1. According to Canadian Blood Services, a
unit of blood is approximately 450 ml. The
amount of blood in one person is five
litres or 10.5 pints. On average, 4.6
units of blood are required per patient.
http://wiki
.answers.com/Q/What_is_a_unit_of_blood_For
_example_in_the_bag_at_the_hospital_is_it_
a_pint_a_liter_that_makes_up_a_unit_or...<
/a>
2. Blood sugar concentration, or glucose
level, is tightly regulated in the human
body. Normally, the blood glucose level is
maintained between about 4 and 6 mmol/L
(70 to 100 mg/dL). The total measurement
of glucose in the circulating blood is
therefore about 3.3 to 7g (assuming an
ordinary adult blood volume of 5 liters).
Glucose levels rise after meals and are
usually lowest in the morning, before the
first meal of the day.
http://en.wikipedia.org
/wiki/Blood_sugar
How is it used?
The blood glucose test is ordered to
measure the amount of glucose in the blood
right at the time of sample collection. It
is used to detect both hyperglycemia and
hypoglycemia, to help diagnose diabetes,
and to monitor glucose levels in persons
with diabetes. Blood glucose may be
measured on a fasting basis (collected
after an 8 to 10 hour fast), randomly
(anytime), post prandial (after a meal),
and/or as part of an oral glucose
tolerance test (OGTT / GTT). An OGTT is a
series of blood glucose tests. A fasting
glucose is collected; then the patient
drinks a standard amount of a glucose
solution to "challenge" their system. This
is followed by one or more additional
glucose tests performed at specific
intervals to track glucose levels over
time. The OGTT may be ordered to help
diagnose diabetes and as a follow-up test
to an elevated blood glucose.
The American Diabetes Association
recommends either the fasting glucose or
the OGTT to diagnose diabetes but says
that testing should be done twice, at
different times, in order to confirm a
diagnosis of diabetes.
Most pregnant women are screened for
gestational diabetes, a temporary form of
hyperglycemia, between their 24th and 28th
week of pregnancy using a version of the
OGTT, a 1-hour glucose challenge. If
either fasting glucose or a random glucose
is above the values used to diagnose
diabetes in those who are not pregnant,
the woman is considered to have
gestational diabetes and neither the
screening nor the glucose tolerance test
is needed. If the 1-hour level is higher
than the defined value, a longer OGTT is
performed to clarify the patient’s
status.
Diabetics must monitor their own blood
glucose levels, often several times a day,
to determine how far above or below normal
their glucose is and to determine what
oral medications or insulin(s) they may
need. This is usually done by placing a
drop of blood from a skin prick onto a
glucose strip and then inserting the strip
into a glucose meter, a small machine that
provides a digital readout of the blood
glucose level.
In those with suspected hypoglycemia,
glucose levels are used as part of the
"Whipple triad" to confirm a diagnosis.
(See “Is there anything else I should
know?” section).
The urine glucose is seldom ordered by
itself. At one time, it was used to
monitor diabetics, but it has been largely
replaced by the more sensitive and “real
time” blood glucose. The urine glucose
is, however, one of the substances
measured when a urinalysis is performed. A
urinalysis may be done routinely as part
of a physical or prenatal checkup, when a
doctor suspects that a patient may have a
urinary tract infection, or for a variety
of other reasons. The doctor may follow an
elevated urine glucose test with blood
glucose testing.
http://www.labtestsonline.org/under
standing/analytes/glucose/test.html
