S TA YI NG O N TA RG ET ™ TARGET THERAPY Staying on Target TM Your Insulin Adjustment Workbook Yes, You Can Do It! YES, YOU CAN DO IT! Your ‘How-To’ Guide for Adjusting Basal and Bolus Insulin This workbook will help you learn new skills so that you can you live a healthier life with your diabetes. “What is Basal-Bolus?” introduces flexible insulin therapy, (also called intensive therapy) as a way to correct your blood glucose levels. “Terms to Learn First” gives you the definitions that you will need. “Making Bolus Insulin Changes,” outlines how to make changes to rapid and short acting insulin doses. “Putting it All Together” gives you a plan to get started. “Adjusting for Basal Insulin,” explains changing long acting insulin doses. “Trouble-Shooting,” tells what to do when you are having a hard time. “Problem-Solving and Exercises” gives you a chance to practice what you learned. Use this guide as you work with your diabetes health care team to help you avoid the complications of diabetes. BD provides this workbook for informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read in this workbook INTERACTIVE TABLE OF CONTENTS To go directly to the topic of interest, click on the link below. Managing Your Blood Glucose....................2 Calculating Your Insulin Sensitivity Factor (ISF)................................19 Practicing Flexible / Intensive Therapy..........2 Insulin/Blood Glucose Formula ............19 Responsibilities / Rewards of Basal-Bolus ....2 Rule of 1500 ......................................21 ‘Normal’ Insulin Delivery ............................3 Rule of 1700 ......................................23 TERMS TO LEARN FIRST ..........................4 Correcting for Known Changes in Meals or Exercise ..................................25 Blood Glucose Goals ..................................5 Correcting for a Change in Meals ......25 Target Glucose............................................5 Calculating Your Carb:Insulin Ratio ....25 Algorithm ..................................................5 Method I ............................................26 Basal Insulin................................................6 Method II ............................................26 Bolus Insulin ..............................................6 Correcting for a Known Change in Exercise ..............................29 WHAT IS BASAL-BOLUS? ........................1 Insulin Adjustment and Pattern Management..................................7 Insulin Sensitivity Factor (ISF) and Correction ..........................................7 PUTTING IT ALL TOGETHER ..................30 Getting Started: A Five-Step Plan ..............31 Peak Action ................................................8 Practice Problems......................................31 MAKING BOLUS INSULIN CHANGES ......9 ADJUSTING THE BASAL DOSE ..............34 Understanding How Insulin Works ............10 Testing the Nighttime Basal ......................35 Blood Glucose Monitoring: When to Test ............................................12 Testing the Daytime Basal ........................37 Making Changes Using Pattern Management................................13 Option II..............................................38 Correcting for Blood Glucose That is Out of Range ................................17 Correction Method I............................18 Option I ..............................................37 Option III ............................................38 TROUBLESHOOTING ..............................39 PROBLEM SOLVING AND EXERCISES ....44 Correction Method II ..........................18 Correction Method III ..........................19 SEE – YOU REALLY CAN DO IT! ............49 WHAT IS BASAL-BOLUS? 1 WHAT IS BASAL-BOLUS? When you have diabetes, it is important to avoid high and low blood glucose (sugar). This section reviews how outof-control blood glucose can lead to diabetes complications. It also introduces flexible/intensive therapy with basal-bolus insulin adjustment1 as a way to help keep you healthy. Managing Your Blood Glucose – Keeping in control means that your blood glucose is always in a range that is not too high or too low. Controlling blood glucose helps you stop or delay the risk of developing eye, kidney, nerve, foot and heart disease caused by blood glucose that is too high for a long period of time. It can be hard to stay in control with one, two, or even three injections of insulin a day. You can still have many times when the insulin does not match your food or exercise, so your blood glucose gets too high or too low. Practicing Flexible / Intensive Therapy – Research shows that flexible (also called intensive) insulin therapy can work to control blood glucose levels in most people. With this therapy you: 1. Take four or more insulin injections a day, adjusting your insulin doses as needed to keep your blood glucose within your goal range OR 2. Use an insulin pump. The goal is to keep your blood glucose close to normal by taking insulin to match the quantity of food you eat and also meet your body’s needs at other times. The insulin that works between meals and through the night is called “basal.” The insulin that works to match food or lower high blood glucose is called “bolus.” “Basal-bolus” is a term used by health care professionals to describe flexible therapy. Responsibilities / Rewards of Basal-Bolus – Before starting flexible (basal-bolus) therapy, you should think about its pros and cons. “Pros” – You will have more freedom and other benefits, such as: • Ability to eat when and how much you want • Freedom to skip a meal • Better diabetes control • Feeling of greater well-being • Reduced risk of complications “Cons” – You will have more work, including: • Checking blood glucose four or more times a day, and sometimes during the night • Learning and practicing carbohydrate (carb) counting 1 All glucose values used in this workbook are plasma values. If you use a blood glucose meter that reads whole blood values, you should decrease them by about 10%. 2 • Deciding on your insulin dose according to the amount of carb you expect to eat and the exercise or activity you plan Although some people can have frequent or severe hypoglycemia (low blood glucose) with this therapy, most people have less because there is a better match between their insulin and food. You can adjust flexible therapy for your lifestyle, eating and sleeping schedules and physical activity. You will learn to match your insulin to your food, exercise, and adjust for high or low blood glucose when it happens. This insulin is released as a “squirt” or a “pulse” that is called a bolus. In someone without diabetes, a bolus of insulin keeps blood glucose levels in range after meals. Figure 1 shows normal insulin delivery in a person without diabetes. The top portion shows the blood glucose curves during a day in which someone eats three meals. The bottom portion shows the blood insulin levels for the same three meals. In basal-bolus therapy, the insulin doses and times are designed to match normal insulin delivery as closely as possible. Figure 1 Normal Insulin Delivery in People without Diabetes 1. Blood glucose rises. 2. The pancreas releases an extra burst of insulin that in turn helps to deliver blood glucose into the body’s cells, where it is used for energy. High Normal Low Blood Insulin A diabetes-free pancreas releases a small amount of insulin throughout the day and night. This insulin is described as basal and is steadily discharged from the pancreas so that there is always some available. At night and between meals, basal insulin works with a small amount of glucose made by the liver that is also being constantly released. After eating a meal or snack with carb in it, two things happen: Blood Glucose ‘Normal’ Insulin Delivery – Bolus Basal Midnight 3 AM 6 AM 9 AM Noon 3 PM 6 PM 9 PM Midnight If you have type 1 diabetes, your pancreas cannot make insulin. To use flexible therapy with basal-bolus insulin, you will decide how much insulin to take to keep blood glucose within your goal range. 3 TERMS TO LEARN FIRST 4 TERMS TO LEARN FIRST The goal of flexible therapy is to imitate the way a normal pancreas works. In someone who does not have diabetes, insulin automatically works at the right times, matching meals, activity or stress. When you have diabetes and use flexible therapy, you have to figure out and deliver the correct dose of bolus insulin yourself. Your Diabetes Team will guide you along the way. Your Diabetes Team may include your doctor, certified diabetes educators such as a diabetes nurse educator and a registered dietitian. Some teams also include an exercise physiologist, social worker and pharmacist. This section teaches you words you need to know before you begin. Blood Glucose Goals – The range your blood glucose should fall into most of the time. The American Diabetes Association (ADA) recommends the following blood glucose goals of 90-130 mg/dl before meals and less than 180 about 2 hours after a meal. Your Diabetes Team will help you set your goals, for your blood glucose. Target Glucose – A single number that falls within your blood glucose goals. The target glucose is used to adjust your insulin dose. Algorithm – A formula that helps you determine the amount of insulin that you take before eating based on your current blood glucose level. Some people may have a different algorithm for each meal. Think of it as following a recipe. A sample algorithm looks like the chart below. This is only a sample. You should not use this table for treatment. SAMPLE ALGORITHM Pre-Breakfast Algorithm For Rapid Or Short Acting Insulin If your Blood Glucose is: Your Rapid-Acting Insulin Dose should be: 0-100: 2 units 101-150 3 units 151-200 4 units 201-250 6 units 251-300 8 units Over 300 12 units STEPS FOR USING A ALGORITHM 1. Test your blood glucose. 