In this week’s conference we covered and reviewed some of the basic management of diabetes in the Emergency Department. I thought it was a good review and reminder of some of the concepts that we sometimes forget about.
So…..In today’s blog post we will be reviewing some of the basic management of diabetics in the Emergency Department with a particular emphasis on the utilization of insulin. To be clear this is meant to be a basic review. This is a topic that does not get much love by residents and attendings alike. However, as Emergency Departments all across the country continued to board patients for extended periods of time, it is our responsibility to keep these patients safe and set them up for success. One responsibility we are being charged with is the management of diabetes. We need to prevent our patients from spiraling into DKA or having an episode of life threatening hypoglycemia under our watch.
I will try to provide a simple and to the point review of basic insulin utilization in the ED. In this post, I do not plan on covering DKA but look out for possible future post regarding this topic.
INTRO
First, let’s review the types of insulin we may encounter in the Emergency department. Summary table below if you do not have the attention span to read the descriptions.
Rapid Acting insulin (Lispro – Humalog, Aspart – Novolog)
This is the insulin patients often use as meal time insulin or prandial insulin. The onset is 5-15 minutes and will start to see peak affect around 1-2 hours. The duration of action is about 4-5 hours.
Short Acting insulin (Regular insulin – Humulin R or Novolin R)
This is the insulin used for IV hyperkalemia protocol and insulin drips at RUMC. The onset is roughly 30-60 minutes and will see peak affect around 2-4 hours. The duration is 6-10 hours.
Intermediate acting insulin (NPH – Humulin NPH or Novalin NPH)
These insulins can be found in a number of combinations in premixed insulin. The onset is approximately 30-60 minutes with a peak onset of 4-10 hours. The duration is 10-16 hrs.
Long acting insulin (Detemir – Levemir, Glargine – Lantus)
Often used as basal insulin to provide coverage for long periods of time in between meals. The onset of action is 2-4 hours. These do not have a defined peak and have a duration of 18-24 hrs.
Table adapted from Dr. Koehl’s presentation during conference.
HOW DO I UNDERSTAND THEIR HOME REGIMEN?
Next, let’s take a look at understanding and identifying a patient’s insulin regimen at home. Are they taking prandial doses, basal doses, both a basal and prandial? I think we have all seen some “interesting” regimens out there often when patients dose themselves. Additionally, identify if they are taking pre-mixed insulin. These are rapid or short-acting insulins with intermediate or long-acting insulins. Such as:
NovoLIN 70/30 = 70% intermediate + 30% short-acting
NovoLOG 70/30 = 70% long-acting + 30% rapid-acting
(note the lower number is always the short or rapid acting insulin)
Example: Patient takes 30 units of Novolin 70/30 at home
- 70% (30 units) = 21 units of NPH (intermediate acting)
- 30% (30 units) = 9 units of regular (short-acting)
Now that we understand the types of insulin and have identified the patients home doses we can apply this to our patients in the emergency department.
If the patient will be in the department for an extended period of time and is eating as they would at home we should attempt to put the patient on a similar regimen as they would be on at home until the hospitalist team takes over patient care. (This is in the case where their home regimen is generally working for them)
Sometimes this may mean converting insulin types based on what is available in the ED. Below is a general guide.
Converting insulins:
- NPH → glargine
- NPH once daily: unit-per-unit conversion
- NPH twice daily: unit-per-unit or reduce daily dose by 20%, give once daily
- Detemir → glargine
- Give 80% Levemir/detemir dose as glargine
- Regular human insulin → rapid-acting
- Unit-per-unit conversion
- Keep in mind: rapid-acting has faster onset and shorter duration of action
IMPORTANT NOTE:
Patients may not be eating in the ED. This is often the case and their insulin needs to be adjusted accordingly.
- Decrease long-acting by 50%, cover other 50% with short-acting
- Correct hyperglycemia with short-acting
- Cover mealtime (when eating) with short-acting
This strategy should cover most patients that present to the emergency department. As always, discuss with your pharmacist with question or concerns when available.
ACUTE THERAPY OF SEVERE HYPERGLYCEMIA
Now that we have our boarding patient tucked away nicely and their blood sugar managed appropriately, let us now review another common event in the emergency department. A patient is going to be admitted and has an elevated blood glucose of 450 for example. No DKA yet but they are symptomatic including excessive urine output and fatigue.
Question: How do you manage this patient?
Answer: Give empiric correction of blood glucose with rapid acting insulin like lispro, volume repletion, correction of any electrolyte imbalance and specific therapy directed toward any identified underlying cause of hyperglycemia.
Let’s focus on the blood glucose.
This can be managed by:
- Weight base dosing
- Based on a correction factor and how much above target
Weight based is my preferred method for providing a correctional dose. It is fast and utilizes simple math.
- 0.05 to 0.1 units/kg of lispro.
- If they are insulin naive I will typically utilize 0.05.
- In general I tend to be on the conservative side for weight based insulin dosing to avoid hypoglycemia.
Based on correction factor
- 1-2 units of lispro per every 40-50 mg/dL above target glucose level.
- Goal hospital BG: 140 to 180 mg/dL
RECHECK blood glucose in one hour after administration of your rapid acting insulin.
Now that we have ordered our patient insulin Let’s also remember to place patients on a hypoglycemia protocol. Remember hypoglycemia can be a killer in the ED.
This includes:
- Frequent blood glucose checks. I like Q4H or more frequently if needed. Recheck POC glucose every 20 minutes if requiring hypoglycemia treatments until glucose is greater than 70mg/dL
- Standing order for appropriate treatment if patient is hypoglycemic
- This includes Glucose oral gel 15-30g
- Juice or crackers if tolerating PO
- If NPO or not alert and glucose is less than 70mg/dL: give 25g 50% dextrose (1 amp) IVP
END
Feel free to comment below with thoughts or feedback on today’s post!
Thank you Kristen Koehl, PharmD for presenting on this topic and giving me permission to adapt information from her lecture.
SOURCES
Koehl, Kristen. A brief review of hyperglycemia treatment and insulin products for people who may not want to know about insulin, but are required for safe medication practice in the Emergency Department. May 2021. PowerPoint Presentation.
Tintinalli, Judith E., et al. Tintinalli’s Emergency Medicine: a Comprehensive Study Guide. McGraw Hill Education, 202.
Image from: https://www.inquirer.com/health/consumer/insulin-ration-diabetes-drug-costs-20190625.html