**Respiratory Care of the Neonate**

**Respiratory Care of the Neonate**

#### Štefan Grosek and Petja Fister Štefan Grosek and Petja Fister Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.69674

#### **Abstract**

The respiratory distress is a very common condition both in term and in preterm neonates and the most frequent reason for admission to the neonatal intensive care unit (NICU). The aetiology greatly depends on the maturation of neonate's organs and perinatal events. The clinical picture is sometimes scarce and very nonspecific for the etiologic determination. Treatment of neonatal RD begins first with the application of a mixture of oxygen and air, then with different modes of non-invasive respiratory support methods. Non-invasive respiratory support can be sustained with nasal continuous positive airway pressure, bi-level positive airway pressure and high-flow nasal cannula ventilation. Non-invasive ventilation with high-frequency oscillations through nasal cannula or masks is also possible with some respiratory devices. Non-invasive ventilation is usually combined with the application of natural surfactant and other therapeutic means, like methylxanthine therapy, prevention and closure of patent ductus arteriosus, and control of infection. In the case of non-invasive ventilation failure, different kinds of invasive ventilation methods are available and being practiced in NICUs. The invasive respiratory support can be maintained by controlled or intermittent mandatory ventilation combined with different supportive synchronous positive inspiratory ventilation, offered by modern respirators.

10.5772/intechopen.69674

**Keywords:** neonate, respiration, ventilation, oxygenation, perfusion, evidence-based therapy, surfactant, respiratory distress

#### **1. Introduction**

The lung is the only organ during foetal development that remains dormant, although foetal breathing occurs; gas exchange is performed by the placenta, but the lung is completely ready for transition to extra-uterine life. Its development and maturation are precisely regulated

Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons

during foetal life and needed to accomplish readiness for extra-uterine exchange of gases. During labour, different obstetric and non-obstetric factors may affect lung inflation in transitional period to extra-uterine life.

**2. Methods**

invasive and invasive tools for artificial ventilation.

**3. Transition from foetal to extra-uterine life**

intensive care unit (NICU) is addressed.

We conducted electronic searches of articles on respiratory management and care of neonates with RD, using key terms: neonate, respiration, ventilation, oxygenation, oxygen, evidence based therapy, caffeine, surfactant, respiratory distress in the PubMed data base from the years 2000 to 2017 and reported the most relevant ones. Also, consensus guidelines on neonates with RD were reviewed [6]. The article describes transition from intra- to extra-uterine life, lists the methods for assessment of neonates with RD, describes the respiratory support in the delivery room, treatment with methylxantines, oxygen and surfactant, and the non-

Respiratory Care of the Neonate

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http://dx.doi.org/10.5772/intechopen.69674

This chapter includes the impact of optimal ventilation, tissue oxygenation and perfusion on the non-invasive and invasive respiratory management of neonates with RD. Also, the shortand long-term outcome in respect of respiratory management of neonates in the neonatal

The transition from foetal to extra-uterine life is a process of rapid physiologic changes in the neonate that begin in utero as the foetus prepares for transition from intrauterine placental support to extra-uterine self-maintenance. The process can last for up to 12 h after birth and depends on the gestational age, placenta, maternal health and congenital anomalies of the neonate. The foetus is preparing to the transition by foetal breathing, producing surfactant storing glycogen in the liver, producing catecholamines and depositing brown fat. After the umbilical cord is cut, placenta no longer does the work of lungs as they begin to exchange gasses. The first breath inflates the lungs and causes circulatory changes: the resistance to blood flow through lungs falls and more blood flows through pulmonary arteries to the lungs. Three foetal shunts close and this results in neonatal circulation. The three processes of the transition—(1) the replacement of amniotic fluid in the alveoli with air, (2) the onset of regular breathing and (3) the increase in pulmonary blood flow—may all be deranged soon after birth and RD ensues [7]. The failure of alveoli fluid clearance results in transient tachypnoea of the newborn (TTN) and causes in turn decreased lung compliance. The deficiency of surfactant mainly in preterm neonates or in term infants of diabetic mothers causes collapse of the alveoli and diffuse and progressive atelectasis that result in decreased lung compliance and small functional residual capacity (FRC) and cause HMD. The abnormal persistence of elevated pulmonary vascular resistance either due to underdevelopment, maldevelopment or maladaptation of pulmonary vessels results in persistent pulmonary hypertension of a newborn (PPHN). PPHN is often associated with congenital anomalies (i.e. congenital diaphragmatic hernia) or chronic intrauterine stress (meconium aspiration syndrome (MAS)).

At the time of birth, the umbilical cord is still pulsating. For term and preterm neonates, delayed cord clamping is recommended. The preterm neonates born before 32 weeks of gestation with delayed cord clamping had better neuro-developmental outcomes at the age of 18 months [8, 9]. Too early umbilical vein clamping, even before the first breath of the neonate,

Even mature neonates have smaller diameter of the airways in comparison to infants, children and also adults; their chest wall is more compliant and the lung volume at the end of expiration is the same as the closing volume. Therefore, their lungs are prone to collapse. Besides, the neonates have fewer alveoli with ventilation perfusion mismatch, but a two–three–fold increase in oxygen demand in comparison to adults [1]. They have relatively inefficient respiratory muscles due to lack of red respiratory muscles and more white ones, which get tired faster. Their pulmonary vascular wall contains more muscle fibres and is therefore more prone to vasoconstriction. The sudden falls in partial oxygen pressure result quickly after short hyperpnoea in hypopnoea or apnoea. The foetal haemoglobin binds oxygen with greater affinity than adult haemoglobin. Neonates also have immature immune system with lack of the acquired immunity against microorganisms and are thus more prone to infection. In a premature infant, all these differences in lung development are more prominent in comparison to the term neonate and further influence the transitional period of extra-uterine life.

Because of all the above-mentioned developmental immaturity of the lungs, heart, blood vessels, circulation and immune system, neonates are more prone to develop idiopathic respiratory distress (RD) at the beginning of the life but also in later days and weeks and these differences are even more pronounced in premature and very premature neonates. The aetiology and pathophysiology of the RD differ between mature and premature infants [2]. In the most extreme prematurity, several forms of RD syndrome or hyaline membrane disease (HMD) may develop because of lack of surfactant and underdevelopment of the lung.

RD is very common in neonates, affecting about 10% of them [3]. Some of them have disorders of transition from foetal to extra-uterine life; others have RD caused by congenital or acquired infection or congenital malformations of different organs (thoracic and extra-thoracic). Regarding perinatal and labour history, gestational age and appropriateness of birth measures, the aetiology of the neonatal RD could be suspected. Clinical picture of neonatal RD is rather nonspecific in regard to the aetiology of it and also the management is quite universal. RD may develop immediately and acutely after birth or more slowly in the next few hours depending on the cause of neonatal breathing difficulties [4].

According to the situation in the delivery room, we have to decide how to approach the neonate with breathing difficulties. A well-equipped and trained neonatology team should be available during all difficult or premature deliveries which have to follow recommended resuscitation care of the neonate. The first golden minutes are the most important not only to properly recognize a neonate who needs our support but also to apply appropriate, sufficient and not too aggressive support if not needed. Appropriate inspiratory pressure and oxygen therapy during artificial ventilation in the delivery room may prevent immediate and later complications especially in the most vulnerable extreme premature infants. Prevention of hypothermia, in premature neonates with plastic bag, is also one of the important preventable methods because it may prevent severe metabolic derangements due to hypothermia, harmful for all organs [5].
