Chapter 61

Respiratory failure is one of the most common problems requiring admission to the neonatal intensive care unit. Respiratory failure is often the final result of restrictive lung disease with regional or global alveolar collapse or consolidation. In order to achieve optimal alveolar gas exchange, the lung needs to be inflated at end expiration (at functional residual capacity) and have sufficient tidal and minute ventilation to eliminate carbon dioxide.1 Under optimal conditions, several factors help prevent the collapse of alveoli at the end of expiration and thereby maintain an adequate functional residual capacity. Surfactant, which is produced in the type II cells of the lung, dramatically reduces surface tension and opposes the tendency of alveoli to collapse when lung volume is at its lowest. In addition, the rigidity of the chest wall opposes lung collapse. In comparison to the adult, several factors present disadvantages for the neonate’s capacity to maintain optimal lung volumes. The neonatal chest is highly compliant, which limits its ability to oppose elastic recoil and collapse during expiration and increases the potential for the development of collapse. This problem is greatly exacerbated in the setting of surfactant deficiency or inactivation, in which unopposed surface tension dramatically increases the chance of alveolar collapse during expiration. Lastly, although the small diameter of the neonatal tracheobronchial tree generally is sufficient to provide unimpeded airflow, further small reductions in its diameter can dramatically increase resistance and adversely affect gas entry and egress.

A hallmark of treatment for most causes of neonatal respiratory failure is the provision of positive airway pressure.2 (See also Chapter 102.) Application of pressure to the proximal airway may result in several beneficial effects. Most importantly, positive pressure opposes the tendency of end-expiratory alveolar collapse caused by elastic recoil and high surface tension. Moreover, positive proximal airway pressure increases the pressure differential between the upper airway and the distal airspace during spontaneous respiratory effort, facilitating increased bulk flow of gas down the tracheobronchial tree. In addition, positive pressure may help to maintain adequate patency of the airway in disease states characterized by inflammation, plugging, or anatomic (either fixed or dynamic) narrowing of the airway.

### Continuous Positive Airway Pressure (CPAP)

The least invasive means for consistently delivering proximal distending airway pressure is via CPAP.3 CPAP may be delivered via prongs, which are placed in the nose, or by a mask affixed over the mouth and nose. Generally, CPAP is provided at a pressure range of 4 to 8 cm H2O, with the specific level based on the type and severity of the underlying lung disease, the degree of inflation achieved, and the baby’s tolerance of the therapy. Common indications for use of CPAP in the neonatal intensive care unit include mild hyaline membrane disease, disease or narrowing of the airways, and as a bridge to extubation in preterm infants recovering from hyaline membrane disease.4 CPAP may also decrease the incidence ...

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.

Ok

## Subscription Options

### AccessPediatrics Full Site: One-Year Subscription

Connect to the full suite of AccessPediatrics content and resources including 20+ textbooks such as Rudolph’s Pediatrics and The Pediatric Practice series, high-quality procedural videos, images, and animations, interactive board review, an integrated pediatric drug database, and more.