Both insertion methods work effectively, so it is entirely up to the user to decide which works best for him.
Angle of insertion
Infusion sets come in two varieties with regard to the angle at which the cannula is inserted into the skin: straight (90°) or angled (10° to 45°). A 90° set means the needle is inserted at a right angle, or straight into the skin. This option allows for use of a shorter needle, which many people view as an advantage. The disadvantage, however, is that a shorter needle can become dislodged more easily. Also, kinks in a soft cannula are more common with a 90° infusion set.
“Angled” infusion sets are popular among people who are physically active and lean. They allow a person to insert the needle into the subcutaneous tissue at different angles ranging from 10° to 45°. The major disadvantage with this type of set is that the introducer needle is longer and may therefore be less appealing for people with needle phobia.
Most manufacturers provide infusion sets with a variety of lengths of tubing. Your preference may depend on where on your body you insert your infusion set and whether you wear the pump itself inside or outside of your clothing. Also, the physical setup of areas, such as the bathroom, where pump users carry out their daily routines often determines what tubing length they choose.
Site selection, care, and rotation
Different areas of the body generally absorb the rapid-acting insulin analogs used in pumps at similar rates. However, people may find slight variations from one body area to another and should keep this in mind if they notice otherwise unexplained fluctuations in their blood glucose levels after changing infusion areas.
The most comfortable place to insert an infusion set for most pump users is the abdominal area, which also has the most consistent absorption rate. During pregnancy it is still appropriate to insert in the abdomen as long as the subcutaneous tissue can be pinched up.
Other infusion sites include the outer thighs, backs of the arms, hips, and buttocks. The thighs and arms usually have slower absorption rates than the abdominal area, but the rates may accelerate with increased activity. The backs of the arms can be a difficult to use if dexterity is an issue. Many people choose the hips and buttocks as their infusion sites since these areas tend to have more subcutaneous fat and may be more comfortable, especially for people who are very active or don’t have much body fat in general.
When selecting an infusion site, avoid bony areas and places where the infusion set might be constricted, such as areas that will be covered with tight-fitting clothing. Also avoid areas that contain scar tissue, superficial (visible) blood vessels, body piercings, or tattoos. It is also important to stay two inches away from the navel.
Proper infusion site care is essential for preventing infections. Good technique starts with cleanliness. All equipment should be stored unopened in the manufacturer’s original packaging until use. Washing hands and the area of insertion with soap will help prevent bacteria from gaining a foothold. One way to insure that the insertion area is clean is to change infusion sites immediately after a shower. It is also imperative that blood glucose levels be checked 1–2 hours after insertion to make sure that insulin is being delivered unimpeded.
Even with impeccable site care, infection can occur, and it is important to recognize the signs of infection so you can respond quickly. Signs and symptoms of infection include redness, swelling, pain, warmth in the area, a lump under the skin, fever, pus, and elevated blood glucose levels. Medical care is always recommended, so contact your health-care team at the first sign of any suspected infection. Antibiotic treatment may be necessary, and more serious infections may require surgical incision and drainage.