Insulin Types and Classifications: A Detailed Guide

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Insulin is an important hormone for managing blood sugar levels in individuals with diabetes. Proper administration and knowledge about insulin types, syringes, preparation, and injection techniques are essential for effective diabetes management.
This article covers everything you need to know about insulin syringes, types, actions, preparation, administration, key considerations, and patient education.

1. Insulin Syringe Types and Identification 

Types of Insulin Syringes:-

  • U-40 Syringes:- These syringes are calibrated for insulin that has 40 units of insulin per milliliter (ml). they have a red cap.
  • U-100 Syringes:- These are calibrated for insulin that has 100 units per ml. They have an orange cap and are more common globally.

Identifying Insulin Syringes:-

  • Color Coding:- U-40 syringes typically have red caps, while U-100 syringes have orange caps.
  • Calibration Marks:- Check the calibration marks on the barrel of the syringe. U-40 syringes have fewer and larger units between marks compared to U-100 syringes.

2. Insulin Classification, Types, and Actions

Classification:- Insulins are classified based on how quickly they start working, when they peak, and how long they last.

Types of Insulin:-

  • Rapid-Acting Insulin:-
    • Examples:- Lispro (Humalog), Aspart (NovoLog), Glulisine (Apidra)
    • Onset:- 10-30 minutes
    • Peak:- 30 minutes to 3 hours
    • Duration:- 3-5 hours
    • Action:- Used for rapid blood sugar control around meal times, reducing postprandial (after meal) glucose spikes.
  • Short-Acting Insulin:-
    • Examples:- Regular insulin (Humulin R, Novolin R)
    • Onset:- 30 minutes to 1 hour
    • Peak:- 2-5 hours
    • Duration:- 5-8 hours
    • Action:- Taken about 30 minutes before meals to control blood sugar spikes post meals.
  • Intermediate-Acting Insulin:-
    • Examples:- NPH insulin (Humulin N, Novolin N)
    • Onset:- 1-2 hours
    • Peak:- 4-12 hours
    • Duration:- 12-18 hours
    • Action:- Provides basal or background insulin coverage, often used in combination with rapid or short-acting insulin.
  • Long-Acting Insulin:-
    • Examples:- Glargine (Lantus), Detemir (Levemir)
    • Onset:- 1-2 hours
    • Peak:- No pronounced peak
    • Duration:- Up to 24 hours
    • Action:- Provides a steady level of insulin throughout the day and night, used once or twice daily for consistent blood sugar control.
  • Ultra Long-Acting Insulin:-
    • Examples:- Degludec (Tresiba)
    • Onset:- 6 hours
    • Peak:- No pronounced peak
    • Duration:- Over 36 hours
    • Action:- Provides an extended duration of insulin action, ensuring stable blood glucose levels over a longer period.

Actions of Insulin:-

  • Rapid-Acting Insulin:- Quickly reduces blood sugar levels after meals. Ideal for controlling postprandial blood glucose spikes.
  • Short-Acting Insulin:- Controls blood sugar levels during meals and snacks. It is also used for intravenous administration in hospital settings.
  • Intermediate-Acting Insulin:- Provides basal insulin coverage, maintaining blood sugar levels between meals and overnight.
  • Long-Acting Insulin:- Ensures a constant level of insulin to control blood sugar levels throughout the day and night without significant peaks.
  • Ultra Long-Acting Insulin:- Offers prolonged insulin action, suitable for individuals requiring long-term insulin therapy with fewer injections.

3. Preparing Insulin for Injection

Steps to Prepare Insulin:-

  1. Wash Hands:- Ensure hands are clean to prevent infection.
  2. Inspect Insulin:- Check the insulin bottle for the correct type, expiration date, and clarity. Do not use it if it appears cloudy (unless it is supposed to be) or has particles.
  3. Mixing Insulin:- Roll the bottle of intermediate or long-acting insulin gently between your hands to mix it.
  4. Clean the Vial:- Use an alcohol swab to clean the rubber stopper on the insulin vial.
  5. Draw Air into Syringe:- Pull back the plunger to draw air into the syringe equal to the dose of insulin required.
  6. Insert Air into Vial:- Push the needle through the stopper and inject air into the vial.
  7. Draw Insulin:- Turn the vial and syringe upside down, and pull the plunger to draw the required amount of insulin into the syringe. Remove any air bubbles by flicking the syringe and pushing the air back into the vial.
  8. Double-Check Dose:- Ensure you have the correct dose before injecting.

