What are insulin pumps? What's a basal rate?
Insulin pumps are small electronic devices, slightly bigger than a pager, worn by people with type 1 or type 2 diabetes. Depending on the model, a pump holds 180-315 units of insulin. It is worn 24 hours a day, with some exceptions like showering, swimming and intimate moments when it’s taken off. It can be carried in a pocket, a bra, underwear…places are limited only by the imagination and comfort. Diabetes pumps deliver insulin through a small tube placed under the skin (canula) that is replaced every 2-3 days. A reservoir holds the insulin inside the pump and is refilled when the insulin runs out (unless the pump is disposable, but most aren’t). Pumps will automatically deliver background basal insulin (once programmed) and need to be manually programmed each meal or snack to deliver bolus insulin. Blood sugar testing and carb counting still need to be done.
Basal and bolus insulinInsulin pumps deliver a tiny amount of rapid acting insulin every hour into fat tissue. This is called basal insulin. Larger amounts of rapid insulin are delivered on demand when the user decides it is needed, like for meals. This is called bolus insulin.Basal or “background” insulin takes the place of NPH or Levemir or Lantus. No intermediate or long acting insulin is used in pump therapy. This basal insulin works with the sugar that the liver makes every hour to keep the blood sugars stable when not eating. Setting Overnight Basal RatesWhen starting pump therapy, each user programs the pump with the amount of basal insulin needed per hour for their individual needs to keep their blood sugars stable if not eating. This is often referred to as “setting the basal rates”. Each clinic has it’s own procedure for doing this but here is an example. Please follow with your medical team.Overnight basal rates are usually tested and changed first. Typically this is done by starting with the same basal rate for each hour of the day, as an example 0.6 units per hour. This is determined by your doctor or health educator and based on your individual needs. To check overnight basal rates, the pumper will not usually eat after 9pm and will test blood glucose levels at midnight, 0300 hr, 0600 hr and 0900 hour. If blood sugars rise or drop too much in any of those time frames, the rate of basal insulin is adjusted for that period until blood sugars stay relatively the same. For example, if blood sugars stay about the same from midnight to 0300 but rise from 0300 to 0600, then stay the same from 0600 to 0900, then the basal rate from 0300 to 0600 is slightly increased, as an example to 0.7 units per hour. The others are left alone. This is done until the person can have relatively stable blood glucose levels from bedtime, overnight till morning. Setting overnight basal rates can take people anywhere from 2 to 14 days or more depending on how many changes need to be made and rechecked and how many days people can manage waking up to check glucose levels. Setting Daytime Basal RatesOnce overnight basal rates are set, daytime rates are checked. This is done by missing breakfast and checking blood sugars every 1-3 hours (the suggested duration varies between books, educators, physicians and the pumper’s personal preference.) If the glucose levels rise or fall too much then the rate is adjusted for those few hours until blood sugars stay stable when the meal is missed. Then onwards to missing lunch, and then supper. Changing Basal RatesAlthough basal rates may have been set when someone with diabetes started a pump, they typically need to be tweaked over time as the body and life changes.Also, temporary basal rates can be programmed within a few seconds. So if someone is going power shopping or playing sports and wants to avoid a low blood sugar, the basal rate can temporarily be decreased by 50% for 2 hours, as an example. The % decrease or increase and the duration are all decided by the person with diabetes with advice from their health care team. Being able to program the background insulin – and change your mind on a dime - is one of the biggest advantages of pumping. It allows you to sleep in, miss meals, play sports and prevent lows or greatly reduce the severity of them. Life with diabetes never seems to stay the same. Thankfully, insulin pumps can be programmed quickly to accommodate this. What Don’t Insulin Pumps do?
I suggest you read, a day in the life of an insulin pumper to get a feel for daily life with insulin pumps. More essential introductory information on pumps:
Advantages and disadvantages of diabetes pumps Is the pump right for your life with diabetes? |
