title: Borderline hypotension: how does it influence cerebral regional tissue oxygenation in preterm infants?
abstract: OBJECTIVE
  To monitor cerebral regional tissue oxygenation (crSO2) of preterm infants continuously and to analyze the influence of arterial hypotension on crSO2.
  
  
  METHODS
  In this prospective, observational study crSO2, peripheral oxygen saturation (SpO2), heart rate (HR) and mean arterial blood pressure (MABP) were monitored continuously for 24 h, starting within the first 6 h after birth. Furthermore, cerebral fractional tissue oxygen extraction (cFTOE) was calculated. Preterm neonates with and without arterial hypotension (MABP below the gestational age in weeks) were compared to each other.
  
  
  RESULTS
  Forty-six preterm infants could be analyzed, 17 with (33.4 ± 1.9 weeks, 2016.5 ± 548.5 g) and 29 without arterial hypotension (33.3 ± 1.3 weeks, 1924.7 ± 451.9 g). Altogether, we detected 30 episodes of hypotension, with a mean duration of 1.6 ± 1.2 h per infant and a mean decrease in MABP of 2.2 ± 0.9 mmHg. During hypotension mean crSO2 was 7 5 ± 11%, 2 h prior to that 76 ± 10% and 2 h after the hypotension 7 7 ± 10%, therefore no significant alterations could be observed. Moreover, there was no significant difference in mean 24-h crSO2, SpO2 and cFTOE between the two groups.
  
  
  CONCLUSIONS
  Mild short-term hypotensive episodes in preterm infants did not affect crSO2. This suggests that cerebral autoregulation is maintained in case of borderline-hypotension and may protect infants from cerebral injury.
authors.affiliation: a Research Unit for Cerebral Development and Oximetry, Medical University of Graz, Graz, Austria .|b Research Unit for Neonatal Micro- and Macrocirculation, Medical University of Graz , Graz , Austria .|c Division of Neonatology, Department of Pediatrics , Medical University of Graz , Graz , Austria .|d The Ritchie Centre, Hudson Institute of Medical Research, Monash University , Clayton , Australia , and.
authors.forename: Corinna
authors.initials: C
authors.lastname: Binder-Heschl
authors.affiliation: a Research Unit for Cerebral Development and Oximetry, Medical University of Graz, Graz, Austria .|b Research Unit for Neonatal Micro- and Macrocirculation, Medical University of Graz , Graz , Austria .|c Division of Neonatology, Department of Pediatrics , Medical University of Graz , Graz , Austria .
authors.forename: Berndt
authors.initials: B
authors.lastname: Urlesberger
authors.affiliation: a Research Unit for Cerebral Development and Oximetry, Medical University of Graz, Graz, Austria .|b Research Unit for Neonatal Micro- and Macrocirculation, Medical University of Graz , Graz , Austria .|c Division of Neonatology, Department of Pediatrics , Medical University of Graz , Graz , Austria .
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schwaberger
authors.affiliation: e Division of Cardiology, Department of Pediatrics , Medical University of Graz , Graz , Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Koestenberger
authors.affiliation: a Research Unit for Cerebral Development and Oximetry, Medical University of Graz, Graz, Austria .|b Research Unit for Neonatal Micro- and Macrocirculation, Medical University of Graz , Graz , Austria .|c Division of Neonatology, Department of Pediatrics , Medical University of Graz , Graz , Austria .
authors.forename: Gerhard
authors.initials: G
authors.lastname: Pichler
mesh_terms: D001794:Blood Pressure / Q000502:physiology; D001921:Brain / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004452:Echocardiography; D006339:Heart Rate / Q000502:physiology; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007022:Hypotension / Q000503:physiopathology*; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D007363:Intensive Care Units, Neonatal; D008991:Monitoring, Physiologic; D010100:Oxygen / Q000097:blood*; D011446:Prospective Studies; D019265:Spectroscopy, Near-Infrared
chemical_list: D010100:Oxygen
keywords: Arterial hypotension; cerebral autoregulation; cerebral regional tissue oxygenation; near-infrared spectroscopy; peterm infants