Insulin Tips

Updated: 31 May 2013

I am the father of a young type-1 diabetic. This is a series of articles hopefully providing some hard-won advice to others who are dealing with this.

Standard disclaimer

By now you probably know that if you are the parent of a young diabetic, their health is up to you! I am not medically qualified, so you follow my advice at your own risk.

Still, I hope you can learn from some of our pain.

Bear in mind that these articles will in some cases reflect the way things are in South Africa, which is where we are. I first wrote this late in 2007 when Jenna (my daughter) was almost three years old.

The pump

We started out using injections, and while you may have the option to start with an insulin pump, we learned to get a good feel for the effects of a certain dosage of insulin. Using syringes for a little while also helps you to get some practice for when you have a problem with the pump. When that time comes, you will probably have to be able to give an accurately measured injection without delay.

Getting the right pump

We have a MiniMed Paradigm pump that can do real-time glucose monitoring that we could never afford. This means we may have paid for more than we really need. This pump can deliver insulin in 0.1 unit increments, which is good, but there are pumps that can do smaller. This is especially important for a small child. Because we can't deliver less than that, we need to dilute insulin, which can be a chore.

Your doctor may take over when it comes to choosing the pump, but I recommend you discuss options with him or her. Look at price (even if your medical scheme pays) and be aware that the price of the pump is small when compared with monthly sets and reservoirs. Look at the dosage sizes that the pump can provide. Try not to pay for features you don't need.

Cost is more of a problem in Africa, and I see that we pay quite a bit more than the converted dollar and pound prices overseas.

Connector conspiracies

The Paradigm has a specific type of connector from their reservoirs which makes it difficult to use non-MiniMed infusion sets with the pump. You'd need to get alternative reservoirs to convert to the luer-lock standard. MiniMed may be innocent in this, but to me it looks like marketing at the expense of people, and so I distrust them. The fact that they provide such limited infusion set options only compounds this problem.

That said, the pump has served us well, and revolutionised Jenna's diabetes management. If there's any way you can manage it, I highly recommend a pump over injections, especially for small children and babies.

Reservoirs

The reservoir is the mini-syringe inside the pump that holds the insulin. Since our pump cannot deliver less than 0.1 units of insulin at a time, we dilute the insulin with saline. This involves me buying a lot of saline solution intended for contact lenses and mangling the reservoir to allow me to mix insulin. Since the saline cannot be reused after the plastic container is punctured, the smaller the better.

The best I've seen are 2ml plastic saline packs made for injections, which I bought at a hospital (UNITAS in Centurion).

You should definitely discuss any diluting you want to do with your doctor. We could not get correct basal rates programmed into the pump without diluting. After diluting, Jenna's blood sugar was a lot more stable.

Bear in mind that the small dosage problem only applies to young children who need very small amounts of insulin.

For detailed information on filling reservoirs, see the reservoirs article.

Infusion sets

Infusion sets are the devices which hold the end of insulin tubing from the pump under the skin. They consist of a plaster part to hold them down, a needle (initially), and a cannula, which is the short tube which is actually inserted under the skin. The needle just aids the insertion of the cannula and is removed afterwards. A set usually stays on for three days, unless the cannula is made of metal - then it is supposed to last two days. We have not tried metal cannulas, we use the flexible plastic ones.

The needle is a bit bigger than that of an insulin syringe, so it can be more painful, but that's only one needle over three days instead of nine or more. Also, food can be eaten and insulin can be delivered at any time, which means you'll never let your child endure a high to avoid a needle. It is very important to avoid highs for long-term good health in a diabetic.

Specific sets

We started on a Paradigm Quick-Set infusion set, with a 6mm cannula. This worked for a while, but we got a lot of kinked cannulas because Jenna seems to have about 5mm of body fat on average. Often, the kinks would block the flow, and since the pump delivers such tiny amounts of insulin for a small child, it cannot detect a blockage, implying a guess-the-high session in a few hour's time.

Once we had four blocked cannulas in a row over a space of two days, many backup syringes and near DKA highs. After that we switched to Silhouette sets which have not yet failed once. These sets go in at 30 degrees, making insertion a lot more hair raising, but then you can see the cannula entry point and never have to wonder if it is sitting above the skin. When it touches muscle tissue below the fat layer, it tends to bend and not block.

Insertion

Insertion of these is with a device called a Sil-Serter, or by hand. Although we were trained to do it by hand, I found it really difficult to control the speed and angle correctly. There's also quite some resistance to a 9mm, fairly thick needle, and I just didn't have the nerve. The Sil-Serter seems to work well, although sometimes the angle goes a bit wrong (or too deep) under the skin and perhaps that's the down-side. Even so, we haven't had a blockage yet.

When using the Serter, I have had the needle pierce the edge of the set's plaster, so I fold the forward-facing piece of plaster back over on itself and hold it there with a tiny bit of prestik.

Once in, I remove the backing from that front piece of plaster and stick it down. Then I open the crocodile clamp and move the rest of the set out of the Serter without lifting it. Then I slowly remove the needle using my left hand to hold the set. I then quickly plug in the tube and deliver the fixed prime to avoid any blood drying and forming a block in the cannula.

The Emla miracle

Set insertions can be painful, and since they are not done as often as with a syringe, I think that makes them worse. We now use Emla anaesthetic cream before every insertion. This takes more planning since it must be applied an hour before, but it makes the ordeal much much easier. It is difficult to explain the need for regular needles to a young child, and Emla just makes things much better. I highly recommend it if you can at all get it.

With Jenna, we draw a shape (of her choice) on the site, being careful to not get ink where the needle must go. We fill that in with lots of Emla and put a 3M clear plastic plaster over it. She then normally goes to sleep, since we change it at night, and we do the insertion while she sleeps. Sometimes she wakes, but often she doesn't feel it.

Some people like to do insertions in the morning so they can monitor blood sugar during the day, but we almost always test at 3am anyway, so we prefer doing it while she sleeps. With Emla she often doesn't wake. Without Emla though, I would be really against trying to insert while the child sleeps. Though you might get away with it a few times, if they often wake from unexpected needle stab wounds they are bound to develop fear and insomnia. I think you'll be doing a much greater damage than by just trying to coach the child through the process, like we used to have to do.