title: Preferential cephalic redistribution of left ventricular cardiac output during therapeutic hypothermia for perinatal hypoxic-ischemic encephalopathy.
abstract: OBJECTIVE
  To determine the relationship between left ventricular cardiac output (LVCO), superior vena cava (SVC) flow, and brain injury during whole-body therapeutic hypothermia.
  
  
  METHODS
  Sixteen newborns with moderate or severe hypoxic-ischemic encephalopathy were studied using echocardiography during and immediately after therapeutic hypothermia. Measures were also compared with 12 healthy newborns of similar postnatal age. Newborns undergoing therapeutic hypothermia also had cerebral magnetic resonance imaging as part of routine clinical care on postnatal day 3-4.
  
  
  RESULTS
  LVCO was markedly reduced (mean ± SD 126 ± 38 mL/kg/min) during therapeutic hypothermia, whereas SVC flow was maintained within expected normal values (88 ± 27 mL/kg/min) such that SVC flow represented 70% of the LVCO. The reduction in LVCO during therapeutic hypothermia was mainly accounted by a reduction in heart rate (99 ± 13 vs 123 ± 17 beats/min; P < .001) compared with immediately postwarming in the context of myocardial dysfunction. Neonates with brain injury on magnetic resonance imaging had higher SVC flow prerewarming, compared with newborns without brain injury (P = .013).
  
  
  CONCLUSIONS
  Newborns with perinatal hypoxic-ischemic encephalopathy showed a preferential systemic-to-cerebral redistribution of cardiac blood flow during whole-body therapeutic hypothermia, which may reflect a lack of cerebral vascular adaptation in newborns with more severe brain injury.
authors.affiliation: Neonatal Intensive Care Unit, Rambam Medical Center, Haifa, Israel.
authors.forename: Ori
authors.initials: O
authors.lastname: Hochwald
authors.affiliation: Division of Neonatology, Department of Pediatrics, University of British Columbia, Vancouver, Canada.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Jabr
authors.affiliation: Division of Neonatology, Department of Pediatrics, University of British Columbia, Vancouver, Canada.
authors.forename: Horacio
authors.initials: H
authors.lastname: Osiovich
authors.affiliation: Division of Neurology, Department of Pediatrics, Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Miller
authors.affiliation: Division of Neonatology, Department of Pediatrics, Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: McNamara
authors.affiliation: Division of Neonatology, Department of Pediatrics, University of British Columbia, Vancouver, Canada.
authors.forename: Pascal M
authors.initials: PM
authors.lastname: Lavoie
mesh_terms: D001930:Brain Injuries / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D002302:Cardiac Output; D016022:Case-Control Studies; D005260:Female; D006339:Heart Rate; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods; D020925:Hypoxia-Ischemia, Brain / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome; D018617:Ultrasonography, Doppler, Pulsed