One of the most critical events in life is the switch from dependence on placental gas exchange in utero to air breathing at birth. In utero several processes take place to ensure an effective transition. However, full respiratory adaptation to extra uterine life takes weeks to complete. The primary function of the lungs is to arterialize mixed venous blood. This is achieved by pulmonary gas exchange and involves three important processes: ventilation, diffusion, and perfusion. When the newborn child is suffering from an incomplete transition due to, e.g., asphyxia, persistent pulmonary hypertension, infection, or prematurity, acute respiratory problems develop soon after birth. Pulmonary disorders represent one the most common diagnoses in infants admitted to neonatal units. In the previous decades, it was common practice to start endotracheal intubation and mechanical ventilation in case of moderate to severe respiratory distress. Nowadays, it is well known that these lifesaving actions may lead to adverse effects on the respiratory system. For example, there is a risk for bronchopulmonary dysplasia (BPD) to develop. The pathogenesis of BPD is mainly linked to the use of mechanical ventilation in the immature lung [
5]. The main factor underlying chronic lung disease of the newborn is immaturity of the respiratory system. Other factors involved in the development of BPD are related to changes in delivered volume (volutrauma), delivered pressure (barotrauma), and intubation (endotrauma) [
20,
24]. The aspect of traumatic exposure related to increased risk of airway colonization and infection with pathogens after intubation (biotrauma) is becoming more relevant. Although there is little evidence to support the hypothesis that prevention of intubation decreases the incidence of BPD, it is widely accepted that when endotracheal intubation is required, it should be as brief as possible [
14]. Minimizing lung injury could lower the incidence of BPD. New modern aspects show that trauma to the respiratory system can be prevented by starting gentle respiratory support as soon as possible after birth. The ultimate objective of non-intubated or noninvasive ventilation (NIV) is to prevent intubations and invasive mechanical ventilation [
8,
11,
12,
14,
15,
28] (Table
1). In the past years, improvements in sensors and flow delivery systems have resulted in the introduction of a variety of other types of NIV in addition to well-known nasal CPAP. For the best possible application of these innovations, a thorough physiological knowledge of the mechanism of the respiratory system in the newborn is a must [
15]. This will be explained below. Furthermore, the modern insights of noninvasive respiratory therapy in newborns are being discussed in this general overview.
Table 1
Noninvasive or non-intubated ventilation in newborns
Delivery room; Neopuff® |
Non-cycled respiratory support |
Low-flow therapy (<2 L/min) |
High-flow therapy (>2 L/min) |
nCPAP; conventional and modern |
Cycled respiratory support |
Noninvasive nasopharyngeal positive pressure ventilation |