2. Find your reading in the blood glucose column. 3. Check the rapid-acting insulin dose column to see how many units to take. For example, according to the algorithm if your blood glucose level were 184 mg/dl, you would need to take 4 units of rapid or short acting insulin before breakfast. 5 NOTE: For an algorithm to work you need to eat the same amount of food and carbohydrate every day. (If you always have a sandwich with 2 slices of bread, a piece of fruit, a glass of milk and a small bag of chips for lunch, this method will be fine.) If you eat a big salad one day and a plate of spaghetti the next, these foods have different effects on your blood glucose and you would need different doses of insulin, so this is not the best way for you to decide how much insulin to take before meals. Basal Insulin – Works steadily day • Ultralente™ - occasionally used as basal insulin, does have some peak action. (See Peak Action.) • Short or rapid-acting insulin (see below) given by an insulin pump – tiny amounts of rapid acting insulin are delivered throughout the day and night. This is the best example of basal insulin and may be closest to imitating the way the pancreas normally works. Another advantage is that basal rates on a pump can be changed to meet your needs at different time periods of the day and night. and night to keep your blood glucose within your goal levels. Taken as an injection, basal insulin is long acting and works around the clock. Taken via insulin pump, a very small amount of basal insulin is released constantly at fractions of a unit per minute. The goal is to match the amount of insulin with the low level of glucose produced by your liver. This helps your blood glucose levels remain stable day and night - even if you don’t eat anything. Types of basal insulin include: eat and to correct for a high blood glucose, it is released in a squirt or pulse. This allows the insulin to provide a rapid burst of action. Bolus insulin acts as the “extra” insulin that is released by a normal pancreas to help your body use the glucose from a meal or snack. The extra insulin will bring your blood glucose levels down before they climb too high. Types of Rapid-acting insulin used for bolus insulin are: • • Long-acting insulin such as insulin glargine (Lantus®) is often used for basal insulin because they last a long time and have no peak action. Bolus Insulin – Taken before you Insulin Lispro (Humalog®), Insulin Aspart (Novolog®), Insulin glulisine (Apidra™) or • Regular insulin, which is referred to as a short-acting insulin. 6 Insulin Adjustment and Pattern Management – Insulin Sensitivity Factor (ISF) and Correction – Adjusting insulin doses based on a pattern of blood glucose readings over three days or more is called “Pattern Management,” or “Pattern Control.” If your blood glucose is too high or too low at certain times of the day or night, an adjustment to your insulin dose may be needed. In this case it is helpful to look for patterns in your blood glucose readings over three days or more. For example, take a look at Jean’s blood glucose readings before dinner for the past three days: • JEAN’S THREE-DAY BLOOD GLUCOSE RECORD (Goal 90 mg/dl-130 mg/dl) Breakfast Lunch Dinner 98 mg/dl 129 mg/dl 250 mg/dl 150 mg/dl 89 mg/dl 105 mg/dl 225 mg/dl 111 mg/dl 102 mg/dl 88 mg/dl Bedtime 240 mg/dl 138 mg/dl You can see that her dinner numbers are all too high. The problem may be related to how much carbohydrate (carb) she ate at lunch, snacking, schedule or basal insulin. However, it is most likely that her food at lunch did not match her pre-lunch bolus. She ate too much carb for her insulin bolus dose. For more information on Pattern Control or Pattern Management, see the BD Publication: Pattern Control. • ISF is the amount that one unit of rapid- or short-acting insulin will lower your blood glucose reading. It is used to calculate your correction or supplemental dose. Correction dose is the amount of insulin you need to correct a high blood glucose level and bring it into the range your blood glucose should fall into most of the time. Once you know your ISF, you can give yourself the right dose of insulin to keep you within your blood glucose goals. The ISF is different for different people and your Diabetes Team will help determine it for you. For instance, if your blood glucose at lunch is 200 mg/dl and your goal is 90-130 mg/dl, you will learn to take a correction dose, an extra amount of rapid- or short-acting insulin to bring your high blood glucose down to the range your blood glucose should be in most of the time. Correction is usually required before a meal, so you will need to add or subtract this dose of insulin to the amount of insulin needed for your carbohydrate intake. The correction dose is extra insulin if your blood glucose is too high or a lower insulin dose if your blood glucose is to low. 7 EXAMPLE: Calculating Laurie’s Correction Dose • Laurie’s ISF is 1 unit of rapid or short acting insulin for every 50 mg/dl of blood glucose. • Her target pre-meal blood glucose is 100 mg/dl, but her pre-dinner blood glucose reading is 250 mg/dl. • She is 150 mg/dl over her target level. Current blood glucose – target blood glucose = amount of glucose over target [250 mg/dl – 100 mg/dl = 150 mg/dl] • Using Laurie’s ISF, she would divide 150 mg/dl by 50 to find that she would need to add an extra 3 units of rapid or short acting insulin to her meal-time dose to correct the blood glucose to 100 mg/dl. Amount of glucose over target = correction dose ISF [ ] 150 = 3 50 If Laurie’s pre-dinner blood glucose was 75, she would reduce her insulin dose in the same manner as outlined above. • Her target pre-meal blood glucose is 100 mg/dl, but her pre-dinner blood glucose reading is 75 mg/dl. • She is 25 mg/dl below her target level. Current blood glucose – target blood glucose = amount of glucose over target • Using Laurie’s ISF, she would divide 25 mg/dl by 50 to find that she would need to subtract 0.5 units of rapid or short acting insulin to her meal-time dose to correct the blood glucose to 100 mg/dl. Amount of glucose over target = correction dose ISF = -0.5 units [-25 ] 50 Peak Action – The time when insulin is working the hardest to bring blood glucose down. It is essential to know when your insulin peaks so that you can prepare for possible low glucose levels at these peak times. Types of insulin with peak action times are: Name of Insulin Type of Insulin Peak Action Humalog®, Novolog®, Apidra® Rapid 30 min. to 1 1/2 hours Lantus® Long No peak action *Regular Short 2 to 4 hours *UltraLente® Long 8 to 30 hours *NPH Intermediate 4 to 12 hours *Lente® Intermediate 7 to 15 hours *Not commonly used in Flexible Insulin Therapy [75 mg/dl – 100 mg/dl = -25 mg/dl] 8 MAKING BOLUS INSULIN CHANGES 9 MAKING BOLUS INSULIN CHANGES Your first step in learning how to make these adjustments should be to consult with your Diabetes Team. This section will give you the tools you need to adjust your bolus insulin effectively using flexible insulin therapy. Understanding How Insulin Works Different types of insulin work at different speeds. Their action can be described as basal (steady and longacting), bolus (rapid burst of action) or somewhere in between. They also act differently in how fast they start working, when they are at their peak and the length of time they last. It is important to understand these differences in order to make the best decisions possible when adjusting your insulin dose. By knowing which insulin peaks and is active you will know which insulin to change if you are having hypoglycemia (low blood sugar) or hyperglycemia (high blood sugar). View the chart(s) and graph(s) below to help you understand the actions of many different types of insulin including Humalog®, Novolog®, Regular, NPH, Ultralente™, Lantus®, etc. INSULIN ACTION CURVES Type of Insulin Onset of Action Peak Action Duration RAPID ACTING (Used for bolus insulin – taken before eating and to correct for a high blood sugar) Insulin lispro (Humalog®), Insulin aspart (Novolog®), Insulin glulisine (Apidra®) 15 minutes 1/2 to 1-1/2 hours 3 to 5 hours SHORT ACTING Regular 1/2 hour 2 to 4 hours 6 to 8 hours Blood Insulin Level Insulin Action 6AM 9AM Noon 3PM 6PM 9PM MidN 3AM 6AM 9AM Insulin Commonly Used in Flexible Insulin Therapy for a bolus dose: Rapid-acting insulin is the most common insulin used, but shortacting insulin is also used for this purpose. 10 Insulin Action Type of Insulin Onset of Action Peak Action Duration LONG ACTING (Use for basal insulin – taken in injection or in a pump to act through day and night to keep blood glucose levels stable) Ultralente™ Approx. 4 to 8 hours 12 to 18 hours Approx. 