title: Volume expansion does not alter cerebral tissue oxygen extraction in preterm infants with clinical signs of poor perfusion.
abstract: BACKGROUND
  Preterm infants with signs of poor perfusion are often treated with volume expansion, although evidence regarding its effect on cerebral perfusion is lacking. Moreover, the effect is questionable in preterm infants with an adequate cerebrovascular autoregulation (CAR). A useful measure to assess perfusion is cerebral fractional tissue oxygen extraction (cFTOE).
  
  
  OBJECTIVE
  To assess the effect of volume expansion on cFTOE in preterm infants with signs of poor perfusion.
  
  
  METHODS
  In this observational study, we assessed cFTOE using near-infrared spectroscopy in preterm infants with signs of poor perfusion before, during and 1 h after volume expansion treatment. Simultaneously, we measured mean arterial blood pressure (MABP). We tested the effect of volume expansion on both cFTOE and MABP, using multi-level analyses. We intended to define a subgroup that responded to volume expansion with an increase in blood pressure and a decrease in cFTOE, suggesting absent CAR.
  
  
  RESULTS
  In 14 preterm infants, with a median gestational age of 26.7 weeks (25.0-28.7 weeks) and a median birth weight of 836 g (615-1,290 g), we found a small increase in MABP during (1.4 ± 1.4 mm Hg, p = 0.003) and after (1.8 ± 1.7 mm Hg, p = 0.001) volume expansion, but no change in cFTOE during (-0.19 ± 0.1% p = 0.44) or after (-0.53 ± 0.1% p = 0.34) volume expansion. We were unable to define a subgroup lacking CAR.
  
  
  CONCLUSIONS
  Cerebral perfusion, as assessed by cFTOE, does not improve in preterm infants with signs of poor perfusion following volume expansion. In these infants, either CAR is present or volume expansion is inadequate to affect cFTOE.
authors.affiliation: Division of Neonatology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. e.kooi@umcg.nl
authors.forename: Elisabeth M W
authors.initials: EM
authors.lastname: Kooi
authors.forename: Michelle E
authors.initials: ME
authors.lastname: van der Laan
authors.forename: Elise A
authors.initials: EA
authors.lastname: Verhagen
authors.forename: Koenraad N J A
authors.initials: KN
authors.lastname: Van Braeckel
authors.forename: Arend F
authors.initials: AF
authors.lastname: Bos
mesh_terms: D062186:Arterial Pressure; D015415:Biomarkers / Q000097:blood; D001810:Blood Volume; D002560:Cerebrovascular Circulation; D016009:Chi-Square Distribution; D005260:Female; D005440:Fluid Therapy; D005865:Gestational Age; D006706:Homeostasis; D006801:Humans; D007022:Hypotension / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D010092:Oximetry / Q000379:methods; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption; D012189:Retrospective Studies; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D010100:Oxygen