Why do self blood glucose monitoring?
Measuring blood sugar levels at home has become a
cornerstone of diabetes care. Measuring your child's blood
sugar regularly can:
prevent low blood sugar at night
reduce the risk of eye, kidney and nerve complications
help you make informed decisions about the amount and
type of insulin to use
help you manage illness at home and alert you if you need
to do a ketone test
help you understand the effects of certain foods,
exercise, and stress on your blood sugar.
What supplies are needed?
Doing a blood test requires a method of pricking the skin to
get a drop of blood as well as a method of reading the
results. Results are read using test strips that are put
in a blood glucose meter or that change color to show the
results.
Finger-pricking (lancing) device: A finger-pricking device
(called a lancet) is used to get the drop of blood. The lancet
can often be set at different depths for different people. The
adjustable lancets are particularly good for young children
who have tender skin and may not need much lancing depth.
Remember to change the lancet everyday. A sharp lancet helps
prevent injury and infection.
Blood glucose meter: Most people use blood glucose meters
to test their blood sugars. In some countries where meters
are not available, color-changing blood sugar strips are
used. Not all meters measure in the same way, so the
results from different meters are not always comparable. It
doesn't matter which type of meter you choose as long as you
consistently use the same meter. Bring your meter to each
clinic visit. Your provider will download the information
from the meter to keep as a record.
Some features to look for in a meter include:
Accuracy (Make sure the meter is accurate in the
environment in which you live, for example, cold, heat,
high humidity, or high altitude.)
Storage of at least the last 100 test values
Ability to be downloaded at clinic and/or at home
Small size
Short determination time
Cleaning is easy or not necessary
A control solution or strip can be used to check meter
accuracy.
Test strips: When choosing test strips, make sure they work
in the meter you are using. Look for strips that need only
a small drop of blood and can draw the blood into the strip
(capillary action). The glucose strips usually add up to a
cost of $2 to $3 per day, so insurance coverage is
important. Make sure you know what strips your insurance
will pay for before you choose your meter.
How do I do a blood sugar test?
To get a drop of blood from a finger (or toe):
Wash the area with warm water. This increases blood flow
and makes sure there is nothing on the finger (or toe)
that may alter the reading. Do not routinely wipe the
finger with alcohol. Any trace of alcohol left on the
skin will interfere with the test. Occasionally, when
away from home (for example, camping and picnics), it is
necessary to use alcohol-free travel wipes to clean the
area.
Air dry the area before pricking.
Use the lancet to prick the side of the finger or toe
rather than the fleshy pad on the fingertip or toe (which
is more painful). It is often helpful to place the
finger on a table. This helps prevent the natural reflex
of withdrawing the finger when poked. If the drop is not
coming easily, hold the hand down to the side of the body
to increase the blood in the finger.
Put the drop of blood on the strip. (If a test strip
has been in a cooler or refrigerator, bring it to room
temperature before using.) Make sure you completely
cover the required area on the strip with blood. Putting
too small a drop on the strip is one of the most common
errors.
Use your blood glucose meter to measure the sugar level
from the strip. If you are using color-changing strips,
compare the color to the color chart on the package at
the appropriate time. You will have to use a watch with
a second hand and be careful to check the level after an
exact amount of time specified on the package directions.
Do I have to prick a finger or toe?
Many children prick sites other than the fingers or toes
because they may not hurt as much. The most common
alternate site is the forearm. Other places to test include
the fleshy part of the hand, upper arm, thigh, and back of
the calf. The lancet must be dialed to the maximum depth to
get enough blood from these sites. Make sure you have a
meter that works for these testing sites.
The main problem with not using the fingertips is that the
blood flow through the arm is slower than through the
fingers. The slower blood flow means the blood sugar value
from the arm is 10 minutes behind the fingertip. It is
important to rub the site to be used on the arm before
pricking. Rubbing increases blood flow in the area. If your
child is having symptoms of low blood sugar, use the
fingertip.
When should my child do a blood sugar test?
Your child should do 3 to 4 blood sugar tests every day,
with occasional days off for a rest.
The most common times to do a blood sugar test include:
Before breakfast: This test reflects the blood sugar
value during the night and is probably the most important
time to test. The short-acting insulin dose can be
adjusted based, in part, by the value of this test. The
dose of Lantus insulin is also based on this test.
Before lunch: This helps you decide if the morning
Humalog/NovoLog and/or Regular insulin dosage was correct.
Before dinner: This test reflects how well the dose of
morning NPH or Lente insulin worked. It may also reflect
the effect of afternoon sports activities and an
afternoon snack. A test should not be done unless it has
been at least 2 hours since food was eaten. If it is time
for dinner and your child had an afternoon snack 1 hour
earlier, it is best to wait and do a test before the
bedtime snack. If this is a common occurrence, change to
doing a blood sugar test before the afternoon snack.
Before the bedtime snack: This test lets you know if the
short-acting insulin dose given at dinner was correct.
This test is important for people who tend to have
reactions during the night, children who play outside
after dinner, and anyone who did not eat well at dinner.
If the bedtime values are low, an extra snack should be
given in addition to the usual solid protein and
carbohydrate so your child's blood sugar does not drop
too low during the night.
The more often you measure your blood sugar level, the more
information you and your diabetes care provider will have
for making the right decisions about your child's diabetes
management.
Testing after meals: Doing a blood sugar test 2 hours after
eating a meal is becoming a more common practice. You should
check blood sugar values 2 hours after each meal once or
twice weekly. The blood sugar value goals are the same for
2 hours after a meal as they are for 2 hours before a meal.
Testing after meals is a useful testing time for people who
count carbohydrates and inject insulin just before eating
based on how many carbohydrates they plan to eat.
Testing at night: Occasionally, you may need to do a blood
test in the middle of the night to make sure the value is
not getting too low. A nighttime blood sugar test is
important for people who tend to have low blood sugars
during the night. More than half of the severe low sugars
occur during the night. It is important to test on nights
when there has been extra physical activity (for example, a
basketball game in the evening or playing hard outside on a
nice summer evening). The best time to do a check varies
with each person. For some, between midnight and 2 a.m. is
the best. For others, the early morning hours are better.
Testing at school: Some health care providers request that
a test be done prior to eating lunch. For some children and
schools this is not a problem and can be done without
interfering with the child's normal school routine. If a low
blood sugar reaction occurs at school, it is helpful for
your child to do a blood sugar test at the time of the
reaction.
What should the blood sugar level be?
The following table shows what the blood sugar level should
be when you test. Bedtime blood sugar levels should be
higher than other tests during the day so your child can
make it through the night without having a low blood sugar
reaction.
Morning OR
2 hours before Before bedtime
Age (years) or after a meal snack
------------------------------------------------------
Below 5 80 to 200 Above 150
(if below 80 do a
test in the night)
5 to 11 70 to 180 Above 120
(if below 70 do a
test in the night)
12 + 70 to 150 Above 100
(if below 60 do a
test in the night)
-------------------------------------------------------
Should I keep written records?
Keeping good records to look for patterns in blood sugars is
essential. It is wise to keep written records even if your
meter is able to store results (in case the meter breaks).
Write down the time of the test, the date, how your child
feels, and the blood sugar value. You may also want to note
times of heavy exercise, illness, or stress. It may be
helpful to record what was eaten for the bedtime snack or
any evening exercise to see if these are related to morning
blood sugars. Also, keep a record of when your child has low
blood sugar reactions and possible causes. Bring these
results to your appointments.
Good record keeping and bringing the results to clinic
visits allow the family and diabetes team to work together
most effectively to achieve good diabetes management.