24 to 28 hours Lantus® 2 to 4 hours No peak, stable 24 hours Blood Insulin Level The most common insulin used for basal doses is Lantus®, although Ultralente™ can also be used. 6AM 9AM Noon 3PM 6PM 9PM MidN 3AM 6AM 9AM Insulin Action Type of Insulin Onset of Action Peak Action Duration INTERMEDIATE NPH, Lente 1 to 3 hours 6 to 12 hours 18 to 24 hours Blood Insulin Level NPH insulin may be used as a partial basal dose in the evening. This is most commonly used with shortacting (regular) insulin as a bolus dose. 6AM 9AM Noon 3PM 6PM 9PM MidN 3AM 6AM 9AM Fill in the chart/graph below to show the action of the types of insulin you are taking now: My Bolus __________________ insulin: Starts to work at: ____________________________ Peaks (Works hardest from) __________________ Lasts until: ____________________________________ My Basal__________________ insulin: Starts to work at: ____________________________ Peaks (Works hardest from) __________________ Lasts until: ___________________________________ Graph your insulin curves below: 7AM Noon 6PM 12MN 7AM 11 Blood Glucose Monitoring: When to Test Checking your blood glucose levels is important. You need the information to 1) Make insulin changes, and 2) See if you made the correct adjustments. Many people using flexible insulin therapy check their blood glucose before each meal and at bedtime. Your Diabetes Team may also ask you to check your blood glucose two hours after a meal. (This reading will show how well the mealtime insulin dose is working.) In addition, to make sure that you are not having hypoglycemia at night, it is sometimes important to check blood glucose at 3AM. The 3 AM blood glucose, although inconvenient, is important because it can help guide the decision to change your nighttime basal insulin. It is common for blood glucose to drop before 3 AM and then to rise by morning. Figure 3 shows the effects of different types of insulin on your blood glucose at different times of day. Figure 3 Effects of Previous Insulin Dose on Blood Glucose Readings Tested at Mealtimes and Bedtime Insulin Dose Blood Glucose Breakfast Lispro Breakfast BGM Lunch Lispro Lunch BGM Supper Lispro Supper BGM Bedtime Lantus Bedtime BGM HINT: If your blood glucose meter can do mealtime averaging, this can help you find the times of day that your blood glucose levels are usually too high or low. Along with your careful reflections about your carbohydrate intake, stress and activity levels, this may also guide your insulin adjustments. 12 Making Changes Using Pattern Management You can learn to adjust your insulin dose by looking at your pre-meal blood glucose levels over three or more days to see if you notice any special pattern. In the following example and throughout the workbook, assume that the blood glucose goals recommended by the American Diabetes Association are in use (pre-meal plasma values of 90-130 mg/dl, blood glucose 2 hours after meals less than 180 mg/dl.)2 and a target of 100 mg/dl. How to Evaluate Your Blood Glucose Record: • Record your blood glucose levels in column format (as below) to more easily identify a pattern. Many of the data management software programs will do this for you automatically when you download the data. • Look at the readings by group according to the time of day. • Select the blood glucose readings by group that are out of your goal range. Three-day Blood Glucose Record: Pre-meal Goals 90-130 mg/dl Post-meal Goals < 180 mg/dl Day # Breakfast Pre Lunch Post Pre Dinner Post Pre Bedtime 3 AM Post Day 1 Day 2 Day 3 Guidelines for Pattern Management Any time you see a consistent pattern of either high or low blood glucose levels over a period of three days, you could adjust your insulin by: • Increasing the appropriate insulin or decrease the food eaten if the blood glucose levels are too high. • Decreasing the appropriate insulin or increasing the food eaten if the blood glucose levels are too low. Most of the time the appropriate meal to change or insulin to adjust is the rapid or short-acting insulin taken the meal before the “out of goal values” appeared. 2 American Diabetes Association, Standards of Medical Care for Patients With Diabetes Mellitus. American Diabetes Association: Clinical Practice Recommendations, Diabetes Care. 27:Supl:10, 2005. 13 Q&A PRACTICE PROBLEMS Q – What is the Pattern in Jane’s Three-day Blood Glucose Record? Pre-meal goals 90-130 mg/dl Day # Breakfast Pre Post-meal goals < 180 mg/dl Lunch Post Pre Dinner Post Pre Bedtime Post 1 – Mon 90 125 110 189 2 – Tues 75 134 116 210 3 – Wed 100 141 131 196 133 119 198 Average 88 3 AM A – Jane’s pre-breakfast, pre-lunch and pre-supper readings are in goal blood glucose range, but her bedtime readings are all high and out of range. Q – Does Jane Need an Insulin Adjustment? A – Maybe! But first she should think about whether she had eaten too much carb at dinner. Over the next few days, she should decrease her portion sizes of food at dinner she is eating (which will decrease the amount of carb). If there is no improvement in her blood glucose readings, Jane should look for other possible causes and solutions. Q – Could Jane’s dinner insulin (Humalog®) be the reason that her bedtime glucose is out of range? A – If Jane suspects her dinner insulin needs to be adjusted, she could try increasing it by 0.5-1 unit. Over the next three to five days she would need to observe whether her bedtime blood glucose readings are improved. NOTE: It is very important to consider all possible causes for an out-of-goal blood glucose reading before you adjust your insulin dose. The nice thing about pattern management is that you can make a small change every few days with great safety! 14 Q – What is Different About Tom’s Three-day Blood Glucose Pattern? Pre-meal goals 90-130 mg/dl Day # Breakfast Pre Post-meal goals < 180 mg/dl Lunch Post Pre Dinner Post Pre Bedtime Post 1 – Mon 90 125 110 239 2 – Tues 75 134 116 73 3 – Wed 100 141 131 266 133 119 193 Average 88 A – In this record, the breakfast, lunch and dinner values are in the goal range. However, the bedtime values are not only too high on average, but also too variable. Tom needs to look for and understand what caused the low value of 73 at bedtime on Tuesday. Any time you see a consistent pattern of either high or low blood glucose levels over a period of three days, you could adjust your insulin as follows. Either increase the appropriate insulin if your blood glucose levels are too high, or decrease it if your blood glucose levels are too low. REMEMBER: Most of the time, the appropriate insulin to adjust is the rapid or short-acting insulin taken at the meal before the “out-of-goal” values. • • • 3 AM The change should be only 1 or 2 units or 10% of the usual dose at that time of day and can be as small as 1/2 unit. You can make changes every three days. Make a change, evaluate the effect for a few days and then make a change again. You do not need to make big changes. (When blood glucose values are quite variable, extra caution is needed because making even a small change in insulin under these conditions might be dangerous). HINT: Sometimes it is too early for you to see a real pattern. In this case you should probably not make any changes and wait a few more days to see if a pattern emerges. Or, by waiting a few days you might find that your blood glucose levels came back into the goal 15 range without any insulin changes. Always make insulin dose changes only after a full examination of the blood glucose levels and do it carefully! If you are unsure, consult with your Diabetes Team. Record Your Blood Glucose for the Past 3 Days and Pick Out the Patterns You See Pre-meal blood glucose goals:________ Post-meal blood glucose goals:________ Day # Breakfast Pre Lunch Post Pre Dinner Post Pre Bedtime 3 AM Post 1 – Mon 2 – Tues 3 – Wed Average Based on your results, fill out the answers to the following questions: 1. Do you see a consistent pattern? ________________________________ 2. Which insulin is affecting the pattern of your glucose levels?_____________ 3. What kind of change might have helped bring your blood glucose levels into goal range?_____________ 4. Do you want to wait a few more days before you make any change to see if there really is a pattern?____________ 5. Have you experienced changes in your stress and/or activity levels over the past three days?_______________ 6. Have your food choices or amounts been different than usual for you? ________________________________ 7. Are you experiencing hormonal changes (such as those during menstruation or perhaps related to any medication you may be taking)? ________________________________ 8. Is your pattern of values before breakfast out of the goal range?