Skin microcirculation in healthy term newborn infants – assessment of morphology, perfusion and oxygenation

Abstract

Day 1-3 (mean (SD)): Microvascular density (CAVM; number of microvessels crossing a grid of lines/mm line, c/mm): 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). Capillary density was significantly higher in the hand than in the chest each day (p < 0.001). Perfusion (LDPM; arbitrary units): Chest: 109.1 (26.0), 101.4 (24.6), 100.8 (25.3). Hand: 58.9 (17.5), 54.3 (15.8), 46.9 (14.8). Perfusion was significantly higher in the chest than in the hand each day (p < 0.01). Microvascular oxygen saturation (DRS; %): Chest: 88.1 (5.2), 87.8 (10.0), 86.7 (9.0). Hand: 79.9 (15.2), 82.7 (11.8), 82.2 (12.1) (p < 0.05). Capillary flow velocities (CAVM) were similar in the chest and hand: 60-70% capillaries had "continuous high flow" and 30-40% "continuous low flow".Multimodal skin microvascular assessments with CAVM, LDPM and DRS are feasible with reproducible data in newborns. The hand has lower perfusion, higher capillary density and higher oxygen extraction than the chest.

Cooling Effect on Skin Microcirculation in Asphyxiated Newborn Infants with Increased C-Reactive Protein

“…In our previous study, we suggested that the increased FCD during cooling compared to healthy term neonates was probably a compensation for reduced oxygen diffusion with lower temperatures [11,17]. In the present study, FCD became significantly lower after rewarming in the high-CRP group compared to infants with low CRP.…”

“…After rewarming, the high-CRP group had significantly more flow in category 5 compared to the infants with low CRP (p < 0.01). In the low-CRP group, 95% of the capillaries had similar velocities as found in healthy normotherm neonates (category 3 and 4) [17] following rewarming compared to only 71% in the high-CRP group.…”

“…Either too low or too high velocities in the capillaries may reduce the capacity of oxygen delivery [11]. In our previous study of healthy term neonates [17], we described the normal and probably the optimal velocities for oxygen delivery, and similar findings have also been found in healthy adults with the same equipment [21]. While an optimal flow velocity was detected in 95% in the low-CRP group following rewarming, it was only found in 71% in the high-CRP group.…”

Acute skin trauma induces hyperemia, but superficial papillary nutritive perfusion remains unchanged

“…With the CAVM technique, capillary morphology and physiology can be visualized and described according to size, shape, density, and blood flow velocity. 7,8,[14][15][16][17] Capillaries were defined as microvessels with a diameter <15 μm. Not all capillaries in a tissue are perfused at a given per millimeter line (c/mm).…”

“…These techniques have been applied in studies of patients with acute heart failure and in healthy and sick newborns. [7][8][9] The measuring depth of the DRS and CAVM methods has been estimated in theoretical models, 10,11 but it remains to be shown that the two techniques in humans assess papillary nutritive perfusion only.…”