Effect of hypoxic myocardial injury on neonatal cerebral hemodynamics and brain tissue oxygen saturation / 中华围产医学杂志

ABSTRACT

Objective To investigate the effect of neonatal hypoxic myocardial injury and bradycardia on cerebral hemodynamics and brain tissue regional oxygen saturation (rSO2),and to provide patho-physiological evidence for treatment of neonatal hypoxic-ischemic encephalopathy (HIE) in acute phase.Methods Ninety nine full-term newborns admitted into Department of Neonatology,Peking University First Hospital from December,2005 to December,2008 were enrolled in this study.There were 18 newborns with both myocardial injury and HIE (group 1),31 newborns with HIE but without myocardial injury (group 2) and 50 cases of neonatal jaundice (control group).From 3 to 7 days after birth,Doppler ultrasound was used to measure systolic velocity (Vs),diastolic velocity (Vd) and resistance index (RI) of the anterior cerebral artery; and brain tissue rSO2 was detected by near infrared spectroscopy.The differences among groups were compared by variance analysis and LSD test.Brain tissue rSO2 before and after treatment of 20 newborns with bradycardia for various causes were detected and the difference was compared by paired t test.Results (1) Vs of group 1,group 2 and the control group was (19.35±5.13),(29.35±4.28) and (32.62±7.47) cm/s respectively; Vd was (6.43±2.98),(11.21±3.16) and (11.50±3.03) cm/s; RI was 0.68±0.10,0.62±0.03 and 0.64±0.06; brain tissue rSO2 was (52.4± 2.8)％,(54.6±3.1)％ and (62.1±1.9)％.There were significant differences among the three group(F=29.999,19.393,5.283 and 137.952,P＜0.01).Vs,Vd and rSO2 of group 1 were lower than that of group 2 and the control group (P＜0.05).RI of group 1 was higher than that of group 2 and the control group (P＜0.05).Vs and rSO2 of group 2 were lower than that of control group,but there were no differences between the two groups in Vd and RI.(2) The brain tissue rSO2 of newborns with bradycardia after treatment was higher than that before treatment [(58.7±4.6)％ vs (50.9±3.2)％,t=6.239,P＜0.01].Conclusions The disturbance of cerebral hemodynamics and cerebral oxygenation in HIE newborns are aggravated by hypoxic myocardial injury.Stable heart rate might be very important to early treatment for HIE.