____ (If YES, this indicates that you need to change your basal insulin. Please refer to p. 37 for a discussion of this topic.) HINT: Some people find it easier to use a computer program to identify blood glucose patterns. If you are interested in this type of a program, contact your meter manufacturer for information on how to obtain one. 16 Correcting for Blood Glucose That is Out of Range Know Your Blood Glucose Goals In this workbook, the American Diabetes Association (ADA) recommended premeal blood glucose goals of 90 to 130 mg/dl will be used. If you are above 130 mg/dl, you will increase your insulin; if you are less than 90 mg/dl you will decrease the insulin. Many people use a target of 100 and make adjustments if they are above or below this target. ‘Correcting’ – The term used for an immediate change in your insulin dose based on one event, such as a: • Single out-of-target blood glucose level. • Change in a single meal (you are invited out to a French restaurant for dinner). • Change in your exercise routine (you are going for a bike ride). Correcting means you make a minor change in your insulin dose based on the event now, but go back to your usual insulin dose tomorrow. EXAMPLE: If you wake up and your blood glucose reading is 200 mg/dl but you want it to be 100 mg/dl, you would make an immediate insulin “correction.” To do this you would take a certain dose of short or rapid-acting insulin to bring that blood glucose value down to 100 mg/dl. NOTE: Correction doses of insulin are calculated for each person and may change throughout the day. People usually need a bigger correction dose at breakfast than at lunch and dinner. Methods of Correction – There are many ways to correct for an abnormal blood glucose value. The three most common methods will be discussed here. Check with your health care professional to see which method is best for you. Correction Method I – Fixed Insulin Dose Based on Blood Glucose Value. Uses an algorithm (formula) to tell you the amount of insulin to take based on your blood glucose levels before meals and at bedtime. The carb you eat at each meal should be the same from day to day. EXAMPLE: Ken’s Diabetes Team gives him an algorithm of blood glucose values and insulin doses. Ken will give the insulin dose that corresponds to his current blood glucose. 17 Ken’s Algorithm for Correction Method 1 Blood Glucose Values Insulin Dose (Rapid or Short -Acting) Breakfast Lunch Supper Bed <50 6 8 9 0 50-69 8 10 11 0 70-89 9 11 12 0 90-130 10 12 13 0 131-160 11 13 14 1 161-190 12 14 15 2 191-220 13 15 16 3 221-250 14 16 17 4 251-280 15 17 18 5 281-310 16 18 19 6 Over 310 18 20 20 8 Correction Method I – How to Use an Algorithm 1. Use the algorithm for a week or two. 2. Monitor your blood glucose often. 3. Record every reading in your logbook. 4. Share your results by fax, phone or in person with your health team member. 5. Your health team member will work with you to make any needed adjustments to your algorithm. 6. After a little practice, you will be able to use the algorithm with confidence on your own. HINT: Remember, for this method to work well you need to eat the same amount of carbs at breakfast, lunch and dinner from day to day! Correction Method II – Change in Insulin Dose Based on Blood Glucose Value Your Diabetes Team prescribes a fixed amount of pre-meal insulin to use for every high, out-of-goal blood glucose reading. Uses an algorithm that tells you how much insulin to add or subtract from your usual dose, depending on your current blood glucose value. EXAMPLE: Joe’s fixed dose of rapid or short acting insulin before breakfast and lunch is 6 units, and his pre-dinner dose is 8 units. His doctor gives him an algorithm of blood glucose values and pre-meal rapid- or short-acting insulin. 18 Joe’s Algorithm for Correction Method II Blood Glucose Values Pre-meal rapid or short acting insulin Less than 60 Subtract 3 units 60-90 Subtract 1 unit 90-130 Take usual dose 130-200 Add 1 unit 200-250 Add 2 units 250-300 Add 3 units 300-350 Add 4 units 350-400 Add 6 units Over 400 Add 8 units Correction Method III – Change in Insulin Dose Based on Your Insulin Sensitivity Factor As you learned earlier, your “Insulin Sensitivity Factor” (ISF) tells you how many points lower your blood glucose will go for every 1 unit of short or rapid acting insulin you take. Method III uses your ISF to figure out how much to raise or lower your insulin dose to bring your blood glucose back to goal range. If you use Correction Method III before a meal you will need to add the correction amount of insulin to the amount of units needed to “cover” the number of carbohydrates you will eat. (See p. 28 for a discussion of carbohydrates.) REMEMBER: The ADA recommended pre-meal values of 90-130 mg/dl as a goal range are used in this workbook. Your Diabetes Team may set a different pre-meal goal for you. Calculating Your Insulin Sensitivity Factor (ISF) – Your Diabetes Team may use any of the following methods to help find your ISF: 1. Insulin/Blood Glucose Formula (One unit of rapid or short-acting insulin for every 50 mg/dl increase or decrease in your blood glucose level). 2. Rule of 1500 - if you are using shortacting insulin (Regular). 3. Rule of 1700 - if you are using rapidacting insulin (Humalog®, Novalog®, Apidra®). ISF Method I – Insulin/Blood Glucose Formula With ISF Method I, you take one unit of rapid or short-acting insulin for every 50 mg/dl increase or decrease in your blood glucose level. EXAMPLE: Blood glucose target is 100 mg/dl. John’s pre-lunch blood glucose is 180 mg/dl and his Insulin Sensitivity is 50. His reading shows that he is above his target by 80 mg/dl. [180 mg/dl – 100 mg/dl = 80 mg/dl] He should take 1 (1.5 if you measure 1/2 units) extra units at lunch. If his usual dose of rapid or short-acting insulin at lunch were 12 units, he would increase it by one and take 13 or 13.5 units. 19 PRACTICE PROBLEMS: Blood glucose target: 100 mg/dl Susan’s pre-lunch blood glucose is 205 mg/dl. Her reading shows that she is above her target by 105 mg/dl [205 mg/dl – 100 mg/dl = 105 mg/dl] Q – How many extra units should Susan take? 105 mg/dl = 2 units 50 A – She should take 2 extra units. In this case she should take a total of 14 units. Bob’s pre-lunch blood glucose is 60 mg/dl. His reading shows that he is below his lower target by 40 mg/dl [100 mg/dl – 60 mg/dl = 40 mg/dl] Using ISF Method I he would: 40 mg/dl = .8 units 50 • Round .8 units to 1 unit • Decrease his insulin dose by 1 unit. • Take a total of 11 units. Find Your Correction Dose for the Highest Pre-Meal Blood Glucose you had yesterday: ISF = 50 mg/dl Target = _____ mg/dl Pre-Breakfast Pre-Lunch Pre-Dinner Record yesterday’s pre-meal blood glucose readings. Take your highest pre-meal blood glucose and subtract your target goal: [_______ – ________ mg/dl = _________.] Target Goal Divide your answer by 50 and add the number to your usual insulin dose: [__________ divided by 50 = _________.] Add to your usual pre-meal dose. If You Had a Low Blood Glucose Yesterday, Figure out the Insulin Dose You Need: Record yesterday’s pre-meal blood glucose readings. Take your lowest pre-meal blood glucose reading and subtract your target goal: [_______ – ________ mg/dl = _________.] Target Goal This will be a negative number. Divide your answer by 50 and subtract the number from your usual insulin dose. [__________ divided by 50 = _________.] Subtract from your usual pre-meal dose. The corrections above using ISF Method I should bring your blood glucose back to normal at the next meal if you make no 20 other changes. Although any single meal may not correct properly, if after a few days they do not, you may have the wrong ISF or the wrong carb-to-insulin ratio for you. Work with your Diabetes Team would have to adjust the ISF and carb-to-insulin ratio. EXAMPLE: Calculate Rita’s ISF Using the Rule of 1500. If Rita took 10 units of Regular insulin at breakfast, 12 at lunch, 13 at supper, and 15 units of Lantus® at bedtime, her total would = 50 units a day. ISF Method II – Using the ‘Rule of Dividing 50 units into 1500 would = 30. 1500’ – To get a good first guess at your insulin sensitivity, divide the sum of all of your daily insulin doses into 1500.3 So as a first guess, each unit of insulin would lower Rita’s blood glucose by 30 mg/dl. (See Rule of 1500 box below) Rule of 1500 1) Add all insulin doses 10 units Insulin Regular 12 units Insulin Regular 13 units Insulin Regular + 15 units Insulin Lantus® 50 units 2) Divide sum of insulin doses into 1500 1500 = 30 mg/dl 50 units of insulin PRACTICE PROBLEMS: 1. Calculate your ISF using the Rule of 1500. Fill in all the insulin doses you take in one day and add them up: # of units Type of insulin 3) Answer = ISF Insulin Sensitivity Factor = 1 unit of short or rapid acting insulin will lower blood glucose 30 mg/dl Divide 1500 by your total units of insulin/day 1500 = (your total units of insulin/day) The answer is your ISF (the number of points one unit of insulin will lower your blood glucose). Total units/day 3 Klingensmith, GJ. American Diabetes Association, Intensive Diabetes Management, Third Edition, 2003. p. 107. 2003. 21 Fill in your pre-meal blood glucose values from yesterday and calculate your adjusted insulin dose using the steps below: Pre-Breakfast Pre-Lunch Fill in the table below with your calculations using your own information: Usual Insulin Dose Pre-Dinner Adjusted Insulin Dose Pre-Breakfast Pre-lunch Circle your high pre-meal blood glucose. Subtract your target goal from your high pre-meal blood glucose. [_______ – ________ mg/dl = _________.] Target Goal Divide this number by your insulin sensitivity factor (ISF) = ________ (ISF) Add the answer to your usual insulin dose. If you had a low blood glucose yesterday find the insulin dose that should be given: Take your low pre-meal blood glucose – your target = ____________. This will be a negative number. You will need to subtract insulin for correction. [_______ – ________ mg/dl = _________.] Target Goal Divide the number by your ISF and subtract answer from your usual insulin dose. [__________ divided by _____ = ______.] Pre-dinner REMEMBER: Guidelines for Taking Correction Doses for Out-Of-Goal Blood Glucose: 1. Check your blood glucose about 2 hours later. Use your post-meal blood glucose goal. In this booklet, the ADA recommendation of less than 180 mg/dl is used. 2. If your blood glucose is still not within your range of blood glucose goals, lower your ISF number (try changing by 5). 