Sliding Scale Insulin: How It Works

Taking insulin on a sliding scale means the size of an insulin dose depends on a person’s current glucose reading. The number of prescribed insulin units "slides" up as your blood sugar level rises. Sliding scale doses are typically taken just prior to meal time, and sometimes at bedtime, to correct for elevated blood sugar. The type of insulin used on a sliding scale is often regular or fast-acting, but there are different sliding scale regimens - using a variety of insulin - to address different diabetic needs.

A Sliding Scale Prescription

Here is an example of a doctor’s insulin order for Ms. Doe:

Monitor blood sugar twice each day - at 9 am and 5 pm;

Take regular insulin for glucose above 200 mg/dl at 9 am and 5 pm according to the following sliding scale:

Blood Sugar (mg/dl) . . . .Regular Insulin
below 70 . . . . . . . . . . . . . . follow rule of 15, notify MD
70 - 200 . . . . . . . . . . . . . . . none
201 - 250 . . . . . . . . . . . . . . 4 units subcutaneously
251 - 300 . . . . . . . . . . . . . . 6 units subcutaneously
301 - 350 . . . . . . . . . . . . . . 8 units subcutaneously
over 351 . . . . . . . . . . . . . . .call MD

Reading the sliding scale:

• The left column is where Ms. Doe looks after taking her 5 pm fingerstick. Her blood sugar reading of 220 mg/dl falls between 201 and 250, so she takes 4 units of insulin.
• The next morning at 9 am, Ms. Doe has a glucose level of 260 mg/dl which lies between 251 and 300. She takes a 6 unit dose of insulin.
• Later, at 5 pm, Ms. Doe’s glucose is 180 mg/dl and she takes no units of insulin.

Many individuals with a sliding orders also have a prescription for a fixed or unchanging background dose of long-lasting insulin.

Sliding Scale Considerations

The sliding scale has some disadvantages. It does not accommodate changing insulin needs related to stress, physical activity, or snacks. Sliding scale users must keep the following in mind.

• A sliding scale prescription may include a bedtime correction dose. This amount is only what is required to get the blood sugar back to target level and does not cover any additional carbs from a non-prescribed bedtime snack.
• When using a sliding scale it is important to eat the same amount of carbohydrate at every meal. Although the foods can change, the time and carb count of the meal should always be constant.
• The timing, type, and duration of your physical activity or exercise should be, as much as possible, the same each day.
• Although there are fewer calculations to make using a sliding scale, its success depends on disciplined adherence to a prescribed diet, and keeping a consistent schedule of activity and meals.
• You must eat the assigned number of carbohydrates at each meal, and at roughly the same times each day.

It is easy to see why sliding scale therapy can only work well when the user has a generally predictable lifestyle. Although there are many variations of sliding scale regimen, each one needs to be followed consistently.

Source: Dibetes Teaching Center, Washington DSHS
Photo: Pexels