title: Which H is the most important in triple-H therapy for cerebral vasospasm?
abstract: OBJECTIVE
  To summarize the recent literature of the hemodynamic management of subarachnoid hemorrhage and cerebral vasospasm, also designated as 'triple-H' therapy, and discuss each component of this management approach individually.
  
  
  RESULTS
  Following the publication of a review on circulatory volume expansion in the Cochrane Registry database in 2004 and a meta-analysis in 2003, there are no new randomized trials of triple-H therapy to prevent or treat cerebral vasospasm. However, physiological studies have been reported that contribute to the understanding of some of the components of triple-H therapy.
  
  
  CONCLUSIONS
  There remains a paucity of information regarding the efficacy and safety of triple-H therapy. The complexity in exploring this topic derives not only from the interdependence of the different components of triple-H therapy but also by the limitation in the assessment of hemodynamic variables. However, there is some emerging physiologic data suggesting that normovolemic hypertension may be the component most likely to increase cerebral blood flow after subarachnoid hemorrhage. In contrast, hypervolemic hemodilution is associated with increased complications and might also lower the hemoglobin to excessively low levels.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Harborview Medical Center, University of Washington, Seattle, Washington 98104, USA. treggmm@u.washington.edu
authors.forename: Miriam M
authors.initials: MM
authors.lastname: Treggiari
authors.forename: Steven
authors.initials: S
authors.lastname: Deem
mesh_terms: D001775:Blood Circulation; D001810:Blood Volume; D002560:Cerebrovascular Circulation / Q000502:physiology; D006438:Hemodilution; D006439:Hemodynamics; D006801:Humans; D006973:Hypertension; D013345:Subarachnoid Hemorrhage / Q000503:physiopathology / Q000628:therapy; D020301:Vasospasm, Intracranial / Q000503:physiopathology / Q000628:therapy*