Positive Pressure Respiratory Support Research Articles

New techniques for neonatal respiratory support

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

Intermittent Positive Pressure Ventilation via Nasal Access in the Management of Respiratory Insufficiency

These are preliminary observations of the introduction of a new technique of noninvasive positive pressure respiratory support for patients with subacute or chronic respiratory failure. Clinical situations where intubation or tracheostomy may have been performed were managed by intermittent positive pressure ventilation via nasal access (NIPPV) with a CPAP mask, or a custom constructed Vel-Foam nose piece. Four patients were managed at home with the use of portable volume ventilators. One patient employed the technique while hospitalized with subacute respiratory failure. Two patients, otherwise dependent on mouth intermittent positive pressure ventilation (MIPPV) 24 hours a day, received necessary dental care with NIPPV support. In a large population with a decade or more follow-up, MIPPV was shown to be an effective noninvasive technique to support respiration in patients with the most severe paralytic respiratory failure. Preliminary observations suggest that NIPPV may compare favorably with MIPPV and deserves more widespread study and application.

Effects of antenatal steroid therapy on mortality and morbidity in very low birth weight infants

A cohort of 678 consecutive very low birth weight infants, liveborn in one tertiary institution during a 63-month period, was studied to investigate whether antenatal steroid therapy had any beneficial or harmful effects on mortality or morbidity over the first 2 years of life. Comparing the 244 babies who received treatment with the 434 controls, 195 (79.9%) and 265 (61.1%), respectively, were discharged home (P less than 0.001). Mortality in the treated group remained substantially lower and was almost halved after adjustment for birth weight, extreme immaturity, lethal malformations, and confounding obstetric variables (P = 0.001). Fatal cases of respiratory distress syndrome were less common in the treated group (P = 0.044). Of in-hospital survivors, those in the treated group required less positive pressure respiratory support (P = 0.003) and fewer days in oxygen (P = 0.018), and the incidences of bronchopulmonary dysplasia (P = 0.003) and patent ductus arteriosus (P = 0.002) were lower. Two-year survivors who had received treatment were heavier (P = 0.016) and had larger head circumferences (P = 0.029). These beneficial associations in the treated group were not at the expense of increased rates of infection or adverse neurologic outcome. We did not detect any adverse effects of antenatal steroid therapy on any relevant aspect of mortality or morbidity in infancy under circumstances in which the chances of finding substantial differences were high.