title: Blood transfusion is an important predictor of hospital mortality among patients with aneurysmal subarachnoid hemorrhage.
abstract: BACKGROUND
  Red blood cell (RBC) transfusion after aneurysmal subarachnoid hemorrhage (aSAH) has been associated with increased mortality but prior studies have not adequately adjusted for transfusion-indication bias.
  
  
  METHODS
  This is a retrospective study of consecutive aSAH patients admitted to the intensive care units of two academic medical centers over a 7-year period. Data collection included demographics, World Federation of Neurosurgical Surgeons score (WFNS), modified Fisher score (mFisher), admission and nadir hemoglobin (Hb) level, vasospasm, cerebral infarction, acute lung injury, and hospital mortality. The association between RBC transfusion and mortality was evaluated using a multivariate logistic regression analysis using the propensity for RBC transfusion as a covariate.
  
  
  RESULTS
  We identified 318 patients. The median age was 54 years (46, 65), and 204 (64 %) were females. Hospital mortality was 13 % (42/318). Seventy-two (23 %) patients were transfused. Predictors of transfusion were admit and nadir Hb levels (p < 0.001), age (p = 0.02), gender (0.008), WFNS score (p < 0.001), mFisher score (p = 0.009), surgical versus endovascular treatment (p < 0.001) and moderate to severe vasospasm (p = 0.025) were predictors of transfusion. After adjustment for probability of receiving RBC transfusion, APACHE IV and nadir Hb, transfusion remained independently associated with hospital mortality (OR 3.16, 95 % CI = 1.02-9.69, p = 0.047).
  
  
  CONCLUSIONS
  Among patients with aSAH, RBC transfusion was independently associated with an increased mortality after adjustment for the most common clinical indications for transfusion.
authors.affiliation: Department of Critical Care Medicine, Mayo Clinic, 4500, San Pablo Rd, Jacksonville, FL 32224, USA. festic.emir@mayo.edu
authors.forename: Emir
authors.initials: E
authors.lastname: Festic
authors.forename: Alejandro A
authors.initials: AA
authors.lastname: Rabinstein
authors.forename: William D
authors.initials: WD
authors.lastname: Freeman
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Mauricio
authors.forename: Maisha T
authors.initials: MT
authors.lastname: Robinson
authors.forename: Jay
authors.initials: J
authors.lastname: Mandrekar
authors.forename: Abba C
authors.initials: AC
authors.lastname: Zubair
authors.forename: Augustine S
authors.initials: AS
authors.lastname: Lee
authors.forename: Ognjen
authors.initials: O
authors.lastname: Gajic
mesh_terms: D018806:APACHE; D000328:Adult; D000368:Aged; D003422:Critical Care; D017707:Erythrocyte Transfusion / Q000401:mortality*; D005260:Female; D006454:Hemoglobins; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000401:mortality* / Q000628:therapy; D016896:Treatment Outcome
chemical_list: D006454:Hemoglobins