title: Accuracy of pulse oximeter readings from probe placement on newborn wrist and ankle.
abstract: OBJECTIVE
  To compare the accuracy of pulse oximetry oxygen saturation (SpO(2)) measured on the wrist compared with the ipsilateral palm, and SpO(2) measured on the ankle compared with the ipsilateral sole.
  
  
  METHODS
  In this prospective observational study, neonates admitted to the neonatal intensive care unit were enrolled. We recorded SpO(2) (Masimo Radical-7 pulse oximeter) detected at the palm and ipsilateral wrist initially, then at 30 s, and at 1 min, and we repeated the same procedure over the sole and ipsilateral ankle. We recorded the time to obtain the SpO(2) readings from all these sites. Regression analysis was performed to determine the relationship between paired SpO(2) measurements. The mean difference (bias) and standard deviation of the paired SpO(2) differences (precision) were calculated (Bland-Altman plots).
  
  
  RESULTS
  A total of 150 patients (birth weight 2381±1020 g, gestational age 34.3±4.3 weeks, median postnatal age 3.5 days (25th-75th percentile 1-16 days)) were enrolled. There was a good correlation between SpO(2) measured at the palm versus the wrist (r=0.95, P<0.001 (right); r=0.97, P< 0.001 (left)) and between SpO(2) measured at the sole versus the ankle (r=0.92, P<0.001 (right); r=0.91, P<0.001 (left)). There was also a good agreement between paired SpO(2) measurements from these sites. The bias and precision for SpO(2) at the right palm and right wrist was 0.08±0.94% and for the left palm and left wrist 0.22±0.87%. Similarly, the bias and precision for SpO(2) at the right sole and right ankle was -0.03±0.93% and for the left sole and left ankle was -0.01±0.93%.
  
  
  CONCLUSIONS
  Our results show that the wrist and ankle can be used as alternative sites to measure SpO(2) in newborn infants in place of the routinely used palm or sole.
authors: Department of Pediatrics, USC Division of Neonatal Medicine, LAC+USC Medical Center and Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
authors: N
authors: N
authors: Phattraprayoon
authors: S
authors: S
authors: Sardesai
authors: M
authors: M
authors: Durand
authors: R
authors: R
authors: Ramanathan
mesh_terms: D000842:Ankle / Q000098:blood supply*; D001724:Birth Weight; D004867:Equipment Design; D005260:Female; D005865:Gestational Age; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D010092:Oximetry / Q000295:instrumentation / Q000379:methods* / Q000592:standards*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D014953:Wrist / Q000098:blood supply*