This Article Full Text Full Text (PDF) All Versions of this Article: 40/4/1275    most recent STROKEAHA.108.527911v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Oddo, M. Articles by Le Roux, P. D. Search for Related Content PubMed PubMed Citation Articles by Oddo, M. Articles by Le Roux, P. D. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB OXYGEN Related Collections Energy metabolism Brain Circulation and Metabolism Cerebral Aneurysm, AVM, & Subarachnoid hemorrhage

(Stroke. 2009;40:1275.)
© 2009 American Heart Association, Inc.

Original Contributions

Hemoglobin Concentration and Cerebral Metabolism in Patients With Aneurysmal Subarachnoid Hemorrhage

Mauro Oddo, MD; Andrew Milby, BS; Isaac Chen, MD; Suzanne Frangos, RN; Eileen MacMurtrie, MSN; Eileen Maloney-Wilensky, MSN; Michael Stiefel, MD; W. Andrew Kofke, MD; Joshua M. Levine, MD Peter D. Le Roux, MD

From the Departments of Neurosurgery (M.O., A.M., I.C., S.F., E.M., E.M.-W., M.S., W.A.K., J.M.L., P.D.L.), Neurology (J.M.L.), and Anesthesia and Critical Care (W.A.K., J.M.L.), University of Pennsylvania Medical Center, Philadelphia, Pa.

Correspondence to Peter D. Le Roux, MD, Department of Neurosurgery, Clinical Research Division, University of Pennsylvania Medical Center, 3rd Floor Silverstein Building, 3400 Spruce Street, Philadelphia, PA 19104-4283. E-mail Peter.LeRoux{at}uphs.upenn.edu

Background and Purpose— The optimal hemoglobin (Hgb) target after aneurysmal subarachnoid hemorrhage is not precisely known. We sought to examine the threshold of Hgb concentration associated with an increased risk of cerebral metabolic dysfunction in patients with poor-grade subarachnoid hemorrhage.

Methods— Twenty consecutive patients with poor-grade subarachnoid hemorrhage who underwent multimodality neuromonitoring (intracranial pressure, brain tissue oxygen tension, cerebral microdialysis) were studied prospectively. Brain tissue oxygen tension and extracellular lactate/pyruvate ratio were used as markers of cerebral metabolic dysfunction and the relationship between Hgb concentrations and the incidence of brain hypoxia (defined by a brain tissue oxygen tension <20 mm Hg) and cell energy dysfunction (defined by a lactate/pyruvate ratio >40) was analyzed.

Results— Compared with higher Hgb concentrations, a Hgb concentration <9 g/dL was associated with lower brain tissue oxygen tension (27.2 [interquartile range, 21.2 to 33.1] versus 19.9 [interquartile range, 7.1 to 33.1] mm Hg, P=0.02), higher lactate/pyruvate ratio (29 [interquartile range, 25 to 38] versus 36 [interquartile range, 26 to 59], P=0.16), and an increased incidence of brain hypoxia (21% versus 52%, P<0.01) and cell energy dysfunction (23% versus 43%, P=0.03). On multivariable analysis, a Hgb concentration <9 g/dL was associated with a higher risk of brain hypoxia (OR, 7.92; 95% CI, 2.32 to 27.09; P<0.01) and cell energy dysfunction (OR, 4.24; 95% CI, 1.33 to 13.55; P=0.02) after adjusting for cerebral perfusion pressure, central venous pressure, PaO₂/FIO₂ ratio, and symptomatic vasospasm.

Conclusions— A Hgb concentration <9 g/dL is associated with an increased incidence of brain hypoxia and cell energy dysfunction in patients with poor-grade subarachnoid hemorrhage.

Key Words: brain oxygen • cerebral microdialysis • hemoglobin • subarachnoid hemorrhage