using CSII. The bolus history function of the newer pump models allows parents and clinicians to track compliance with administration of bolus doses by school-age and adolescent patients. Similar methods are not available in children being treated with MDI therapy. 9

17 Pregnancy In pregnant women with diabetes, fetal abnormalities associated with hyperglycemia and other metabolic anomalies are most likely to occur in the first trimester of pregnancy. 54,55 The attainment of intensive glycemic control is therefore very important for all pregnant women with diabetes. Diabetes care before conception and early in pregnancy has been shown to reduce the risk of congenital abnormalities. 55 CSII may be an alternative to MDI for women who intend to become pregnant but have not been able to achieve appropriate blood glucose control with a regimen of 2, 3, or 4 daily insulin injections. CSII may also be appropriate for pregnant women with a history of hypoglycemia or problems with the dawn phenomenon (increased insulin need in the early morning). 12 One study compared the level of glycemic control and safety experienced by 3 groups of pregnant women: those initially using MDI therapy who were switched to CSII therapy at 6 to 8 weeks of gestation; those on MDI throughout their pregnancy; and those on CSII prior to and throughout their pregnancy. 56 Postpartum A1C levels were ~7% for women in both CSII groups compared with ~9% for those in the MDI group. Overall, congenital malformations (eg, polydactyly, cleft hand, ventricular septal defects) were observed in 10% of the neonates in this study. There were, however, no significant differences in maternal or perinatal outcomes between the groups. Hypoglycemic rates were also similar for all 3 groups. In pregnant patients with type 1 diabetes, CSII was effective and safe for those individuals not achieving acceptable glycemic control with MDI. 57 CSII is also effective and safe in pregnant patients with either type 2 diabetes or gestational diabetes needing high doses of insulin. 58 The Healthcare Team To achieve optimal glycemic control, the patient with diabetes requires not only the care of a physician but also that of other healthcare professionals. Many diabetes centers routinely include the services of nurse educators, dietitians, pharmacists, psychologists, and podiatrists in the management of diabetes and its related problems. 59 Managing diabetes with CSII therapy requires considerable resources, substantial expertise, and a long-term commitment by the patient and their healthcare providers. The patient must have the necessary knowledge, training, support, and resources to be successful with CSII therapy. If the physician, physician assistant, or nurse practitioner does not have the resources for delivering this level of care, the patient should be referred to an endocrinologist or diabetes center that has the required resources. Unfortunately, some patients receive insulin pumps without adequate plans for proper follow-up, resulting in limited effectiveness of the therapy as well as an increased risk for adverse consequences. A qualified pump trainer is the most appropriate person to train and help patients begin CSII therapy. The training is a multifaceted endeavor, and pump trainers include physicians, nurses, pharmacists, dietitians, and lay trainers. Some trainers may only be responsible for technical aspects of pump therapy whereas others troubleshoot elevated plasma glucose, pump alarm systems, and skin infection problems. The trainer should be well educated on the topic and possess a wide range of educational and communication skills to be able to instruct patients on the pump. Trainers should also be able to determine if the patient is capable of using the pump after adequate education and should follow up after the initiation of therapy. Table 3 lists the knowledge and skills required of the insulin pump trainer. 10

18 The trainer, as well as the other members of the healthcare team, should know when and to whom to refer a patient if the need arises. 60 There should be general agreement among the team members about blood glucose goals, initial basal and bolus doses, procedures for adjusting insulin doses, plasma glucose testing schedule, treatment of hyperglycemia and hypoglycemia, and a variety of other issues. Team members should be supportive of each other and provide backup support for the pump trainer. Table 3. Knowledge and Skills Necessary for Pump Trainers Understanding and knowledge of diabetes and its complications Knowledge of how to correctly respond to and treat hypoglycemia and hyperglycemia Understanding the advantages and disadvantages of various diabetes treatment options Ability to individualize therapy based on patient needs Knowledge of the use of insulin infusion pumps and infusion sets Programming Troubleshooting Installing batteries, cleaning and maintaining the pump Filling the reservoir and establishing infusion lines Calculation of basal rates and bolus doses Calculation of multiple basal rates Calculation of insulin to carbohydrate ratios Ability to understand and explain teaching materials Effective communication skills Familiarity with local patient support programs Reprinted from Brackenridge B, D Almeida B, Fredrickson L, et al. The Pump Trainer Manual. Sylmar, Ca: MiniMed Technologies; Initiating CSII Therapy Prepump Training The patient should receive comprehensive training on the principles of diabetes selfmanagement and CSII as the first step in beginning CSII therapy. 12 The goal of this phase is that the patient understands and is able to explain the following: The benefits and risks of CSII. Prevention of diabetic ketoacidosis (DKA) is feasible and dependent upon the following factors: (1) the patient s ability to recognize an insulin delivery problem; (2) development of medical conditions that trigger adverse metabolic changes (eg, infection, inflammation, emotional stress, myocardial infarction, trauma, surgery, and pregnancy); (3) medications (eg, glucocorticoids, diuretics, and sympathomimetics); and (4) substance abuse. A potential change in hypoglycemia awareness. Most patients, their family members, or significant others benefit from having 3 separate preparatory visits. It is recommended that the pump trainer, along with the patient, family members, and significant others discuss the following at each visit

