Effect of External Inspiratory Loading on Ventilation of Premature Infants

Abbasi, Soraya; Duara, Shanaz; Shaffer, Thomas H.; Fox, William W.

doi:10.1203/00006450-198402000-00007

Cited by 16 publications

(14 citation statements)

References 9 publications

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“…Recent short-term load response studies in neonates would support this hypothesis (20,21). Longer term load studies, however, are required before definite conclusions are possible.…”

Section: Developmental Differencesmentioning

confidence: 70%

Postnatal Changes in Transdiaphragmatic Pressure in Piglets

et al. 1986

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“…Recent short-term load response studies in neonates would support this hypothesis (20,21). Longer term load studies, however, are required before definite conclusions are possible.…”

Section: Developmental Differencesmentioning

confidence: 70%

Postnatal Changes in Transdiaphragmatic Pressure in Piglets

et al. 1986

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“…40 A number of studies suggest that preterm infants tolerate respiratory loads poorly and are at higher risk for respiratory failure when compared with older infants and children. 5,30,31 This was thought to be because of the relative lack of highly oxidative, fatigue resistant type I fibers, in the neonatal diaphragm. 11 In animal models and humans, diaphragm myofiber composition changes significantly during postnatal development.…”

Section: Discussionmentioning

confidence: 99%

Diaphragm Dimensions of the Healthy Preterm Infant

Rehan

Laiprasert²,

Wallach³

et al. 2001

Pediatrics

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ABSTRACT. Background. The diaphragm is the major inspiratory muscle in the neonate; however, human neonatal diaphragm development has not been extensively studied. We hypothesized that diaphragm thickness (t di ) would be positively related to postmenstrual age (PMA), body weight, body length, head circumference, and nutritional intake.Objectives. To evaluate the evolution of diaphragm growth and motion in the healthy, preterm infant.Methods. We used ultrasound to measure t di at the zone of apposition to the rib cage and diaphragm excursion (e di ) during inspiration. Thirty-four stable, preterm infants (16 males and 18 females) between 26 and 37 weeks' PMA were studied during quiet sleep at weekly intervals until the time of discharge or transfer from the neonatal intensive care unit. All infants were clinically stable and not receiving ventilatory support.Results. We found that 1) t di increased from 1.2 ؎ 0.1 to 1.7 ؎ 0.05 mm between 26 to 28 and 35 to 37 weeks' PMA; 2) t di was positively correlated with PMA (r ‫؍‬ 0.40), body weight (r ‫؍‬ 0.52), body length (r ‫؍‬ 0.53), and head circumference (0.49), but not with postnatal nutritional intake (r ‫؍‬ 0.09); and 3) e di decreased with increasing PMA.Conclusions. Our findings suggest that diaphragm development in premature infants scales with body dimensions. We speculate that the increase in t di with age is likely attributable to increased diaphragm muscle mass, and the reduced e di with age may be resulting from a reduction in chest wall compliance. Pediatrics 2001; 108(5). URL: http://www.pediatrics.org/cgi/content/full/ 108/5/e91; diaphragm, development, ultrasound.ABBREVIATIONS. t di , diaphragm thickness; FRC, functional residual capacity; ⌬t di , change in diaphragm thickness; PMA, postmenstrual age; BL, body length, HC, head circumference; NI, nutritional intake; GA, gestational age; e di , diaphragm dome excursion; BW, body weight.

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“…Airway muscle activity modulates the cross-sectional area and the compliance of the airway. Although term and preterm infants show a brisk genioglossal EMG response to upper airway occlusion or increased resistance during sleep (42,43), an immediate and sustained decline in minute ventilation is observed (11,44). The mean airway closing pressure for infants at 2 months of age is -0.5 cm H 2 O under complete paralysis during anesthesia (41) and is -0.7 6 2 cm H 2 O in postmortem studies (45).…”

Section: Ontogeny Of Airway and Respiratory Physiologymentioning

confidence: 99%

“…These infants typically manifest loud snoring with marked labored breathing and complete obstructions often terminating with an arousal. Despite a brisk genioglossal EMG response to upper airway occlusion or increased resistance during sleep (42,43) infants have an immediate and sustained decline in minute ventilation (11,44). Infants with OSA have a decreased activation of the major upper airway dilator muscle compared with nonapneic control subjects (43) in response to airway occlusion, potentially impairing the ability to respond to airway closure (43).…”

Section: Pathophysiology Of Obstructive Patterns In Infancymentioning

confidence: 99%

Obstructive Sleep Apnea in Infants

Katz

Mitchell

D’Ambrosio

2012

Am J Respir Crit Care Med

225

224

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Obstructive sleep apnea in infants has a distinctive pathophysiology, natural history, and treatment compared with that of older children and adults. Infants have both anatomical and physiological predispositions toward airway obstruction and gas exchange abnormalities; including a superiorly placed larynx, increased chest wall compliance, ventilation-perfusion mismatching, and ventilatory control instability. Congenital abnormalities of the airway, such as laryngomalacia, hemangiomas, pyriform aperture stenosis, choanal atresia, and laryngeal webs, may also have adverse effects on airway patency. Additional exacerbating factors predisposing infants toward airway collapse include neck flexion, airway secretions, gastroesophageal reflux, and sleep deprivation. Obstructive sleep apnea in infants has been associated with failure to thrive, behavioral deficits, and sudden infant death. The proper interpretation of infant polysomnography requires an understanding of normative data related to gestation and postconceptual age for apnea, arousal, and oxygenation. Direct visualization of the upper airway is an important diagnostic modality in infants with obstructive apnea. Treatment options for infant obstructive sleep apnea are predicated on the underlying etiology, including supraglottoplasty for severe laryngomalacia, mandibular distraction for micrognathia, tonsillectomy and/or adenoidectomy, choanal atresia repair, and/or treatment of gastroesophageal reflux.Keywords: sleep-disordered breathing; adenotonsillar hypertrophy; craniofacial; micrognathia; laryngomalacia Infants experience a wide range of sleep-disordered breathing patterns, including periodic breathing (1), apnea of prematurity (2), and central apnea, but little attention has been given to obstructive sleep apnea (OSA). Infants are particularly vulnerable to obstructive sleep-disordered breathing related to their upper airway structure (3), adverse pulmonary mechanics (4), ventilatory control (5), arousal threshold (6), laryngeal chemoreflex (7), and an REM-predominant sleep state distribution (8). The anatomical and physiological predispositions toward airway obstruction in infants are summarized in Table 1. Airway collapse may occur passively related to the balance between the viscoelastic properties of the pharynx, pharyngeal dilators, and the transmural pressure. Alternatively, obstructive apnea may result from active glottic closure, termed the laryngeal chemoreflex. The diagnosis of OSA in infants is confirmed by polysomnography and the etiology is often determined via direct endoscopic visualization of the airway. Infants with severe OSA will often have marked hypoxemia or sleep fragmentation, which is likely to result in considerable morbidity. As such, successful therapy is mandatory, even if this requires invasive treatment including nasopharyngeal tubes, continuous positive airway pressure (CPAP), supraglottoplasty, or even tracheostomy. This review focuses on the clinical features, polysomnographic patterns, pathogenesis, diagnosis, and mana...

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Effect of External Inspiratory Loading on Ventilation of Premature Infants

Cited by 16 publications

References 9 publications

Postnatal Changes in Transdiaphragmatic Pressure in Piglets

Postnatal Changes in Transdiaphragmatic Pressure in Piglets

Diaphragm Dimensions of the Healthy Preterm Infant

Obstructive Sleep Apnea in Infants

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