Serum cholinesterase is a blood test that looks at levels of 2 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.
A blood sample is needed. Most of the time blood is drawn from a vein located on the inside of the elbow or the back of the hand.
No special steps are needed to prepare for this test.
You may feel slight pain or a sting when the needle is inserted. You may also feel some throbbing at the site after the blood is drawn.
Your health care provider may order this test if you may have been exposed to chemicals called organophosphates. These chemicals 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) or 8 and 18 kilounits per liter (kU/L).
Note: Normal value ranges may vary slightly among different laboratories. Talk to your provider about the meaning of your specific test results.
Decreased pseudocholinesterase levels may be due to:
Smaller decreases may be due to:
Reviewed By: Amit M. Shelat, DO, FACP, Attending Neurologist and Assistant Professor of Clinical Neurology, SUNY Stony Brook, School of Medicine, Stony Brook, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.