CHEARS

• Insulin is a naturally occurring hormone secreted by the pancreas. Many people with diabetes are prescribed insulin, either because their bodies do not produce insulin (type 1 diabetes) or do not use insulin properly (type 2 diabetes).

Insulin Basics

• There are different types of insulin depending on how quickly they work, when they peak, and how long they last.Insulin is available in different strengths

• In people with type 1 diabetes, the pancreas no longer makes insulin. The beta cells have been destroyed and they need insulin shots to use glucose from meals. Insulin is the mainstay of therapy for individuals with type 1 diabetes. Generally, the starting insulin dose is based on weight, with doses ranging from 0.4 to 1.0 units/kg/day of total insulin. The American Diabetes Association/JDRF Type 1 Diabetes Sourcebook notes 0.5 units/kg/day as a typical starting dose in patients with type 1 diabetes who are metabolically stable, with higher weight-based dosing required immediately following presentation with ketoacidosis and provides detailed information on intensification of therapy to meet individualized needs. The Diabetes Control and Complications Trial (DCCT) clearly showed that intensive therapy with multiple daily injections or CSII delivered improved glycemia and resulted in better long-term outcomes The study was carried out with short-acting and intermediate-acting human insulins. Despite better microvascular, macrovascular, and all-cause mortality outcomes, intensive therapy was associated with a high rate of severe hypoglycemia .Since the DCCT, a number of rapid-acting and long-acting insulin analogs have been developed. These analogs are associated with less hypoglycemia, less weight gain, and lower A1C than human insulins in people with type 1 diabetes .Longer-acting basal analogs (U-300 glargine or degludec) may additionally convey a lower hypoglycemia risk compared with U-100 glargine in patients with type 1 diabetes. People diagnosed with type 1 diabetes usually start with two injections of insulin per day of two different types of insulin and generally progress to three or four injections per day of insulin of different types. The types of insulin used depend on their blood glucose levels. Studies have shown that three or four injections of insulin a day give the best blood glucose control and can prevent or delay the eye, kidney, and nerve damage caused by diabetes.

• People with type 2 diabetes make insulin, but their bodies don't respond well to it. Some people with type 2 diabetes need diabetes pills or insulin shots to help their bodies use glucose for energy. Most people with type 2 diabetes may need one injection per day without any diabetes pills. Some may need a single injection of insulin in the evening (at supper or bedtime) along with diabetes pills. Sometimes diabetes pills stop working, and people with type 2 diabetes will start with two injections per day of two different types of insulin. They may progress to three or four injections of insulin per day.insulin cannot be taken as a pill because it would be broken down during digestion just like the protein in food. It must be injected into the fat under your skin for it to get into your blood.

MNEMONICS

• Rapid-Acting Insulin:

• Onset: 15 minutes Peak: 1 hour Duration: 3 hours

• “15 minutes feels like an hour during 3 rapid responses.”

Short-Acting Insulin:

• Onset: 30 minutes

• Peak: 2 hours

• Duration: 8 hours

“Short-staffed nurses went from 30 patient to (2) 8 patients.”

Intermediate-Acting Insulin:

• Onset: 2 hours

• Peak: 8 hours

• Duration: 16 hours

“Nurses Play Hero to (2) eight 16 year olds.”

Long-Acting Insulin:

• Onset: 2 hours

• Peak: NONE

• Duration: 24 hours

“The two long nursing shifts never peaked but lasted 24 hours.”

Short acting insulin mnemonic:NO LAG Novalog Lispro (Humalog) Aspart (Novalog) Glusiline

• Long acting insulin mnemonic: "Plez Gladly take Ultra Long to Deteriorate." Protamine zinc insulin Glargine Ultralente Detemir

• Intermediate acting insulin mnemonic: "I am Intermediate, NAH?" Isophane (NPH) Also, I looks like a L for lente.

