Neonates (birth through 1 month post-term) with respiratory failure are typically cared for in the neonatal intensive care unit (NICU). Physical therapists working with this population must have specialized on-the job training, have completed advanced coursework, and gained additional expertise. Clinical competencies and evidence-based practice guidelines for this setting, including a clinical decision-making algorithm, have been published and are recommended for review.1,2 As part of the developmental team, physical therapists are most often looked to as experts in the neuromotor development of preterm infants.3 Often overlooked is the effect that our expertise could have on the developing respiratory system during this initial period of respiratory compromise. Direct targeting of the respiratory system via careful, ongoing observation and subsequent individualized positioning strategies provides a unique opportunity for physical therapists practicing in the NICU to extend their influence and have an even broader impact on the lives of the littlest patients.
This chapter specifically targets those therapists who currently work in the NICU to provide additional information specifically related to pulmonary development, management, and functional relationships. It is intended to bring an increased awareness to the developing respiratory system as related to provision of care. Increased participation in the initial management of critically ill infants (as related to the respiratory system) will help to decrease and avoid additional negative musculoskeletal and respiratory sequelae of preterm birth. Respiratory failure is a natural byproduct of premature birth. Better management of the respiratory pump will not only improve in-the-moment status but will also facilitate improved neurodevelopmental outcomes and decrease long-term pulmonary morbidities. For those who provide more general pediatric care, the information shared may serve to broaden the therapist’s knowledge in terms of more completely recognizing the effects of prematurity on the pulmonary systems in infancy, childhood, and into adulthood.
The chapter begins with a basic review of developmental anatomy and physiology and reviews respiratory function in the neonatal period, including a more in-depth look at the development and biomechanics of the respiratory pump. Effects of prematurity are reviewed and common neonatal respiratory disorders are outlined. It concludes with examination and intervention. All is provided from a respiratory system perspective.
Heart and Lung Development
The human heart begins to develop at 19 days gestational age, to beat on day 22, and can circulate blood on day 24 of life.4 By the end of the eighth week, a heart with its definitive structures is functioning. Further growth of the myocardium results via hypertrophy of the existing cells.5 The circulatory system is the first organ system to become fully functional in the human embryo. Cells that give rise to the pulmonary system begin differential growth just a few days later at approximately 21 days gestational age. The bronchial structures are formed by approximately 16 weeks, associated vascular structures present by week 24, and ...