Well, after a few posts all about general life as a diabetic, it's back to some features of the pump I am starting to discover. And I think this is perhaps the best function yet! So much so that I had to write about it one day one!
One of the biggest challenges to a diabetic, is conquering the the art of working out how quickly or slowly the carbohydrate you have eaten will work off. Now, how quickly the insulin works will depend on each person, but for me it is generally around 3-4 hours. The pain about carbohydrates is that some work quicker whilst others work slower. For example, complex carbohydrates found in pasta, will take longer to burn off than simple carbs, such as sugar or glucose (or in fact, any of the 'oses' you find in foods). So in theory, if you have one type of carbs, you can inject according to how quickly or slowly your body will use them.
BUT, and it is a big [pain the the] but[t], when these carbs are mixed, you need to adjust your insulin in order to cater for carbs which will release quickly and those which will take longer. The best example I know of is a Korma Indian curry, for which the knowledge of calculation of insulin has completely baffled and evaded me for years. A Korma is very sweet (simple carbs which release very quikcly) but also has rice with it (which has complex carbs which take longer to work). The problem is, in order to manage this meal on multiple daily injections (MDIs), you would undoubtedly have to inject several times just for one meal in order to counteract the effect of the slow and fast acting carbs. Yeah, pain in the butt! And when you alreayd inject 4 or 5 times a day, injecting another 3 for one meal is just not worth it. So much so that for the past 3 years my partner and I have had to eat a Korma on a Friday or Saturday night. Why? Because the effect it would have on my sugars would be so huge, the whole of that night I would be almost drowning in beakers of water and visiting the loo every five minutes, thanks to the 20+ BG readings I would have throughout the night. In turn, this would leave me feeling hideous the day after. In fact, I even had to call in sick at work on one occasion (the first occasion) that I ate a Korma, because of the effect the night before had made. That was when 'the rule' was put in place.
Two of the fantastic benefits the pump offers are something called dual-wave bolusing or square-wave bolusing. Now, a bolus is the name for the dose of insulin you give yourself before a meal. This would be used if you are eating a meal which contains carbs that you think will take around the time to burn off that your insulin will be effective for. The meal is probably one which has a source of steady releasing carbohydrates, but which remain active for longer than your insulin normally takes to burn off.
The square wave bolus is designed to release insulin steadily over a time you specify. Therefore, if you are eating a meal like a jacket potato with beans, the potato (due to the way it's cooked) will get into your system quickly and therefore will require insulin to go in straight away. The beans however release slowly and are likely to continue releasing energy longer than the insulin I take. Before this would have mean I would have needed to inject in the middle of the meal (yeah, I didn't exactly go for that either!). Instead, square wave-bolus means that I can set the total amount of units I will need for the meal, only I can tell the pump to continue releasing this insulin over say, 5 hours. This will mean I won't need to worry about my insulin running out and my blood sugars going up, after the 3-4 hours it normally takes me to run out. Awesome!!!!
The square-wave bolus function is similar, but instead of releasing it steadily, you can use it for a meal such as the dreaded (loved) Korma. The instant effect of a Korma is that your sugars will fly up, due to the sweetness, meaning you need an immediate dose of insulin to counteract that. But later, the rice will continue to release energy. Thanks to this function, I can work out how many units I need for the rice, and set the pump to carry on working for several hours afterwards! I haven't tried a Korma yet (mainly because I don't have total confidence in how long to set the dose for and how many units I need in total), BUT, for the past week I have been trying to figure out how much to inject for my lunch, which was a sandwich and a chocolate bar. For the past week, I've been battling with it and coming out with any range of numbers, but all over 15. Today, my sugars were a little on the high side anyway (10mmol), but I decided to give it a go, as I had a good night and a stable morning, meaning an 'experiment' had less variables than the usual 12 I can find at any one time!
So, today I gave the dual-wave bolusing a go! My thinking was that chocolate isn't too bad in itself, but it was honeycomb which was sweet would kick in quickly. The sandwich on the other hand was wholegrain bread, meaning it would work much slower and would last longer. So, in total I needed 10 units overall. So I decided to inject 5 units straight away, as that was for the honeycomb which would kick in quick and work off quick, while the bread would start to work almost immediately and continue releasing. The rest of the dose I asked it to release over the space of two hours.
What happened? It worked perfectly. Well, almost. My sugars are now at 4.3mmol, which is a little on the low side, but for the first time in two weeks, I didn't have my horrible high which I was expecting. Meaning something must have gone right! It may be that I needed to ask it to release over one hour, seeing as that would then mean that I still had active insulin for around 5 hours, and it is fairly unlikely the few seeds in the bread were still releasing energy 6 hours after the meal. BUT, it was the first time I have eaten that meal with success.
Over the next few weeks I will continue to play with the pump and ask them team at the hospital about how to use these functions properly, but it has finally opened the doors for me to eat the meals I enjoy without the nasty after effect that I know so well!
Anna - about to eat a curry!