Serum cholinesterase is a blood test that looks at levels of two substances that help the nervous system work properly. They are called acetylcholinesterase and pseudocholinesterase. Your nerves need these substances to send signals.
Acetylcholinesterase is found in nerve tissue and red blood cells. Pseudocholinesterase is found primarily in the liver.
Acetylcholinesterase; RBC (or erythrocyte) cholinesterase; Pseudocholinesterase; Plasma cholinesterase; Butyrylcholinesterase; Serum cholinesterase
A blood sample is needed. For information on how this is done, see: Venipuncture
No special preparation is necessary for this test.
When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.
Your health care provider may order this test if you may have been exposed to chemicals called organophosphates, which are used in pesticides. This test can help determine your risk of poisoning.
Less often, this test may be done:
Typically, normal pseudocholinesterase values range between 8 and 18 units per milliliter (U/mL).
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.
Decreased pseudocholinesterase levels may be due to:
Smaller decreases may be due to:
There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
Ford MD. Acute poisoning. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier. 2007: chap 111.
Aminoff MJ. Effects of toxins and physical agents on the nervous system: effects of occupational toxins on the nervous system. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Bradley: Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann Elsevier; 2008:chap 62A.