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, such as Raid
and Black Flag. 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
You make more saliva than normal
You urinate more often than normal
You have trouble breathing
Vomiting and diarrhea
These signs and symptoms vary, based on:
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?
Many things may affect your lab test results. These include the method each lab uses
to do the test. Even if your test results are different from the normal value, you
may not have a problem. To learn what the results mean for you, talk with your healthcare
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 requires a blood sample, which is drawn through a needle from a vein in your
Does this test pose any risks?
Taking a blood sample with a needle carries risks that include bleeding, infection,
bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight
stinging sensation or pain. Afterward, the site may be slightly sore.
What might affect my test results?
Certain drugs 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. But 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.