Manejo respiratorio del recien nacido prematuro y otros factores asociados con la displasia broncopulmonar: una evaluación desde la evidencia existente y la situación actual en algunas unidades de cuidado neonatal de Colombia.

Abstract

Background Despite all the advances in the care of premature infants with respiratory distress syndrome including the use of antenatal steroids and early management with surfactant, bronchopulmonary dysplasia continues to be a major complication of prematurity and cause of chronic morbidity among this population, and in some places persists incidence rates higher than 40% among preterm infants. Many different studies have been conducted with the aim of identifying risk factors of bronchopulmonary dysplasia and the best practices for caring preterm babies in order to avoid lung injury, chronic lung disease, neurological sequelae and death in preterm infants. However, there is no consensus regarding the effectiveness of these interventions in preventing bronchopulmonary dysplasia and other undesirable neonatal outcomes. Objectives To identify, among the interventions more commonly used in the respiratory treatment of preterm neonates (surfactant replacement therapy and ventilation support techniques), those associated with better pulmonary and neurological outcomes, particularly with reduction on the risk of bronchopulmonary dysplasia when used as part of the initial treatment within the first ours of life. 2) To identify the factors associated with higher risk of bronchopulmonary dysplasia, and the potential causes of variation in BPD rates among different cities and populations. Methods We designed four research studies; three of them (one randomized clinical trial, one systematic review of randomized controlled trials and one overview of reviews and trials) were conducted with the aim of evaluating the effectiveness of different respiratory treatment strategies, and one ( a case control study) was conducted with the aim of identifying among maternal, infant and environmental characteristics, those associated with higher risk of broncopulmonary displasya as well as those factors that can explain the differences in rates of broncopulmonary displasya among cities in a Colombian population of preterm infants. Results Each one of these studies generated a scientific publication, therefore, this thesis is presenting in the modality of compendium of publications and its results are the results from the independent studies. Conclusions Findings support the adoption of the treatment strategy known as the “Scandinavian strategy”: prophylactic stabilization with nasal CPAP to all preterm infants, since the time of birth, followed by early surfactant replacement therapy just in the cases that a sings of more severe respiratory disease appear. If nasal CPAP is allowed, the use of prophylactic surfactant is no longer necessary, by contrary, reserving it use as selective therapy could result in better outcomes. If the infant is spontaneous breathing but is not receiving CPAP from the time of birth, the use of very early surfactant combined with the initiation of early nasal CPAP (as soon as sings of more severe respiratory disease appear) is the most adequate care strategy since it has shown to reduce the need of mechanical ventilation and pulmonary air leaks. From existing evidence it is not possible to identify which of the ventilation modes and targeting strategies should be used preferably as part of the initial treatment of the respiratory distress in preterm infants to reach better outcomes and prevent BPD. Bronchopulmonary dysplasia in the Colombian population was mainly explained by traditional risk factors. Findings suggest that altitude may play an important role in the development of this disease. Prenatal steroids did not appear to be protective at high altitude. There is a special need for high quality designed trials conducted under the current clinical practice, to assess the respiratory care interventions that allow defining its real impact on sequels and impairment. New observational studies using more accurate diagnosis of BPD are needed to test the hypothesis regarding high altitude increases the risk of BPD among preterm infants.

Date of Award	30 Sept 2013
Original language	Spanish
Supervisor	Xavier Bonfill Cosp (Director)