Dependence of intrapulmonary pressure amplitudes on respiratory mechanics during high-frequency oscillatory ventilation in preterm lambs

J. Jane Pillow, Peter D. Sly, Z. Hantos, Jason H T Bates

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

In the healthy animal lung, high-frequency oscillatory ventilation (HFOV) achieves effective ventilation at tidal volumes (VT) less than or equal to dead space while generating very small pressure fluctuations in the alveolar spaces (ΔPA). We hypothesized that the respiratory mechanical parameters influence the magnitude of the intrapulmonary pressure fluctuations during HFOV. A computer model of the neonatal respiratory system was used to examine the independent effects of altering the compliance, nonlinear and linear resistance, and inertance of the respiratory system on VT, and cyclic intrapulmonary pressures under homogeneous and heterogeneous conditions. The impact of low compliance on the transmission of pressure from the airway opening to the trachea (ΔPtr/ΔPao) and alveolar compartment (ΔPA/ΔPao) during HFOV was determined in a preterm lamb lung model. In the computer model, an increase in flow-dependent resistance to simulate changing the internal diameter of the tracheal tube from 4.0 mm to 2.5 mm halved the transmission of the pressure waveform to both the carina and the alveolar compartment. Increased peripheral resistance was associated with an increased ΔPtr/ΔPao but a reduction in ΔPA/ΔPao. The ΔPA/ΔPao also decreased with increasing alveolar compartment compliance, a finding that was verified in the preterm lamb lung. There was an exponential decrease in the magnitude of ΔPA1 compared with ΔPA2 as the ratio of the time constants of the two parallel compartments (τ12) increased in the heterogeneous computer lung model. The transmission of driving pressure amplitude to both the proximal airways and lung tissue during HFOV is dependent on lung mechanics and may be greater in the poorly compliant lung than that observed previously in experiments on healthy animals.

Original languageEnglish
Pages (from-to)538-544
Number of pages7
JournalPediatric Research
Volume52
Issue number4
DOIs
Publication statusPublished - Oct 1 2002

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High-Frequency Ventilation
Respiratory Mechanics
Pressure
Lung
Computer Simulation
Compliance
Respiratory System
Tidal Volume
Trachea
Mechanics
Vascular Resistance
Ventilation

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health

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Dependence of intrapulmonary pressure amplitudes on respiratory mechanics during high-frequency oscillatory ventilation in preterm lambs. / Pillow, J. Jane; Sly, Peter D.; Hantos, Z.; Bates, Jason H T.

In: Pediatric Research, Vol. 52, No. 4, 01.10.2002, p. 538-544.

Research output: Contribution to journalArticle

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