title: Ephedrine requirements during spinal anesthesia for cesarean delivery in Jordanian parturients: association with b2 adrenoceptor gene variants.
abstract: BACKGROUND
  Maternal hypotension after spinal anesthesia for cesarean delivery is common. Many studies performed on the b2-adrenoceptor (b2AR) gene variants and their association with vasopressor requirements during and after neuroaxial block have contradictory conclusions.
  
  
  OBJECTIVE
  The aim of the study was to evaluate the influence of the b2AR in codons 16 and 27 on the incidence of maternal hypotension and ephedrine consumption after spinal anesthesia for cesarean delivery in an Arab ethnic group.
  
  
  METHODS
  A prospective gene association study.
  
  
  METHODS
  Jordan University Hospital from 1 July 2013 to 31 January 2014.
  
  
  METHODS
  We enrolled parturients who underwent cesarean delivery under spinal anesthesia. Spinal anesthesia was performed with 10 mg plain bupivacaine along with 25 micro g fentanyl. Hypotension was treated with ephedrine and the amount consumed in the first 30 minutes after spinal anesthesia was calculated. The b2AR genotype at codons 16 and 27 was determined. We studied the correlation between the b2AR genotype and the amount of ephedrine consumption after spinal anesthesia.
  
  
  METHODS
  Amount of ephedrine used.
  
  
  RESULTS
  Of 250 patients enrolled in the study, genotype and clinical data were available for 234 cases. Ephedrine was used in 94% of patients. There was a significant effect of b2AR genotype on ephedrine dose in the first 30 minutes after spinal anesthesia in codon 16 and 27. Arg16 homozygotes received less ephedrine (14.0 [11.2] mg) than Gly16 homozygotes (38.6 [25.7] mg) and Arg16Gly heterozygotes (33.42 [22.70] mg) (P < .0001). Gln27 homozygotes received less ephedrine (18.2 [12.8] mg) than Glu 27 homozygotes (47.5 [27.0] mg) and Gln27Glu heterozygotes (48.2 [23.7] mg). (P < .0001).
  
  
  CONCLUSIONS
  In an Arab ethnic group, the b2AR gene has a role in maternal hypotension after spinal anesthesia. The Gly16 and Glu27 alleles have a higher incidence of arterial hypotension and required a greater amount of vasopressor to treat hypotension compared with homozygous Arg16 and Gln27 carriers.
  
  
  CONCLUSIONS
  Fasting time and hydration protocol, the use of a fixed dose of ephedrine, and relatively small sample size.
authors.affiliation: Associate Professor Mahmoud Mansour Almustafa, King Faisal Specialist Hospital and Research Center,, Anesthesia Department MBC 22, PO Box 3354 Riyadh,11211,, Saudi Arabia, T: 966 146 47272 Ext: 32700, mahmoud_juh@hotmail.com.
authors.forename: Mahmoud M
authors.initials: MM
authors.lastname: Almustafa
authors.forename: Abdelkareem S
authors.initials: AS
authors.lastname: Al-Oweidi
authors.forename: Khaled R
authors.initials: KR
authors.lastname: Al-Zaben
authors.forename: Ibraheem Y
authors.initials: IY
authors.lastname: Qudaisat
authors.forename: Sami
authors.initials: S
authors.lastname: Abu-Halaweh
authors.forename: Subhi M
authors.initials: SM
authors.lastname: Alghanem
authors.forename: Islam M
authors.initials: IM
authors.lastname: Massad
authors.forename: Walid
authors.initials: W
authors.lastname: Samarah
authors.forename: Reem A
authors.initials: RA
authors.lastname: Al-Shaer
authors.forename: Said
authors.initials: S
authors.lastname: Ismail
authors.forename: Fawaz
authors.initials: F
authors.lastname: Khazawla
mesh_terms: D000328:Adult; D000775:Anesthesia, Spinal / Q000009:adverse effects / Q000379:methods; D000779:Anesthetics, Local / Q000008:administration & dosage; D018912:Arabs / Q000235:genetics; D002045:Bupivacaine / Q000008:administration & dosage; D002585:Cesarean Section; D003062:Codon; D004809:Ephedrine / Q000008:administration & dosage / Q000378:metabolism*; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage; D056726:Genetic Association Studies; D005838:Genotype; D006720:Homozygote; D006801:Humans; D007022:Hypotension / Q000453:epidemiology / Q000235:genetics*; D015994:Incidence; D007597:Jordan / Q000453:epidemiology; D000071184:Pharmacogenomic Variants; D011183:Postoperative Complications; D011247:Pregnancy; D011446:Prospective Studies; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics*; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: D000779:Anesthetics, Local; D003062:Codon; D018343:Receptors, Adrenergic, beta-2; D014662:Vasoconstrictor Agents; D004809:Ephedrine; D005283:Fentanyl; D002045:Bupivacaine