title: The effect of blood transfusion on cerebral hemodynamics in preterm infants.
abstract: BACKGROUND
  Anemia of prematurity commonly occurs in infants with very low birth weight; blood transfusion is an important treatment. However, there is no clear evidence to support the criteria currently widely used, based on blood hemoglobin (bHb) and hematocrit indices. Previous studies showed that overtransfusion or a low threshold for transfusion could induce complications or neurologic sequelae, respectively. We hypothesized that a cerebral hemodynamic index may provide an appropriate criterion for determining the need for transfusion in anemic preterm infants.
  
  
  METHODS
  We used near-infrared time-resolved spectroscopy to measure cerebral hemoglobin oxygen saturation (ScO2 ) and cerebral blood volume (CBV) before and after transfusion in 19 infants (24 measurements) with anemia of prematurity. The median gestational age was 27 weeks 0 days, median birth weight was 751 g, and median postconceptual age at transfusion was 30 weeks 4 days.
  
  
  RESULTS
  bHb levels before and after transfusion (mean ± SD) were 9.3 ± 1.4 and 13.7 ± 1.3 g/dL, respectively. After transfusion, CBV significantly decreased from 2.63 ± 0.60 to 2.13 ± 0.26 mL/100 g of brain, and ScO2 significantly increased from 72.8 ± 4.3% to 74.7 ± 4.2%.
  
  
  CONCLUSIONS
  After transfusion, CBV changes were significantly greater with low compared to high pretransfusion Hb levels. This reflected the physiologic response to severe anemia in premature infants, which is to increase CBV and decrease ScO2 . Therefore, CBV and ScO2 may be useful markers for determining the need for transfusion in very-low-birth-weight infants.
authors.affiliation: Maternal Perinatal Center, Department of Pediatrics, Department of Anatomy and Neurobiology, Kagawa University, Kitagun, Kagawa, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Koyano
authors.forename: Takashi
authors.initials: T
authors.lastname: Kusaka
authors.forename: Shinji
authors.initials: S
authors.lastname: Nakamura
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakamura
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Konishi
authors.forename: Takanori
authors.initials: T
authors.lastname: Miki
authors.forename: Masaki
authors.initials: M
authors.lastname: Ueno
authors.forename: Saneyuki
authors.initials: S
authors.lastname: Yasuda
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Okada
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nishida
authors.forename: Kenichi
authors.initials: K
authors.lastname: Isobe
authors.forename: Susumu
authors.initials: S
authors.lastname: Itoh
mesh_terms: D001803:Blood Transfusion; D001810:Blood Volume; D001921:Brain / Q000378:metabolism; D002560:Cerebrovascular Circulation; D006439:Hemodynamics; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019265:Spectroscopy, Near-Infrared
chemical_list: D006454:Hemoglobins