title: Quiescent variability of cerebral, renal, and splanchnic regional tissue oxygenation in very low birth weight neonates.
abstract: OBJECTIVE
  In extremely premature neonates, data concerning the normal baseline variability of near-infrared spectroscopy (NIRS)-derived regional oxygen saturation (rSO2) are lacking. We sought to determine: 1) the quiescent variability of cerebral, renal, and splanchnic rSO2 in clinically stable, undisturbed very low birth weight neonates and 2) the effects of different data averaging epochs on site-specific variability.
  
  
  METHODS
  In this prospective, observational study, neonates between 500 and 1250 g underwent seven days of continuous, real-time cerebral, renal, and splanchnic NIRS monitoring starting within the first seventy-two postnatal hours. Demographic, cardiopulmonary, bedside care, and rSO2 data were collected. rSO2 variability was analyzed utilizing data from quiescent periods identified using pre-specified stability criteria. Between- and within-monitoring site comparisons of data averaging methods were made utilizing ANOVA.
  
  
  RESULTS
  Twenty-four subjects (GA 27 ± 0.3 wk, birth weight 988 ± 34 g; mean ± SEM) were monitored. Coefficients of variation (CoVar = SD/mean) were calculated for each monitoring site using varied data averaging epochs. CoVar was lowest for cerebral, intermediate for renal, and highest for splanchnic rSO2 (P < 0.01). For renal and splanchnic sites, shorter epochs (5- and 15-min) resulted in significantly smaller CoVars [P < 0.01 and P < 0.05, respectively]. Splanchnic variability was highly dependent on epoch length, ranging from 16% over 5 min to 23% over 60 min.
  
  
  CONCLUSIONS
  1) rSO2 variability differs significantly between monitoring sites and 2) shorter data sampling epochs decrease rSO2 variability. These observations may assist clinicians in operationally defining minimally significant departures to enable medical decision making utilizing this monitoring technique.
authors.affiliation: Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Stony Brook Children's Hospital, Stony Brook, NY, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Mintzer
authors.affiliation: Department of Pediatrics, Division of Newborn Medicine, The Regional Neonatal Intensive Care Unit, Maria Fareri Children's Hospital at Westchester Medical Center, Valhalla, NY, USA.
authors.forename: B
authors.initials: B
authors.lastname: Parvez
authors.affiliation: Department of Pediatrics, Division of Newborn Medicine, The Regional Neonatal Intensive Care Unit, Maria Fareri Children's Hospital at Westchester Medical Center, Valhalla, NY, USA.
authors.forename: M
authors.initials: M
authors.lastname: Chelala
authors.affiliation: Department of Pediatrics, Division of Newborn Medicine, The Regional Neonatal Intensive Care Unit, Maria Fareri Children's Hospital at Westchester Medical Center, Valhalla, NY, USA.
authors.forename: G
authors.initials: G
authors.lastname: Alpan
authors.affiliation: Department of Pediatrics, Division of Newborn Medicine, The Regional Neonatal Intensive Care Unit, Maria Fareri Children's Hospital at Westchester Medical Center, Valhalla, NY, USA.
authors.forename: E F
authors.initials: EF
authors.lastname: LaGamma
mesh_terms: D034841:Abdominal Cavity / Q000502:physiology*; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000378:metabolism*; D019102:Infant, Very Low Birth Weight / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D008991:Monitoring, Physiologic / Q000379:methods; D010092:Oximetry / Q000379:methods; D010100:Oxygen / Q000378:metabolism*; D011446:Prospective Studies; D019265:Spectroscopy, Near-Infrared
chemical_list: D015415:Biomarkers; D010100:Oxygen
keywords: Near-infrared spectroscopy (NIRS); monitoring; neonate; noninvasive; oxygen delivery; oxygenation; regional tissue oxygenation