DYNAMICS OF THE MEAN PRESSURE IN THE PULMONARY ARTERY OF NEWBORNS IN NEONATAL PERIOD

Abstract

Determination of mean pressure in the pulmonary artery trunk and its dynamics at the stage of neonatal hemodynamic adaptation is an urgent but insufficiently studied question. Objective. The objective of the research was the study of mean pressure dynamics in the pulmonary artery trunk in mature newborns in the early neonatal period according to Doppler echocardiography findings.Materials and methods. The research included examination of 203 “conditionally” healthy newborns (54.2% of boys and 45.8% of girls) with gestational age of 38-41 weeks. Doppler echocardiography was performed from two hours after birth and till 7 days of life. The mean pressure in the pulmonary artery trunk was determined according to A. Kitabatake et al. (1983) under physiologic sleep conditions.Results of the study. Newborns were divided into two groups such as: 1) babies born to mothers with physiological course of pregnancy and delivery; 2) babies born to mothers with extragenital pathology.General health condition of newborns from the first group was satisfactory. Apgar score was 8 and 9 points at the first and the fifth minutes of life, respectively. Adaptation period was favorable without pathologic somatic and neurologic symptoms. Postpartum adaptation of the cardiovascular system was satisfactory. Newborns were given the breast during the first two hours after birth and in the following days they were breastfed; they were discharged on the 3-5th day of their lives in satisfactory condition. General health condition of newborns from the second group was considered to be satisfactory. Apgar score was 7.7±0.2 and 8.7±0.2 points at the first and the fifth minutes of life, respectively. The early neonatal period was unremarkable, no cardiovascular pathologic symptoms were determined. All babies were given to the breast during 2-6 hours after birth and in the following days they were breastfed. Newborns were discharged in satisfactory condition on the 3-7th day of their lives due to mother’s condition.The conducted research demonstrated that 58.9% (p≤0.05) of babies from the second group were from the second and consequent pregnancies, and 4.7% – from multiple pregnancy. Pregnancy course analysis showed that 52.3% (p≤0.05) of mothers had complicated course. Anemia was reported in 13.1% of expectant mothers. 45.8% (p≤0.05) of babies were born by means of caesarean section. Exacerbation of chronic pyelonephritis during pregnancy was found in 11.2% of women, varicose veins of lower extremities and obesity – in 9.3% of expectant mothers. 58.9% (p≤0.05) of women had compromised heredity, among them 29.9% – from the side of the cardiovascular system in the form of heart rhythm and conduction disorders (AV-block of the II stage, WPW-syndrome, extrasystole), congenital heart disease (secondary defect of inter-atrial septum, anomalous pulmonary veins drainage, pulmonary artery stenosis), vegetative-vascular dysfunction, hypertensive disease, secondary cardiomyopathy, Ehlers-Danlos syndrome.Doppler echocardiography findings showed that during first 12 hours after birth 17.5% patients were registered to have high pressure in the pulmonary artery trunk up to 43.7±12.8mmHg (p≤0.05) and bidirectional shunting through open arterial duct and open oval window. By the end of the first day of life the mean pressure in the pulmonary artery trunk was 27.1±6.6mmHg; left-right shunting through open arterial duct and open oval window was consistently determined. From the second day of life there was stabilization of the mean pressure in the pulmonary artery, the average value of which was 22.8±4.1mmHg, from the third day – 22.2±2.4mmHg, from the fourth day – 23.2±3.1mmHg, and from the fifth-seventh day – 23.4±3.4mHg. The received data corresponded to physiologic time of open arterial duct closing. Indices of the mean pressure dynamics in the pulmonary artery trunk in both groups and also concerning days of life inside of groups did not have significant differences and characterized only general tendencies of intra-cardiac hemodynamics changes in newborns at the stages of hemodynamic adaptation. During individual analysis of mean pressure dynamics in the pulmonary artery trunk in 5.4% of babies (among them 54.5% (p≤0.05) of newborns born to women with extragenital pathology) on the fifth-seventh day of life a moderate increase of pressure in the pulmonary artery trunk was retained (25.5±2.0mmHg) which was connected with later period of fetal communications closing. While performing correlation analysis between level of mean pressure in the pulmonary artery trunk and floor, diameter of open oval window and width of open arterial duct no correlations were detected. Conclusions. Thus, healthy mature newborns in the first day of life are characterized by alteration of hemodynamics in the pulmonary circulation with the tendency to normalization of mean pressure in pulmonary artery trunk. In 5.4% of babies by the end of the early neonatal period increased pressure in the pulmonary artery trunk is retained which is connected with late period of fetal communications closing.