Temp Basals: Getting the Most Out of Your Insulin Pump
D-Mom, M.S. (Psychology)
If you have mastered some basic pump features, but are still looking for more ways to help your insulin pump help you, then take a look at temporary basal rates. They are one of the best features for preventing low and high blood glucose! Here we'll define a temp basal, look at some situations in which a temp basal is handy, and talk about how they're different from Alternate Basal profiles.
What is a Temp Basal?
A Temporary Basal Rate (or “temp basal”) is an insulin pump feature which allows you to override your current active basal rate in order to add or subtract a specified amount of insulin from each basal dose, for a specified period of time.
For example, you could choose to increase the current basal rate by 50% for the next 3 hours; if your current basal rate is 3 U/hr, the resulting temporary basal rate would be 50% more, or 4.5 U/hr. Or you could choose to decrease the programmed basal rate by 30% for 24 hours; for an active basal rate of 3 U/hr, the resulting temporary basal rate would be 30% less, resulting in 2.1 U/hr.
How this temp basal is expressed depends on which pump model you use:
Some pump models allow the programmed basal rates to be increased or decreased by a percentage of the current rates, for a duration of 30 minutes to 24 hours, for example.
- If 100% is the starting point (representing the usual basal insulin rate), then a temp basal increase is expressed as a number over 100 (150% would be an increase of 50%) and a temp basal decrease is expressed as a number less than 100 (75% would be a decrease of 25%).
- Some pump models instead use zero as the starting point that represents the usual basal insulin rate; in this case a temp basal increase is expressed as “plus” a certain percentage (+50% would be an increase of 50%) and a temp basal decrease as “minus” a certain percentage (-25% would be a decrease of 25%),
Some pump models allow the programmed basal rates to be increased or decreased by units per hour (rather than percentages). For example, you could program the pump to reduce the current basal rate by 0.05 units/hour. If the basal rate in the first Time Block is 1.0 u/hr and then it goes up to 1.5 u/hr in the second Time Block, then the adjusted temp basal rates would be 0.95 u/hr and then 1.45 u/hr, respectively. You could also choose to increase the current basal rate by 0.05 units/hour. Then the resulting temporary basal rates in the same example would be 1.05 u/hr and 1.55 u/hr.
Note that in all cases, the temp basal rate adjusts insulin based on the current basal rate; when it changes according to the basal profile, the temp basal changes, too, by the same amount that you have requested, until the temp basal program ends.
For detailed and current information on how temporary basal rates operate in a particular pump model, please consult your pump manufacturer.
Waltzing the dragon also has a side-by-side comparison chart of all of the pumps available in Canada that includes their temp basal specs.
Why Bother With a Temp Basal?
There are conditions under which you can predict that your child will need proportionally more or less insulin (due to hormones, stress/excitement, illness, or exercise, when your child’s activity level varies from the usual), but changing the programmed basal rates would be inconvenient, as would having to remember to change them back when that condition ends. At these times, using a temp basal allows you to adjust the basal rate temporarily, without actually changing the basal program.
Note: For many of these conditions, you could use an Alternate Basal program instead. The choice is up to you.
Some specific examples of times when a temp basal may be helpful:
During and After Spontaneous Exercise (when the body likely needs less insulin)
Before Planned Exercise (when the body will likely need less insulin)
Before, During and/or after experiencing a cold, flu, infection, stomach bug, etc
During a long car or plane trip (in which there is significantly less physical activity than usual)
As the driver on an extended road trip, to reduce the potential for hypoglycemia at the wheel
When on an extended fast (such as Ramadan, Lent, or Yom Kippur)
During menses, when additional basal insulin may be needed.
Before and/or during a test
During or after a scary movie/TV show
During or after a day at an amusement park
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Tips from the Trenches
When Paul was 12, he decided it would be a good idea to run barefoot on a treadmill. Needless to say, he slipped off and ended up severely cutting the top of his foot open (requiring 14 stitches). By the next day, we noticed Paul’s blood sugar was continually climbing. We felt like we were doing constant corrections for high BG’s (which is a good indication that his basal insulin wasn’t high enough). Knowing that his body had just experienced huge trauma, it made sense that the reason for the high BG’s was because of an outpouring of stress hormones (and the dramatic change in his activity level didn’t help the situation). We found it helpful to use a temp. basal increase of up to 60% rather than permanently changing basals because his insulin needs would change every day.