DOSAGE CALCULATION

• Bolus – Carbohydrate coverage

The bolus dose for food coverage is prescribed as an insulin to carbohydrate ratio.The insulin to carbohydrate ratio represents how many grams of carbohydrate are covered or disposed of by 1 unit of insulin.Generally, one unit of rapid-acting insulin will dispose of 12-15 grams of carbohydrate. This range can vary from 4-30 grams or more of carbohydrate depending on an individual’s sensitivity to insulin. Insulin sensitivity can vary according to the time of day, from person to person, and is affected by physical activity and stress.

• Bolus – High blood sugar correction (also known as insulin sensitivity factor)

• The bolus dose for high blood sugar correction is defined as how much one unit of rapid-acting insulin will drop the blood sugar.Generally, to correct a high blood sugar, one unit of insulin is needed to drop the blood glucose by 50 mg/dl. This drop in blood sugar can range from 15-100 mg/dl or more, depending on individual insulin sensitivities, and other circumstances.

Carbohydrate coverage at a meal

• First, you have to calculate the carbohydrate coverage insulin dose using this formula:

• CHO insulin dose = Total grams of CHO in the meal÷ grams of CHO disposed by 1 unit of insulin (the grams of CHO disposed of by 1 unit of insulin is the bottom number or denominator of the Insulin:CHO ratio).

For Example #1, assume:

• You are going to eat 60 grams of carbohydrate for lunch

• Your Insulin: CHO ratio is 1:10

• To get the CHO insulin dose, plug the numbers into the formula:

• CHO insulin dose = Total grams of CHO in the meal (60 g) ÷ grams of CHO disposed by 1 unit of insulin (10) = 6 units

• You will need 6 units of rapid acting insulin to cover the carbohydrate

High blood sugar correction dose

• Next, to calculate the high blood sugar correction dose.

High blood sugar correction dose =Difference between actual blood sugar and target blood sugar ÷ correction factor.Actual blood sugar minus target blood sugar

• For Example #2, assume:

• 1 unit will drop your blood sugar 50 points (mg/dl) and the high blood sugar correction factor is 50.

• Pre-meal blood sugar target is 120 mg/dl.Your actual blood sugar before lunch is 220 mg/dl.

• Now, calculate the difference between your actual blood sugar and target blood sugar: 220mg -120 mg/dl = 100 mg/dl

• to get the high blood sugar correction insulin dose, plug the numbers into this formula:

• Correction dose = Difference between actual and target blood glucose (100mg/dl)÷ correction factor (50) = 2 units of rapid acting insulin

• So, you will need an additional 2 units of rapid acting insulin to “correct” the blood sugar down to a target of 120 mg/dl.

• To get the high blood sugar correction insulin dose, plug the numbers into this formula:

• Total mealtime dose

Finally, to get the total mealtime insulin dose, add the CHO insulin dose together with the high blood sugar correction insulin dose:CHO Insulin Dose+ High Blood Sugar Correction Dose = Total Meal Insulin Dose

• For Example #3, assume:

• The carbohydrate coverage dose is 6 units of rapid acting insulin.

• The high blood sugar correction dose is 2 units of rapid acting insulin.

• Now, add the two doses together to calculate your total meal dose.

• Carbohydrate coverage dose (6 units)+ high sugar correction dose (2 units) = 8 units total meal dose

• The total lunch insulin dose is 8 units of rapid acting insulin.

Total Daily Insulin Requirement(in units of insulin)= Weight in Pounds ÷ 4

• If you are measuring your body weight in pounds:

• Assume you weigh 160 lbs.

• TOTAL DAILY INSULIN DOSE = 160 lb ÷ 4 = 40 units of insulin/day

Alternatively, if you measure your body weight in kilograms:

• Total Daily Insulin Requirement (in units of insulin) = 0.55 X Total Weight in Kilograms

• If you are measuring your body weight in kilograms:

• Assume your weight is 70Kg

• TOTAL DAILY INSULIN DOSE= 0.55 x 70 Kg = 38.5 units of insulin/day

Basal/background insulin dose:

• Basal/background Insulin Dose = 40-50% of Total Daily Insulin Dose

• Example

• Assume you weigh 160 pounds

• Your total daily insulin dose (TDI) = 160 lbs ÷ 4 = 40 units

• The carbohydate coverage ratio:

