Doctors order urine tests for kids to make sure that the kidneys and certain other
organs are working as they should, or when they think that a child might have an infection
in the kidneys, bladder, or other parts of the urinary
tract.
The kidneys make urine (pee) as they filter wastes from the bloodstream, while
leaving substances in the blood that the body needs, like protein and glucose. So
when urine contains glucose, too much protein, or has other irregularities, it can
be a sign of a health problem.
Urinalysis
A urinalysis is usually ordered when a doctor suspects that a child has a urinary
tract infection (UTI) or a health problem that can cause an abnormality in
the urine. This test can measure:
- the presence of red and white blood cells
- the presence of bacteria or
other organisms
- the presence of substances, such as glucose, that usually shouldn't be found in
the urine
- the pH, which shows how acidic or basic the urine is
- the concentration of the urine
Sometimes, when the urine contains white blood cells or protein, or the test results
seem abnormal for another reason, it's because of how or when the urine was collected.
For example, a dehydrated
child may have concentrated (darker) urine or a small amount of protein in the
urine. But that might not mean that there's a health problem. Once the child is rehydrated,
these "abnormal" results may disappear. Depending on the amount of protein or other
cells in the urine, the doctor may repeat the urine test at another time, just to
make sure that everything is back to normal.
How a Urinalysis Is Done
In most cases, urine is collected in a clean container, then a small plastic strip
that has patches of chemicals on it (the dipstick) is placed in the urine. The patches
change color to indicate things like the presence of white blood cells or glucose.
Next, the doctor or laboratory technologist also usually examines the same urine
sample under a microscope to check for other substances that indicate different conditions.
If the dipstick test or the microscopic test shows white blood cells, red blood
cells, or bacteria (possible signs of a kidney or bladder infection), the doctor
may send the urine to a lab for a urine culture to identify the bacteria that
may be causing the infection.
Getting a urine sample. It can be difficult to get urine samples
from kids to test for a possible infection. That's because the skin around the urinary
opening (urethra) normally is home to some of the same bacteria that cause UTIs.
If these bacteria contaminate the urine, the doctors might not be able to use the
sample to tell if there is a true infection or not.
To avoid this, the skin surrounding the urinary opening has to be cleaned and rinsed
immediately before the urine is collected. In this "clean-catch" method, the patient
(or parent) cleans the skin, the child then urinates, stops momentarily (if the child
is old enough to cooperate), then urinates again into the collection container. Catching
the urine in "midstream" is the goal.
In some cases (for instance, if a child is not toilet trained), the doctor or nurse
will insert a catheter (a narrow, soft tube) through the urinary tract opening into
the bladder to get the urine sample. In certain situations, a sterile bag can be placed
around a baby’s diaper area to collect a urine sample.
If you have any questions about urine tests, talk with your doctor.
