title: Differential pressor response to intravenous ephedrine during recovery from deliberate hypotension.
abstract: OBJECTIVE
  To determine whether nitroglycerin or trimethaphan alters pressor response to intravenous (i.v.) ephedrine.
  
  
  METHODS
  Prospective, randomized study.
  
  
  METHODS
  Operating room of a university hospital.
  
  
  METHODS
  60 ASA physical status I female patients scheduled for mastectomy.
  
  
  METHODS
  Patients were assigned to one of six groups (n = 10 in each). Group 1: nitroglycerin + normal saline (NS) i.v., Group 2: nitroglycerin + ephedrine 0.1 mg/kg i.v., Group 3: nitroglycerin + ephedrine 0.15 mg/kg i.v., Group 4: trimethaphan + NS i.v., Group 5: trimethaphan + ephedrine 0.1 mg/kg i.v., and Group 6: trimethaphan + ephedrine 0.15 mg/kg i.v.
  
  
  METHODS
  Hemodynamic responses to ephedrine following withdrawal of vasodilators were observed for 15 minutes.
  
  
  RESULTS
  Ephedrine increased heart rate and mean blood pressure. After ephedrine 0.1 mg/kg i.v., the maximum pressor response in the trimethaphan group was approximately twofold that of the nitroglycerin group (p = 0.038).
  
  
  CONCLUSIONS
  Ephedrine restored BP more easily in those patients who had received trimethaphan compared with those who had received nitroglycerin for deliberate hypotension.
authors.affiliation: Department of Anesthesiology, Sapporo Medical University School of Medicine, Sapporo, Japan. kanaya@sapmed.ac.jp
authors.forename: Noriaki
authors.initials: N
authors.lastname: Kanaya
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Nakayama
authors.forename: Masayasu
authors.initials: M
authors.lastname: Nakayama
authors.forename: Kayoko
authors.initials: K
authors.lastname: Okazaki
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Hattori
authors.forename: Saori
authors.initials: S
authors.lastname: Kurosawa
authors.forename: Mitsutaka
authors.initials: M
authors.lastname: Edanaga
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Namiki
mesh_terms: D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects*; D004809:Ephedrine / Q000008:administration & dosage; D005730:Ganglionic Blockers / Q000008:administration & dosage; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007023:Hypotension, Controlled; D007275:Injections, Intravenous; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage; D011446:Prospective Studies; D013997:Time Factors; D014294:Trimethaphan / Q000008:administration & dosage; D014662:Vasoconstrictor Agents / Q000008:administration & dosage; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D005730:Ganglionic Blockers; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D014294:Trimethaphan; D005996:Nitroglycerin; D004809:Ephedrine