title: Epinephrine Vasoconstriction Effect Time in the Scalp Differs According to Injection Site and Concentration.
abstract: BACKGROUND
  There have been few studies of the action of epinephrine injected into scalp tissue, or whether the action of epinephrine differs according to vascular anatomy within the same surgical field. Effective perioperative control of bleeding is critical during hair transplantation due to its time-consuming nature.
  
  
  OBJECTIVE
  To identify the vasoconstriction time of epinephrine by concentration and injection site in the scalp tissue.
  
  
  METHODS
  Twenty-five volunteers were injected with epinephrine at concentrations of 1:400,000, 1:200,000, 1:100,000, and 1:50,000 in the path of the supraorbital artery on the anterior hairline in the midfrontal area (Point A) and at the frontotemporal junction of the frontal hairline (Point B). Laser Doppler was used to measure scalp blood flow, and vasoconstriction time at Points A and B with each concentration of epinephrine was recorded.
  
  
  RESULTS
  The duration of action of epinephrine increased in direct proportion with the concentration of epinephrine. The duration of vasoconstriction was shorter at Point A than at Point B, but this difference was only statistically significant at an epinephrine concentration of 1:50,000.
  
  
  CONCLUSIONS
  The vasoconstriction time of epinephrine in the scalp correlated positively with concentration, and the duration of vasoconstriction was longer at Point B than at Point A.
authors.affiliation: *Department of Plastic and Reconstructive Surgery, Wonkwang University Hospital, Iksan, Korea; †Department of Microbiology, Wonkwang University School of Medicine, Iksan, Korea; ‡Department of Plastic and Reconstructive Surgery, Kangnam Sacred Heart Hospital, Hallym University Medical Center, Hallym University College of Medicine, Seoul, Korea; §Dana Plastic Surgery Clinic, Seoul, Korea.
authors.forename: Young-Cheon
authors.initials: YC
authors.lastname: Na
authors.forename: Raekil
authors.initials: R
authors.lastname: Park
authors.forename: Hii-Sun
authors.initials: HS
authors.lastname: Jeong
authors.forename: Jae Hyun
authors.initials: JH
authors.lastname: Park
mesh_terms: D000328:Adult; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004837:Epinephrine / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow / Q000187:drug effects*; D012535:Scalp / Q000098:blood supply*; D013997:Time Factors; D018608:Ultrasonography, Doppler; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D014662:Vasoconstrictor Agents; D004837:Epinephrine