Brief Description: The test is used to measure levels of cholinesterase in your blood’s serum, plasma, and red blood cells.
Also Known As: CHS Test, CHS Serum Test, CHS Plasma Test, CHS RBC Test, CHS Blood Test, AChE Test, AChE Serum Test, AChE RBC Test, AChE Plasma Test, AChE Blood Test, Serum Cholinesterase, RBC Cholinesterase, Plasma Cholinesterase, Red Cell Cholinesterase, Acetylcholinesterase test, butyrylcholinesterase test, BChE Test, BChE Serum Test, BChE RBC Test, BChE Plasma Test, BChE Blood Test, Pseudocholinesterase Test, PCHE Test
Collection Method: Blood Draw
Specimen Type: Whole Blood, Plasma, and Serum
Test Preparation: No preparation required
When is a Cholinesterase test ordered?
Once baseline levels have been established, those who deal with organophosphate substances in the farming or chemical industries may undergo routine monitoring to evaluate any detrimental exposure. Testing for cholinesterase can be performed to determine any acute exposure to these substances, which can harm the neuromuscular system. Rapid absorption of the substance in the lungs, skin, or digestive system may be followed by toxicity. Depending on the substance, its dose, and the exposure site, poisoning symptoms can vary. Early signs could include:
- headache and vertigo
- excessive sweating, salivation, and/or eye tears
As the poisoning's effects grow, more symptoms could develop, including:
- nausea, diarrhea
- vision that is dim or fuzzy because of restricted pupils
- twitching, jerking, and lack of coordination in the muscles
- slowed breathing that causes respiratory failure and calls for ventilator support to survive
- In severe situations, coma, death, and convulsions may occur.
If a person or a close relative has experienced extended paralysis and apnea following the administration of succinylcholine for anesthesia during an operation, pre-operative screening for pseudocholinesterase activity is indicated.
What does a Cholinesterase blood test check for?
Enzymes called cholinesterase play a role in the healthy operation of the nervous system. The body contains two different cholinesterase enzymes: pseudocholinesterase, which is found in the serum as well as the liver, muscle, pancreas, heart, and white matter of the brain, and acetylcholinesterase, which is found in red blood cells as well as the lungs, spleen, nerve endings, and gray matter of the brain. The activity of these enzymes is measured by cholinesterase testing.
By degrading acetylcholine, a substance that aids in signal transmission across nerve ends, acetylcholinesterase contributes to the transmission of nerve impulses. Acetylcholine is produced in excess at nerve endings when the activity of the enzyme acetylcholinesterase declines. Overstimulation of nerves in human tissues and organs may result from this. Processing and metabolizing medicines involves the enzyme pseudocysteinesterase.
The following are the top two justifications for analyzing blood activity levels:
- exposure to organophosphate pesticides. The activity of cholinesterase and pseudocholinesterase can be inhibited by insecticides containing organophosphates. When these pesticides are exposed acutely, symptoms may be severe, while persistent exposure may cause symptoms to develop more gradually. Ingestion, inhalation, and skin contact are all possible methods of absorption. To identify acute poisoning or to keep track of people who are exposed to these chemicals on the job, such as agricultural laborers or people who work with industrial chemicals, tests for red blood cell acetylcholinesterase and serum pseudocholinesterase may be performed.
- Pseudocholinesterase deficit that is inherited. Some people have a genetic variation of the pseudocholinesterase enzyme that results in an inherited deficit. The body uses this enzyme to render succinylcholine, a popular anesthetic muscle relaxant, inactive. A prolonged muscle paralysis and apnea after anesthesia are possible side effects of the medication in people who have low levels or faulty pseudocholinesterase. Additionally, individuals who are homozygous for genetic polymorphisms may be more susceptible to negative consequences than individuals who are heterozygous. Before surgery, patients with a family history of prolonged apnea following succinylcholine use can have pseudocholinesterase testing to see if they are at risk of problems from the medication.
Lab tests often ordered with a Cholinesterase test:
How does my health care provider use a Cholinesterase test?
There are two main purposes for cholinesterase testing:
- It can be used to identify and treat exposure to or poisoning from organophosphate pesticides. As well as monitoring persons who are being treated for exposure to organophosphate chemicals, it may also be used to monitor those who may be at an elevated risk of exposure to these substances, such as those who work in the chemical and agricultural industries. Tests for serum pseudocholinesterase and red blood cell acetylcholinesterase are frequently used for this reason.
- It can be used a few days before surgery to ascertain whether a patient is at danger of developing post-operative paralysis if succinylcholine, a common muscle relaxant used for anesthesia, is used during the operation. The test for pseudocholinesterase is typically used in these circumstances. To ascertain the degree to which the enzyme's activity has been diminished, a second test known as a dibucaine inhibition test may be carried out.
What do my Cholinesterase test results mean?
In assessing the exposure to pesticides at work
AChE and PChE activity can decrease after exposure to organophosphate substances to about 80% of normal before any symptoms show up and to 40% of normal before the symptoms worsen. By first establishing a baseline activity level for acetylcholinesterase or pseudocholinesterase, and then testing on a frequent basis to look for a noticeably decreased level of activity, those who are regularly exposed to these substances can be monitored for harmful exposure.
When assessing for acute pesticide toxicity or exposure
Significantly reduced levels of cholinesterase activity typically signify an increased uptake of organophosphate substances. After exposure, pseudocholinesterase and RBC acetylcholinesterase activity typically declines between minutes to hours. While acetylcholinesterase activity will remain low for up to three months, pseudocholinesterase activity can rebuild in a matter of days to weeks. Pesticide exposure quickly affects the plasma and RBC activity, although AChE and PChE regenerate at various rates after exposure is over because AChE is created in blood cells, which have a lifespan of 120 days, whilst PChE is formed in the liver, which has a half-life of roughly two weeks.
Succinylcholine sensitivity evaluations
About 3% of individuals have poor pseudocholinesterase activity because of a hereditary deficit, and these individuals will experience extended effects from the muscle relaxant succinylcholine. Prior to surgery, total quantitative pseudocholinesterase levels will be assessed in individuals who have a personal or family history of prolonged apnea following use of this medication. Low pseudocholinesterase activity levels suggest that these individuals may be more susceptible to the long-lasting effects of the muscle relaxant. To determine how sensitive a person is to the medicine, a second test called the dibucaine inhibition test may also be carried out. The likelihood of developing medication sensitivity increases with a lower dibucaine inhibition test result.
Malnutrition and chronic liver disease are additional factors that might lead to decreased cholinesterase levels. Pregnancy, renal disease, shock, and various malignancies are just a few more circumstances that might cause a decrease in total cholinesterase activity.
We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.