4. Administering Insulin

Injection Sites:-

  • Abdomen:- The best site for consistent absorption.
  • Upper Arms:- The back of the arms can be used.
  • Thighs:- The front and outer thighs are suitable.
  • Buttocks:- The upper outer part can be used.

Injection Technique:-

  1. Pinch the Skin:- Gently pinch the skin where you plan to inject.
  2. Insert the Needle:- Insert the needle at a 90-degree angle for shorter needles or a 45-degree angle for longer needles.
  3. Inject Insulin:- Push the plunger down slowly and steadily to inject the insulin.
  4. Withdraw Needle:- Pull the needle out and apply gentle pressure to the injection site for a few seconds.

5. Key Considerations During Insulin Preparation

  • Accuracy:- Always double-check the insulin type and dose.
  • Storage:- Keep insulin refrigerated but do not freeze. Once opened, keep it at room temperature.
  • Rotation of Sites:- Rotate injection sites to prevent lipodystrophy (abnormal or degenerative conditions of the body’s fat tissues).
  • Timing:- Adhere to the timing of insulin administration as prescribed to maintain effective blood sugar control.

6. Dawn and Somogyi Phenomena

Dawn Phenomenon:-

  • Definition:- A natural rise in blood sugar in the early morning hours due to hormone changes.
  • Hormones Involved:- Growth hormone, cortisol, glucagon, and adrenaline increase in the early morning, leading to higher blood sugar levels.
  • Symptoms:- High fasting blood glucose levels in the morning.
  • Management:-
    • Adjusting the timing or dose of insulin, especially long-acting insulin taken before bed.
    • Changing the type of insulin to one that has a more extended duration of action.
    • Using a continuous glucose monitor to track blood sugar levels overnight and adjust the treatment accordingly.
    • Avoiding carbohydrates before bedtime can sometimes help mitigate the effect.

Somogyi Phenomenon:-

  • Definition:- Rebound hyperglycemia following nighttime hypoglycemia. The body releases counter-regulatory hormones (like glucagon and adrenaline) to raise blood sugar levels in response to the low levels.
  • Symptoms:- High blood glucose levels in the morning, similar to the Dawn phenomenon, but caused by an overnight low blood sugar episode.
  • Management:-
    • Adjusting the evening insulin dose to prevent hypoglycemia.
    • Having a bedtime snack to maintain steady blood glucose levels overnight.
    • Changing the type of insulin or its administration schedule.
    • Monitoring blood glucose levels during the night to identify and correct hypoglycemia.

7. Patient Education

Teaching Patients About Insulin Use:-

  • Understanding Insulin:- Explain the different types of insulin and their actions.
  • Self-Monitoring:- Teach how to monitor blood glucose levels.
  • Injection Technique:- Demonstrate the correct injection technique and site rotation.
  • Hypoglycemia Management:- Educate on the signs of low blood sugar and how to treat it.
  • Storage:- Instruct on proper insulin storage.

8. Nursing Care and Responsibilities

Responsibilities of Nurses:-

  • Educating Patients:- Provide comprehensive education on diabetes management.
  • Monitoring:- Regularly monitor blood glucose levels and insulin administration techniques.
  • Support:- Offer emotional support and encourage adherence to the treatment plan.
  • Assessment:- Assess for signs of complications such as hypoglycemia, hyperglycemia, or lipodystrophy.

9. Mixing Two Insulins

Which Insulin to Draw First and Why:-

  • Short-Acting or Regular Insulin:- Always draw short-acting (clear) insulin first to prevent contamination with long-acting (cloudy) insulin. This avoids altering the action of the short-acting insulin.

Steps to Mix Insulins:-

  1. Inject Air into Intermediate or Long-Acting Insulin Vial:- Inject air into the vial without drawing insulin.
  2. Inject Air into Short-Acting Insulin Vial:- Inject air and draw the required dose of short-acting insulin. (fill first clear insulin then cloudy)
  3. Draw Intermediate or Long-Acting Insulin:- Draw the required dose of intermediate or long-acting insulin into the same syringe.

Conclusion

Proper knowledge and techniques in insulin administration are crucial for effective diabetes management. Understanding the types, their actions, correct preparation, and injection techniques can significantly improve patient outcomes. With the right education and support, individuals with diabetes can manage their condition effectively and maintain a healthy lifestyle.

Also Read About⇒ ABG Interpretation

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