CONTROL OF SKIN BLOOD-FLOW IN PRE-TERM AND FULL-TERM INFANTS

The response of skin blood flow to local ischemia, heating and cooling was investigated at different intervals after birth in 10 healthy ful l-term babies and 10 preterm postincubator infants using 2 noninvasive and locally neutral methods of microcirculatory measurement: laser Do ppler flowmetry and cutaneous oxygen partial pressure (cPO(2)) estimat ion with a probe temperature of 37 degrees C. Both groups of infants w ere capable of myogenic and neural control of skin blood flow. Higher cPO(2) values under basal conditions and during reactive hyperemia sug gest a raised nutritive capillary blood flow in the preterm group. The increase in cutaneous blood flow during local warming and reactive hy peremia shows that even in neonates on the first day of life no maxima l skin vasodilatation is present. An increase in the periodic flow wav es attributed to arteriolar vasomotion in 19- to 22-day-old infants, c ompared to the preterm group and younger babies, indicates that myogen ic activity in skin arterioles increases with advancing age.