rates but is an important factor in the genesis of chronic lung dis ease of prematurity-bronchopulmonary dypasia (BPD). Namely, and volutrauma. Moreover, hyperoxia can create reactive oxy gen species that trigger inflammation. Infection can also be con tributory. In afected newborns, alveolar and pulmonary vascular development is disrupted and leads to hypoxia, hypercarbia, and chronic oxygen dependence (Davidson, 2017; Kair, 2012).
As prevention, hightequency oscilatory ventilation has been evaluated. However, beneits and risks varied considerably between studies (Cools, 2015).
Treatment of the ventilator-dependent neonate with gluco corticoids was also used previously to prevent BPD. he Ameri can Academy of Pediatrics now recommends against routine steroid use because of limited beneits and greater rates of in exposed neonates (Doyle, 20a14a,b; Watterberg, 2010).
In other eforts for BPD prevention, early animal studies demonstrated significant improvements in lung function with weeks of inhaled nitric oxide (McCurnin, 2005). Despite initial enthusiasm, clinical trials failed to demonstrate a consistent benefit. A National Institutes of Health (NIH) consensus statement and the American Academy of Pediatrics (2014) concluded that the available data do not support its use to prevent or treat BPD (Cole, 2011).
Caeine has been used widely to treat apnea of prematurity, but it also has bronchodilatory efects. One large randomized trial of cafeine versus placebo showed lower BPD rates, improved neurodevelopmental outcomes during early childhood, and good evidence of safety up to 11 years (Schmidt, 2006, 2012, 2017). This therapy is now widely used for newborns weighing ; 1250 g.
The antioxidant vitamin A is necessary for normal lung growth and the integrity of respiratory tract epithelial cells. Preterm newborns have low vitamin A levels at birth, and this has been associated with a greater risk of developing BPD. Randomized trials support the use of vitamin A to achieve a modest reduction in BPD rates for very-Iow-birthweight neonates weighing <1500 g (Darlow, 2016) .
Exogenous surfactant products are delivered via endotracheal tube to help prevent RDS. They contain biological or animal surfactants such as bovine-Survanta, calf-Inasu,or porcine-Curosuf Synthetic surfactants such as irst-generation Exosuf and second-generation Suaxin R are equivalent but not superior to animal-derived surfactant (Moya, 2007). In a Cochrane review, Ardell and coworkers (2015) found that animal-derived surfactants led to better outcomes than synthetic surfactants, which do not contain important surfactant proteins. here are currently no synthetic surfactants available.