Cerebral and somatic near-infrared spectroscopy in normal newborns

PurposeNear-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.MethodsForty-four term newborns were recruited. Near-infrared spectroscopy probes were placed on the forehead and over the right kidney to record cerebral (rSO2C) and renal-somatic (rSO2R) regional oxyhemoglobin saturation. Readings were collected continuously for 2 to 8 hours, spanning 1 to 3 feeding episodes.ResultsData were available on 26 patients, with an average age of 44 ± 28 hours. The overall average rSO2C was 77.9% ± 8.5%, rSO2R was 86.8% ± 8.1%, and ΔrSO2RC (somatic-cerebral rSO2 difference) was 8.9% ± 9.4%. During feeding, rSO2C was minimally decreased (78.6% ± 8.4% versus 78.0% ± 9.0%, P = .023), rSO2R did not change (87.0% ± 8.1% versus 87.3% ± 8.0%, P = .31), and ΔrSO2RC was minimally increased (8.5% ± 9.5% versus 9.2% ± 9.1%, P = .014). Over the first 120 hours after birth, average rSO2C decreased (P < .01), and rSO2R remained relatively unchanged.ConclusionsClinical 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.