Continuous subcutaneous insulin Infusion: Good blood glucose control for up to 4 days
(1) Unit for Metabolic Medicine, Guy's Hospital Medical School, London
(2) Laboratory for Endocrine Physiology and Pharmacology, National Institute
for Medical Research, Mill Hill, London
(3) Department of Clinical Biochemistry, Royal Victoria Infirmary, Newcastle-upon-Tyne,
England
Received: 5 October 1978 Revised: 3 January 1979
Summary Six insulin-dependent diabetics were studied on their conventional
insulin treatment and during continuous, dual-rate, subcutaneous insulin
infusion for periods of up to 4 days. Diabetic control, as assessed by mean
plasma glucose, range of plasma glucose values, M-value or range of M-values
was improved significantly in 5 patients (mean ± âH SD plasma glucose concentration
on final infusion day 6.9± âH1.3 mmol/l, versus 11.3± âH3.2 mmol/l on conventional
treatment). Once a suitable insulin dose was established blood glucose control
could be maintained by continuous subcutaneous insulin infusion using the
same daily infusion rate without frequent adjustment. In some cases this
was less than the daily dose on the conventional treatment. However, glycaemic
control in one brittle diabetic, with unpredictable swings in blood glucose
on her normal regimen, was not improved by continuous subcutaneous insulin
infusion. During the period tested there was no sepsis at the cannula implantation
site and patients did not find the system uncomfortable or unduly inconvenient.
Key words Subcutaneous insulin infusion - near-normoglycaemia - diabetic
control - open-loop device
Insulin: Things You Should Know
Syringes, pens, injectors and pumps
Syringes, pens, jet injectors and pumps all have one thing in common ?they
deliver insulin. Each carries insulin through the skin and into the fatty
tissue underneath so that it can be absorbed and used by the body.
Syringes
Today's syringes are smaller, have finer needles and have special coatings
on the needles so injecting is as painless as possible. If you can, try
several brands before you commit to one. Ask yourself the following questions:
Does your syringe match your insulin dosage? Using a syringe that matches
your dose will help you draw up your insulin more accurately. For example,
if you take less than 30 units of insulin, use a 30-unit syringe.
Do you want a short or long needle? Which is more comfortable for you? Some
syringes have shorter needles; however, the depth of the injection does
affect the absorption of the insulin. This is something you will want to
mention to your diabetes educator or doctor.
Will you reuse your syringe? Insulin syringes are approved and designed
to be used one time only. Discuss with your diabetes educator or doctor
if you are considering reuse of syringes.
Pens and jet injectors
Insulin pens look similar to a slightly oversized writing pen. The insulin
comes in 1.5 mL or 3.0 mL cartridges containing 300 units of insulin. The
cartridge is inserted into the pen and remains there until all the insulin
is used. A short needle is attached to the end of the pen. Many people find
insulin pens convenient, accurate and those on a multi-dose regimen often
prefer them to syringes.
The cartridges come in many different varieties of insulins, including premixed
insulins. Disposable pens are also now available and are disposed of once
the insulin is finished. Ask for instructions in the use of the pen to ensure
that you are injecting the correct amount of insulin.
People who are visually impaired may also prefer insulin pens as some models make a ?licking' sound that helps to measure the required amount of insulin. Jet injectors, on the other hand, have no needles at all.These devices, release a tiny stream of insulin, which is forced through the skin by pressure. Some people find that bruising occurs at the injection site.You should consult with your diabetes healthcare team before buying one of these devices. Also, be sure that you learn how to properly use your pen or jet injector, and how to care for it and troubleshoot should something malfunction.
Pumps
Insulin pumps are fast becoming a popular choice for people who want greater
flexibility or an improvement in their blood glucose control. An insulin
pump is a microcomputer, about the size of a pager, that can deliver insulin
in increments as small as 1/10 of a unit. A syringe reservoir is filled
with regular or rapid-acting insulin and is placed inside the pump. A thin
tube called an ?nfusion set' is connected to the reservoir. At the end of
the set is a small needle, which is inserted into fatty tissue and left
there. The infusion set is changed every two to three days.
The pump is programmed to deliver a continuous infusion of background or ?asal' insulin. Whenever food is eaten the user delivers a ?olus' or surge of insulin. For pump therapy to be safe, it is essential to check the blood glucose a minimum of four to six times per day. Carbohydrate counting and diabetes problem solving are other important components of successful pumping. To ensure safe and effective pump therapy you will require assistance and intensive education from your diabetes healthcare team.