title: Genetics of pain perception, COMT and postoperative pain management in children.
abstract: BACKGROUND
  Effective perioperative analgesia is lacking for children owing to interindividual variations and underdosing of opioids caused by fear of adverse effects. We investigated the role of COMT SNPs on postoperative pain management in children.
  
  
  METHODS
  One hundred and forty nine children undergoing adenotonsillectomy were enrolled. The associations of four COMT SNPs (rs6269, rs4633, rs4818 and rs4680) with postoperative pain were analyzed and outcome measures included maximum pain scores, need for postoperative opioid interventions and postoperative morphine requirements.
  
  
  RESULTS
  We detected an association of postoperative opioid intervention need with all four COMT SNPs. Minor allele carriers of COMT SNPs were approximately three-times more likely to require analgesic interventions than homozygotes of major alleles (p-value range: 0.0031-0.0127; odds ratio range: 2.6-3.1). In addition, significant association was detected between maximum Face, Leg, Activity, Consolability, Cry (FLACC) pain scores and three COMT SNPs (rs6269, rs4633 and rs4680). Haplotype 1 (ATCA: 51.3%) and Haplotype 2 (GCGG: 36.2%) are more frequent. Haplotype 2 was associated with higher odds of intravenous analgesic intervention need in postanesthesia recovery unit with an odds ratio of 2.6 (95% CI: 1.2-5.4; p-value = 0.022).
  
  
  CONCLUSIONS
  COMT SNPs may play a significant role in interindividual variation in postoperative pain perception and postoperative morphine requirements in children. Original submitted 16 August 2013; Revision submitted 13 December 2013.
authors.affiliation: Clinical Anaesthesia & Paediatrics, Acute & Perioperative Pain Service, Department of Anaesthesia, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MLC 2001, Cincinnati, OH 45229, USA.
authors.forename: Senthilkumar
authors.initials: S
authors.lastname: Sadhasivam
authors.forename: Vidya
authors.initials: V
authors.lastname: Chidambaran
authors.forename: Vanessa A
authors.initials: VA
authors.lastname: Olbrecht
authors.forename: Hope R
authors.initials: HR
authors.lastname: Esslinger
authors.forename: Kejian
authors.initials: K
authors.lastname: Zhang
authors.forename: Xue
authors.initials: X
authors.lastname: Zhang
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Martin
mesh_terms: D000293:Adolescent; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D002648:Child; D005260:Female; D056726:Genetic Association Studies; D006239:Haplotypes; D006801:Humans; D008297:Male; D009020:Morphine / Q000008:administration & dosage; D059408:Pain Management; D058748:Pain Perception; D010149:Postoperative Pain / Q000188:drug therapy / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide
chemical_list: D009020:Morphine; C588010:COMT protein, human; D002394:Catechol O-Methyltransferase