title: Under general anesthesia arginine vasopressin prevents hypotension but impairs cerebral oxygenation during arthroscopic shoulder surgery in the beach chair position.
abstract: BACKGROUND
  Patients undergoing surgery in the beach chair position (BCP) are at a risk of cerebral ischemia. We evaluated the effect of arginine vasopressin (AVP) on hemodynamics and cerebral oxygenation during surgery in the BCP.
  
  
  METHODS
  Thirty patients undergoing shoulder surgery in BCP under propofol-remifentanil anesthesia were randomly allocated either to receive IV AVP 0.07 U/kg (AVP group, N = 15) or an equal volume of saline (control group, N = 15) 2 minutes before taking BCP. Mean arterial blood pressure (MAP), heart rate (HR), jugular venous bulb oxygen saturation (SjvO2), and regional cerebral tissue oxygen saturation (SctO2) were measured after induction of anesthesia and before (presitting in supine position) and after patients took BCP.
  
  
  RESULTS
  AVP itself given before the positioning increased MAP and decreased SjvO2 and SctO2 (P < 0.0001), with HR unaffected. Although MAP was decreased by BCP in both groups, it was higher in the AVP group (P < 0.0001). While in BCP, HR remained unaltered in the control and decreased in the AVP group. SjvO2 in BCP did not differ between the groups. SctO2 was decreased by BCP in both groups, which was more pronounced in the AVP group until the end of study. The incidence of hypotension (13% vs 67%; P = 0.003) was less frequent, and that of cerebral desaturation (>20% SctO2 decrease from presitting value) (80% vs 13%; P = 0.0003) was higher in the AVP group. The incidence of jugular desaturation (SjvO2 <50%) was comparable between the groups.
  
  
  CONCLUSIONS
  A prophylactic bolus administration of AVP prevents hypotension associated with BCP in patients undergoing shoulder surgery under general anesthesia. However, it was associated with regional cerebral but not jugular venous oxygen desaturation on upright positioning.
authors.affiliation: From the Department of Anesthesiology and Pain Medicine, School of Dentistry, Chonnam National University Medical School, Gwangju, South Korea.
authors.forename: Soo Y
authors.initials: SY
authors.lastname: Cho
authors.forename: Seok J
authors.initials: SJ
authors.lastname: Kim
authors.forename: Cheol W
authors.initials: CW
authors.lastname: Jeong
authors.forename: Chang Y
authors.initials: CY
authors.lastname: Jeong
authors.forename: Sung S
authors.initials: SS
authors.lastname: Chung
authors.forename: JongUn
authors.initials: J
authors.lastname: Lee
authors.forename: Kyung Y
authors.initials: KY
authors.lastname: Yoo
mesh_terms: D061605:Administration, Intravenous; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000768:Anesthesia, General / Q000009:adverse effects; D001127:Arginine Vasopressin / Q000008:administration & dosage / Q000009:adverse effects*; D062186:Arterial Pressure / Q000187:drug effects; D001182:Arthroscopy / Q000009:adverse effects; D001921:Brain / Q000098:blood supply* / Q000187:drug effects* / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000187:drug effects; D016009:Chi-Square Distribution; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007022:Hypotension / Q000139:chemically induced / Q000503:physiopathology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010092:Oximetry / Q000379:methods; D010100:Oxygen / Q000097:blood*; D056888:Patient Positioning / Q000009:adverse effects; D056910:Republic of Korea; D012785:Shoulder Joint / Q000601:surgery*; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D001127:Arginine Vasopressin; D010100:Oxygen