Sorted By Test Name - Mayo Medical Laboratories

PCHES
8518
(0%-20%) and usually low levels of enzyme. Heterozygous patients have intermediate PCHE levels and
response to inhibitors. The atypical gene is inherited in an autosomal recessive pattern. In a positive
patient, family members should be tested. Several reports have shown that 65% to 75% of patients who
respond abnormally to succinylcholine had at least 1 abnormal gene, had low activity due to an acquired
deficiency such as liver disease, or had received an inappropriate dose of drug. The remaining 25% to
35% of patients appeared to have the usual or normal genotype but nevertheless displayed long periods of
apnea. Although reasons could not be established, it is possible that these cases represent unknown
genotypes. Therefore, although many symptomatic patients will show moderate to significant resistance to
dibucaine and low enzyme activity, not all will. In all cases, it is recommended that succinylcholine and
mivacurium be avoided, or the dose greatly reduced.
Reference Values:
DIBUCAINE INHIBITION
70-90%
Congenital deficiency: 18-20%
PSEUDOCHOLINESTERASE, TOTAL
Males: 3,100-6,500 U/L
Females
18-49 years: 1,800-6,600 U/L
> or =50 years: 2,550-6,800 U/L
Reference values have not been established for patients that are