University College Hospital. Insulin Pump Advanced Bolus Options

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1 University College Hospital Insulin Pump Advanced Bolus Options Children and Young People s Diabetes Service Introduction When you use an insulin pump, the insulin given to cover food is called an insulin bolus. Different foods and meals have different effects on your blood glucose levels. Altering the timing and type of bolus to match the food eaten can help to keep post-meal blood glucose levels under control. Evidence suggests that those who use the pumps advanced bolus options, such as dualwaves, multiwaves or combo boluses, can achieve better control of their diabetes. The terminology vaies depending on the model of pump that you use. This information is designed to help you choose your bolus type and make the most of your insulin pump. Guide to Glycaemic Index The glycaemic index (GI) is a guide to how carbohydrate foods affect your blood glucose levels. The GI of glucose is 100 as it absorbed rapidly. A high GI food (more than 70) increases the blood glucose levels quickly for a shorter amount of time, whereas a low GI food (less than 55) results in a slower and more prolonged rise in your blood glucose levels, therefore two meals with the same carbohydrate content can affect your blood glucose levels differently depending on their glycaemic index. A normal or standard bolus, similar to an insulin injection, may not be appropriate for all meals. You may have noticed Blood glucose Low GI

2 that giving a normal or standard bolus with a low GI and/or high fat food, such as pizza or pasta, results in a low blood glucose level (hypoglycaemia) soon after eating followed by a subsequent rise in blood glucose level. This is due to the slow release of the carbohydrate in comparison to the insulin action. Very high GI foods may also be difficult to manage, for example a high GI breakfast may result in an initial rise in blood glucose levels followed by a low blood glucose level as the insulin action lasts longer than the release of carbohydrate into the bloodstream. The table below shows the glycaemic index of commonly eaten foods Glycaemic Index Table Glycaemic Index Starches Cereals Fruits and fruit juices Potatoes Vegetables and Pulses Desserts, Confectionary Drinks Low GI (GI = less than 55) Multigrain bread, rye bread, chapatti, corn tortilla, barley, pasta, tagliatelle, spaghetti, rice noodles, noodles, basmati rice. Rolled oat porridge, All Bran, Apple, orange, banana, mango, dates, peaches, Sweetcorn, peas, carrots, plantain, taro, chickpeas, kidney beans, lentils, soybeans, yam Strawberry jam, chocolate, ice cream, yoghurt, nuts Milk (all kinds), chocolate milkshake, apple juice, orange juice, pineapple juice Medium GI (GI = 56-70) Roti, brown rice, cous cous, pitta bread, crumpet Weetabix, millet porridge, muesli (varies depending on composition), Fruit and Fibre, Pineapple, Chips, baked potato, sweet potato, new potato Pumpkin Popcorn, potato crisps, honey, croissant Cola, fizzy orange drinks (GI = more than 70) White bread, whole meal bread, bagel, baguette, glutenfree bread, white rice, easy cook rice, gluten free pasta Cornflakes, Branflakes, Cheerios, Cocopops instant oat porridge, rice porridge, rice krispies, branflakes, Watermelon Boiled potatoes, instant mashed potato, mashed potatoes (without added fat and milk) Swede Rice crackers, doughnut, pancakes, jelly beans Cranberry juice, sports drinks, Rice milk

3 The glycaemic index is calculated based on a set amount (50g carbohydrate) of an individual food, however the amount you eat and combination of foods is likely to vary, which will change how the meal affects your blood glucose levels. Other factors that affect the blood glucose response to meals include: Fat and protein - the presence of fat (fried foods, oil, butter, cream, cheese) and protein (meat, fish, eggs) as part of a meal will slow down the rate of digestion meaning the glucose is released more slowly into the bloodstream. Fat may also increase resistance to insulin. Fibre higher fibre foods such as granary breads, wholegrain or bran cereals, fruits, vegetables, beans, pulses and potato skins are digested and released more slowly resulting in a slower rise in your blood glucose levels. Meal size - a larger amount of any type of carbohydrate will take longer to digest than a smaller amount, this is sometimes referred to as the glycaemic load (glycaemic index multiplied by the grams of carbohydrate). You may therefore find meals above a certain size require the use a dualwave, multliwave or combo bolus. You may find an amount of carbohydrate that is large for you. It is likely to vary from person to person, a starting point is more than 1.5g carbohydrate per kilogram of body weight. For example, if you weigh 50kg, try a dualwave, multliwave or combo bolus for 75g carbohydrate or more. Type of starch different types of starch have different chemical structures and are therefore digested and absorbed at different speeds. This is why pasta has a lower GI compared to rice. Processing for example, easy cook rice has a higher GI than basmati rice and whole jumbo oats has a lower GI than rolled oats. Different brands of the same cereal, such as cornflakes, can have different GI s due to different processing methods. Cooking methods for example, a mashed potato has a higher GI than a boiled new potato or chip due to the level of processing (and addition of extra fat) Ripeness for example, a riper banana will have a higher GI than an unripe banana as the starch naturally breaks down into sugars and is digested and absorbed more quickly. Individual variation different individuals respond differently to the same foods.

