title: Acute normovolemic hemodilution is safe in neurosurgery.
abstract: OBJECTIVE
  To determine the safety of acute normovolemic hemodilution (ANH) for patients undergoing neurosurgical procedures.
  
  
  METHODS
  A group of 100 patients undergoing neurosurgical procedures was assigned prospectively to receive ANH. A group of 47 patients who underwent craniotomy for aneurysm clipping and standard anesthetic management was used as a control. Procedures conducted under ANH were performed without significant variations in physiologic parameters.
  
  
  RESULTS
  Compared with controls, intraoperative blood loss, operative time, incidence and grade of complications, and length of hospital stay were similar between the two groups. Although the ANH group showed a difference in prothrombin levels before and after hemodilution procedures, the levels were still considered within physiologic parameters. Platelet counts and partial thromboplastin time (PTT) levels indicated no significant variations in either group. During the ANH procedure, a considerable reduction of brain oxygen extraction was observed in individuals with worse preoperative neurologic status (P < 0.05), indicating potential benefit. Among patients with cerebral aneurysm, patients with good initial clinical grades had better clinical results as indicated by Glasgow Outcome Scale scores (P < 0.02).
  
  
  CONCLUSIONS
  ANH is a safe procedure for patients undergoing neurosurgical procedures. Further studies are necessary to confirm the improvement in brain oxygen extraction and the clinical impact. Nonetheless, patients undergoing aneurysm clipping with good clinical grades seem to profit from ANH.
authors.affiliation: Department of Neurosurgery, Hospital Cristo Redentor, Cristo Redentor, Brazil.
authors.forename: Paulo P
authors.initials: PP
authors.lastname: Oppitz
authors.forename: Marco A
authors.initials: MA
authors.lastname: Stefani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017542:Aneurysm, Ruptured / Q000503:physiopathology / Q000601:surgery*; D016063:Blood Loss, Surgical / Q000503:physiopathology; D001810:Blood Volume / Q000502:physiology; D001932:Brain Neoplasms / Q000503:physiopathology / Q000601:surgery*; D002648:Child; D003399:Craniotomy / Q000379:methods*; D017707:Erythrocyte Transfusion; D005260:Female; D005440:Fluid Therapy; D006438:Hemodilution / Q000379:methods*; D006801:Humans; D002532:Intracranial Aneurysm / Q000503:physiopathology / Q000601:surgery*; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D010314:Partial Thromboplastin Time; D010976:Platelet Count; D011446:Prospective Studies; D013345:Subarachnoid Hemorrhage / Q000503:physiopathology / Q000601:surgery; D013996:Time and Motion Studies; D055815:Young Adult