3. If you have hypoglycemia (low blood sugar), increase your insulin sensitivity number. ISF Method III – Using the Rule of 1700 – Another way to get a good first guess at your insulin sensitivity is to divide the sum of all of your insulin doses into 1700.4 Subtract from your usual pre-meal dose. [Usual dose – __________ = __________.] 4 American Diabetes Association, Intensive Diabetes Management, third Edition, p. 107. 2003. 22 EXAMPLE: If you take 10 units of Humalog® at breakfast, 12 at lunch and 13 at dinner, and you take 15 units of Lantus® at bedtime, your total would = 50 units a day. Dividing this into 1700 would give you 34 (this number can be rounded up to 35). So as a first guess, each unit of insulin would lower your blood glucose by 35 mg/dl. Rule of 1700 1) Add all insulin doses 10 units Insulin Humalog® 12 units Insulin Humalog® 13 units Insulin Humalog® + 15 units Insulin Lantus® 50 units of insulin/day 2) Divide sum of all insulin doses into 1700 1700 = 34 mg/dl 50 units of insulin Now you try it using the 1700 rule. PRACTICE: Calculate Your ISF Using the Rule of 1700. Using the chart below, fill in all the insulin doses you take in one day and add them up: # of units 3) Answer = ISF Insulin Sensitivity Factor = 1 unit of short or acting insulin will lower blood glucose 34 mg/dl Figure out your adjusted insulin dose based on your pre-meal blood glucose readings: Target Goal = ______________ Pre-Breakfast Pre-Lunch Pre-Dinner Type of insulin Fill in your pre-meal blood glucose values from yesterday in the chart above. Circle your high pre-meal blood glucose. Total units per day = Divide 1700 by your total units of insulin/day. 1700 = ________ Subtract your target goal from your high blood glucose reading. _______ – ________ mg/dl = _________ Target Goal Divide this number by your ISF. = ________ (your total units/day) The answer is your ISF (the number of points one unit of insulin will lower your blood glucose). (ISF) Add the answer to your usual pre-meal dose. 23 If you had a “low blood glucose” yesterday, figure out your correction insulin dose. Subtract your target goal from your low pre-meal blood glucose. _______ – ________ mg/dl = _________ Target Goal This will be a negative number. You will need to subtract insulin to make the correction. Divide your answer by your ISF and subtract answer from your usual insulin dose. = ________ (ISF) Subtract the answer from your usual pre-meal dose. ________ – _________ = _____________ Every time you take a correction dose for an out of goal blood glucose you should note the effect on your blood glucose. If your glucose correction doses never bring you back to your goal range, you should lower your sensitivity number. If you are under-correcting you are not giving enough insulin. You will know this because your high blood glucose readings will remain high and the low blood glucose readings will stay low. This means you need a larger correction dose, so reduce your ISF by 5. If you are over-correcting you are taking to much insulin. You will know this because your high blood glucose values will become low and your lows may become high. This means you need to decrease your correction dose, raise the ISF by 5. Fill in the table below with your calculations using your own information: Usual Insulin Dose Adjusted Insulin Dose Pre-Breakfast Pre-lunch Pre-dinner 24 Correcting for Known Changes in Meals or Exercise You have learned to adjust insulin to stay within your blood glucose goals. Insulin doses are also commonly adjusted for changes in diet or exercise. Changing your insulin dose based on what you will eat and the activity you plan to do is often called “insulin dosing.” Correcting for a Change in Meals Since most people do NOT eat the same thing every day, you need to learn how to calculate your short or rapid acting (bolus) insulin for different meals and different amounts of carbohydrates. If you are not sure about which foods are carbohydrates, discuss this with your diabetes educator. As with insulin correction for out-of-goal blood glucose, different methods are available for insulin dosing for a change in the food that is usually eaten at meals. One method involves adding or subtracting insulin for more or less food. Another way is to take a certain amount of insulin for a specific amount of carbohydrate. Check with your Diabetes Team to see which method they recommend for you. Both methods require that you learn how to count carbohydrates. In addition, you also need to learn how sensitive your insulin dose is to the carb you eat. This is called your Carb:Insulin Ratio. For information about carb counting, see the BD Publication “Carbohydrate Counting: Eat to Win” and talk to your diabetes educator. Calculating Your Carb:Insulin Ratio – A carb:insulin ratio is the amount of rapid or short acting insulin you need to match or “cover” the amount of carbohydrate you eat. Your ratio depends on how sensitive your blood glucose is to insulin. The more you weigh, the less sensitive your body is to insulin. The more sensitive you are to insulin, the more carbohydrate that will be covered by one unit of insulin. Knowing your ratio and how to calculate your mealtime insulin to match the carbohydrate in your meal gives you the greatest flexibility with improved glucose control. You will be much freer to eat what you want, when you want, with fewer concerns about high or low blood glucose. 25 Method I: A Quick and Easy Way to Start Before you begin, keep the following guidelines in mind. Use 1 unit of insulin for every 15 grams of carbohydrate (1:15). Some people will need more insulin (1 unit for every 10 grams of carbohydrate). Others will need less insulin and use 1 unit for every 20 grams of carbohydrate. Most people with type 1 diabetes have ratios between 6 and 10, but you may want to start with a very sensitive level of 15 grams of carbohydrate per unit of insulin and see if this works for you. Method II: The Rule of 500:5 Add up all the insulin given for 24 hours and divide it into 500. The answer is your carb:insulin ratio. EXAMPLE: Your total insulin dose is 50 units. 500 divided by 50 = 10 Your carb: insulin ratio is 10:1 Again, this is a starting point, you need to start with this ratio and adjust it based on your blood glucose records. Your Diabetes Team can guide you in this process. Keep Detailed Records for About One Week The best way to find your carb:insulin ratio is to use the following Food and Carbohydrate Counting Record below and write down: 1. Everything you eat and how much you eat - you will need to weigh and measure! (If you know how to count carbs, include them. Otherwise, use tables or a calculator to figure out the carbs in all of the food you eat and record each amount.) 2. Your insulin dose for each meal. 3. Your blood glucose levels before the meal. 4. Your blood glucose records after the meal. (Your blood glucose level should increase about 50 mg/dl 2 hours after you eat. If it is much higher or lower than that, your Insulin:Carb ratio will need to be adjusted.) NOTE: If you have never used a carb:insulin ratio, discuss this with your Diabetes Team and let them guide you through this process. Also, like the ISF, you may have a different carb: insulin for each meal. Typically, this ratio is lower at breakfast. 5 Warshaw, H.S. and Kulkarni, K., Complete Guide to Carb Counting. P. 146. American Diabetes Association 2001. 26 Food and Carbohydrate Counting Record Brkfst time: AM Carb PM goal: gms BG before meal Food Eaten __________________________________________________ __________________________________________________ __________________________________________________ __________________________________________________ BG 2 hours after meal Insulin Comments: Amount Grams Carb ____________________________ _______________________________________ ____________________________ _______________________________________ ____________________________ _______________________________________ ____________________________ _______________________________________ Total: _____________________________ Snack Time: Food Eaten Amount Grams Carb _______________ __________________________________ ____________________________ ______________________________________ _______________ __________________________________ ____________________________ ______________________________________ Total: ____________________________ Lunch time: AM Carb PM goal: gms BG before meal Food Eaten __________________________________________________ __________________________________________________ __________________________________________________ __________________________________________________ BG 90 min after meal Insulin Comments: Amount Grams Carb ____________________________ _______________________________________ ____________________________ _______________________________________ ____________________________ _______________________________________ ____________________________ _______________________________________ Total: _____________________________ Snack Time: Food Eaten Amount Grams Carb _______________ __________________________________ ____________________________ ______________________________________ _______________ __________________________________ ____________________________ ______________________________________ Total: ____________________________ Supper time: AM Carb PM goal: gms BG before meal Food Eaten __________________________________________________ __________________________________________________ __________________________________________________ __________________________________________________ BG 90 min after meal Insulin Comments: Amount Grams Carb ____________________________ _______________________________________ ____________________________ _______________________________________ ____________________________ _______________________________________ ____________________________ _______________________________________ Total: _____________________________ Snack BG before snack_________ Time: Food Eaten Amount Grams Carb _______________ __________________________________ ____________________________ ______________________________________ _______________ __________________________________ ____________________________ ______________________________________ Total: ____________________________ 27 Method I – Insulin Dosing Based on Carb Intake – A set dose of insulin is given for a meal and a specific amount of carbohydrate is eaten at the meal. If you eat the usual amount of carbs, you take the usual amount of insulin. Your health provider will prescribe a specific amount of carbohydrate for each meal. If you eat more carbs, you take more insulin, as determined by your prescribed carb:insulin ratio. If you eat less carbs, you reduce your insulin, again using the ratio. EXAMPLES: George’s Health Team prescribed carbohydrates for his meals as follows: • • 60 grams of carbohydrate for breakfast and lunch. 