Neonatal respiratory failure

Abstract

The classic entity of neonatal distress syndrome, as a lung disease expressing predominant surfactant deficiency, is currently changing to a more complex disease of the developing lung as a result of the number of extremely immature preterm infants. Prenatal factors, such as the fetal inflammatory response syndrome influence short- and long-term outcome in these premature infants presenting with respiratory distress syndrome at birth. Therefore, various previously dismissed treatment strategies, such as surfactant prophylaxis or newer anti-inflammatory approaches have to be reinvestigated in this emerging population. Despite the resurrection of a new picture of bronchopulmonary dysplasia, lung injury induced by mechanical ventilation remains a major issue in neonatal intensive care. With the advance in understanding of mechanical ventilation, it is becoming evident, that improvement in outcome can not be achieved by restoring normal lung physiology in the diseased lung using sophisticated ventilators and ventilation modes. A more disease specific ventilator strategy that will target as early as possible homogenous lung opening while at the same time avoiding overdistention of the lung, has the potential to affect outcome. The possible antiinflammatory properties of surfactant-proteins, nitric oxide and corticosteroids, despite some drawbacks, may show to have a synergistic effect. However, this needs further exploration.

Three horses with severe respiratory distress like Adult Respiratory Distress Syndrome

“…The syndrome was first described in human beings, who showed an acute onset of progressive dyspnea, hypoxemia and panlobular alveolar infiltrates in thoracic radiographs (Ashbaugh et al 1967). The clinical findings are similar to those of an acute respiratory distress in newborns (Riemensberger 2002). Generally, two major categories of risk have been characterized in humans: direct injury of alveolar function, such as pulmonary infection, aspiration, toxic inhalations, or indirect injury of alveolar function, such as severe organ injuries, septicemia or severe trauma (Petty 1985, Bernard et al 1994, Lazarov et al 2001.…”

Establishing lung gas volumes at birth: interaction between positive end-expiratory pressures and tidal volumes in preterm rabbits

“…Although lung aeration is important for gas exchange after birth, uniform aeration and distribution of ventilation are also thought to be important to minimize regional overexpansion and injury (25,26). Our findings indicate that when providing PPV, adequate PEEP and V T are needed to create and establish FRC.…”

Setting the Ventilator in the NICU

“…It has become clear that to apply ventilation optimally requires a well-recruited lung with adequate end-expiratory volume (Rimensberger 2002 ;Clark et al 2000 ). Such an approach is dependent on the application of suffi cient PEEP, and the physiological considerations that guide PEEP setting are discussed in this section.…”

“…In comparison to ventilation of infants with RDS with rates of at least 60/min, ventilation at slow rates of 30-40/min (and therefore higher V T ) was associated with a marked increase in pulmonary interstitial emphysema (Pohlandt et al 1992 ) and pneumothorax (OCTAVE Study Group 1991 ). Other markers of over-ventilation in early life, such as hypocapnia, are known to increase the risk for the development of chronic lung disease (Garland et al 1995 ;Kraybill et al 1989 ), with one putative mechanism being volutrauma related to high V T (Rimensberger 2002 ).…”

“…If, and only if, the lung is adequately recruited can the benefi ts of "gentle ventilation" with relatively small tidal volumes be realised. The combination of an "open lung" (Lachmann 1992 ) and low V T provides adequate gas exchange and markedly reduces the risk of lung injury during mechanical ventilation (Rimensberger 2002 ;Rimensberger et al 1999a , b ;van Kaam et al 2004 ). Studies of this approach in ventilated adults with acute respiratory distress syndrome have shown reduced mortality and more rapid weaning from ventilation (Amato et al 1998 ;ARDS Network 2000 ).…”