Functional capillary density decreases after the first week of life in term neonates.

BACKGROUND Changes in the microcirculation have been recognized to play a crucial role in many disease processes. In premature neonates, functional capillary density (FCD) decreases during the first months of life. OBJECTIVES The aims of this study were to obtain microcirculatory parameters in term neonates and older children who did not present with compromised respiration or circulation and to determine developmental changes in the microcirculation in young children. METHODS This single-center prospective observational study was performed at a level III university children's hospital. Subjects eligible for inclusion were children up to the age of 3 years who did not have any respiratory compromise, circulatory compromise or signs of dehydration. The buccal mucosa of 45 children was assessed, using orthogonal polarization spectral imaging. RESULTS We found a significantly higher FCD in neonates younger than 1 week compared with older children. The median FCD was 8.1 cm/cm(2) (range 7.3-9.4) for 0- to 7-day-old neonates (n = 12), 6.9 cm/cm(2) (range 4.7-8.7) for 8- to 28-day-olds (n = 10), 7.3 cm/cm(2) (range 6.1-8.8) for 1- to 6-month-olds (n = 19) and 6.7 cm/cm(2) (range 6.5-9.2) for 3-year-olds (n = 4). After the first week, there was no significant correlation between age and FCD. CONCLUSION FCD of the buccal mucosa decreases after the first week of life.