Bolus calculators are increasingly becoming a standard feature of insulin pumps. This means that some of the difficult mathematical calculations when using a pump become much easier. For example, if you take 1 unit of insulin for 10g of carbohydrate, and you are eating 30g of carbohydrate, it isn't too difficult to work out that you need 3 units of insulin to match. But if you take 1.2 units for every 10g of carbohydrate, and you are having 43g of carbohydrate, suddenly it becomes much more difficult. Rounding figures up and down slightly can work, but it is still very easy to make a mistake.

To use a bolus calculator, you first need to ensure that the pump has the correct information about your doses in its memory. This would include what your ratio of insulin to carbohydrate is (as discussed above), what range of blood glucose you are aiming for (with a highest and lowest value), and what your insulin correction ratio is, ie by how much 1 unit of insulin will lower your blood glucose level.

Once those values are stored, you also need to programme additional information in for the pump to be able to make individual calculations. The pump needs to know what your current blood glucose level is, and what (if anything) you are about to eat. In some cases, the information about your blood glucose level will be transferred automatically, if your pump has a wireless connection to your blood glucose meter or your continuous glucose monitoring system, but for many, this information will still need to be added manually. Depending on the type of pump, there may be other parameters that you can programme in, such as relating to physical activity.

The pump will then take account of all the information you have provided, and will suggest an insulin dose for you. It will not deliver the insulin automatically, as there may be reasons why you would not choose to follow the recommendations, so you need to agree to the dose before it will be delivered.

Bolus wizards have made it much easier for many people to use pumps safely. But there are some important aspects to consider. For example, whether you want your blood glucose level as low as you have programmed into your pump - if you are about to undertake physical activity for example, you may want to aim for a higher level, so will need to calculate how much to reduce the suggested dose by. If you are unwell, your insulin requirements may be much higher than usual, so the dose of insulin the pump has suggested may be much lower than you need. If you are unsure whether you will be eating the amount of carbohydrate you have in front of you, again you may need to have a smaller dose than the pump suggests. And if your meal contains a high proportion of fat or protein, the dose may need to be split or given over a longer period - your pump may or may not provide you with the option of calculating this for you. So when using your bolus wizard, keep in mind the circumstances when you may still need to add some of your own calculations!

The guidance produced by the organisation NICE (see 'pump websites and support' page) gives greater support to insulin pump use in children than adults, in that it can be used for children under 12 years of age if multiple injection therapy 'is considered to be impractical or inappropriate' - thereby by-passing the need for a trial of multiple injections. However, it also states that in these circumstances, multiple injection therapy should be tried between the ages of 12 and 18.

It can be difficult to decide if your child should have an insulin pump, or, if you are a young person yourself, whether it is for you. Pumps have had great success when used with very young children, as insulin doses can be adjusted much more easily to deal with unpredictable eating patterns, and in teenagers, the hormone changes, rapid growth and sexual development that make diabetes difficult to control can be managed more successfully with such a flexible system. They have also been successful in children and young people who experience a lot of night-time hypos, and have reduced the large swings that some people regularly experience between high and low blood glucose levels.

In terms of lifestyle, pumps help children fit in much more easily with their peers. They find they are no longer singled out to 'go and have their medication' from the teacher's office, or having to go to a private room to do their injection - instead, they can meet their daytime insulin needs by simply programming their pump as they go. Eating away from home and dealing with variable and unpredictable physical activity also all become easier.

For children using a pump, there are many similarities with adult pump use, although setting basal rates and bolus amounts can require more attention, simply because of the smaller amounts of insulin involved. Whilst that is no different from managing childhood diabetes with injection therapy, in many cases it can be easier because of the very small doses that insulin pumps can provide - for example with some pumps, hourly basal rates can be set as low as 0.01 unit per hour.

What is important when using pumps in children and young people is that families work together, and that everyone concerned is clear about what the pump will mean and that they all agree it is the right course of action, rather than, for example, parents wanting a pump but their child being resistant to the idea.

Despite NICE recommendations for pump use, which will include some people in every diabetes clinic across the UK, pump services are still patchy and lack uniformity. If you are less familiar with using pumps but wish to set up a service, there are many considerations, and the more planning you do, the easier it will be to set up the service in the way that you desire. These considerations are discussed here, and if you want more in-depth information, it can be found in our book 'Using Insulin Pumps in Diabetes'.

Firstly, deciding how your team want to approach pump therapy is important. This includes what your overall team philosophy is about using pumps (which can sometimes be difficult to agree on but helps to avoid inequality later on!), as well as what level of service will be provided by your team and when people will be referred to another service. Even if a minimal pump service is provided, clear lines of referral should be established.

Funding pathways are important and most usefully should be determined at the outset, although may change over time. Also how the service will be provided, which includes who will be involved, how people will be assessed, and how pump services will be integrated into existing services. This is particularly important if only some of the diabetes team staff deal with pumps, because those who are more experienced are, as they gain confidence, more likely to think of using a pump earlier than those who have less experience.

There are many other aspects of pump therapy that will need to be planned and agreed. These include ongoing support and access to emergency care for pump users, staff training, which pumps to use, how to provide objective information to your clinic population, what educational materials to use, what records to keep, and also, becoming more important in today's NHS, how to measure the success and effectiveness of your service. And across all of these, the thoughts, wishes and opinions of people with diabetes, both those using pumps and those not using pumps, should be sought to help you ensure your service meets their needs.