70 grams of carbohydrates for supper. If George expects to eat more carbs, he will take more insulin, as determined by his prescribed carb:insulin ratio. If he plans on eating less carbs, he will reduce his insulin, again using the ratio. What should George do if he is going to change the amount of food he is going to eat? (George usually eats 70 grams of carb for dinner, and he takes 7 units.) • • • If George is very hungry today and plans to eat 90 grams of carb for dinner, he would eat an extra 20 grams of carb. If his carb:insulin ratio is 10:1, for every 10 extra grams of Carb, he needs 1 extra unit, so for an extra 20 grams, he needs 2 extra units of insulin. In this case, for a 90-gram dinner, he would take 9 units of insulin (see the chart below). Usual Grams of Carbohydrate Carb:Insulin Ratio: 10:1 Usual Dose of Insulin 70 Grams Carb 7 Units Humalog® 90 Grams Carb 9 Units Humalog® 28 Method II – Insulin Dosing Based on Carb:Insulin Ratio Unlike Method I, you do not have a usual amount of food that you take or a usual insulin dose. You simply use the Carb:Insulin Ratio to determine your dose. EXAMPLE: Mary’s Carb:Insulin Ratio is 10:1 Mary is meeting an old friend at a favorite restaurant and she is planning to eat a 90-gram lunch. To figure out her insulin dose, knowing that her ratio is 10:1, all she has to do is to divide the number of carb by her ratio as follows: 90 grams of carbohydrate divided by 10 units of insulin = 9 units of Humalog® 90 [ 10 ] = 9 units of Humalog® Correcting for a Known Change in Exercise Exercise lowers your blood glucose levels. If you have started an exercise program and your blood glucose levels are too low and you are using an insulin pump, you will need to adjust your basal insulin. (See “Adjusting the Basal Dose” p. 37). This is the hardest of the adjustments because everyone responds to exercise differently. If you are giving bolus injections of insulin, you should lower your bolus dose before exercise. An example of how to do this can be found on p. 37. Try to measure your exercise by intensity (how hard you work) and how much time it takes. Think of your exercise as mild, moderate or intense. • Mild exercise – you will not sweat at room temperature, no matter how long you do it. • • Moderate exercise – you will sweat after 15-30 minutes. Intense exercise – you will start to sweat almost right away. The more intense your exercise and the longer it lasts, the more you will need to decrease you insulin. 29 PUTTING IT ALL TOGETHER 30 PUTTING IT ALL TOGETHER You have learned a lot of information about making changes to your bolus insulin doses. Now it is time to put these facts to work for you. This section will help you practice using your new knowledge in your everyday routine. Getting Started: A Five-Step Plan 1. Define your target blood glucose level. 2. Calculate your insulin sensitivity factor (ISF). 3. Try starting a carb:insulin ratio of 10 or 15 grams of carb:1 unit of insulin. 4. Count the number of carbohydrates you will be eating. 5. Reduce, if necessary for exercise. PRACTICE PROBLEMS: Tom’s Night Out Let’s look at how Tom uses the 5-step plan above to calculate his insulin adjustment. Tom has a fun evening planned. He is going out to an Italian restaurant for dinner with some friends after a game of singles tennis. When he tests his blood glucose before dinner, he finds it is 190 mg/dl. Here is his information for the five steps. • Blood Glucose Goals: 90-130 mg/dl • Target blood glucose level is 100 mg/dl • The initial ISF is 1 unit for every 30 mg/dl of blood glucose. Tom’s total insulin dose is 50 units/day. Using the rule of 1500, 1500/50 = 30 • The initial carb:insulin ratio is 10:1, 1 unit of Regular insulin for every 10 grams of carb. Using the rule of 500, 500/50 = 10 • Tom is planning on eating about 90 grams of carbohydrates • See below for step 5 Tom’s Calculations: Insulin needed for carbohydrates 9 units (90 divided by 10) Insulin needed to correct for high blood glucose (190-100=90) divided by 30 (ISF)=3 Total insulin for food and carb 9 + 3 = 12 units Reduction for high intensity exercise (Step 5) 3 units TOTAL amount of pre-dinner insulin 9 units 31 Your Night Out – Using the Five Steps, calculate the answers in the chart below: Planned Food (Carbs) ________ Carbs Divided by Carb/Insulin Ratio ________ Carbs/U of Insulin = ________ Units of Insulin Current Blood Glucose ________ mg/dl Your Target Blood Glucose ________ mg/dl Current Blood Glucose – Target Blood Glucose ________ mg/dl Your Insulin Sensitivity Factor? ________ Divide your Blood Glucose Calculation by Insulin Sensitivity ________ U of insulin Subtract for Exercise if Necessary ________ U of insulin ________ Total Dose Your Morning Breakfast and Run Let’s say you are going to eat 2 slices of toast (30 grams), a fried egg, hash browns (15 grams) and a 1/2 glass of juice (15 grams). This is a total of (60 grams of carb), but you are going to run 2 miles before lunch. Using the five steps, use the space below to figure out your insulin adjustment based on your plans for breakfast and exercise: Now check the following chart and see how well you did! Your Morning Breakfast and Run Planned Food (Carbs) 60 Carbs Divided by Carb/Insulin Ratio 60/8 = 8 Carbs/U of Insulin 7.5 U of Insulin Current Blood Glucose 180 mg/dl Current Blood Glucose – Target Blood Glucose 180 – 100 = 80 Insulin Sensitivity 30 Current BG – Target BG _______________________ Insulin Sensitivity = 80 __ 30 = + 2.5 U of insulin Reduction for Exercise (Should be Negative) -3 U of Insulin Add Units of Insulin (7.5 U + 2.5 U -3 U) = 7 U TOTAL DOSE 32 After correcting for food, elevated blood glucose and expected exercise, you would take 7 units of short-acting insulin. IMPORTANT REMINDERS: • After adjusting your insulin dose for exercise you must check to see if the insulin given was too much or too • little. (Checking your blood glucose level before, during and after exercise will provide the information you need to change future doses.) Talk to your Diabetes Team about how your doses are working for you. • • Be sure to test for urine ketones if blood glucose levels are over 250 mg/dl.6 Do not exercise when you have ketones in your urine. Eat a carb food if blood glucose levels are <100 mg/dl. This is a lot to take in at first, but most people get very good at doing these calculations and quickly learn to keep their blood glucose levels very close to normal. It is helpful to have a small calculator when you begin. 6 American Diabetes Association, Position Statement: Physical Activity/Exercise and Diabetes. American Diabetes Association: Clinical Practice Recommendations, Diabetes Care. 27:Sup1:1, S58-S62. January 2004. 33 ADJUSTING THE BASAL INSULIN DOSE 34 ADJUSTING THE BASAL INSULIN DOSE Adjusting the basal dose is more challenging than changing the bolus dose. Basal insulin is designed to always be working in the background to keep your blood glucose steady when you are not eating. The basal insulin has the major job of keeping your blood glucose normal during the night, if you do not eat or if you delay a meal. Insulin used to provide a basal dose include Lantus® and Ultralente™ insulin and the basal setting on an insulin pump. This section will help explain how to make changes to your basal insulin. How to Test and adjust The Basal Insulin To Normalize Your Morning Blood Glucose 1. Check your blood glucose at bedtime, at 3 AM and in the morning before you eat. 2. Pick a day when your bedtime glucose is close to your goal range. 3. Set your alarm for 3 AM and write down your blood glucose value after you test (it is too easy to go back to sleep and forget the reading you got at 3 AM). Bedtime 3:00 AM Pre-Breakfast Testing the Nighttime Basal Figure 4 Graph for Adjusting Basal Insulin 400 300 Blood Glucose Adjusting the basal insulin is done much less often than the bolus insulin corrections. The best way to check your basal insulin is to look at your nighttime and morning glucose readings first. It is easier and more important to be sure that the basal is correct at night, since you may be hypoglycemic (have a low blood sugar) at night but not know it! Many people become less sensitive to insulin between 3 AM and 7 AM. As a result, you could have a high blood glucose value when you wake up in the morning or you could have a low blood glucose level in the middle of the night. 