title: Clinical trial of esmolol-induced controlled hypotension with or without acute normovolemic hemodilution in spinal surgery.
abstract: BACKGROUND
  Drug-induced controlled hypotension (CH) combined with acute normovolemic hemodilution (ANH) is being widely used for blood conservation in surgical patients. The purpose of this study was to investigate the efficacy and safety of esmolol-induced CH combined with ANH (hematocrit down to 28%).
  
  
  METHODS
  Thirty patients who were scheduled to receive spinal surgery were randomly divided into two groups: an esmolol-induced CH alone group (esmolol group, n=15) and a CH-ANH combined group (E-ANH group, n=15). Controlled hypotension was induced with esmolol 500 micro g/kg, followed by a continuous infusion of 0-300 micro g/kg/min to maintain mean arterial pressure at 55-65 mmHg.
  
  
  RESULTS
  The mean infusion rate of esmolol in the esmolol-ANH group was 46+/-6 micro g/kg/min (mean+/-SD), which was significantly lower than the 77+/-9 micro g/kg/min used in the esmolol group (P<0.05). The number of units of homologous blood (packed RBC) transfused perioperatively was 2.2+/-0.6 units in the esmolol-ANH group, which was significantly less than 4.3+/-0.4 units used in the esmolol group (P<0.01). While O2 delivery decreased significantly during CH, O2 consumption remained unchanged in both groups. No complications resulted from CH or ANH in any of the groups.
  
  
  CONCLUSIONS
  Our data suggest that ANH of moderate degree can be combined with esmolol-induced CH to improve blood conservation in surgical patients.
authors.affiliation: Department of Anesthesiology and Clinical Research Institute, Seoul National University Hospital, Korea.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Lim
authors.forename: C S
authors.initials: CS
authors.lastname: Kim
authors.forename: J H
authors.initials: JH
authors.lastname: Bahk
authors.forename: B M
authors.initials: BM
authors.lastname: Ham
authors.forename: S H
authors.initials: SH
authors.lastname: Do
mesh_terms: D000319:Adrenergic beta-Antagonists; D000368:Aged; D016063:Blood Loss, Surgical / Q000517:prevention & control; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D002318:Cardiovascular Diseases / Q000150:complications / Q000503:physiopathology; D019299:Decompression, Surgical; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006438:Hemodilution; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007023:Hypotension, Controlled; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D011412:Propanolamines; D013116:Spinal Cord / Q000601:surgery*; D013123:Spinal Fusion
chemical_list: D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; C036604:esmolol