324 Skin Microcirculation in Healthy Newborns - Assessments of Morphology, Perfusion and Oxygenation

Abstract

Background and aims: Measurements of central hemodynamics, blood gases and urinary output are commonly used to monitor patients, but values within reference range do not guarantee adequate cellular nutrition and oxygenation. We have examined skin microvascular perfusion, morphology and oxygenation in healthy newborns. Material and Methods: Twenty-five healthy newborns (gestational age >37 weeks) were enrolled within 24 hours after delivery. Skin microvascular assessments were performed day one, two and three, on the chest and the hand, using three different techniques: Computer-assisted video microscopy, CAVM (morphology); Laser Doppler Perfusion Monitoring, LDPM (perfusion); Diffuse Reflectance Spectroscopy, DRS (oxygen saturation of capillary erythrocytes). Results: (Mean with SD) CAVM: Microvascular density (number of microvessels crossing a grid of lines/mm line): Chest: 11.3 (1.5), 11.0 (1.7), 10.7 (1.6). Hand: 13.2 (2.0), 13.2 (1.9), 12.4 (1.6).LDPM: Perfusion (arbitrary units): Chest: 110.4 (32.1), 102.7 (27.8), 100.5 (28.1). Hand: 58.5 (26.2), 55.1 (17.5), 46.6 (14.9).DRS: Microvascular oxygen saturation (%): Chest: 71.9 (7.3), 73.5 (12.2), 74.5 (9.2). Hand: 68.3 (11.5), 63.1 (11.6), 65.5 (11.7). Conclusions: We were able to obtain noninvasive reproducible data for skin microvascular morphology, perfusion and oxygen saturation. The number of skin vessels is fewer in chest than in hand, with a slight reduction from day 1 to day 3. There is higher perfusion in the chest than in the hand, probably due to higher skin temperature (+2.8°). Since all the infants has arterial oxygenation >97%, oxygen extraction in the skin microvessels were approximately 20% in the chest and 30% in the hand.