Determination of butyrylcholinesterase (BChE) phenotypes to predict the risk of prolonged apnea in persons receiving succinylcholine in the healthy population of western Iran

Objective: The best known clinical application of serum BChE assay is to predict abnormally prolonged apnea following the application of the muscle relaxant succinylcholine. The aim of the present study was to assess the frequency of BChE phenotypes and to predict the risk of apnea for those receiving succinylcholine among the residents in western Iran. Methods: We examined the frequency of nine BChE phenotypes in 1548 volunteers including 816 males and 732 females with the mean age of 35 15 years from an apparently healthy group living in western Iran. The frequencies of BChE phenotypes were determined using BChE activity measurements and by inhibition with dibucame, fluoride, and the compound Ro2-0683 (Hoffman-La-Roche). Results: The reference range for serum total BChE activity was 4600-14000 U/L (using butyrylthiocholine iodide as substrate). The mean value obtained for men (9030 U/L) was significantly (p < 0.05) higher than that for women (8550 U/L). The frequencies of four alleles U, A, F, S were calculated to be 0.9826, 0.0165, 0.008 and 0.001, respectively. The frequency of phenotypes of BChE was as follows: normal phenotype (UU) 95.5%, moderate sensitive to succinyleholine including UA,US,UF phenotypes was 3.9% and hypersensitive to succinylcholine (AA, AF, AS, FF, SS) was 0.58%. Conclusion: This study indicates that the population of western Iran has a medium frequency of succinyleholine-sensitive individuals compared to other populations. We suggest that determination of BChE activity and phenotype by the micro automated method is well suited to pre-operative screening and detection of at-risk of prolonged apnea in persons receiving succinylcholine in the healthy population of western Iran. (c) 2007 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.