Insulin pumps

How insulin pumps work

Insulin pumps replace daily insulin injections. The pump delivers insulin to the body through a thin, flexible tube that sits under the skin, called a cannula. This cannula is replaced every 2 to 3 days.

The insulin pump holds rapid-acting insulin only. It delivers small amounts of this insulin continuously to cover your basal (background) insulin needs. The amount it delivers can be matched to your needs at different times of the day and night.

Mealtime insulin, or insulin to treat a high glucose level can be given using the pump’s buttons or via a smartphone app.

Insulin pumps must be worn all the time, but can be removed for short periods to shower, swim or for other activities.

Types of insulin pumps

There are two main types of insulin pumps.

Patch (pod) insulin pumps

• Stick directly to the skin with no tubing
• Contain insulin inside a pod
• The entire pod must be replaced every 2 to 3 days – they cannot be refilled.

Tethered insulin pumps

• Attach to the body with a thin tube
• Need to be refilled with insulin every few days, depending on your insulin dose and the pump reservoir size.

Linking with a continuous glucose monitor (CGM)

Most pumps can link to a CGM device, usually through a smartphone app. These systems are called automated insulin delivery systems.

The CGM sends your glucose readings to the app. The app then tells the pump how much insulin to give you to keep your glucose levels in your target range.

Automated insulin delivery systems can:

• reduce or pause insulin delivery if a low glucose level is predicted
• give extra insulin if glucose levels rise.

This can make it easier to keep your glucose levels in your target range and means you don’t have to make as many decisions to manage your diabetes.

Automated insulin delivery systems are not fully automatic. You still need to:

• enter carbohydrates for meals
• respond to alerts
• make other changes advised by your diabetes health professional.

Not all insulin pumps can link with all CGMs or mobile phones. Find out what devices work together on our CGM device summary chart. A diabetes educator can give you more information about the different systems available. 

Pros and cons of insulin pumps

Insulin pumps have many benefits for managing your diabetes, but there are some downsides too. Talking these through with your diabetes educator or health professional can help you decide if an insulin pump is right for you.

Pros

No daily injections

You can deliver the insulin you need with the pump’s controls or a smart device. You may need injections if the pump malfunctions, so it’s a good idea to keep some insulin pens in the fridge in case of emergency. 

More flexibility

You can easily adjust the amount of insulin you need at any time – for example, reducing your insulin before exercise, or giving insulin for food at any time without an injection. 

Fewer hypos

You may have fewer and less severe hypos, as your insulin dose can be better matched to your needs throughout the day and night.

Increased time in range

Your glucose levels may become more stable, especially if you are using an automated system. 

Reduced mental load

This is especially true if you use an automated system, which takes over a lot of the decision-making and worry about keeping your glucose levels in your target range. 

Improved quality of life

These benefits may improve your diabetes management, help you feel better, and improve your quality of life overall. 

Cons

Potential for diabetic ketoacidosis (DKA) 

Like all technology, a pump can malfunction, or the tubing or cannula can become blocked. As you have no long-acting insulin on board, this can quickly lead to DKA. You will need a backup plan if the pump fails – for example, going back to daily injections for a while. 

Being attached 24/7 

Some people do not want to always be attached to a pump, and while small, pumps may be difficult to wear with some types of clothing. 

A lot to learn at the start 

You will need to:

• learn how the pump works
• work out your pump settings
• know how to count carbs
• learn how to change your pump site and tubing
• spend some time getting your settings right.

Cost 

Pumps are expensive but may be covered by private health insurance. Omnipod pumps are partially subsidised by the NDSS for eligible people. 

Accessing an insulin pump and supplies

If you are interested in getting an insulin pump, the first step is talking to your diabetes specialist (endocrinologist) about whether it may be a good option for you.

Next, talk with your diabetes educator or diabetes nurse practitioner. They can:

• discuss the different options available
• explain the pros and cons of each system
• show you sample pumps.

They will take you through the process of purchasing your pump. If your private health insurance has a waiting period, they may be able to help you get a pump on loan from the manufacturer while you wait.

Private health insurance

If you are planning to use private health insurance to cover your insulin pump, check: 

• you have the right level of cover to get an insulin pump 
• your policy includes replacing the pump every 4 years in line with standard insulin pump warranties 
• if you will have to serve a waiting period. 

Most private health funds need a Letter of Clinical Need from your diabetes specialist to cover a pump. Your diabetes educator will help you organise this and anything else you need. 

Insulin pump supplies

Some insulin pump supplies need to be replaced every few days. These are called insulin pump consumables and are subsidised through the NDSS for people with type 1 diabetes. 

These supplies include: 

• infusion sets (includes a cannula and tubing) 
• insulin reservoirs 
• insulin pods (for people using Omnipod^® systems).  

When to see your health professional

Always ask your health professional if you have any questions or concerns about using an insulin pump, even if it’s something they have already talked about with you.

They know that starting an insulin pump can feel overwhelming, and they are there to help you.