Exercise typically lowers blood glucose. If your child has pretty much the same amount of physical activity every day, then the regular programmed basal rates will likely be set to account for this. But what if your child has soccer practice on Wednesday and games on Saturday, but not much activity the other days of the week? You could set a temp basal decrease on soccer days to account for the increased physical activity. What if your child is active at school recess during the week, but is a weekend couch potato? You could set a temp basal increase to account for the decreased physical activity.
Sometimes exercise leads to a rise in blood glucose. Under these conditions, a temp basal increase (rather than the typical decrease) may be helpful.
Illness can either raise or lower blood glucose. If your child is vomiting, setting a temp basal decrease takes off the pressure from having to “feed the insulin”. If your child has a cold, fever, or similar, her body may be insulin resistant, in which case a temp basal increase is a handy way to avoid the predictable high blood glucose over the next few days.
Tips from the Trenches
This has been one of the MAJOR benefits of a pump for our family… we value not having to keep pushing a steady stream of carbs when our son can’t keep anything in his stomach long enough to maintain an in-target BG against the effects of basal insulin! We just set a temp basal decrease (of something around 30 – 50% less) and then within an hour or two, we don’t have to worry about pushing sugar. Conversely, when he starts to get the sniffles, accompanied by highs that are likely a result of his cold, we bump up the basal insulin by 30 – 60% to allow for the increased basal needs while his body is fighting off the “bug”. It is not uncommon for a body to need twice the usual amount of insulin, or even more, when dealing with illness. It’s wise to start with relatively small adjustments, increasing the adjustment in reasonable steps until you see an effect on blood sugar. It took several tries for us to figure out a good amount to increase or decrease the insulin, and it’s not exactly the same with every sickness, but we’re so much closer than we would be without a temp basal feature. ~Michelle
Hormones & Stress
Hormones can either raise or lower blood glucose. When hormones surge, due to physiological processes such as menstruation, due to physiological stress such as surgery, or due to emotional stress/excitement from an exam, a scary movie or a day riding roller coasters, these hormones affect the way your child’s body uses insulin; a temp basal setting (increase or decrease, depending on whether, in the past, you have observed your child’s blood glucose rise or drop under these conditions) may be helpful a few hours in advance of the stressful event, or for a few days during her menstrual period.
A Note on Stress: In some individuals, stress hormones may cause insulin resistance, in which case you need more insulin to keep blood glucose in target during stress. However, the OPPOSITE is also true for some individuals. We have heard from some students who say their blood glucose tends to go low around test time. We suggest that you base your strategy on blood glucose data from previous occasions of these conditions. As in all things related to the dragon, consider both alternatives when addressing your individual situation. In short, YDMV! (Your Diabetes May Vary)
A Few Notes On Temporary Basal Rates…
If you find that too often you have to set the same temporary basal rate (increase or decrease), across a variety of different conditions, it may be helpful to change the regular programmed basal rates instead.
A temporary basal rate changes the background (i.e. basal) insulin only – it does not affect the amounts given as bolus to cover food or correct high blood glucose. Under some conditions, you may also choose to increase or decrease the amount of bolus insulin in addition to setting a temp basal. For example, if your child has a gastro-intestinal (stomach) illness, he may not be absorbing as much from his food as usual, and you may find that a weaker insulin-to-carb ratio is needed in addition to a temp basal decrease.
Tips from the Trenches
We both find that even after symptoms of a tummy bug have completely disappeared and our son is eating normally again, if we do not provide less insulin for food (via a weaker I:C ratio) for a few days, he will have repeated lows. It seems that even after he’s back to normal on the outside, he is still recovering on the inside; perhaps his GI system isn’t absorbing as much nutrition from his food as it normally does, so less insulin is needed to cover the food that is absorbed. ~Danielle and Michelle
The above information was reviewed for content accuracy by clinical staff of the Alberta Children’s Hospital Diabetes Clinic.
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