title: The association between hemoglobin concentration and neurologic outcome after cardiac arrest.
abstract: The purpose of the study is to determine the association between hemoglobin concentration (Hgb) and neurologic outcome in postarrest patients.
  
  
  
  We conducted a retrospective cohort study using the Penn Alliance for Therapeutic Hypothermia (PATH) cardiac arrest registry. Inclusion criteria were resuscitated cardiac arrest (inhospital or out of hospital) and an Hgb value recorded within 24 hours of return of spontaneous circulation. The primary outcome was favorable neurologic status at hospital discharge. Survival to hospital discharge was a secondary outcome.
  
  
  
  There were 598 eligible patients from 21 hospitals. Patients with favorable neurologic outcome had significantly higher median Hgb in the first 2 hours (12.7 vs 10.5 g/dL; P<.001) and 6 hours (12.6 vs 10.6 g/dL; P<.001) postarrest. Controlling for age, pulseless rhythm, etiology, location of arrest, receipt of targeted temperature management, hematologic or metastatic malignancy, or preexisting renal insufficiency, there was a significant relationship between Hgb and neurologic outcome within the first 6 hours after arrest (odds ratio, 1.23; 95% confidence interval, 1.09-1.38) and survival to hospital discharge (odds ratio, 1.20; 95% confidence interval, 1.08-1.34).
  
  
  
  Higher Hgb after cardiac arrest is associated with favorable neurologic outcome, particularly within the first 6 hours. It is unclear if this effect is due to impaired oxygen delivery or if Hgb is a marker for more severe illness.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, University of Washington, Seattle, WA; Division of Emergency Medicine, University of Washington, Seattle, WA. Electronic address: nickjjohnson@gmail.com.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Johnson
authors.affiliation: OhioHealth, Columbus, OH.
authors.forename: Babette
authors.initials: B
authors.lastname: Rosselot
authors.affiliation: Department of Emergency Medicine, University of Colorado School of Medicine, Aurora, CO.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Perman
authors.affiliation: School of Public Health, Drexel University, Philadelphia, PA.
authors.forename: Kalani
authors.initials: K
authors.lastname: Dodampahala
authors.affiliation: Department of Emergency Medicine, Medstar-Washington Hospital Center, Washington, DC.
authors.forename: Munish
authors.initials: M
authors.lastname: Goyal
authors.affiliation: Department of Emergency Medicine, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA.
authors.forename: David F
authors.initials: DF
authors.lastname: Gaieski
authors.affiliation: Center for Resuscitation Science, Department of Emergency Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA.
authors.forename: Anne V
authors.initials: AV
authors.lastname: Grossestreuer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000453:epidemiology* / Q000378:metabolism; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006323:Heart Arrest / Q000150:complications / Q000453:epidemiology / Q000378:metabolism / Q000628:therapy*; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D002534:Hypoxia, Brain / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology; D016017:Odds Ratio; D012042:Registries; D051437:Renal Insufficiency / Q000453:epidemiology; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D006454:Hemoglobins
keywords: Anemia; Cardiac arrest; Hemoglobin; Postcardiac arrest syndrome