Cholinesterase, Plasma

Test ID: 

702837

CPT code:

82480

Synonyms:

Benzoylcholinesterase
Choline Esterase II
Pseudocholinesterase, Plasma

Clinical Use:

Evaluate preoperative patients for succinylcholine (suxamethonium) anesthetic sensitivity, genetic or secondary to insecticide exposure, in appropriate circumstances. To prevent or evaluate prolonged anesthetic effect, prolonged apnea, after surgery. Very small amounts (0.04−0.06 mg/kg) of succinylcholine are needed to obtain 90% of neuromuscular blockade in patients with low levels of plasma cholinesterase activity.1

Test Information:

Two types of cholinesterase are found in blood: “true” cholinesterase (acetylcholinesterase) in red cells and “pseudocholinesterase” (acylcholine acylhydrolase) in serum (plasma). Low plasma or serum cholinesterase activity may relate to exposure to insecticides or to one of a number of variant genotypes. Dibucaine and fluoride numbers are useful to phenotype such homozygous and heterozygous individuals, who are genetically sensitive to succinylcholine.

Specimen Type:

Plasma

Requested Volume: 

0.5 mL

Minimum Volume: 

0.2 mL

Container Type: 

Lavender-top (EDTA) tube

Collection:

Separate plasma from cells immediately and place in transport tube. Mark transport tube “plasma.” Use of other anticoagulants is not recommended.

Storage Instructions:

Maintain specimen at room temperature.

Stability Requirements:

Temperature                           Period
Room temperature                14 days
Refrigerated                            14 days
Frozen                                      14 days
Freeze/thaw cycles               Stable x3

Rejection Criteria

Whole blood specimen (a 20% to 25% increase can occur during a 24-hour period if plasma is left in contact with the red cells); anticoagulants other than EDTA; hemolysis