syringe in one hand, vigorously shake them back and forth 6-10 times as shown in Figure 16-6. Holding the upward- pointing syringe and vial vertically, rapidly draw back the plunger immediately after shaking to fill the syringe with in sulinweU beyond your dose. Do not delay, as the grayparticles wUl settle very rapidly. 5-6. StiU holding verticaUy, slowly push plunger in until desired dose is reached, then remove needle and filled syringe from vial (seesteps 5-6, above).
Insulin: The Basics ofSelf-Injection 257
Fig. 16-5. Filling the syringe, holding Fig. 16-6. Shaking a vialofcloudy vial and syringe vertically. insulin before drawing outthe dose.
ON THE REUSE OF DISPOSABLE INSULIN SYRINGES
The annual cost of sterUe disposable insulin syringes can beconsider able, especiaUy if you take multiple daUy injections.
You may become tempted to reuse your syringes, especiaUy if your medical insurance doesn't reimburse you for the cost. (Many medical insurance poUcies inthe United States do at least partiaUy cover this expense.) Although Ihaven't encountered any infection caused by asingle person reusing his own syringes, I have encountered the problem of polymerization of insulin.* Many of mypatients pass through astage when they routinely reuse their syringes several times, to save money orto enable themto travel with only asmaU supply.
These patients never use the same syringe for two different types of insulin, so we can't say that one insulin is con taminating another.
Inevitably, Iget atelephone caU with the message,
*A polymer is a large molecule made up of identical smaUer molecules bound together.
258 Treatment
"My blood sugars are high and I can't get them down." I ask, "Bring your clear insulin to the phone.
Is it crystal clear, like water?" In evitably the reply is, "No, it's slightly hazy." Insulin that becomes hazy has been partially deactivated by polymerization and will not ade quately control blood sugars.
This is not found bypeople who do not reuse their syringes.* Of course, I advise such patients to immediately replace all insulin vials, whether long- or short-acting, that have been used to fill reused syringes.
Replacement of the vials always cures the problem.
Naturally, syringes should not subsequently be reused.
What if you encounter a situation whereyou only haveone syringe to last for a week and have no way of getting new ones?
Flush the syringe with air several times after each use to clear out any remaining insulin.
When filling the syringe, do not inject air into the insulin vial (step 3), and don't inject the excess insulinback into the vial (step 5).
Just draw the needle from the vial and squirt the excess into the air.This way, you won'tcontaminate yourvial with the minute amount of old insulin that may remain in the needle or syringe.
If you have a second unused sy ringe, you can useit justto inject air intoyour vials, making certain the needle does not come into contact with the insulin in the vials.
If for financial reasons you really must reuse your syringes, the fol lowing procedure should help minimize contamination with poly merized insulin.
You will, at the minimum, need three syringes, but four would be better.
• Set aside one syringe for each of the different insulins you may be using.
Put a small piece of adhesive tapeon each syringe, marked with the abbreviated name of the insulin (see page 269). • Use your insulin vials for a week without injecting air into them.
Squirt any excess insulin from each filling into a sink or waste- basket, not back into the vial. • At the end of a week, remove the plunger from an unused sy ringe.
Stand the vial stopper up on a flat surface and push the needle of the unused syringe into the stopper of the vial.Within seconds, the vacuum in the vial will suck in enough air through the needle to replace the vacuum.
The reason for this is that the minute amount of insulin remaining in a used needlewill becomepolymerized (inactivated) within a few hours. If it is injected back into the vial, it will eventuallyact as a seed for the polymerization of much of the insulin in the vial.
Insulin: TheBasics of Self-Injection 259
• PuU theneedle out ofthestopper, reinsert theplunger, andrecap the "air" syringefor use the next week.
WHAT IF YOU INJECT SEVERAL DIFFERENT INSULINS AT THE SAME TIME?
As discussed in Chapter 19, "Intensive Insulin Regimens," you might have to inject several different insulins at thesame time.
For example, when you arise in the morning, you might inject an ultrarapid in sulin (e.g., Uspro) to bring down a sUghtiy elevated blood sugar, then a rapid-acting insulin (regular) to cover your breakfast, then a long-acting (basal) insulin (i.e., detemir or glargine).
Take the most- rapid-acting (lispro), then the rapid-acting (regular), and last the long-acting, one injection after another, aU using the same syringe.
You cansafely do thisbecause the insulin has not had enough time to polymerize in theneedle (this takes several hours).
Ifyour long-acting insulin is glargine, however, don't use the same syringe.
Just a smaU amount of Uspro or regular in the needle mayeventuaUy cause the in sulin in thevial ofglargine to turn cloudy andlose some ofitsactivity.
This is very important.
Don't mix different insulins together, either in thesame syringe or in thesame vial, as this wiU result in a new insuUn with new, inappro priate timing.
The only exception wouldbe to slowdown the action of regular insulin when dealing with gastroparesis.
MUST YOUR SKIN BE WIPED WITH ALCOHOL?
Most textbooks and instruction sheets that teach insulin injection or finger stickingadvisethat the skin should be "sterilized" with alcohol before puncturing with a needle.
Alcohol wUl not sterilize your skin.
Atbest it wiU clean off dirt.
My patients and I have given miUions of injections and finger sticks without using alcohol.
Noneof us has be comeinfected as a result.
Certainly it's a sensible idea to cleanoff visi ble dirt first, but you can do this with simple soap and water on the rare occasions that it may be necessary.
I often inject myself right through myshirtor trousers (but not through the trouser pockets).
260 Treatment
DISPOSAL OF USED SYRINGES
A Cost-Free Method I recommend the foUowing cost-free, safe method for disposing of used syringes. Again, this is contrary to the recommendations of the ADA.