19 Visit 1: At this visit, the pump trainer should accomplish the following with the patient: (1) collect the patient s diabetes history; (2) give a detailed overview of pump therapy, including advantages and disadvantages; (3) set realistic goals and expectations of CSII therapy; (4) discuss precautions associated with CSII; (5) identify support groups, dietitians, or counselors; (6) select the insulin pump model to be used; and (7) begin the process of obtaining insurance coverage and discussion of financial issues. Visit 2: This visit is usually scheduled after the patient receives the insulin pump. Before the visit, the patient should read the pump instruction manual, use an accompanying CD-ROM for home computers, watch an educational videotape, experiment with the pump and tubing, and perform minor pump operations. At this visit, the trainer will instruct the patient on all aspects of the pump programming and operation. The patient will learn how to wear the pump, practice using the pump (with saline), prime the tubing, insert the needle using proper hygiene, and how to change the insertion site in the home setting. The patient may also learn that the catheter is not as noticeable or intrusive as initially feared. The patient should also meet with a dietitian (unless the trainer performs this function) prior to the initiation of CSII to obtain a personalized meal plan and to learn carbohydrate counting. Visit 3: Actual CSII therapy may be initiated at this visit or within the next few days. 12 The objectives of this visit are to review the patient s technique, answer questions, and assess the patient s skills and understanding of pump use and his or her readiness to begin pump therapy. Starting to Use the Pump Except for the pregnant women who need rapid normalization of glucose levels, 5 few, if any, patients need to be admitted to the hospital to initiate pump therapy. It is important to commit the necessary time and resources to get the patient off to a good start. Blood glucose levels should be closely monitored during the first week of therapy, and the insulin regimen should be changed as necessary (see Establishing and Adjusting Initial Insulin Doses). Patients should have 24-hour access to information, which can be provided by the pump manufacturer hotline, healthcare team, and the patient s pump trainer. Patients should be provided with detailed instructions about their treatment plan and how to keep a daily diary that will provide the physician (or other healthcare team member acting under physician supervision) with sufficient data for making precise adjustments in insulin dose and timing. 61 Establishing and Adjusting Initial Insulin Doses Determining the Initial Basal Rate and Bolus Doses In general, patients beginning therapy with an insulin pump are started on a lower total daily dose (eg, 10% 25% less) than their total prepump daily insulin dose. 62 In adults, basal insulin usually accounts for ~50% of the pump dose and the remaining 50% of the total daily insulin requirement is comprised of the bolus insulin doses administered at mealtimes. 62 The basal dose in children is usually >50%. 12 If an adult patient was receiving 42 units/day of insulin prior to initiating CSII, the starting pump total insulin dose would be 32 units/day (0.75 * 42). The initial basal rate would therefore be 0.7 unit/hour (0.50 * 32/24 hours) and the starting bolus doses would be 5.3 U/bolus (0.50 * 32/3). Sample guidelines for establishing a patient s initial basal and bolus insulin doses provided by one of the insulin pump manufacturers are shown in Table 4.

20 Table 4. Sample Guidelines for Calculating Basal and Bolus Insulin Doses for Adults Using Continuous Subcutaneous Insulin Infusion Basal and Bolus Dose Calculation Based on the Total Prepump Insulin Dose: Identify the total prepump daily insulin amount Reduce the total prepump dose by 10% to 25% = the starting pump total daily insulin amount Basal insulin dose (units/hour) = 50% of the starting pump total dose/24 hours Bolus* insulin dose = 50% of the starting pump total dose/3 Reprinted from Fredrickson L, ed. The Insulin Pump Therapy Book: Insights from the Experts. Sylmar, Ca: MiniMed Technologies; *Calculate as carbohydrate to insulin ratio with injection therapy or as total daily carbohydrate intake/50% of total daily dose. According to the American Diabetes Association (ADA), blood glucose targets should range between 90 to 130 mg/dl for average preprandial plasma values and be <180 mg/dl for peak postprandial plasma glucose levels in adults with diabetes. 63 The American Association of Clinical Endocrinologists recommends that fasting plasma glucose be <110 mg/dl and 2-hour postprandial blood glucose <140 mg/dl. 64 Blood glucose target values should be carefully selected to reduce the risk of serious hypoglycemia. Target averages are somewhat lower for pregnant patients, generally not exceeding 105 mg/dl before meals or 130 mg/dl 2 hours after a meal. 5,65 These goals are somewhat higher for patients with a history of hypoglycemic unawareness, at least at the start of therapy. 9,63 Most adult patients require basal doses ranging from 0.4 to 2.0 units/hour; toddlers and younger children will require less. Patients begin CSII therapy with 1 basal rate but may add 1 or 2 additional rates during the day and/or night as their daily insulin requirements are further established. 62 For example, a patient may have a certain basal rate programmed for 9 PM to 3 AM to cover nocturnal insulin needs, a second rate to deliver slightly more insulin from 3 AM to 9 AM to address increased insulin need in the dawn hours, and a third rate to cover the daytime hours from 9 AM to 9 PM. If a patient s basal rate(s) results in persistent hypoglycemia or hyperglycemia, then a new basal rate should be calculated. 62 In adults, once the patient s individual basal rates are established, they often do not need to be adjusted unless changes in lifestyle, body weight, or health status occur. In children, basal and bolus doses are constantly changing due to growth and pubertal development. 66 The basal insulin rate is correctly established if blood glucose levels remain in the target range under fasting conditions. Blood glucose levels should be checked before and after meals (or more frequently if needed) during initiation of CSII. The initial basal rate should also be verified based on overnight blood glucose levels obtained at bedtime, nighttime (midnight and/or 3 AM), and breakfast (7 AM). This is helpful for the early recognition of nocturnal hypoglycemia. The actual test schedules may vary for a specific patient based on varied life schedules and mealtimes. It is important that the patient is instructed in the proper timing of the bolus dose, depending on the type of insulin used. Bolus doses of regular human insulin should be administered 30 minutes prior to eating a meal whereas bolus doses of a rapid-acting insulin analog should be 13