New techniques for neonatal respiratory support

Abstract

Considerable progress has been made in the management of respiratory distress in newborns since the introduction of positive pressure ventilation over 20 years ago. More recently, the introduction of surfactant and the increased use of steroids predelivery have led to a major increase iri survival in preterms with hyaline membrane disease. Conventional ventilation refers to the positive pressure respiratory support that is practised in newborn units. A wide variety of mechanical ventilators are currently in use in the UK and ventilator management policies vary widely between units with no consensus view as to the best approach. Trauma from ventilation is an important factor in the aetiology of the airway and lung damage seen in bronchopulmonary dysplasia (BPD). Asynchrony between the ventilator and the infant's respiration and the use of large tidal volumes to accomplish adequate ventilation are the major components of this trauma? In a study limiting tidal volume by constraints applied to the chest wall in an animal model the use of high airway pressures did not produce as much damage as when tidal volume was not limited) Therefore, changes in lung volume may be more important than changes in airway pressure in the production of lung injury. For this reason, the term volutrauma is preferred to barotrauma. In animals with healthy lungs 13 large tidal volume ventilation can damage the pulmonary capillary endothelium, alveolar and airway epithelium and basement membranes allowing fluid, protein and blood to leak into the airways, alveoli and lung interstitium. 1 This sequence is well described in the evolution of respiratory distress syndrome to chronic lung disease in newborns. Despite the excellent achievements in neonatal respiratory care, a number of infants continue to respond