4. In the morning check your prebreakfast reading. 5. Using the graph below (Figure 4), put a dot that matches each of your blood glucose readings - at bedtime, 3 AM and fasting (pre-breakfast). 6. Connect the dots. 200 100 0 Bed 3 AM Time Fasting 35 7. Your graph should look like one of the 6 patterns shown in the next graph (Figure 5) and labeled A-F. Figure 5 Patterns of Overnight Blood Glucose Values Blood Glucose 400 A 300 B C D E F 200 100 0 Bed 3 AM Time Fasting Bed 3 AM Time Fasting Bed 3 AM Time Fasting Bed 3 AM Time Fasting Bed 3 AM Time Fasting Bed 3 AM Time Fasting 8. Select the example that looks the closest to the pattern of your Basal Insulin in Figure 4. 9. Look up the change in Table 1 below. The table below will indicate the change to your basal dose that is needed. Table 1: Changes to Basal Insulin Changes to Basal for an Insulin Pump Pattern What to do... Expected Pattern A Normal – leave alone Pattern A B Increase 10 PM - 3 AM Pattern A C Increase 10 PM - 3 AM Pattern A D Decrease 10 PM - 3 AM Pattern A or E E Increase 3 AM - 7 AM Pattern A F Decrease 3 AM - 7 AM Pattern B or C Changes to Basal for Lantus® or Ultralente™ Pattern What to do... Expected Pattern A Normal – leave alone Pattern A B Increase Lantus® or Ultralente™ Pattern A C Reduce bedtime snack, keep insulin dose the same Pattern A D Decrease Lantus® or Ultralente™ Pattern A or E E Increase or add bedtime Lantus® or Ultralente™ Pattern A F Decrease bedtime Lantus® or Ultralente™ or reduce bedtime snack Pattern A 36 For many people, the suggestion under the column, What to Do will correct the problem and give an expected normal pattern A. In some cases, the pattern may require more than one change. The result of the first, usually safer change is shown under the column, Expected Pattern. You may want to make a second change based upon the new problem. Talk to your Diabetes Team about how that change should be made. Changing more than one dose of insulin at a time can be complicated and should be left to your Diabetes Team. How much to change the insulin is very individual, please check with your Diabetes Team for advice. It is safest to make small changes often rather than big changes infrequently. Testing the Daytime Basal Your health care provider may ask you to check your daytime basal dose. Here are a few methods to use. Follow your provider’s best recommendation for your individual case. Option I: Skip a meal (the simplest method). • Day 1 - skip breakfast, then check your blood glucose every 2 hours, until lunch) • Day 2 – skip lunch and check your blood glucose every 2 hours, until dinner • Day 3 – skip dinner, again checking your blood glucose every 2 hours, until bedtime • In all cases, if your blood glucose is rising, your basal is too low; if it is falling, your basal is too high. Blood Glucose Results to Test Daytime Basal Rate Time of Day Meal Breakfast - Day 1 Lunch - Day 2 Lunch - Day 3 37 Option II: See if your basal rises after your last bolus has finished working. (This only works with rapid or shortacting insulin.) • • Measure your blood glucose four hours after you take your rapid or short-acting insulin. Continue to measure your blood glucose every hour until you are sure that your blood glucose is not rising or falling. Blood Glucose Results to Test Daytime Basal Rate Time of Day Meal Breakfast - Day 1 Lunch - Day 2 Lunch - Day 3 Option III: Delay a meal and measure the effect on your blood glucose. have a BIG effect on your blood glucose levels! Whichever method you choose, decide if you need a change in your basal dose and do it very carefully. Your Diabetes Team may recommend that you collect data over two time periods before making a change. It is also advised that this process be used on nights or days when your activity level is similar to your usual pattern. Small dose changes can After you make your adjustments, keep checking your blood glucose closely for the next few days. You need at least 4 days to 1 week to see if your adjustment resulted in better blood glucose control. An adjustment on the basal rate for an insulin pump may take less time to evaluate. Use a chart like the following to write down your blood glucose results. Day Breakfast Lunch Bedtime 3 AM 38 TROUBLESHOOTING 39 TROUBLESHOOTING Sometimes you may find your blood glucose levels go up and down wildly, without any pattern that you can figure out. This might make you feel like giving up at times. Getting caught up in the frustration and anger just makes you feel more upset and hopeless. This section can help you cope with these feelings and put you on the right track to finding the answers you need. “I am doing everything right and my blood sugars still aren’t in my goal… I just don’t understand it anymore!” Go back to the drawing board with a record log that includes: • • • • Pre-meal, 2 hours post-meal and bedtime blood glucose levels. Time you eat. Amount of carb you eat. Amount and type of insulin you take. The Food and Carbohydrate Counting Record on p. 30 may be helpful. Now it is time to begin your detective work If this sounds like you it’s time to: • • • • Take a deep breath. Take a step back. Put on your detective hat. Figure out what is going on! Here are some guidelines to help you in your search for the answer. (There is an answer - really!) Although you may groan at the suggestion, the best way to figure out your problem is to keep written records. Round up the usual suspects and concentrate. Then ask yourself a few easy questions. Any time your answer is YES, place a checkmark in the appropriate box: 1. Insulin: ❑ Is there something wrong with your insulin? Was it allowed to get to warm or freeze? ❑ Is it expired? ❑ Are you giving it at the same time of day? Are you missing doses or giving it after a meal because you forgot to give it before? 40 2. Absorption of Insulin ❑ Are your injection sites lumpy or scarred? ❑ Do you have any redness around your injection sites? Are you having trouble with your insulin pump infusion site or are you injecting in a scarred area? (This could affect how your body is absorbing the insulin and can lead to problems with control.) ❑ Have you changed how you give insulin? ❑ Have you changed the brand of syringe or size of insulin needle? ❑ If you are using an insulin pump, is the tubing clogged? 3. Stress ❑ Are you experiencing unusual stress? ❑ Did you know both physical and emotional stress could affect your blood glucose levels? 4. Infection ❑ Do you have an infection? ❑ Did you know infections are a stress to the body and can increase blood glucose levels? 5. Illness ❑ Are you ill? Do you have a fever, a cold, or a virus? ❑ Did you know illness could increase blood glucose levels? 6. Physical Activity ❑ Have you changed your physical activity a lot? ❑ Are you more or less active than usual? (If so, this can increase or decrease your blood glucose levels) 7. Food ❑ Are you eating more carb and not taking enough insulin? ❑ Is it possible you are not counting your carbohydrates accurately? ❑ Are you eating at the same time of day or does it vary? ❑ Are you eating less and taking too much insulin? 8. Self-Monitoring of Blood Glucose and Test Strips ❑ Are your test strips outdated or have the strips been outside the vial? (This will make your glucose readings inaccurate.) ❑ Are you checking at the right time of day to understand the effect of your insulin, food and physical activity? ❑ Did you clean your hands before checking your blood glucose? Even small amounts of food residue can affect results. If you answered YES to any of the above questions, correct the problem, give yourself a few days and see if your blood glucose levels out. If you answered NO to all of the above questions, your next step is to sort through your insulin doses. 41 Which Insulin is the Problem? Read the following problem and see if it can help you figure out your basalbolus questions. Sam takes 19 units of insulin glargine (Lantus®) at bedtime and insulin boluses of insulin lispro (Humalog) in the following amounts: 10 units for breakfast; 8 units for lunch, and 12 units for dinner. His mealtime carb amounts are 75 at breakfast; 60 at lunch; and 100 grams at dinner. His insulin/carb ratio is 8:1 and his correction dose is 1 unit for every 50 mg/dl and his target glucose is 100 mg/dl. On days 1-3 he always eats his normal amount of carb. He does not eat an afternoon snack. Look at his blood glucose values and insulin doses in the chart below. 1. Basal Insulin ❑ Am I taking enough or too much basal insulin? ❑ Are my blood glucose levels always too high or too low? 2. Bolus Insulin ❑ Is my bolus insulin dose correct? ❑ Are my blood glucose levels too high or too low 2 hours after eating? 8 AM 12 noon 6 PM 10 PM BG Ins BG Ins BG Ins BG Ins Day 1 94 10 L 104 8L 205 13 L 150 1 LP 19 G Day 2 108 10 L 103 8L 197 13 L 155 1 LP 19 G Day 3 97 10 L 112 8L 215 14 L 125 19 G Now, read the questions below and circle the letter that you think is the correct answer to each question. 1. What is the problem? A. Blood glucose too low at breakfast? B. Blood glucose too high at lunch? C. Blood glucose too high at supper? D. Blood glucose too low at bedtime? 2. Which of the following types of problems does Sam have? A. A basal problem? B. A bolus problem? C. An eating problem? 