Page 140 - Physiological based CPAP for preterm infants at birth Tessa Martherus

General discussion
Introduction
Preterm infants often fail to aerate their lungs and require respiratory support immediately at birth in order to initiate pulmonary gas exchange. To minimise the risk of injury, respiratory support in the delivery room (DR) has shifted from elective intubation and mechanical ventilation towards non-invasive support (1-3). While the effectiveness of non-invasive respiratory support is dependent on infants having a patent airway, if the infant is not breathing at birth (apneic) the larynx is mainly closed and only opens during a breath (4-7). Recent research has focussed on stimulating spontaneous breathing using repetitive tactile stimulation, caffeine and adequate oxygenation (8-10). However, there is no data on the optimal CPAP level needed to assist preterm infants establish and maintain adequate lung aeration (11-14).
Lung aeration is predominantly driven by the transpulmonary (across the airway wall) pressure gradient generated during spontaneous breathing. Hypothetically, the application of continuous positive airway pressure (CPAP) increases the transpulmonary pressure to enhance lung aeration (Figure 1). Currently, 4-8 cmH2O CPAP is recommended in the DR (15, 16). However, this has predominantly been extrapolated from CPAP support used in the neonatal intensive care unit (NICU), where CPAP is used to support infants hours to days after birth when the lung is well aerated. This is strikingly different to the DR setting, where CPAP is used to promote lung aeration and infants undergo major physiological changes at birth.
Figure 1. The use of higher CPAP levels increases the transpulmonary pressure (ΔP). 136