title: Meconium and transitional stools may cause interference with near-infrared spectroscopy measurements of intestinal oxygen saturation in preterm infants.
abstract: In a pilot study, we found that the NIRS measurements were highly variable and dramatically decreased or disappeared sporadically while monitoring gastro-intestinal (GI) StO(2) on preterm neonates. We hypothesized that the light absorption characteristics of different neonatal and infant stool types may be interfering with NIRS GI measurements.
  
  
  METHODS
  Meconium, transitional, and mature stool samples collected from preterm neonates and older infants (ranging from a few days to weeks in age) were analyzed by a bench-top spectrometer to measure light absorbance in the near infrared range (650-950 nm).
  
  
  RESULTS
  Some meconium and transitional stool samples were noted to have a more marked increase in light absorbance as wavelength decreases towards 650 nm, when compared to more mature stools. When compared to the light absorbance spectra of deoxy-hemoglobin (Hb) and oxy-hemoglobin (HbO(2)), there is a high potential that Hb and HbO(2) may be erroneously calculated, resulting in falsely low GI StO(2).
  
  
  CONCLUSIONS
  Meconium and green colored transitional stools demonstrate a light absorbance spectra that may interfere with NIRS GI measurements, possibly due to their higher biliverdin content, which exhibits a broad spectral absorption peak at 660 nm. Caution is warranted in interpreting GI StO(2) NIRS results in neonates still passing meconium and transitional stools until NIRS-based tissue oximeters to measure GI StO(2) can compensate for the presence of these stool types.
authors.affiliation: Division of Neonatology, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA.
authors.forename: Alecia
authors.initials: A
authors.lastname: Thompson
authors.affiliation: CAS Medical Systems, Inc, Branford, CT, USA. pbenni@casmed.com.
authors.forename: Paul
authors.initials: P
authors.lastname: Benni
authors.affiliation: CAS Medical Systems, Inc, Branford, CT, USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Seyhan
authors.affiliation: Division of Newborn Medicine, Yale New Haven Hospital, New Haven, CT, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Ehrenkranz
mesh_terms: D005243:Feces / Q000737:chemistry*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism*; D008470:Meconium / Q000378:metabolism*; D010100:Oxygen / Q000032:analysis* / Q000378:metabolism*; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
chemical_list: D006454:Hemoglobins; D010100:Oxygen