Stimulating and maintaining spontaneous breathing during transition of preterm infants

Abstract

Most preterm infants breathe at birth, but need additional respiratory support due to immaturity of the lung and respiratory control mechanisms. To avoid lung injury, the focus of respiratory support has shifted from invasive towards non-invasive ventilation. However, applying effective non-invasive ventilation is difficult due to mask leak and airway obstruction. The larynx has been overlooked as one of the causes for obstruction, preventing face mask ventilation from inflating the lung. The larynx remains mostly closed at birth, only opening briefly during a spontaneous breath. Stimulating and supporting spontaneous breathing could enhance the success of non-invasive ventilation by ensuring that the larynx remains open. Maintaining adequate spontaneous breathing and thereby reducing the need for invasive ventilation is not only important directly after birth, but also in the first hours after admission to the NICU. Respiratory distress syndrome is an important cause of respiratory failure. Traditionally, treatment of RDS required intubation and mechanical ventilation to administer exogenous surfactant. However, new ways have been implemented to administer surfactant and preserve spontaneous breathing while maintaining non-invasive support. In this narrative review we aim to describe interventions focused on stimulation and maintenance of spontaneous breathing of preterm infants in the first hours after birth.

Ductal Flow Ratio as Measure of Transition in Preterm Infants After Birth: A Pilot Study

“…After birth the primary site of gas exchange shifts to the lungs, after which oxygenation is largely determined by the surface area available for gas exchange, the gas diffusion distance and the partial pressure gradient for oxygen between the alveoli and adjacent capillaries. Thus, oxygenation depends on adequate lung aeration (surface area), gas diffusion distance and the amount of additional oxygen given during neonatal support (partial pressure gradient), all of which are largely dependent on the success of neonatal transition especially in preterm infants ( 7 , 23 ).…”

“…Preterm born infants often fail to aerate their immature lungs and need respiratory support in order to transition from a foetus into a neonate. The success of transition is usually reflected by heart rate and pulmonary gas exchange efficiency, which is largely determined by the gas exchange surface area of the lungs and the gas diffusion distance, and is reflected by the need for altering the alveolar oxygen gradient (7,8). Currently, there are various versions of an oxygenation index (OI) used to identify hypoxic respiratory failure in neonates and paediatric patients (9)(10)(11).…”

Versorgung und Reanimation des Neugeborenen nach der Geburt

“…Bei Frühgeborenen kann bereits ein übermäßiger Druck mit der Maske auf das Gesicht eine effektive Beatmung behindern. Auch eine Engstellung des Larynx kann bei diesen möglicherweise die Ursache für eine insuffiziente Beatmung sein [ 10 , 155 , 156 , 194 ].…”

“…Dieses kritische Ereignis löst eine Folge voneinander abhängiger kardiopulmonaler Veränderungen aus, die den Übergang zum extrauterinen Leben ermöglichen [9]. Spontane Atemanstrengungen (Unterdruck) oder eine weniger effektive künstliche Beatmung (Überdruck) sind unerlässlich, um den notwendigen transpulmonalen Druck zu erzeugen, der erforderlich ist, um die mit Flüssigkeit gefüllte Lunge zu belüften, und eine adäquate funktionelle Residualkapazität herzustellen und aufrechtzuerhalten [10,11]. Die meisten, aber nicht alle Neugeborenen erleben diese Anpassungspha-se an das extrauterine Leben völlig ohne Probleme.…”

Feasibility and Effect of Physiological-Based CPAP in Preterm Infants at Birth

“…The effectiveness of non-invasive support is dependent on infants having a patent airway since the larynx of newborn infants closes during apnea (4)(5)(6)(7)(8). As the larynx only opens during a breath, support at birth now focuses on stimulating and supporting spontaneous breathing (9). Recent studies showed that breathing effort can be stimulated by adequate oxygenation, repetitive tactile stimulation and caffeine (10)(11)(12).…”