title: Plasma Free Hemoglobin Is an Independent Predictor of Mortality among Patients on Extracorporeal Membrane Oxygenation Support.
abstract: BACKGROUND
  Hemolysis is common in all extracorporeal circuits as evident by the elevated plasma free hemoglobin (PFHb) level. We investigated whether increased hemolysis during extracorporeal membrane oxygenation (ECMO) is an independent mortality predictor.
  
  
  METHODS
  We performed a retrospective observational study of consecutive subjects who received ECMO at a tertiary care facility from 2007-2013 to investigate independent predictors of in-hospital mortality. We examined variables related to patient demographics, comorbidities, markers of hemolysis, ECMO characteristics, transfusion requirements, and complications. 24-hour PFHb > 50 mg/dL was used as a marker of severe hemolysis.
  
  
  RESULTS
  154 patients received ECMO for cardiac (n = 115) or pulmonary (n = 39) indications. Patients' mean age was 51 years and 75.3% were males. Compared to nonsurvivors, survivors had lower pre-ECMO lactic acid (p = 0.026), lower 24-hour lactic acid (p = 0.023), shorter ECMO duration (P = 0.01), fewer RBC transfusions on ECMO (p = 0.008) and lower level of PFHb 24-hours post ECMO implantation (p = 0.029). 24-hour PFHb > 50 mg/dL occurred in 3.9 % versus 15.5% of survivors and nonsurvivors, respectively, p = 0.002. A Cox proportional hazard analysis identified PFHb > 50 mg/dL 24-hours post ECMO as an independent predictor of mortality (OR= 3.4, 95% confidence interval: 1.3 - 8.8, p = 0.011).
  
  
  CONCLUSIONS
  PFHb > 50 mg/dL checked 24-hour post ECMO implantation is a useful tool to predict mortality. We propose the routine checking of PFHb 24-hours after ECMO initiation for early identification and treatment of the cause of hemolysis.
authors.affiliation: Department of Internal Medicine, Mercy Medical Center, Clinton, Iowa, United States of America.
authors.forename: Hesham R
authors.initials: HR
authors.lastname: Omar
authors.affiliation: Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, IL, United States of America.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Mirsaeidi
authors.affiliation: Department of Research, Florida Gulf-to-Bay Anesthesiology Associates, Tampa, Florida, United States of America.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Socias
authors.affiliation: Department of Research, Florida Gulf-to-Bay Anesthesiology Associates, Tampa, Florida, United States of America.
authors.forename: Collin
authors.initials: C
authors.lastname: Sprenker
authors.affiliation: Department of Cardiothoracic Surgery, Florida Advanced Cardiothoracic Surgery, Tampa, Florida, United States of America.
authors.forename: Christiano
authors.initials: C
authors.lastname: Caldeira
authors.affiliation: University of South Florida, FGTBA and TEAMHealth, Tampa, Florida, United States of America.
authors.forename: Enrico M
authors.initials: EM
authors.lastname: Camporesi
authors.affiliation: Department of Anesthesia, Tampa General Hospital, FGTBA, TEAMHealth, Tampa, Florida, United States of America.
authors.forename: Devanand
authors.initials: D
authors.lastname: Mangar
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001803:Blood Transfusion; D009202:Cardiomyopathies / Q000097:blood / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D015199:Extracorporeal Membrane Oxygenation / Q000401:mortality*; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006461:Hemolysis; D017052:Hospital Mortality; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D016040:Lung Transplantation / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D012131:Respiratory Insufficiency / Q000097:blood / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D012189:Retrospective Studies; D012770:Shock, Cardiogenic / Q000097:blood / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D016019:Survival Analysis; D063128:Tertiary Health Care; D013997:Time Factors
chemical_list: D015415:Biomarkers; D006454:Hemoglobins; D019344:Lactic Acid