Study On Influencing Factors Of Brain Oxygenation And Its Correlation With Intraventricular Haemorrhage In Very Premature Infants In Early Postnatal

Objective:Monitoring the cerebral regional tissue oxygen saturation(CrSO2)of very preterm infants continuously by near-infrared spectroscopy(NIRS)in 7 days after birth to study the changes trend of CrSO2,the factors affecting CrSO2 and the correlation between CrSO2 and intraventricular haemorrhage(IVH).Methods:105 newborns with the gestational age of 28-31 weeks were selected from the neonatal intensive care unit of the seventh medical center of the PLA General Hospital from June 2019 to December 2020.CrSO2 of very preterm infants were continuously monitored after admission.CrSO2,transcutaneous arterial oxygen saturation(SpO2),heart rate(HR)and mean arterial blood pressure(MABP)in a quiet state were collected once every hour.CrSO2,SpO2,HR and MABP were recorded before clinical treatment(such as adjusting ventilation mode,pulmonary surfactant(PS),volume expansion),half an hour after treatment and 1 hour after treatment.According to the results of brain ultrasound and Papile classification method,all children were divided into non IVH group,mild IVH group and severe IVH group.Analyze the risk factors of IVH,the impact of clinical intervention on CrSO2,the correlation between clinical monitoring data such as blood gas and CrSO2,and the relationship between CrSO2 and IVH.Results:1.Multiple births and placental abnormalities are risk factors for severe IVH in very preterm infants(P<0.05).2.In clinical intervention,only PS and sputum aspiration had significant effects on CrSO2.CrSO2 in the half hour and one hour after PS in the non IVH group and mild IVH group were significantly higher than that before PS(P<0.05);in the severe IVH group,CrSO2 in the half hour after PS was significantly higher than that before PS(P<0.05),but there was no significant difference between CrSO2 in one hour after PS and that before.CrSO2 in non IVH group and severe IVH group decreased significantly at 5 minutes after sputum suction(P<0.05),and there was no significant difference between CrSO2 at 10 minutes after sputum suction and before sputum suction(P>0.05);In mild IVH group,there was no significant change in CrSO2 at 5 minutes after sputum suction,and CrSO2 at 10 minutes after sputum suction was significantly higher than that before sputum suction(P<0.05).However,CrSO2 in severe IVH group maintained at a low level before and after sputum aspiration.3.The mean value of CrSO2 in the first 7 days of the severe IVH group was significantly lower than that in the non IVH group and mild IVH group(P<0.001).4.When the threshold of cerebral hypoxia was 73%and 75%,the time of hypoxia in the severe IVH group was significantly longer than that in the non IVH group(P<0.05);When the cerebral hypoxia threshold was 75%,77%,and 79%,the hypoxia load in severe IVH group was significantly higher than that in non IVH group(P<0.05).5.In the non IVH group,PaO2 and Hb were positively correlated with CrSO2(P<0.05),and Glu was negatively correlated with CrSO2(P<0.05).In the mild IVH group,PaO2,Hb and SO2 were positively correlated with CrSO2(P<0.05).In the severe IVH group,there was a negative correlation between pH,BE and CrSO2(P<0.05)and a positive correlation between MABP and CrSO2(P<0.05).Conclusion:1.The risk of severe placental abnormalities is very high.2.The low level and repeated fluctuation of CrSO2 in the early postnatal period of very preterm infants are closely related to IVH.The time and intensity of cerebral hypoxia in the early postnatal period of very preterm infants are closely related to severe lVH.3.The risk of IVH is higher in children with low CrSO2 level before and after sputum aspiration and in children with significantly increased but unstable CrSO2 after PS treatment.4.Children with cerebrovascular autoregulation dysfunction in the early postnatal period have a higher risk of IVH.Their CrSO2 is passively affected by MABP and is more likely to be accompanied by hypotension,acidosis,hypercapnia and anemia.5.During the treatment of very preterm infants,it is very necessary to monitor CrSO2 by NIRS for early recognition of cerebral hypoxia.