Cerebral and somatic near-infrared spectroscopy in normal newborns

Abstract

Purpose: Near-infrared spectroscopy has been used increasingly in the pediatric population as a continuous, noninvasive indicator of trends in organ perfusion and oxygenation. We studied healthy newborn babies to establish normal values during rest and feeding.

Methods: Forty-four term newborns were recruited. Near-infrared spectroscopy probes were placed on the forehead and over the right kidney to record cerebral (rSO(2)C) and renal-somatic (rSO(2)R) regional oxyhemoglobin saturation. Readings were collected continuously for 2 to 8 hours, spanning 1 to 3 feeding episodes.

Results: Data were available on 26 patients, with an average age of 44 +/- 28 hours. The overall average rSO(2)C was 77.9% +/- 8.5%, rSO(2)R was 86.8% +/- 8.1%, and DeltarSO(2)RC (somatic-cerebral rSO(2) difference) was 8.9% +/- 9.4%. During feeding, rSO(2)C was minimally decreased (78.6% +/- 8.4% versus 78.0% +/- 9.0%, P = .023), rSO(2)R did not change (87.0% +/- 8.1% versus 87.3% +/- 8.0%, P = .31), and DeltarSO(2)RC was minimally increased (8.5% +/- 9.5% versus 9.2% +/- 9.1%, P = .014). Over the first 120 hours after birth, average rSO(2)C decreased (P < .01), and rSO(2)R remained relatively unchanged.

Conclusions: Clinical utility of near-infrared spectroscopy was partly limited by lack of normative data. These data demonstrate that regional oxygen extraction is greater across cerebral than across renal-somatic beds in normal newborns. Healthy newborns do not have clinically significant changes in organ oxygenation with feeding.