title: Factors Influencing the Accuracy of Noninvasive Blood Pressure Measurements in NICU Infants.
abstract: OBJECTIVE
  Compare invasive blood pressure (IBP) and noninvasive blood pressure (NIBP) measurement methods in the neonatal intensive care unit (NICU) across various gestational age and postmenstrual age (PMA), and determine the effect of gestational age and PMA on accuracy of NIBP measurements.
  
  
  METHODS
  Retrospective chart review of paired mean IBP and NIBP measurements from infants admitted to a single NICU from January 2008 through December 2010. Infants with congenital anomalies or receiving therapeutic hypothermia were excluded. Difference between paired measurements was analyzed using Bland-Altman method. We examined the association between PMA, sex, race, mechanical ventilation, medications, and axillary temperature, and the difference in measurements using a mixed effects linear regression model.
  
  
  RESULTS
  Eighty-seven infants had 243 observations. The mean (range) gestational age at birth was 31.9 (23-41) weeks and PMA at time of measurement ranged from 26 to 52 weeks. We found poor agreement between IBP and NIBP measurements, with mean difference (95% limits of agreement) of -8.8 (11, -28.7) mm Hg. The mean blood pressure percent difference ( ±  SD) was -28.3 ( ±  35.6%). A greater blood pressure percent difference between the two measurement techniques was associated with lower PMA and lower mean IBP.
  
  
  CONCLUSIONS
  NIBP measurements overestimate IBP measurements particularly in smaller, sicker infants at lower IBP measurements.
authors.affiliation: Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Baylor College of Medicine, Houston, Texas.
authors.forename: Shaeequa
authors.initials: S
authors.lastname: Dasnadi
authors.affiliation: Division of Neonatal-Perinatal Medicine, Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina.
authors.forename: Sofia
authors.initials: S
authors.lastname: Aliaga
authors.affiliation: Division of Neonatal-Perinatal Medicine, Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina.
authors.forename: Matthew
authors.initials: M
authors.lastname: Laughon
authors.affiliation: Division of Neonatal-Perinatal Medicine, Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina.
authors.forename: Diane D
authors.initials: DD
authors.lastname: Warner
authors.affiliation: Division of Neonatal-Perinatal Medicine, Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina.
authors.forename: Wayne A
authors.initials: WA
authors.lastname: Price
mesh_terms: D000367:Age Factors; D001724:Birth Weight; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000379:methods*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015931:Intensive Care, Neonatal; D008297:Male; D015203:Reproducibility of Results; D012189:Retrospective Studies