3. What should Sam do? A. Change the basal insulin glargine? B. Change the breakfast bolus? C. Change the lunch bolus? D. Change the supper bolus? 42 4. How much of an adjustment is needed? A. Decrease 1-2 Units B. Increase 1-2 Units C. Increase 3-4 Units D. Increase 5-6 Units ANSWERS: 1. C – Sam has detected that he is always too high at supper. 2. B – This is a bolus pattern that requires adjustment. 3. B – He should change his lunch bolus 4. B – He should increase his lunch bolus (insulin lispro Humalog®) by 1 Unit. Notice that while his dinner glucose values were too high, Sam was taking a correction dose of 1 unit of insulin for day 1 and 2. Since his blood glucose values were too high by about 75 mg/dl this was not enough and on day 3 he increased the correction to 2 units of insulin lispro (Humalog®). If you have remaining basal-bolus questions, check back with your Diabetes Team. He should check back in 3 days to see if this was enough. 43 PROBLEM SOLVING AND EXERCISES 44 PROBLEM SOLVING AND EXERCISES Use the problems and exercises in this section to help you reinforce and strengthen what you have learned about insulin adjustment. The more experienced you become at spotting problems and figuring out the answers, the more rewards you will enjoy from practicing basal-bolus insulin therapy! B. Increase the daytime basal rate by 0.2 units per hour? C. Set her alarm and check her blood glucose level at 3 AM? D. Give a bolus at 10 PM? A – Choice C is the correct answer - the only way to find out what is happening to Sally’s blood glucose level during the Sally’s on Goal at Bedtime but Gets High Readings in the Morning Sally has been using an insulin pump for 3 months. Her basal rate is set at 0.7 units per hour from 10 PM to 3 AM and her daytime basal rate is 0.5 units per hour. She has been going to bed with normal blood glucose values but always wakes up with blood glucose levels over 165 mg/dl. She increased her basal rate from 10 PM to 3 AM from 0.6 to the current rate of 0.7 units per hour but is still having a problem. night is to test it at 3 AM. Choice A Increasing the basal rate overnight might cause hypoglycemia in the middle of the night. Choice B - Increasing her daytime basal rate would do nothing to help the overnight blood glucose levels. Choice D Giving a bolus at 10 PM could cause a problem with hypoglycemia at midnight. Q – What should Sally do if she checks her blood glucose at 3 AM and discovers that it was 60 mg/dl? A. Lower the 10 PM to 3 AM basal rate? B. Eat a big snack at 10 PM? C. Decrease the snack bolus? D. Increase the 10 PM to 3 AM basal rate? Q – What should Sally do to try to bring her morning blood glucose level to her goal range of 90-130 mg/dl? A. Increase the basal rate from 10 PM to 3 AM? A – Choice A is the correct answer. Sally has pattern D. Figure 5 Patterns of Overnight Blood Glucose Values Blood Glucose 400 A 300 B C D E F 200 100 0 Bed 3 AM Time Fasting Bed 3 AM Time Fasting Bed 3 AM Time Fasting Bed 3 AM Time Fasting Bed 3 AM Time Fasting Bed 3 AM Time Fasting 45 By lowering the 10 PM to 3 AM basal rate, Sally can avoid becoming hypoglycemic at 3 AM. By doing this, she may find that her fasting blood glucose level normalizes because she will not get a rebound high blood glucose in the morning. The other choices will not result in preventing hypoglycemia at 3 AM. If her morning glucose rises higher, she can increase her 3 AM to 7 AM bolus dose. Jack Needs Help Figuring Out His Bolus Dose for Certain Meals Jack takes a bedtime basal dose of insulin glargine (Lantus®) of 20 units and bolus meal doses based on a carb:insulin ratio of 12 grams of carbohydrate/unit and an insulin sensitivity factor (ISF) of 1 unit for every 40 mg/dl. His goal blood glucose range is 90-130 mg/dl, with a target of 100. He exercises regularly and seems to do well on his current basal dose of insulin glargine. Q – What should Jack’s bolus dose be for the following breakfast meal? • His pre-meal blood glucose is 112 mg/dl. • He will have 2 slices of toast, 1 orange, 1 slice of cheese, 1 cup of milk and coffee. A – Jack needs 5 units of rapid- or shortacting insulin for his meal of 60 grams of carb with a blood glucose within his blood glucose goals. Q – Can you find Jack’s bolus dose for the following dinner? • Jack’s pre-dinner meal blood glucose is 212 mg/dl. • He is planning to eat 2 pieces of bread, a salad with croutons and dressing, steak; large baked potato, side order of peas and broccoli. For dessert he will have 1/2 cup of vanilla ice cream with a small cookie. • Use this space to figure out Jack’s bolus dose before peeking at the following answer! Planned Food (Carbs) _____Carbs Divided by Carb/Insulin Ratio _____Carbs/U of Insulin = ___units of insulin Current blood glucose _____mg/dl What is Jack’s target blood glucose? _____ mg/dl Current blood glucose - target blood glucose _____ mg/dl What is Jack's Insulin sensitivity factor? _____ Divide Jack's blood glucose calculation by Insulin sensitivity _____ U of insulin _____ Total Dose 46 A – Jack needs 13 units of insulin. Here’s why! • His carbs total 120 grams (bread = 30 grams, croutons = 15 grams, large baked potato = 30 grams, peas = 15 grams, ice cream and cookie = 30 grams • His carb:insulin ratio is 12:1 • 120 divided by 12 grams of carb per unit of insulin = 10 units. [ • • • 120 grams of carb 12 grams of carb per unit of insulin =10 units] His blood glucose is 82 mg/dl over his target [212 – 100 = 112] 112 divided by Jack’s ISF of 40 = 2.8 units, round to 3 units. 3 units + 10 = 13 units (Jack’s total bolus insulin dose for dinner) (correction dose + dose to cover meal based on carb:insulin ratio = total bolus) Jack Wants to Exercise More to Lose Weight – Should His Insulin Dosing Change? Jack thinks he could look better and decides to increase the intensity of his exercise program to lose weight. He has increased his walking from 20 minutes to 45 minutes of brisk daily walks. Jack’s blood glucose levels for the past 5 days: Pre-breakfast Pre-lunch Pre-dinner Bedtime 100 70 89 72 85 100 88 65 68 87 92 60 90 68 66 80 83 77 62 79 Q – What should he do now? 1. Change his insulin:carb ratio? 2. Increase the amount of food he eats? 3. Lower his basal insulin glargine? 4. Change the insulin sensitivity factor to 1 unit for every 25 mg/dl? A – Looking at the pattern of blood glucose levels, it is clear that all the values are lower than the desired target of 100 mg/dl. The best response is Choice 3 – to lower the basal insulin glargine by 1-2 units, which will help bring the blood glucose levels higher overall. Choice 1 – any change to the bolus dose from changing his carb:insulin ratio will have little effect for the entire day. Choice 2 – increasing the amount of food, will only result in higher bolus doses and perhaps a weight gain, neither of which is desired. Choice 4 – changing the insulin sensitivity factor will result in higher doses of insulin and lower blood glucose values. 47 Juan Has Had a Change in His Blood Glucose Levels Juan has had blood glucose levels within his goal range for the past several months on his basal/bolus insulin regimen of 10 units insulin glargine (Lantus®) and pre-meal insulin doses of 6 units of insulin aspart (Novolog®). He uses an ISF of 1 unit for every 50 mg/dl and a target of 100 mg/dl. For the past 4 days his blood glucose values have increased to over 140 mg/dl consistently. He has not changed anything in his routine and is not sick. He always carries his insulin aspart with him in the car so it is available if he decides to stop and eat. Q – What Could Have Made Juan’s Blood Glucose Reading So High Over the Past Four Days? 1. His car might have been too hot, causing his insulin not to work. 2. Juan might have been under a great deal of stress. 3. His blood glucose test strips might have expired. A – Any or all of the above choices could be correct. Choice 1 – Insulin must always be kept at least at room temperature. Juan would have to open a new bottle and watch his glucose levels closely. Choice 2 – If Juan is having unusual stress, he might need a small adjustment in his insulin while this is going on. Choice 3 – Expired blood glucose test strips could be giving him inaccurate readings. 48 SEE – YOU REALLY CAN DO IT! 49 SEE – YOU REALLY CAN DO IT! This workbook is only a starting point and guideline in your move to flexible therapy with basal-bolus insulin adjustment. The best approach is to consult your Diabetes Team and work on this together. If things go out of control, refer back to this “how-to” guide and do some of the exercises. Like anything new, basal-bolus therapy is not easy at first and you will need help in learning how to adjust your insulin for food, activity, sleeping and waking. However, once you have learned these skills, you should be able to get your diabetes under excellent control and live a more flexible, healthy life. Written by: Marjorie Cypress, RN, MSN, C-ANP, CDE Albuquerque, NM We wish to acknowledge the following health professionals for reviewing this publication and providing their valuable insights: Jean E. Betschart Roemer, CPNP, MSN, MN, CDE Pittsburgh, PA Linda Urso, APRN, BC-ADM Warren, MI Kathleen C. Arnold, CS-ANP, BC-ADM, CDE Gulfport, MS BD and BD Logo are trademarks of Becton, Dickinson and Company. ©2005 BD. All other brands are trademarks of their respective owners. 50
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