Insulin Pumps

What is an Insulin Pump?

An insulin pump is a portable device that is attached to the body, and continuously delivers insulin through a catheter placed under the skin. The insulin is delivered to the layer of fat that lies just below the skin.

Insulin pumps are always attached to the body. They are seen as a better alternative to insulin injections because pumps allow a user to change the amount of insulin by pressing a few buttons. This can be done at any time of the day and is much simpler than requiring multiple injections throughout the day. Furthermore, pump users are given an increased ability to control blood glucose levels.

Obtaining an Insulin Pump

Currently, the UK is behind other European countries in the provision of insulin pumps. One option would be to have the pump funded by the NHS, if you meet the eligibility criteria. Generally, insulin pump therapy isn’t recommended for people with type 2 diabetes.

According to NICE, insulin pump therapy is recommended for the following people:

  • Adults and children 12 years and over with type 1 diabetes, if trying to reach their target haemoglobin A1c levels with daily injections results in “disabling hypoglycaemia”. Additionally, there will be consideration if a person in this age range has tried to carefully manage their diabetes but their haemoglobin A1c levels remain high. Insulin pump therapy should only be continued in adults and children 12 years and over if there has been sustained improvement in the control of blood glucose levels. This will be shown through a decrease in haemoglobin A1c levels and hypoglycaemic episodes.
  • Children under the age of 12 with type 1 diabetes, if daily injections are impractical or not considered appropriate. Children who use insulin pump therapy should have a trial with daily injections between the age of 12 and 18 years.

“Disabling hypoglycaemia” is when a hypo occurs frequently or without warning. As a result, the person suffering such episodes are constantly in a state of anxiety which has an extremely negative impact on their life.

The process of obtaining an insulin pump varies across the UK Available budgets, level of demand for insulin pumps and the number of healthcare professionals with the relevant experience are all significant factors that can affect the process of getting an insulin pump.

The problem with getting an insulin pump through the NHS is that the time it takes is uncertain. The process of obtaining a pump can take a few weeks, several months or even over a year. Furthermore, there’s also the possibility that a person may not meet the NICE guidelines and they will not qualify.

However, the chance of having an insulin pump without any cost often allows people to overlook the disadvantages.

Insulin pump therapy should only be provided by a healthcare team with the relevant knowledge and experience. You should be provided with structured education programmes for the insulin pump. Additionally, you should also receive comprehensive advice on diet, lifestyle and exercise.

The NHS doesn’t operate a scheme in which it funds pumps that have already been bought privately.

The other funding option would be doing so privately. The overall cost needs to be considered if you are opting to pay for an insulin pump yourself. Pumps tend to cost between £2,000 and £3,000. In addition to the pump itself, you will also need to purchase infusion sets, reservoirs and batteries, which can cost around £1,000 to £2,000 per year.

How to Use an Insulin Pump

Setting up:

  • Fill the reservoir – This usually involves drawing insulin from a vial into or loading a new cartridge into the reservoir – When using a cartridge, you should reduce the amount of air that goes in before installing.
  • Attach the infusion set – The tubing that’s connected to the cannula needs to be attached to the reservoir outlet.
  • Prime the pump – Priming is important because it pushes any air out of the tubing and the reservoir. Priming the insulin pump is activated by pressing the controls on the pump. This informs the pump that to start moving the plunger.
  • Insert the infusion set – With as much air removed from the reservoir and tubing as possible, apply the infusion set to the body. The thighs, stomach and buttocks are good areas to choose from. The arms can also be used, but not if you are very lean.

Applying the infusion set involves pushing the cannula under the skin and holding it in place with an adhesive patch. In some cases, a tool can be used to help the cannula insert smoothly and consistently.

Setting the basal rate of insulin:

  • Insulin pumps don’t use long acting insulin. Instead, they constantly deliver a small amount of fast acting insulin throughout the day. The basal rate of insulin can be changed at any point of the day, simply by pressing a few buttons.
  • Initially, your health team will help set the basal rate that works best for you. Once you become more accustomed to your pump, you should become used to increasing and decreasing your basal rate to suit your needs.

Delivering boluses:

  • A shot of insulin is known as a bolus.
  • Increasing glucose levels can be done so with the push of a few buttons. It is extremely easy to deliver a bolus through a pump compared to an injection. There is no need to change a needle each time or insert a needle.

Changing infusion sites and refilling the pump:

  • Once an insulin pump is set up, you will need to regularly change infusion sites and refill the insulin every 2 to 3 days. Overall, this will only take a few minutes and it is easy to find time to do it. Low insulin levels will require a replacement in the reservoirs, either through drawing insulin from a vial or installing a new cartridge.

Starting on an Insulin Pump

Once you get your insulin pump, you’ll need an induction day at your local clinic. It is highly likely that there will be a group of people attending who are starting on the same type of pump. It will be comforting knowing that there are other people in the same situation as you. In the presence of a healthcare professional, you will become familiar with the equipment and informed on how everything works.

Insulin Pump Dosage

There are two types of doses for insulin pumps:


  • Basal doses act as a background dose of insulin.
  • The pump provides a constant flow of insulin in the same way the pancreas operates in a person who doesn’t have diabetes.
  • The steady dose of insulin is required to counteract the steady flow of glucose going into the blood; which is provided by the liver each day.
  • Most modern pumps will allow you to specify an hourly rate, which is especially convenient given that you may need more of less background insulin at different parts of the day.
  • Working alongside your healthcare team, you should be able to gradually tailor your dosage to your needs. It can still be changed either temporarily or permanently. If necessary, the basal dosage can be turned off. You may require a change in dosage in response to the seasons and during periods of illness. During these times, blood glucose levels are usually trending higher.


  • Bolus doses are specifically taken at meal times, which helps control blood glucose levels following a meal.
  • This dosage is designed to mimic the release of insulin by the pancreas which occurs in people who don’t have diabetes.
  • Modern pumps can deliver a range of different boluses. The standard dose would be very similar to a single injection. More advanced doses involve insulin being steadily delivered over a period of ours to cope with meals that are digested more slowly.

Pump Maintenance

Insulin pumps are designed to be durable. Most maintenance is simply to do with refilling the insulin reservoir and changing the batteries.

Problems and Troubleshooting


  • Bubbles can form in the reservoir or tubing.
  • This usually happens when you haven’t primed the air out of the reservoir when refilling the reservoir or using a new cartridge or when changing to a new infusion set. Having a loose connection at either end of the tubing can also cause bubbles. Using insulin straight from the fridge causes bubbles when the insulin warms up to room temperature.
  • The presence of bubbles mean that you won’t get the full insulin dose. This can lead to high glucose levels and a potential rise in ketone levels.


  • Any blockage that prevents your pump from delivering insulin properly is known as an occlusion. Some modern pumps can signal the pump user of a blockage with an alarm.
  • Occlusions can occur if pressure is applied to the tubing or infusion site. Insulin pump tubing can become kinked and crystals can form in the insulin, leading to occlusions in the cannula. Blockages can also occur if the cannula is bent during inserting. This is more common amongst Teflon cannulas.

Leaking pump reservoir:

  • Leaks can happen when the rubber seals (O-rings) around the plunger become weak or damaged. This usually happens if the seals haven’t been properly lubricated properly during the manufacturing process.
  • If a reservoir is faulty and starts leaking, you may need to contact the manufacturer to get a new one.

Infusion sets coming loose:

  • This is a relatively common problem.
  • When sweat gathers at the infusion site can cause the adhesive to break contact with the skin and could result in the cannula coming free.
  • If contact is broken, you may need to consider trying a more durable adhesive.