Injection site rotation
The site should be changed at each injection (rotated) to reduce the risk of lipohypertrophy developing. A simple way to reduce this risk is to systematically rotate the site where the insulin is injected (Chowdhury and Escudiet, 2003). There are four main injection sites - abdomen, thigh, arm and buttocks (Fig 5). Each of these has different characteristics, and the rate at which human insulin is absorbed differs for each one (however, there does not appear to be any difference with analogue insulin).
One scheme with proven effectiveness involves dividing the injection site into quadrants (or halves when using the thighs, buttocks or arms) (Hicks et al, 2011). One quadrant should be used per week and moving always in the same direction, either clockwise or anti-clockwise, keeping the injections at least 2cm apart (Fig 5).
Reusing needles
Reuse can lead to bruising and bleeding as a result of the needle being blunted by overuse. Infection is possible if needles are reused or an injection is given through clothing. It is recommended needles are used only once, and injections should not be given through clothing (Hicks et al, 2011).
Principles for teaching patients
Some patients do not remember being taught all the aspects of injection technique when they started insulin therapy.
It is therefore essential to review injection technique regularly; nurses should not assume that patients injecting insulin are doing it correctly either from the start or over a period of time. The following should be revisited at least every year: