Elevated airway liquid volumes at birth: A potential cause of transient tachypnea of the newborn

Erin V. McGillick, Katie Lee, Shigeo Yamaoka, Arjan B. te Pas, Kelly J. Crossley, Megan J. Wallace, Marcus J. Kitchen, Robert A. Lewis, Lauren T. Kerr, Philip DeKoninck, Janneke Dekker, Marta Thio, Annie R.A. McDougall, Stuart B. Hooper

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Excessive liquid in airways and/or distal lung tissue may underpin the respiratory morbidity associated with transient tachypnea of the newborn (TTN). However, its effects on lung aeration and respiratory function following birth are unknown. We investigated the effect of elevated airway liquid volumes on newborn respiratory function. Near-term rabbit kittens (30 days gestation; term ~32 days) were delivered, had their lung liquid-drained, and either had no liquid replaced (control; n = 7) or 30 ml/kg of liquid re-added to the airways [liquid added (LA); n = 7]. Kittens were mechanically ventilated in a plethysmograph. Measures of chest and lung parameters, uniformity of lung aeration, and airway size were analyzed using phase contrast X-ray imaging. The maximum peak inflation pressure required to recruit a tidal volume of 8 ml/kg was significantly greater in LA compared with control kittens (35.0 ±0.7 vs. 26.8 ± 0.4 cmH2O, P < 0.001). LA kittens required greater time to achieve lung aeration (106 ± 14 vs. 60- 6 inflations, P- 0.03) and had expanded chest walls, as evidenced by an increased total chest area (32 ± 9%, P = 0.0001), lung height (17 ± 6%, P = 0.02), and curvature of the diaphragm (19 < 8%, P =0.04). LA kittens had lower functional residual capacity during stepwise changes in positive end-expiratory pressures (5, 3, 0, and 5 cmH20). Elevated lung liquid volumes had marked adverse effects on lung structure and function in the immediate neonatal period and reduced the ability of the lung to aerate efficiently. We speculate that elevated airway liquid volumes may underlie the initial morbidity in near-term babies with TTN after birth. NEW & NOTEWORTHY Transient tachypnea of the newborn reduces respiratory function in newborns and is thought to result due o elevated airway liquid volumes following birth. However, the effect of elevated airway liquid volumes on neonatal respiratory function is unknown. Using phase contrast X-ray imaging, we show that elevated airway liquid volumes have adverse effects on lung structure and function in the immediate newborn period, which may underlie the pathology of TTN in near-term babies after birth.

Original languageEnglish
Pages (from-to)1204-1213
Number of pages10
JournalJournal of Applied Physiology
Volume123
Issue number5
DOIs
Publication statusPublished - 1 Nov 2017

Keywords

  • Airway liquid clearance
  • Lung aeration
  • Transient tachypnea of the newborn

Cite this

@article{129a73d0888342e8b08fde388fcbe3ad,
title = "Elevated airway liquid volumes at birth: A potential cause of transient tachypnea of the newborn",
abstract = "Excessive liquid in airways and/or distal lung tissue may underpin the respiratory morbidity associated with transient tachypnea of the newborn (TTN). However, its effects on lung aeration and respiratory function following birth are unknown. We investigated the effect of elevated airway liquid volumes on newborn respiratory function. Near-term rabbit kittens (30 days gestation; term ~32 days) were delivered, had their lung liquid-drained, and either had no liquid replaced (control; n = 7) or 30 ml/kg of liquid re-added to the airways [liquid added (LA); n = 7]. Kittens were mechanically ventilated in a plethysmograph. Measures of chest and lung parameters, uniformity of lung aeration, and airway size were analyzed using phase contrast X-ray imaging. The maximum peak inflation pressure required to recruit a tidal volume of 8 ml/kg was significantly greater in LA compared with control kittens (35.0 ±0.7 vs. 26.8 ± 0.4 cmH2O, P < 0.001). LA kittens required greater time to achieve lung aeration (106 ± 14 vs. 60- 6 inflations, P- 0.03) and had expanded chest walls, as evidenced by an increased total chest area (32 ± 9{\%}, P = 0.0001), lung height (17 ± 6{\%}, P = 0.02), and curvature of the diaphragm (19 < 8{\%}, P =0.04). LA kittens had lower functional residual capacity during stepwise changes in positive end-expiratory pressures (5, 3, 0, and 5 cmH20). Elevated lung liquid volumes had marked adverse effects on lung structure and function in the immediate neonatal period and reduced the ability of the lung to aerate efficiently. We speculate that elevated airway liquid volumes may underlie the initial morbidity in near-term babies with TTN after birth. NEW & NOTEWORTHY Transient tachypnea of the newborn reduces respiratory function in newborns and is thought to result due o elevated airway liquid volumes following birth. However, the effect of elevated airway liquid volumes on neonatal respiratory function is unknown. Using phase contrast X-ray imaging, we show that elevated airway liquid volumes have adverse effects on lung structure and function in the immediate newborn period, which may underlie the pathology of TTN in near-term babies after birth.",
keywords = "Airway liquid clearance, Lung aeration, Transient tachypnea of the newborn",
author = "McGillick, {Erin V.} and Katie Lee and Shigeo Yamaoka and {te Pas}, {Arjan B.} and Crossley, {Kelly J.} and Wallace, {Megan J.} and Kitchen, {Marcus J.} and Lewis, {Robert A.} and Kerr, {Lauren T.} and Philip DeKoninck and Janneke Dekker and Marta Thio and McDougall, {Annie R.A.} and Hooper, {Stuart B.}",
year = "2017",
month = "11",
day = "1",
doi = "10.1152/japplphysiol.00464.2017",
language = "English",
volume = "123",
pages = "1204--1213",
journal = "Journal of Applied Physiology",
issn = "8750-7587",
publisher = "American Physiological Society",
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}

Elevated airway liquid volumes at birth : A potential cause of transient tachypnea of the newborn. / McGillick, Erin V.; Lee, Katie; Yamaoka, Shigeo; te Pas, Arjan B.; Crossley, Kelly J.; Wallace, Megan J.; Kitchen, Marcus J.; Lewis, Robert A.; Kerr, Lauren T.; DeKoninck, Philip; Dekker, Janneke; Thio, Marta; McDougall, Annie R.A.; Hooper, Stuart B.

In: Journal of Applied Physiology, Vol. 123, No. 5, 01.11.2017, p. 1204-1213.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Elevated airway liquid volumes at birth

T2 - A potential cause of transient tachypnea of the newborn

AU - McGillick, Erin V.

AU - Lee, Katie

AU - Yamaoka, Shigeo

AU - te Pas, Arjan B.

AU - Crossley, Kelly J.

AU - Wallace, Megan J.

AU - Kitchen, Marcus J.

AU - Lewis, Robert A.

AU - Kerr, Lauren T.

AU - DeKoninck, Philip

AU - Dekker, Janneke

AU - Thio, Marta

AU - McDougall, Annie R.A.

AU - Hooper, Stuart B.

PY - 2017/11/1

Y1 - 2017/11/1

N2 - Excessive liquid in airways and/or distal lung tissue may underpin the respiratory morbidity associated with transient tachypnea of the newborn (TTN). However, its effects on lung aeration and respiratory function following birth are unknown. We investigated the effect of elevated airway liquid volumes on newborn respiratory function. Near-term rabbit kittens (30 days gestation; term ~32 days) were delivered, had their lung liquid-drained, and either had no liquid replaced (control; n = 7) or 30 ml/kg of liquid re-added to the airways [liquid added (LA); n = 7]. Kittens were mechanically ventilated in a plethysmograph. Measures of chest and lung parameters, uniformity of lung aeration, and airway size were analyzed using phase contrast X-ray imaging. The maximum peak inflation pressure required to recruit a tidal volume of 8 ml/kg was significantly greater in LA compared with control kittens (35.0 ±0.7 vs. 26.8 ± 0.4 cmH2O, P < 0.001). LA kittens required greater time to achieve lung aeration (106 ± 14 vs. 60- 6 inflations, P- 0.03) and had expanded chest walls, as evidenced by an increased total chest area (32 ± 9%, P = 0.0001), lung height (17 ± 6%, P = 0.02), and curvature of the diaphragm (19 < 8%, P =0.04). LA kittens had lower functional residual capacity during stepwise changes in positive end-expiratory pressures (5, 3, 0, and 5 cmH20). Elevated lung liquid volumes had marked adverse effects on lung structure and function in the immediate neonatal period and reduced the ability of the lung to aerate efficiently. We speculate that elevated airway liquid volumes may underlie the initial morbidity in near-term babies with TTN after birth. NEW & NOTEWORTHY Transient tachypnea of the newborn reduces respiratory function in newborns and is thought to result due o elevated airway liquid volumes following birth. However, the effect of elevated airway liquid volumes on neonatal respiratory function is unknown. Using phase contrast X-ray imaging, we show that elevated airway liquid volumes have adverse effects on lung structure and function in the immediate newborn period, which may underlie the pathology of TTN in near-term babies after birth.

AB - Excessive liquid in airways and/or distal lung tissue may underpin the respiratory morbidity associated with transient tachypnea of the newborn (TTN). However, its effects on lung aeration and respiratory function following birth are unknown. We investigated the effect of elevated airway liquid volumes on newborn respiratory function. Near-term rabbit kittens (30 days gestation; term ~32 days) were delivered, had their lung liquid-drained, and either had no liquid replaced (control; n = 7) or 30 ml/kg of liquid re-added to the airways [liquid added (LA); n = 7]. Kittens were mechanically ventilated in a plethysmograph. Measures of chest and lung parameters, uniformity of lung aeration, and airway size were analyzed using phase contrast X-ray imaging. The maximum peak inflation pressure required to recruit a tidal volume of 8 ml/kg was significantly greater in LA compared with control kittens (35.0 ±0.7 vs. 26.8 ± 0.4 cmH2O, P < 0.001). LA kittens required greater time to achieve lung aeration (106 ± 14 vs. 60- 6 inflations, P- 0.03) and had expanded chest walls, as evidenced by an increased total chest area (32 ± 9%, P = 0.0001), lung height (17 ± 6%, P = 0.02), and curvature of the diaphragm (19 < 8%, P =0.04). LA kittens had lower functional residual capacity during stepwise changes in positive end-expiratory pressures (5, 3, 0, and 5 cmH20). Elevated lung liquid volumes had marked adverse effects on lung structure and function in the immediate neonatal period and reduced the ability of the lung to aerate efficiently. We speculate that elevated airway liquid volumes may underlie the initial morbidity in near-term babies with TTN after birth. NEW & NOTEWORTHY Transient tachypnea of the newborn reduces respiratory function in newborns and is thought to result due o elevated airway liquid volumes following birth. However, the effect of elevated airway liquid volumes on neonatal respiratory function is unknown. Using phase contrast X-ray imaging, we show that elevated airway liquid volumes have adverse effects on lung structure and function in the immediate newborn period, which may underlie the pathology of TTN in near-term babies after birth.

KW - Airway liquid clearance

KW - Lung aeration

KW - Transient tachypnea of the newborn

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U2 - 10.1152/japplphysiol.00464.2017

DO - 10.1152/japplphysiol.00464.2017

M3 - Article

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JF - Journal of Applied Physiology

SN - 8750-7587

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