4 Choosing your bolus type Normal or Standard bolus this type of bolus works with small snacks and high glycaemic index foods. If you are not sure how much you are going to eat give half of the insulin at the beginning of a meal and the remainder at the end, the total amount should match the total amount of carbohydrate actually eaten. Remember you should always have some insulin before you eat. Bolusing 15-30mins in advance of eating may help to manage blood glucose levels after very high GI foods. Normal or standard bolus 100% 0% Dualwave or multiwave or combo bolus this type of bolus is recommended to help you achieve the best possible post meal blood glucose levels. It is a combination of the normal/standard and extended/squared bolus. Some of the insulin is delivered at the start of a meal; the remainder is given as an extended bolus. You can decide how much insulin is given immediately and how much is given as an extended bolus and for how long. 100% 0%

5 Extended or squarewave bolus - the bolus delivery is extended over a longer time period. Most foods will require a certain amount of insulin to be given initially, therefore you should always use a dualwave, multiwave or combo bolus. Only use the extended or squarewave bolus if you have been recommended to do so by your Diabetes team for a specific situation. 100% 0% When should I use a Dualwave or multiwave or combo bolus? Use the table below to help make choices about your bolus type, if you have found a normal bolus unsuccessful in managing your blood glucose levels. Continue to count the carbohydrates your are eating and use your insulin:carbohydrate ratio to work out your total insulin dose, then choose the bolus type and adjust the timing according to the type of meal you are eating. This is just a guide to get you started, each individual is likely to respond differently. If a normal bolus is working, there s no need to change the bolus. If the bolus doesn t work initially, make some adjustments to the duration or split and try again until you have worked out a suitable method. Keep a note of what has worked for specific meals. Meal/Snack type carbohydrate snacks Breakfast Mostly high GI carbohydrate, small meals Example Biscuits, crisps, fruits, cereal bars breakfast cereals and milk, toast Sandwich Amount of Carbohydrate When to start delivery Any Before eating standard bolus Small amount of carbohydrate Large amount of carbohydrate Up to minutes before eating Before eating standard bolus Dualwave or multiwave or combo bolus? No No (it may also be necessary to reduce basal rates after breakfast to prevent hypos mid-morning discuss this with your diabetes team) No

6 Meal/Snack type Low fat mixed meal with high GI carbs, larger meals High fat, high GI mixed meal or Low GI mixed meal Example Fish fingers, mash and peas or chicken, easy-cook rice and vegetables Cheese on toast, roast dinner Pasta with tomato sauce Amount of Carbohydrate Large amount of carbohydrate When to start delivery Before eating Dualwave or multiwave or combo bolus? Try 70%:30% or 50%:50% over 60-90minutes Any Before eating 70%:30% or 50%:50% over 1-3 hours* Any Before eating 70%:30% or 50%:50% over 1-3 hours High fat low GI mixed meal Pasta with cheese sauce, pizza, fish and chips, Chinese or Indian takeaway Any Before eating 70%:30% or 50%:50% over 4-8hours* *It may also be necessary to add additional insulin to account for the additional fat and/or protein if the dualwave or multiwave or combo bolus is not successful in preventing post-meal rises in blood glucose levels, you can discuss this with the diabetes team. What do I do if I decide to have more food, such as a pudding or snack, while the bolus is still running? You can deliver a normal or standard bolus for extra foods while a dualwave or multiwave or combo bolus is running, although this is not recommended if you are testing the bolus. The bolus can be stopped if necessary, each type of pump works slightly differently, therefore make sure you know how to stop the bolus should you need to. How do I know if the bolus is working? To check your bolus type is working you will need to check your blood glucose levels after eating. For a normal or standard bolus, check your blood glucose levels 2-3 hours after eating. For a dualwave or multiwave or combo bolus, check your blood glucose levels hourly for the duration of the bolus. For example, if you have extended your bolus for 3 hours, check your blood glucose level before eating, then at 1, 2 and 3 hours after eating. You can then decide if the chosen bolus has worked well for the food eaten or if you need to try something different next time. If you use sensors, they may also help you to test the bolus.

7 Remember, if you have been very active, have eaten low GI foods earlier in the day or if you are unwell it is likely to be difficult to test whether or not the advanced boluses are working. Worked Example Jack is having pasta with cheese sauce, chicken, mushrooms, and peas for dinner. His blood glucose is 6.9mmol/l He has counted the carbohydrate in his meal, which equals 50g carbohydrate His insulin:carbohydrate ratio is 1u:8g, therefore his pump calculates an insulin dose of 6.25units (no correction insulin is required). The pasta is low GI and the cheese sauce is high in fat, Jack has noticed his blood glucose levels are low an hour after eating and high during the night when he has eaten this meal before and used a normal insulin bolus. He decides to try a dual-wave bolus of 50% initially and the remaining 50% over 4 hours. His pump gives 3.125units straight away and 3.125units over the next 4hours. Jack checks his blood glucose levels each hour for the next four hours. His blood glucose levels are as follows: Before meal: 6.9mmol/l Post meal: 1 hour: 3.8mmol/l 2 hour: 7.8mmol/l 3 hour: 9.2mmol/l 4 hour: 10.1mmol/l A hypo soon after eating followed by a rise in blood glucose levels suggests too much insulin has been given initially. The blood glucose remains raised 4 hours after eating, therefore Jack makes a note of this and decides that next time he eats this meal he will give less insulin initially and extend the bolus for a longer period of time. He decides to 40% initially and the remaining 60% over five hours. Contact Numbers: Office Hours (8am 6pm): (Dietitian and Childrens Diabetes Nurses) Out of Hours: and page Paediatric On-call Registrar If you need a large print, audio or translated copy of this document, please contact us on We will try our best to meet your needs. First published: Sign off text style 31/07/13 Date last reviewed: 31/07/13 Date next review due: 01/08/14 Leaflet code: UCLH/ SH/PAED/CYPDS/BOLUS/1 University College London Hospitals NHS Foundation Trust