title: Accuracy of non-invasive blood pressure monitoring in very preterm infants.
abstract: OBJECTIVE
  Blood pressure (BP) monitoring is an essential procedure in intensive care. There is controversy about the reliability of non-invasive BP measurements in very preterm infants. This prospective trial compared non-invasive BP monitoring with BP monitoring via an umbilical arterial catheter (UAC) in this population.
  
  
  METHODS
  Preterm infants born at less than 32 weeks gestation requiring a UAC for clinical management were eligible. Enrolled infants had up to three BP measurements on the right arm (RA) and right leg (RL) when in a resting state. UAC-BP measurements were noted immediately after the non-invasive BP was displayed on the monitor. Measurements were analysed in subgroups according to birth weight: no greater than 750 g, 751-1,000 g, above 1,000 g. Statistical analysis reports median, range, and Bland-Altman analysis.
  
  
  RESULTS
  Sixty infants were included. Median (range) gestational age was 26.4 weeks (23.6, 31.2); birth weight 924 g (581, 1,518). A total of 1,865 measurements were performed (RA: 935, RL: 930). Mean difference (95% limits of agreement) for infants no greater than 750 g: RA 2.53 mmHg (-11.18, 16.24), RL -0.804 mmHg (-12.65, 11.04); for infants 751-1,000 g: RA 3.535 mmHg (-9.6, 16.7), RL -1.239 mmHg (-13.14, 10.66); for infants above 1,000 g: RA -1.65 mmHg (-13.47, 10.17), RL -4.101 mmHg (-14.17, 5.96).
  
  
  CONCLUSIONS
  Although the average differences between invasive and non-invasive BP measurements are acceptable, the range of under- and overestimation of non-invasive BP measurements is large and not consistent, making reliance on non-invasive modalities to guide circulatory management problematic. If arterial BP monitoring is not available, our results suggest measuring non-invasive BP on the leg in preterm infants with a birth weight no greater than 1,000 g.
authors.affiliation: Department of Paediatrics, Mercy Hospital for Women, 163 Studley Road, Melbourne, VIC 3084, Australia. kaikonig@gmail.com
authors.forename: Kai
authors.initials: K
authors.lastname: König
authors.forename: Dan M
authors.initials: DM
authors.lastname: Casalaz
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Burke
authors.forename: Andrew
authors.initials: A
authors.lastname: Watkins
mesh_terms: D001724:Birth Weight; D001795:Blood Pressure Determination / Q000379:methods*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007363:Intensive Care Units, Neonatal; D008297:Male; D011446:Prospective Studies; D015203:Reproducibility of Results; D014469:Umbilical Arteries