What Is a Blood Test?
A blood test is when a sample of blood is taken from the body to be tested in a
lab. Doctors order blood tests to check things such as the levels of glucose, hemoglobin,
or white blood cells. This can help them detect problems like a disease or medical
condition. Sometimes, blood tests can help them see how well an organ (such as the
liver or kidneys)
is working.
What Is a Hepatic (Liver) Function Panel?
A liver function panel is a blood test that helps doctors check for liver injury,
infection, or disease. Liver function panels also can check for side effects in the
liver from some medicines.
Why Are Liver Function Panels Done?
A liver function panel is done to learn information about the levels of:
- Albumin and total protein, which help build and maintain muscles,
bones, blood, and organ tissue. Low levels may be seen with liver or kidney disease,
or nutritional problems.
- Liver enzymes: Alkaline phosphatase (ALP), alanine
aminotransferase (ALT), and
aspartate aminotransferase (AST). These enzymes help the liver convert
food into energy. When their levels are high, it can be a sign of that the liver is
injured or irritated.
- Bilirubin. Bilirubin is made when red blood cells break down.
The liver changes the bilirubin so that it can be excreted from the body. High bilirubin
levels may mean there is a problem with the liver. This can make skin look yellow,
a condition called jaundice.
How Should We Prepare for a Liver Function Panel?
Your child may be asked to stop eating and drinking for 8 to 12 hours before the
test. Tell your doctor about any medicines your child takes because some drugs might
affect the test results.
Wearing a T-shirt or short-sleeved shirt for the test can make things easier for
your child, and you also can bring along a toy or book as a distraction.
How Is a Liver Function Panel Done?
Most blood tests take a small amount of blood from a vein. To do that, a health
professional will:
- clean the skin
- put an elastic band (tourniquet) above the area to get the veins to swell with
blood
- insert a needle into a vein (usually in the arm inside of the elbow or on the
back of the hand)
- pull the blood sample into a vial or syringe
- take off the elastic band and remove the needle from the vein
In babies, blood draws are sometimes done as a "heel stick collection." After cleaning
the area, the health professional will prick your baby's heel with a tiny needle (or
lancet) to collect a small sample of blood.
Collecting a sample of blood is only temporarily uncomfortable and can feel like
a quick pinprick.
Can I Stay With My Child During a Liver Function Panel?
Parents usually can stay with their child during a blood test. Encourage your child
to relax and stay still because tensing muscles can make it harder to draw blood.
Your child might want to look away when the needle is inserted and the blood is collected.
Encourage your child to relax by taking slow deep breaths or singing a favorite song.
How Long Does a Liver Function Panel Take?
Most blood tests take just a few minutes. Occasionally, it can be hard to find
a vein so the health professional may need to try more than once.
What Happens After a Liver Function Panel?
The health professional will remove the elastic band and the needle and cover the
area with cotton or a bandage to stop the bleeding. Afterward, there may be some mild
bruising, which should go away in a few days.
When Are Liver Function Panel Results Ready?
Blood samples are processed by a machine, and it may take a few hours to a day
for the results to be available. If the test results show signs of a problem, the
doctor might order other tests to figure out what the problem is and how to treat
it.
Are There Any Risks From Liver Function Panels?
A liver function panel is a safe procedure with minimal risks. Some kids might
feel faint or lightheaded from the test. A few kids and teens have a strong fear of
needles. If your child is anxious, talk with the doctor before the test about ways
to make the procedure easier.
A small bruise or mild soreness around the blood test site is common and can last
for a few days. Get medical care for your child if the discomfort gets worse or lasts
longer.
If you have questions about the test, speak with your doctor or the health professional
doing the blood draw.
