206 Thymus Size as a Prognostic Size in Bronchopulmonary Dysplasia

Abstract

BDP is major cause of premature neonates mortality and morbidity. Causes of BDP are oxygen toxicity, injuries caused by ventilators and respiratory volumes, perinatal inflammations. Chorioamnionitis is related to thymus functions through the intrauterine actions of cytokines. The purpose is to check the reliability of the chest X-Ray as prognostic sign in the development of BDP. Method: 34 chest X-Rays, taken from VLBW neonates, within the first 6 hours after birth, were reviewed. The following criteria were taken into account: 1 Mechanical ventilation = or > 3 days within the first week after birth. 2 Need for O2 administration for 28 days after birth. 3 Radiological findings of BDP in the chest X-Ray. Moreover, 34 chest X-Rays of VLBW neonates who did not develop BDP were reviewed. Thymus size was measured as a ratio between thymus diameter on the level of velum and thorax diameter(CT/T). Statistic analysis was performed by using ANOVA and t-test. Results: ANOVA method:34 neonates complied with the criteria of the study. Another 34 neonates were considered as witnesses. The mean CT/T of the first group was 0,33 and of the second group was 0,42. We found F=15,5>rate criterium F=7,035 with freedom degrees 1/66. Error probability was 1%. By this mean CT/T of the witnesses is statistically higher than the one of the patients with BDP. T-test: t=-3,93 with t-crucial double-sided=2,66. This method confirms that CT/T of witnesses is higher than CT/T of the patients. Discussion: The results show that the chest X-Ray within the first hours of life of VLBW premature neonates has prognostical value in the development of BDP. Small thymus size at birth shows that all mechanisms related to BPD have been activated intrauterus.