Introduction. Persistent pulmonary hypertension is a problem that leads to high morbidity and mortality in preterminfants. In clinical studies, oxidative stress (OS) contributes to the development of pulmonary hypertension (PH). Themost specific biomarker of OS in preterm infants is urinary 8-hydroxy-2-deoxyguanosine (8-OHdG).The aim of the study. To determine the clinical and diagnostic relationship between the value of 8-hydroxy-2-deoxyguanosine and the level of mean trunk pulmonary artery pressure in premature infants with respiratory distresssyndrome and asphyxia in the early neonatal period.Material and methods. Determination of 8-OHdG (ng/ml) by enzyme-linked immunosorbent assay (ELISA) andPH by echocardiography (EchoCG) in 60 premature infants at 26-32 weeks of gestation at 1 and 3-5 days of life in2 groups: I - 32 children with respiratory distress syndrome (RDS); II - 28 children with RDS in combination withperinatal asphyxia.Results. The average value of pulmonary artery pressure (mmHg) in the group II of children in comparison withgroup I was higher both in 1 and 3-5 days of life. The level and dynamics of 8-OHdG correlated with the severity of PH,which required longer respiratory support in group II. Sexual dimorphism of 8-OHdG levels and dynamics was noted.Conclusions. Perinatal asphyxia in preterm infants with RDS on the 1st day of life complicates the course of PH, asindicated by a higher level of the urinary 8-OHdG and correlated to mPAP. Gender characteristics of the dynamics of8-OHdG levels in children with perinatal pathology reveal reduced adaptability and reactivity of boys to OS at birth.Dynamics in the form of a decrease in the level of 8-OHdG in the urine is a favorable prognostic sign of pulmonaryhypertension. Gender characteristics of the dynamics of 8-OHdG levels in children with perinatal pathology revealreduced adaptability and reactivity of boys to OS at birth.

The aim of this study was to determine the clinical significance of the levels and dynamics of the urinary 8-hydroxy-2-deoxyguanosine, degree of pulmonary hypertension on choosing the duration and form of respiratory support in premature infants with respiratory distress syndrome in combination with perinatal asphyxia. Materials and methods. The levels of the urinary 8-hydroxy-2-deoxyguanosine (8-OHdG), ng/ml were determined by enzyme immunoassay (ELISA) method and the degree of pulmonary hypertension (PH) - by echocardiography in 60 premature new-borns at 26-32 weeks of gestation on the 1st and the 3rd–5th days of life. A comparative analysis of indicators was carried out in 2 groups: I – 32 children with respiratory distress syndrome (RDS); II – 28 children with RDS combined with perinatal asphyxia. All infants received a respiratory support, depending on the clinical condition, blood gas analyses, and the chest X-ray. Results. The level and dynamics of the urinary 8-OHdG correlated to degree of PH, form, and duration of respiratory support. Children of the group II on the 1st day of life had echocardiogram indicators of mild PH and indicators of the urinary 8-OHdG 2.27±0.39 ng/ml; by 3rd–5th days of life – level of the urinary 8-OHdG increased to 4.10±0.42 ng/ml and the level of PH – to moderate, required 76.2 % longer respiratory support compared to children of the group I. Conclusions. Prematurely born infants with RDS in combination with perinatal asphyxia have a higher oxidative stress (OS) levels and more significant pulmonary hypertension, which requires a longer respiratory support by 76.2 % and more often use of high frequency oscillatory ventilation (HFOV) by 9.3 %

Introduction. Oxidative stress (OS) is recognized as a contributing factor to the development of persistent pulmonary hypertension (PPH) in premature infants. In the modern scientific literature, there is a lack of unequivocal recommendations for the management of PPH, considering the levels of OS, what determines the need for the development of a differentiated approach for management to infants with pulmonary hypertension.The aim of the study. To increase the efficacy of management of premature infants with persistent pulmonary hypertension with asphyxia and respiratory distress syndrome based on the development of the algorithm of a differentiated approach for management of pulmonary hypertension considering the levels of oxidative stress as determined by the urinary 8-hydroxy-2-deoxyguanosine (8-OHdG).Material and methods. Were analyzed the observations of 96 infants born prematurely at gestational age of 26/1–34/6 weeks: group I consisted of 50 infants with respiratory distress syndrome (RDS), group II - 50 infants with RDS associated with perinatal asphyxia. PPH was determined by echocardiography on the 1st and on the 3rd-5th day of life, and quantitative determination of the urinary 8-OHdG (ng/ml) was performed on 44 neonates on the 1st and in dynamics on the 3rd-5th day of life using enzyme-linked immunosorbent assay (ELISA). For comprehensive radiographic assessment of PPH, all infants received chest X-Ray with determination of Moore's, Schwedel's, and cardiothoracic indexes (CTI).Statistical analysis was performed using Microsoft Excel 2019 software. Under the conditions of normal distribution of quantities, parametric statistical methods were used to calculate the arithmetic mean (M) and the representativeness error of the mean (m). Using Fisher`s exact test (φ) we analyzed the quantitative parameters. Using the heterogeneous sequential Wald procedure, development of diagnostic criteria was performed. The essence of the procedure is to determine both diagnostic (DC), prognostic coefficients (PC) and diagnostic informativeness (I) of the investigated indicators. The minimum informativeness of the feature required for addition to the developed algorithm was considered I ≥ 0.25.The algorithm was developed on the basis of diagnostic coefficients of clinical and anamnestic data of the examined groups of children, echocardiographic criteria for the presence and determination of the degree of PPH, the dynamics of OS levels and their comparison with the indicators of a comprehensive radiological assessment of pulmonary hypertension in prematurely born infants with RDS and perinatal asphyxia in association with RDS in gestational age of 26-34 weeks.Design of a study was discussed and approved at a session of the Ethical commission of the Kharkiv Medical Academy of Postgraduate Education (Prot. № 5 from 18.12.2020). All parents gave an informed consent for examination of their children.The study was carried out in accordance to the plan of the research work of the Department of Neonatology of the Kharkiv Medical Academy of Postgraduate Education "Study of features of the course of oxidative stress diseases in newborns" (January 2022 - December 2024), state registration number 0122U000025.Results. Has been developed an algorithm of a differentiated approach to management of premature infants with RDS and asphyxia with PPH, the essence of which - is to improve and individualize the method of mechanical lung ventilation (MLV) for each individual case.Conclusions. For prematurely born infants at gestational age 26-34 weeks, is important to determine the level of the urinary 8-OHdG on the 1st and 3rd-5th days of life to decide the severity of OS. For management of newborns with PPH, in the case of an increase of the level of 8-OHdG by the 3rd-5th day of life, is recommended to increase the ventilator parameters; in the case of a decrease - diminish the ventilation parameters or extubate an infant.