title: Cerebral oxygenation in the beach chair position before and during general anesthesia in patients with and without cardiovascular risk factors.
abstract: OBJECTIVE
  To evaluate changes in cerebral tissue oxygen index (TOI) values under the beach chair position before and during general anesthesia in surgical patients with or without cardiovascular risk factors.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Operating room in the university hospital.
  
  
  METHODS
  Ninety-one patients undergoing surgery, including healthy patients (n = 28), patients with 1 cardiovascular risk factor (n = 33), and those with more than 1 risk factor (n = 30).
  
  
  METHODS
  Cerebral TOI the day before and during general anesthesia was evaluated using a near-infrared spectroscopy NIRO-200 (Hamamatsu Photonics, Hamamatsu, Japan) for each patient. The initial TOI measurement in the supine position after a 10-minute rest or 10 minute after the endotracheal intubation was followed by measurements in 30° and subsequent 60° upright position for 5 minutes. Phenylephrine 0.1 mg and/or ephedrine 4 mg was administered intravenously to maintain mean blood pressure above 60 mm Hg accordingly.
  
  
  RESULTS
  The beach chair position decreased mean arterial blood pressure and heart rate under general anesthesia, although patients with more than 1 cardiovascular risk factor needed significantly more phenylephrine doses to maintain mean blood pressure above 60 mm Hg. Values of TOI were within the normal range of about 70% before and during anesthesia in all groups.
  
  
  CONCLUSIONS
  The beach chair position under general anesthesia did not alter cerebral oxygenation in patients with or without cardiovascular risk factors showing normal preoperative cerebral TOI values when the mean blood pressure was maintained above 60 mm Hg. The careful management using the cerebral oxygenation monitoring appears to maintain cerebral perfusion in the beach chair position during general anesthesia.
authors.affiliation: Department of Anesthesiology, Aichi Medical University School of Medicine, 1-1 Yazako Karimata, Nagakute 480-1195, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Mori
authors.affiliation: Department of Anesthesiology, Toyama University School of Medicine, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Masana
authors.initials: M
authors.lastname: Yamada
authors.affiliation: Department of Anesthesiology, Aichi Medical University School of Medicine, 1-1 Yazako Karimata, Nagakute 480-1195, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Akahori
authors.affiliation: Department of Anesthesiology, Aichi Medical University School of Medicine, 1-1 Yazako Karimata, Nagakute 480-1195, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Hatakeyama
authors.affiliation: Department of Anesthesiology, Toyama University School of Medicine, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Yamazaki
authors.affiliation: Department of Anesthesiology, Aichi Medical University School of Medicine, 1-1 Yazako Karimata, Nagakute 480-1195, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Fujiwara
authors.affiliation: Department of Anesthesiology, Aichi Medical University School of Medicine, 1-1 Yazako Karimata, Nagakute 480-1195, Japan. Electronic address: hkinoshi@aichi-med-u.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kinoshita
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General; D001794:Blood Pressure / Q000187:drug effects; D001923:Brain Chemistry; D002318:Cardiovascular Diseases / Q000150:complications / Q000453:epidemiology*; D004809:Ephedrine / Q000494:pharmacology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D056888:Patient Positioning; D010656:Phenylephrine / Q000494:pharmacology; D011446:Prospective Studies; D012307:Risk Factors; D012782:Shoulder / Q000601:surgery; D019265:Spectroscopy, Near-Infrared; D016683:Supine Position; D014662:Vasoconstrictor Agents / Q000494:pharmacology
chemical_list: D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D004809:Ephedrine
keywords: Beach chair position; Cerebral oxygenation; General anesthesia; Near-infrared spectroscopy; Tissue oxygen index