Insulin Flashcards
What is is insulin sensitivity factor? So called correction factor. How to calculate?
How much the BG level will change for an individual per unit of insulin.
Percent rule means can calculate by 100/TDD. Ie ALL insulin. B and bolus
Why is ISF used?
To help calculate the most appropriate bolus dose and ensure the insulin dose will cover the patients current BG level.
What is the CHO to insulin ratio?
The g of CHO one unit on insulin will “cover”
What do you start adjusting with a patient on basal bolus whose BG readings are consistently above target?
Start with bringing FBG under control with basal. Adjust basal until pre-prandial is 4-7
After that then adjust bolus. May need to reasses insulin carb ratio or insulin sensitivity factor.
Insulin basal should be titrated until FBG is between
4-7
Basal Insulin dose should not be further increased if patient experiences ____ episodes of hypo in 1 week or ANY episode of nocturnal hypo.
2
What is the typical total daily dose of insulin for type 2 patient in units per kg
1-1.5 units/kg
A smaller number of patients may require 2 u/kg
What is typical insulin dosing for type 1,in units per kg
0.3-0.8 units per kg per day.
Adolescents 1-1.5 units per kg per day.
If bedtime glucose is less than 7
Have a CHO snack before bed.
What to do if a patient misses a bolus dose?
Hyperglycemia will
Occur but not cause significant risk. Patient can adjust next bolus dose to accommodate.
What if patient cannot remember if they had their basal dose at bedtime?
Difficult to determine until
Several hours later when they are sleeping.
Do not administer another dose due to risk of hypo.
If they suspect accidentally injecting bolus instead, recheck BG 1 hour later to see if BG is falling rapidly.
How would you add one bolus dose to a type 2 patient only on basal?
Typically 10% of basal dose given as bolus at largest meal of the day. Increase by 1 unit per day until 2 hour PP is 5-10. OR if measure before next meal, target 4-7. Patients can titrated themselves if deemed appropriate.
Or start 2-4units
When should a pre-mix be considered? Ie: 30/70. Humalog mix 25 or mix 50. Or novamix 30
When patients cannot handle two types of insulin.
When patient had regimented lifestyle in terms of qty of food and activity as cannot adjust.
What are the limitations of using pre-mix insulin?
Lack of mealtime flexibility
Increased risk of nocturnal hypo
Cannot fine tune doses without adding separate bolus
More weight gain can occur m
How do you initiate a pre-mix insulin?
Suggested starting is 5-10 units once or twice a day. Pre-breakfast and/or pre-supper.
**pre-breakfast achieves pre-supper target BG value. 4-7.
Pre-supper achieves pre-breakfast target. 4-7.
30/70 should be given a half hour before meals.
Humalog or novo mix give immediately before eating.
If BG targets are not reached, increase the relevant dose until both targets are reached.
Must monitor at least twice a day
Do not increase dose if 2 or more episodes of hypo in a week or ANY episode of nocturnal hypo
Oral hypoglycemics may need to be reduced or stopped if daytime hypo occurs
Can also use: 0.5units/kg *from essentials!
When bolus is initiated what po drugs are usually stopped?
Secretegogues.
What if patient is on basal bolus but cannot carb count?
They should have consistent carb intake. They will initiate on a low bolus prior to meals and titrated based on pre- meal readings.
Insulin sensitivity factor can also be called correction factor as it can correct for pre-meal hyper by adding additional bolus insulin.
There are two ways to calculate.
100/total daily insulin dose. Ie: basal +bolus
10% rule. Use 10 % of usual bolus dose to reduce BG 2mmol
Eg. Patient uses total of 30 units insulin daily. 5 at each meal.
100/30 is approx 3. So 1 unit of bolus will reduce pre-meal BG by 3 mmol/l.
10% rule: 0.5 units are required to reduce BG by 2 mmol/l.
What are the 2 methods to calculate the carbohydrate: insulin ratio?
Use as example patient using 5 units bolus at each meal and 15 glargine. Consuming 180g CHO daily.
Calculate total daily intake of CHO in grams.
Divide this by total daily BOLUS insulin.
180/15 = 12 g CHO per unit of insulin.
Rule of 500 method Ie: assume pt eats 500g CHO
500/ basal +bolus
500/30=16.7. Approx 17g CHO per unit of insulin.
ALSO can calculate the individual CHO:insulin ratio for each meal separately to account for changes in insulin requirement during the day, counterreg hormones, exercise etc.
Initiating brand new type 1 on insulin.
From essentials: 0.5 units per kg
Divide up with 40% basal. Then take the 60% prandial and divide by 35-30-35 for meals.
**if pt is not acutely I’ll or ketotic the dose may be too high. If this is an adolescent, you should expect to need a higher dose due to insulin resistance during puberty.
Changing type one from bid premix to basal/bolus
Add total units of insulin. Basal and bolus or premix. REDUCE by 20-25% to compensate for a more physiologic insulin delivery. Than give 40 percent as basal and 60 percent as bolus in a 35-30-35 split.
When starting a basal insulin, what dose do you start at?
Ie: 2 ways to decide
10 units is pretty common.
Can also calculate 0.1 to 0.2 units per kg.
Eg. Patient is 80 kg. Start with 8-16 units.
If a type 2 patient is only on oral and you want to start basal bolus right away, how do you calculate dose of insulins?
0.3 to 0.5 units per kg. Then distribute as:
40% basal
20-20-20 bolus
Storing insulin at room temperature. How long for:
NPH
Detemir
All other insulins
NPH 30 days
Detemir 42 days
All other 28 days
When a type one pt reaches adolescence why do they need a higher dose of insulin?
Adolescence is associated with increased insulin resistance. Likely due to hormones.
Why does glycemic control typically worsen in adolescence?
1-physiological changes in insulin sensitivity
2- behavioral changes.
Why is sliding scale no longer used?
It is reactive and treats hyperglycemia AFTER the fact. The proactive approach of using the insulin correction factor is better
When switching from insulin injections to CSII how do you calculate dosage to program into the pump?
Take total daily dose of current insulin.
Reduce by 10-25%.
Take 50% of that to use as basal.
Eg. TDD=40u
-25%= 30u
Program pump to give 15 units as basal. Ie: divide by 24. So… 0.625u per hour.
The other 50% (or 60% if you used 40% as basal which is possible) is split between meals.
**degree of reduction of dose depends on glycemic control, A1C, hypoglycemic unawareness present?, any nocturnal hypo, patients ability to monitor nighttime hypo and clinical judgement.
Note: can also go by weight with 0.5u/kg if you think current doses of insulin are not managing BG well
Basal rates are typically 0.7-0.9u/hour
What lifestyle factors would indicate that CSII is a good fit for the patient?
Erratic lifestyle
Shift work
Frequent travel through multiple time zones.
How can you tell if a pts basal rate in CSII is correct based on monitoring?
Pt can go for 5 hours without eating and have less than a 1.7mmol change in BG
How soon after pump failure Ie: zero insulin being delivered, will DKA set in?
4-8 hours.
Patients should always have on hand syringes and insulin just in case. If a bolus of rapid is given and BG does not come down, insulin pump failure should be considered and the system changed for a new one.
Is severe hypo a contraindication for CSII?
No. Though pts must be educated and motivated to learn about managing hypo and use of glucagon
Should the CHO to insulin ratio be rounded up
Or down? Why?
Round up Ie: more CHO covered per unit of insulin. Prevents lows
