Changes Of Cerebrovascular Hemodynamics In Asphyctic Preterm Infants In The Early Days And Their Signification

Objective To determine the intracranial arterial Cerebral hemodynamic parameters ofpreterm infants with asphyxia Within72hours after birth and to study their cerebralhemodynamic change regularities In the early days and their clinical significance Bymeans of color Doppler ultrasound.Methods The research was prospectively performed on48preterm infants clinicallydiagnosed asphyxia and20normal preterm infants from November2010to October2012in our Hospital. The cerebral arterial blood stream parameter On48cases withcomplete data of preterm infants and20cases of normal newborns on the24，48and72hours after birth were observed by bedside color Doppler ultrasonography, to assess thedegrees of asphyxia in premature infants by using Apgar score assessment, and todivide the patients into two groups according to the degree of asphyxia:30cases Inmild asphyxia group and18cases In severe asphyxia group, and to compare them with20normal premature infants，to analyze the characteristics of the changes of cerebralhemodynamics in preterm infants of the three groups.Results Compared with the control group, ACA, MCA and PCA of cerebral bloodflow and RI changed significantly, Within72h after birth premature infants with asphyxia the cerebral artery flow velocity decreased and the resistance index increasedto varying degrees:（1）The hemodynamic changes of ACA①The blood flow velocity increased within48hours after birth in mild asphyxia group and severe asphyxia group，as comparedwith the normal control group，while severe asphyxia group was lower than the mildgroup．72hours after birth the severe asphyxia group had still not returned to normal。②In the early48hours RI in mild asphyxia group and severe group increasedsignificantly (p<0.05), and in72hours it didn’t returned to normality.（2）The hemodynamic changes of MCA①The blood flow velocity increasedwithin24hours after birth in mild asphyxia group and severe asphyxia group，ascompared with the normal control group，while severe asphyxia group was lower thanthe mild group．72hours after birth the severe asphyxia group returned to normal。②Inthe early24hours RI in mild asphyxia group and severe group increased significantly(p<0.05), and in72hours it returned to normality.（3）The hemodynamic changes of PCA①There was no significant difference inblood flow velocity and RI between the mild asphyxia group and the control groupwithin72hours after birth．②compared with the normal group and the mild asphyxiagroup，severe group preterm infants showed blood flow velocity decrease and RIincreased(p<0.05), and in48hours it returned to normality.Conclusion （1）Asphyxia have an effect on cerebral hemodynamic of preterminfants，the changes of cerebrovascular hemodynamics in asphyctic preterm infantswithin72hours after birth are remarkable determined by color Doppler ultrasound.（2）Compared with normal newborns, asphyctic preterm infants showed blood flowvelocity decrease and resistance index increased to varying degrees, and when the degree of asphyxia was more serious，the changes were more obviously and sustainedlonger time.（3）Hemodynamic parameters such as Vs, Vd,Vm and RI are sensitive indicators ofasphyxia, along with the change of asphyxial degree and changed, can guide Childrendivided into different group,and accurate evaluation of cerebral blood flow perfusion..