Insulin

Administration of insulin

Injection technique

• Injections by syringe are usually given into the deep SC tissue through a two-finger pinch of skin at a 45–90° angle
• The pinch of skin is used to avoid the risk of administering insulin IM
• The SC fat layer should be thicker than the needle length. Very short needle lengths (e.g. 5 or 8 mm) are now available in some countries and they are particularly useful for young, slim children
• All suspensions of insulin (e.g. NPH, IZS, pre-mixes) must be resuspended before injection by rolling or inverting the vial or pen injector device (10 times) so that the cloudy suspension mixes thoroughly and uniformly
• Pen injector technique requires careful education including the need to ensure that no airlock or blockage forms in the needle; a wait of 5–10 seconds after pushing in the plunger helps to ensure complete expulsion of insulin through the needle

Self-injection

• It should be emphasized that a proportion of people with diabetes have a severe and long-lasting dislike of injections, which may influence their glycemic control
• There is great individual variation in the appropriate age for children to self-inject
• The appropriate age relates to developmental maturity rather than chronological age
• Most children over the age of 10 years either administer their own injections or help with them
• Younger children sharing injection responsibility with a parent or other care provider may help to prepare the device or help push the plunger and subsequently under supervision be able to perform the whole task successfully
• Self-injection is sometimes triggered by an external event such as overnight stay with a friend, a school excursion or diabetes camp
• Parents or care providers should not expect that self-injection will automatically continue and should accept phases of non-injection and the need to provide help
• Younger children on multiple injection regimens may need help to inject sites that are difficult to reach (e.g. buttocks) to avoid lipohypertrophy

Regular checking of injection sites, injection techniques and skills remains the responsibility of parents, care providers and health professionals

Self-mixing of insulin

• There is no uniformity of advice but most often it is taught that clear insulin (short-acting) is drawn up into the syringe before cloudy insulin (intermediate- or long-acting)
• If the cloudy insulin is lente type, the mixture must be administered immediately otherwise the short-acting component interacts
• Insulins from different manufacturers should be used together with caution as there may be interaction between the buffering agents
• NPH and lente insulins should never be mixed
• Rapid-acting insulin analogs may be mixed in the same syringe as NPH or lente