title: Phenylephrine as a simulated intravascular epidural test dose in pediatrics: a pilot study.
abstract: BACKGROUND
  A test dose is used to detect intravascular injection during neuraxial block in pediatrics. Accidental intravascular epidural local anesthetic injection might be unrecognized in anesthetized children leading to potential life-threatening complications. In children, sevoflurane anesthesia blunts the hemodynamic response when intravascular cathecolamines are administered. No studies have explored the hemodynamics and the criteria for a positive test dose result following phenylephrine in sevoflurane anesthetized children.
  
  
  METHODS
  Healthy children undergoing minor procedures were randomly assigned to receive intravenous placebo, or 5 μg∙kg(-1) phenylephrine (n = 11/group) during sevoflurane anesthesia. Hemodynamic response was assessed using electrocardiography, pulse oxymetry and non-invasive blood pressure monitoring for 5 min following drug administration in anesthetized patients.
  
  
  RESULTS
  All patients receiving phenylephrine showed a decreased heart rate (HR) but not all of them met the positive criterion for test dose response. Overall, at 1 min, patients receiving phenylephrine showed a 25% decrease in HR from the baseline while an increase in blood pressure was noticed in 54% of patients receiving phenylephrine.
  
  
  CONCLUSIONS
  Phenylephrine might be a future indicator of positive intravascular test dose. Further investigation is needed to find out the phenylephrine dose that elicits a reliable hemodynamic response and whether phenylephrine needs to be dose age-adjusted in order to appreciate relevant hemodynamic changes in children receiving neuraxial blocks undergoing general anesthesia.
authors.affiliation: Department of Anesthesiology, Tufts University School of Medicine, Boston, MA 02111, USA. carlopancaro@hotmail.com
authors.forename: Carlo
authors.initials: C
authors.lastname: Pancaro
authors.forename: Viviane G
authors.initials: VG
authors.lastname: Nasr
authors.forename: Jessica K
authors.initials: JK
authors.lastname: Paulus
authors.forename: Iwona
authors.initials: I
authors.lastname: Bonney
authors.forename: Alejandro F
authors.initials: AF
authors.lastname: Flores
authors.forename: Jonas B
authors.initials: JB
authors.lastname: Galper
authors.forename: Iqbal
authors.initials: I
authors.lastname: Ahmed
mesh_terms: D000767:Anesthesia, Epidural / Q000379:methods*; D000769:Anesthesia, Inhalation / Q000379:methods*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D001794:Blood Pressure / Q000187:drug effects; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007223:Infant; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage*; D016343:Monitoring, Intraoperative; D010656:Phenylephrine; D010865:Pilot Projects; D018401:Sample Size; D000077149:Sevoflurane; D014662:Vasoconstrictor Agents
chemical_list: D018685:Anesthetics, Inhalation; D000779:Anesthetics, Local; D008738:Methyl Ethers; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D000077149:Sevoflurane