Does this test have other names?
RBC cholinesterase, true cholinesterase, red cell cholinesterase, acetylcholinesterase
What is this test?
This test looks for signs of chemical poisoning in your blood.
Cholinesterase is an enzyme that helps your nervous system work the way it should.
Certain toxic chemicals in the environment can interfere with this enzyme and affect
your nervous system.
These chemicals include organophosphates and carbamates. They are most often found
in insecticides used in fields. They have also been used as chemical warfare agents.
These chemicals can be found in common household insect sprays, too. They have been
used in insecticides for more than 50 years.
If these chemicals get into your body, they can affect how you breathe and can cause
general muscle weakness. They are called cholinesterase inhibitors. An overdose of
these chemicals can be fatal.
Why do I need this test?
You may need this test if your healthcare provider thinks you have been overexposed
to insecticides. Signs and symptoms of overexposure include:
Slow heart rate
Pupils in your eyes get smaller with eye pain or headache
You make more saliva than normal
You urinate more often than normal
You have trouble breathing
Watery eyes or blurred vision
Runny nose, coughing, or wheezing
Vomiting and diarrhea
These signs and symptoms vary, based on:
Amount of the overdose
What part of your body was exposed
Type of chemical
How you are exposed, such as by breathing, eating or drinking, or skin contact
You may also have this test if you have symptoms of nervous system problems. These
Weakness when you bend your neck
Problems with the nerves in your neck
General muscle weakness
You aren’t able to breathe normally
This test is rarely used in an emergency because the results usually aren't available
in time to suggest treatment. Instead, treatment of cholinesterase poisoning is usually
based on symptoms.
What other tests might I have along with this test?
Your healthcare provider may also order other tests if you need treatment right away.
These tests include:
What do my test results mean?
Test results may vary depending on your age, gender, health history, the method used
for the test, and other things. Your test results may not mean you have a problem.
Ask your healthcare provider what your test results mean for you.
The range of normal results varies greatly from lab to lab. But signs of poisoning
start to appear in ranges that are 40% to 75% of normal.
How is this test done?
The test is done with a blood sample. A needle is used to draw blood from a vein in
your arm or hand.
Does this test pose any risks?
Having a blood test with a needle carries some risks. These include bleeding, infection,
bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may
feel a slight sting or pain. Afterward, the site may be sore.
What might affect my test results?
Certain medicines can affect your results. These include birth control pills and medicines
used to prevent malaria.
How do I get ready for this test?
You don't need to prepare for this test. Be sure your healthcare provider knows about
all medicines, herbs, vitamins, and supplements you are taking. This includes medicines
that don't need a prescription and any illicit drugs you may use.