Expert: Ronald Levy, M.D. - 2/12/2010

Question
Dr.Levy:

I cared for a patient last week for CSection whose mother revealed a family history consistent with cholinestearase deficiency.  So I ordered the lab test for the patient for counselling purposes.  The specimen was collected less than 24 hrs after the CSection and was sent by my hospital in Houston to a lab in Utah. Now I need advice on interpreting the results and counselling the patient.  The lab reported Total Pseudocholinesterase of 2653 U/L with the normal range being 2900-7100.

Obviously this is low, but my questions are 1) does this result represent the severe deficiency of a homozygote or the less severe heterozygous form.  2)Does pregnancy alter the normal range.

I appreciate your opinion.

Don Westheimer
UTMB class of '71

Answer
Generally Pseudocholinesterase deficiency is reported with a Dibucaine Number. I am not aware of any direct correlation between the absolute value and which form of the disease they have. Base on the information, I would suppose that this is not the severe form of the disease although she clearly has a deficiency and should not be given succinylcholine. I am not aware of any studies linking pregnancy to lower levels of pseudocholinesterase.

Ronald Levy, MD
Professor of Anesthesiology
UTMB-Galveston