• 500 ÷ Total Daily Insulin Dose = 1 unit insulin covers so many grams of carbohydrate

• This can be calculated using the Rule of “500”: Carbohydrate Bolus Calculation

• Example:

• Assume your total daily insulin dose (TDI) = 160 lbs ÷ 4 = 40 units

• In this example:

• Carbohydrate coverage ratio = 500 ÷ TDI (40 units) = 1unit insulin/ 12 g CHO

• The high blood sugar correction factor:

• Correction Factor = 1800 ÷Total Daily Insulin Dose = 1 unit of insulin will reduce the blood sugar so many mg/dl.This can be calculated using the Rule of “1800”.

• Example:

• Assume your total daily insulin dose(TDI) = 160 lbs ÷ 4 = 40 units

• In this example:

• Correction Factor = 1800 ÷ TDI(40 units) = 1 unit insulin will drop reduce the blood sugar level by 45 mg/dl

• While the calculation is 1 unit will drop the blood sugar 45 mg/dl, to make it easier most people will round up or round down the number so the suggested correction factor may be 1 unit of rapid acting insulin will drop the blood sugar 40-50 mg/dl.

SLIDING SCALE

sliding scale regimens:The sliding scale is a chart of insulin dosages. A doctor creates this chart with the individual depending on the person’s body responds to insulin, their daily activity. Insulin dosage will vary, depending on two factors:

Pre-meal blood glucose level: This usually appears on the left-hand side on the chart, from low to high, with higher doses of insulin toward the bottom of the chart. The more blood sugar a person has, the more insulin they will need to deal with it.

Mealtime: This usually appears along the chart’s top row. This row will show breakfast, then lunch, then dinner. Throughout the day, the dose will change. This is because insulin sensitivity — the way the body responds to insulin — can change as the day progresses. The composition of meals can also change through the day, and the doctor may take that into consideration.

Common sliding scale regimens

• Long-acting insulin (glargine/detemir or NPH), once or twice a day with short acting insulin (aspart, glulisine, lispro, Regular) before meals and at bedtime

• Long-acting insulin (glargine/detemir or NPH), given once a day

• Regular and NPH, given twice a day

• Pre-mixed, or short-acting insulin analogs or Regular and NPH, given twice a day

The general principles of sliding scale therapy are:

• The amount of carbohydrate to be eaten at each meal is pre-set.

• The basal (background) insulin dose doesn’t change. You take the same long-acting insulin dose no matter what the blood glucose level.

• The bolus insulin is based on the blood sugar level before the meal or at bedtime

• Pre-mixed insulin doses are based on the blood sugar level before the meal

Reading the chart:

To work out the right dosage using a sliding scale, people should follow these steps:

1. Test their blood glucose level.

2. Find the matching blood glucose value along the chart’s left-hand column.

3. Slide horizontally along that value’s row until they reach the current meal.

4. Take a dosage that matches the number where the two values meet. The person should test their blood sugar levels before mealtimes, depending on the type of insulin they use.

Disadvantages of the sliding scale regimen:

• The sliding scale method does not accommodate changes in insulin needs related to snacks or to stress and activity.

• You still need to count carbohydrates.

• Sliding scales are less effective in covering a pre-meal high blood sugar, because the high blood glucose correction and food bolus cannot be split.

• Sliding scale regimens may include a bedtime high blood sugar correction. As the nighttime scale only considers the amount of insulin required to drop your blood sugar level back into the target range, it should not be used to cover a bedtime snack.

• When using a sliding scale, eat the same amount of carbohydrate at each meal. In other words, while the foods may change, the time and the carbohydrate content of the meal should not vary.

• Engage in an equivalent level of activity from day to day. Try not to vary the timing, type or duration of activity.

• The sliding scale method may seem easier, because there are fewer calculations. However, to be successful, it requires a strict adherence to a consistent schedule of meals and activity, and following your prescribed diet.

• Eat the pre-assigned amount of carbohydrate for each meal, and at a similar time of the day.