title: Noninvasive assessments of oxygen delivery from the microcirculation to skin in hypothermia-treated asphyxiated newborn infants.
abstract: Therapeutic hypothermia (TH) has become standard treatment for severe and moderate hypoxic-ischemic neonatal encephalopathy (HIE). Our group has developed an optically based, noninvasive concept of assessing the capacity for oxygen delivery from the microcirculation to the cells of a tissue under investigation. The hypothesis was that mechanisms of reduced oxygen delivery due to reduced metabolism in cooled asphyxiated neonates could be characterized with this concept.
  
  
  
  The skin of 28 asphyxiated newborn infants was studied on days 1 and 3 during TH and on day 4 following rewarming with laser Doppler perfusion measurements (LDPM), computer-assisted video microscopy (CAVM), and diffuse reflectance spectroscopy (DRS). Twenty-five healthy neonates served as a control group.
  
  
  
  The LDPM decreased during cooling (P < 0.01). Functional capillary density was higher both during and following TH compared with control infants (P < 0.01). Capillary flow velocities were reduced during TH (P < 0.05). The heterogeneity of the flow velocities was larger in the HIE infants than in the control infants. Tissue oxygen extraction was higher during TH (P < 0.01).
  
  
  
  This study indicates that assessments of skin microvascular density, capillary flow velocity, and oxygen extraction can be used to characterize reduced oxygen delivery to cells during TH.
authors: Department of Neonatal Intensive Care, Oslo University Hospital, Ullevål, Oslo, Norway.|Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
authors: Siv
authors: S
authors: Fredly
authors: Department of Neonatal Intensive Care, Oslo University Hospital, Ullevål, Oslo, Norway.|Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
authors: Drude
authors: D
authors: Fugelseth
authors: Department of Neonatal Intensive Care, Oslo University Hospital, Ullevål, Oslo, Norway.
authors: Cathrine S
authors: CS
authors: Nygaard
authors: Department of Biomedical Engineering, Linköping University, Linköping, Sweden.
authors: E Göran
authors: EG
authors: Salerud
authors: Department of Neonatal Intensive Care, Oslo University Hospital, Ullevål, Oslo, Norway.|Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
authors: Tom
authors: T
authors: Stiris
authors: Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.|Department of Cardiothoracic Surgery, Oslo University Hospital, Ullevål, Oslo, Norway.
authors: Knut
authors: K
authors: Kvernebo
mesh_terms: D001238:Asphyxia Neonatorum / Q000628:therapy*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced; D020925:Hypoxia-Ischemia, Brain / Q000628:therapy*; D007231:Infant, Newborn; D008297:Male; D008833:Microcirculation; D010100:Oxygen / Q000627:therapeutic use*; D010477:Perfusion; D011446:Prospective Studies; D012867:Skin / Q000098:blood supply
chemical_list: D010100:Oxygen