Baroreceptors in preterm infants: their relationship to maturity and disease.
Using passive tipping to a 45 degrees head-up position, an attempt was made to elicit reflex vasoconstriction in 13 non-distressed preterm infants and 27 infants with hyaline membrane disease, all between 26 and 38 weeks gestation. An increase in vascular tone associated with a significant reduction in peripheral blood-flow was found in 11 of the 13 non-distressed infants, while the same response was lacking in 23 of the 27 distressed infants. No infant demonstrated significant tachycardia with tilting, and the non-distressed infants failed to maintain their mean aortic blood-pressure during tilting. The results suggest that reflex control of vascular tone is present in non-distressed infants as early as 26 weeks gestation, but not in infats with hyaline membrane disease, possibly because of a maximal increase in vascular tone as a response to illness. This is indicated by the findings of significantly higher resting peripheral vascular resistance and lower peripheral blood-flow in infants with this diesease.
D000375:Aging; D001795:Blood Pressure Determination / Q000295:instrumentation / Q000379:methods; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000503:physiopathology*; D007234:Infant, Premature; D011311:Pressoreceptors / Q000502:physiology*; D012018:Reflex; D012127:Respiratory Distress Syndrome, Newborn / Q000503:physiopathology*; D014661:Vasoconstriction