Non-invasive measurement of local tissue perfusion and its correlation with hemodynamic indices during the early postnatal period in term neonates

Objective:monitoring the changes in buccal tissue oxygen saturation (sto2) may aid in early diagnosis of circulatory compromise. our objective was to define the normal value of buccal sto2 and its correlation to the middle cerebral artery (mca) flow indices and cardiac output in healthy term infants during the first 48 h after birth.study design:in this prospective study, we assessed buccal sto2 by visible light spectroscopy and assessed the left ventricular output (lvo) and mca flow indices by ultrasound on postnatal days 1 and 2. we enrolled 20 term neonates. the wilcoxon-matched pairs signed-rank test and pearson correlation were used to analyze the data.result:median (range) buccal sto2 readings were 68% (62 to 72) on day 1 and 66% (61 to 69) on day 2 (p=0.03). a weak but significant positive correlation was found between buccal sto2 and lvo (r=0.37, p=0.023). there was no correlation between buccal sto2 and mca mean velocity or pulsatility index.conclusion:under a physiological state, buccal sto2 in resting healthy neonates is 61 to 72%, regardless of variability in systemic and cerebral blood flow. because of its ease of use and non-invasive nature, the use of visible light spectroscopy in conditions with circulatory compromise needs to be further investigated.