What is the proper procedure for administering insulin?

Proper Insulin Administration Technique

Insulin should be injected subcutaneously using proper technique with site rotation to ensure optimal absorption and glycemic control. 1, 2

Preparation and Storage

• Allow insulin to reach room temperature before injection (remove from refrigerator 30-60 minutes before use) to reduce pain and prevent lipodystrophy 2
• For cloudy insulins (e.g., NPH), gently roll or tip the vial/pen until crystals dissolve; avoid vigorous shaking which may introduce air bubbles 2
• Always check the insulin label before administration to avoid medication errors 2

Injection Sites and Rotation

• Recommended injection sites include abdomen, thighs, buttocks, and upper arms 1
• Absorption rates vary by site: abdomen has fastest absorption, followed by arms, thighs, and buttocks 2
• Systematically rotate injection sites to prevent lipohypertrophy, which can cause inconsistent insulin absorption 1
• Inject at least 1 cm away from previous injection sites 2

Injection Technique

1. Clean the injection site with an alcohol swab and allow it to dry completely 2
2. For pen needles or syringes, use short needles (4-5mm) and inject at a 90° angle for most adults 1
3. Thin individuals may need to pinch skin and inject at a 45° angle to avoid intramuscular injection 1
4. Insert the needle through the skin 3
5. Slowly push the plunger all the way down 3
6. Keep the needle embedded in the skin for 5-10 seconds after complete delivery of insulin 1, 3
7. Remove the needle straight out of the skin 3
8. Gently press the injection site for several seconds but do not rub the area 3

Insulin Mixing Guidelines

• Insulin glargine should not be mixed with other forms of insulin due to its low pH 1
• Rapid-acting insulin can be mixed with NPH, lente, and ultralente insulins 1
• When rapid-acting insulin is mixed with intermediate or long-acting insulin, inject within 15 minutes before a meal 1
• Mixing of short-acting and lente insulins is not recommended except for patients already adequately controlled on such a mixture 1
• Phosphate-buffered insulins (e.g., NPH) should not be mixed with lente insulins 1

Needle Safety and Disposal

• Never reuse needles or syringes to maintain sterility and prevent blocked needles 1, 3
• Do not recap, bend, or break needles after use to avoid needle-stick injuries 1
• Dispose of used sharps in a puncture-resistant container according to local regulations 1, 3

Common Pitfalls to Avoid

• Injecting cold insulin directly from the refrigerator (causes pain and may affect absorption) 2
• Injecting into lipohypertrophy areas (causes unpredictable absorption) 1
• Inconsistent rotation of injection sites (leads to lipohypertrophy) 1
• Injecting through clothing (prevents proper site inspection) 2
• Removing the needle too quickly after injection (causes insulin leakage) 1
• Injecting intramuscularly instead of subcutaneously (causes unpredictable absorption and hypoglycemia) 1

Special Considerations

• For patients who report frequent skin leakage, count to 10 after the plunger is fully depressed before removing the needle 1
• Local bruising and bleeding do not adversely affect clinical outcomes or insulin absorption 1
• Use needles with thin-wall or extra-thin-wall technology to minimize leakage 1

Following these guidelines will help ensure proper insulin delivery, consistent absorption, and optimal glycemic control while minimizing complications such as lipohypertrophy and injection site reactions.