title: Efficacy of near-infrared spectrometry for monitoring the cerebral effects of severe dilutional anemia.
abstract: BACKGROUND
  Clear guidelines for red cell transfusion during cardiac surgery have not yet been established. The current focus on blood conservation during cardiac surgery has increased the urgency to determine the minimum safe hematocrit for these patients. The aim of this study was to determine whether monitoring of cerebral regional oxygen saturation (rSO2) via near-infrared spectrometry (NIRS) is effective for assessing the cerebral effects of severe dilutional anemia during elective coronary arterial bypass graft surgery (CABG).
  
  
  METHODS
  The prospective observational study involved patients who underwent cerebral rSO2 monitoring by NIRS during elective isolated first-time CABG: an anemic group (N=15) (minimum Hemoglobin (Hb) <7 g/dL at any period during cardiopulmonary bypass (CPB) and a control group (N=15) (Hb >8 g/dL during CPB). Mean arterial pressure (MAP), pump blood flow, blood lactate level, pCO2, pO2 at five time points and cross-clamp time, extracorporeal circulation time were recorded for each patient. Group results statistically were compared.
  
  
  RESULTS
  The anemic group had significantly lower mean preoperative Hb than the control group (10.3 mg/dL versus 14.2 mg/dL; P = .001). The lowest Hb levels were observed in the hypothermic period of CPB in the anemic group. None of the controls exhibited a >20% decrease in cerebral rSO2. Eleven (73.3%) of the anemic patients required an increase in pump blood flow to raise their cerebral rSO2.
  
  
  CONCLUSIONS
  In this study, the changes in cerebral rSO2 in the patients with low Hb were within acceptable limits, and this was in concordance with the blood lactate levels and blood-gas analysis. It can be suggested that NIRS monitoring of cerebral rSO2 can assist in decision making related to blood transfusion and dilutional anemia during CPB.
authors.affiliation: Department of Cardiovascular Surgery, Acıbadem University School of Medicine, Atasehir, Istanbul, Turkey.
authors.forename: Arıtürk
authors.initials: A
authors.lastname: Cem
authors.affiliation: Department of Anesthesiology and Reanimation, Acıbadem University School of Medicine, Atasehir, Istanbul, Turkey.
authors.forename: Ustalar Ozgen Zehra
authors.initials: UO
authors.lastname: Serpil
authors.affiliation: Department of Anesthesiology and Reanimation, Acıbadem University School of Medicine, Atasehir, Istanbul, Turkey.
authors.forename: Toraman
authors.initials: T
authors.lastname: Fevzi
authors.affiliation: Department of Cardiovascular Surgery, Acıbadem University School of Medicine, Atasehir, Istanbul, Turkey.
authors.forename: Okten
authors.initials: O
authors.lastname: Murat
authors.affiliation: Department of Cardiovascular Surgery, Acıbadem University School of Medicine, Atasehir, Istanbul, Turkey.
authors.forename: Güllü
authors.initials: G
authors.lastname: Umit
authors.affiliation: Department of Cardiovascular Surgery, Acıbadem Healthcare Group, Acıbadem Kadikoy Hospital, Kadikoy, Istanbul, Turkey.
authors.forename: Erkek
authors.initials: E
authors.lastname: Esin
authors.affiliation: Department of Cardiovascular Surgery, Acıbadem Healthcare Group, Acıbadem Kadikoy Hospital, Kadikoy, Istanbul, Turkey.
authors.forename: Uysal
authors.initials: U
authors.lastname: Pinar
authors.affiliation: Department of Cardiovascular Surgery, Acıbadem University School of Medicine, Atasehir, Istanbul, Turkey.
authors.forename: Sensy
authors.initials: S
authors.lastname: Sahin
authors.affiliation: Department of Cardiovascular Surgery, Acıbadem University School of Medicine, Atasehir, Istanbul, Turkey.
authors.forename: Karabulut
authors.initials: K
authors.lastname: Hasan
authors.affiliation: Department of Cardiovascular Surgery, Acıbadem University School of Medicine, Atasehir, Istanbul, Turkey.
authors.forename: Alhan
authors.initials: A
authors.lastname: Cem
mesh_terms: D000740:Anemia / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D001921:Brain / Q000378:metabolism*; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D017707:Erythrocyte Transfusion / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010092:Oximetry / Q000379:methods; D010100:Oxygen / Q000378:metabolism*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D010100:Oxygen