Physicans Dosing Guidelines for Subcutaneous Insulin
1. TARGET: Hyperglycemia increases risk for mortality, infection, overall morbidity and length of stay.
- For most patients on the medical/surgical floors, fasting blood sugars of 90-130 mg/dl and less than 180 mg/dl at all times are the goal.
If a patient has hypoglycemic risk factors (renal failure, endd stage liver disease, hyperbaric therapy, recent hypoglycemia, tapering steroid doses, etc), then goal fasting glucose values should be 90-150 mg/dl.
- Post op cardio-thoracic surgery goals are 80-110 mg/dl fasting and less than 180 at all times.
2. Estimating Insulin Doses: Calculate the estimated total daily dose (TDD) of insulin based on ONE of the following methods (in order of preference).
a. Transferring from insulin gtt. Use average hourly rate over the last 6 hours (assuming that the dose has not been adjustedin the last 3 hours), mulitply by 20 to get the TDD --> some newly hyperglycemic patients on very low gtts ( < 1 unit perhour) may not require schedules subcutaneous insulin.
b. Use total insulin required at home (all types added together): For example, a patient on 70/30 40 units in the morning and 20 units at dinner would have a TDD of 60 units.
c. Calculate/estimate insulin requirement as follows based on body size:
- Dialysis (regardless of BMI) OR CrCl<15 use 0.3units/kg/day
- Lean(BMI < 25), CrCl 15-30, new steroid indiced hyperglycermia or new diagnosis of DM: use 0.4 inits/kg/day
- Overweight (BMI 25-30) use 0.5 units/kg/day
- Obese (BMI >30) or high dose steroids use 0.6 inits/kg/day
d. In known type 2 diabetes whose outpatient blood sugars were controlled with diet alone, or stress/steroid induced hyperglycemia supplemental scale may be sufficient to control blood sugars in the hospital.
3. For the first day
- If it is prior to noon, consider giving 1/2 of the usual HS dose of glargine X 1 then usal hs dose OR give a dose of NPH X 1 and then the usual HS dose of long acting insulin.
- If it is after noon, consider giving the hs dose of glargine early.
- If you are stopping an insulin gtt, gice glargine (lantus) or NPH 2-4 h prior to turning gtt off.
4. Special Situations
a. ICU Patients:
- An IV insulin drip is preferred and should be used for almost all ICU patients this provides the safest and most effective control.
- Subcutaneous basal/bolus per protocol may be appropriate as extubated patients, off pressors, insulin after they leave the ICU. Also, if they are on very high requirements (5-8 units/hour) then there may be infusion delivery failure.
- Be sure to give basal insulin at least 2 hours before the insulin drip is turned off.
- See the dosing algorithm for transition doses.
b. CV Surgery
- Almost all patients will be on IV insulin in the ICU. Use the guides in "Transitioning to home" and "ICU patients" to help determine how to adjust insulin as they transition out of the ICU and to home.
- IV insulin is preferred so as long as they are in the SICU, they generally should not be transitioned to subcutaneous insulin until their transfer to tele is ready.
- Pressors should be off and blood glucose values should be stable in the preceding 3 hours before IV insulin is transitioned to subcutaneous.
c. Type 1 diabetes
- Require at least some schedules insulin at all times to prevent ketosis even when NPO--They will need dextrose containing IVF to prevent hypoglycemia.
- Many times, you can use the regimen the patient has at home including basal and meal insulin, often with carbohydrate counting to account for the variable oral intake in the hospital.
- Sliding scale insulin as the only coverage should not be used.