RESUMO
INTRODUCTION: Retrospective analysis on some factors possibly influencing survival rate of very low birthweight infants on respiratory life support has been carried out. AIM: The aim was to find out about roles played by prenatal steroid prophylaxis, neonatal surfactant therapy and methods of reduction of complication risk emanating from respiratory life support in the outcome of treatment. METHOD: The frequency rate of pneumothorax, pneumomediastinum and bronchopulmonary dysplasia was comparatively examined for all very low birthweight (less than 1500 g) neonates treated by respiratory life support in the I. Department of Obstetrics and Gynecology, Semmelweis University in 1999 (n = 178) and in 1989 (n = 78). Corresponding data were compared using t-tests. RESULTS: In 100% of the 1999 patients in the focus of the current investigation (178 newborn infants) have received prenatal steroid prophylaxis and 55% of them (98 neonates) have received neonatal surfactant therapy. Respiratory life support resulted in pneumothorax in 7.8% of them (14 patients) and bronchopulmonary dysplasia in 12.3% of them (22 neonates). Frequency rate of complications for the neonates under investigation attributable to respiratory support or initial illness decreased from 38.6% in 1989 to 19.6% in 1999, a difference proven significant by t-test (p < 0.05). Survival rate increased from 34.6% in 1989 to 63.5% in 1999, which is again a significant difference indicated by t-test (p < 0.05). The differences are especially consequential considering that the average gestation age of the infants in the 1999 group was lower than that of the infants in the 1989 group. CONCLUSION: Decrease in complication rate emanating from respiratory support and increase in survival rate over the 10 year period between 1989 and 1999 can be attributed to the combined effect of improvement in respiratory support therapy applied (aiming to minimise its adverse effects like barotrauma and volutrauma more effectively by refined technological means) and of the introduction of administering prenatal steroid prophylaxis and (if judged necessary) neonatal surfactant therapy. A considerable limitation of this study is the lack of separation of independent variables (the separate effects due to the separate treatments applied), but it is reasonable to believe that improvement was due to a combined effect of all changes in treatments indicated above. It is deemed probable that results can be further improved by finding ways to decrease barotrauma and volutrauma even more effectively than now.