Is the conventional insulin injection out? No. In an emergency, one still needs to know how to use it. Here are some valuable tips on how to use injections as well as pens. In addition, we summarize the advantages and disadvantages of both.

Pen, syringe, or pump? Today, one has the choice between these three devices, as well as between various types of insulin. Those who do not wear a pump usually use a pen. But in emergencies, one still needs to the use the conventional injection with syringe. The pen, however, is not without its own pitfalls.

The conventional syringe
The insulin injection is a single-use plastic syringe, with needle, on which a scale clearly indicates the amount of insulin in half units. Using the injection, one draws the right amount of insulin from the ampule. In this way, one can mix normal insulin with delayed-action insulin directly into the same syringe, thereby avoiding the need for more pricks. For children, the syringes used are usually 8 mm in length. And: Single-use injections should always be kept in the house, but need not always be taken with you.

Drawing two different types of insulin
If you want to mix two different types of insulin from the 10 ml glass ampules – for example, 8 units of normal insulin with 4 units of basal insulin –   one proceeds as follows:

• Draw 12 units of air into the syringe and inject 4 units of this into the ampule with the basal insulin.
• The remaining 8 units of air must be injected into the ampule with normal insulin, leaving the needle inside.
• Turn the ampule with normal insulin on its head, and draw a little more than 8 units from the ampule.
• Take the needle out of the ampule.
• Tap the syringe gently, in order to gather the air bubbles, and push these carefully out with the syringe.
• Adjust the amount in the syringe to exactly 8 units.
• Before drawing the basal insulin, shake the bottle by rolling it 20 times between the palms of the hands.
• Finally, insert the needle into the basal insulin and draw exactly 4 units.

Note: One needs to carry out this procedure with the utmost care, to achieve an accurate mix. If you draw too much, you must not use it! One needs to start again with a new single-use syringe and new ampules, and to repeat the entire procedure.

Extra dilution for children
If a child, after diagnosis, requires only minimal amounts of insulin, one can obtain individual insulin solutions, ranging in concentration from 10 - 40 units, from the pharmacist.

Handy: the pen
Since 1985, the pen for injecting insulin has been available. It is called a ‘pen’ for the obvious reason that it looks like one. Instead of an ink cartridge, however, there is an insulin cartridge of 300 units. The insulin is released by pressing a button, after having set the exact amount of insulin by turning a small disc.

Every insulin manufacturer produces pens that vary in colour, shape and size. Only insulin cartridges belonging to a particular pen can be inserted. One should never try to insert a cartridge into a pen from a different firm. If so, you can no longer be sure as to whether the right amount of insulin has indeed been injected.

How to use a pen

• Before every injection with the pen, you should squirt 2 units of insulin out, in order to get rid of air in the needle and to test for any blockages.
  
• Only use the needles once. If not, the needles become blunt and injure the skin unnecessarily.
  
• In order to make sure basal insulin is mixed properly, you must shake it 20 times.
  
• After injecting, leave the needle in the skin for 10 seconds before extracting it.
  
• For emergencies (in case of a defect or loss), you should keep 100-unit single-use conventional injections at home.

Ampules
It is also possible to draw insulin from a pen cartridge, albeit only with 100-unit injections, as only these have the right scale on them! If another injection is used, you may inject too much insulin, which can be very dangerous!
Here’s how it goes, assuming you want to mix 8 units of normal insulin with 4 units of basal:

• Draw 8 - 9 units of normal insulin.
  
• Take the needle out of the ampule.
  
• Tap lightly on the syringe in order to get rid of air bubbles, which you then carefully push out.
  
• Adjust the amount of insulin in the syringe to exactly 8 units.
  
• Shake the basal insulin before extraction by rolling the ampule 20 times between the palms of the hands.
  
• Insert the needle into the ampule with the basal insulin and draw exactly 4 units.

	Injection	Pen
Advantages	amount of insulin is clearly seen minute doses possible insulins can easily be mixed available everywhere always ready to use	doesn't look like an injection easy to take everywhere no need to draw insulin by hand quick and easy to use available in syringe lengths of 5 - 12.7 mm
Disadvantages	insulin must be drawn by hand may attract too much attention syringes only available in lengths of 8 mm or 12.7 mm	cannot mix various insulins can become defect not available everywhere

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Kerstin Remus
Diabetes Consultant
Centre for Diabetes and Endocrinology
Krankenhaus auf der Bult
Hanover
E-Mail: onset(at)hka(dot)de