High-frequency oscillation in adolescents

Moganasundram, S.; Durward, Andrew; Tibby, SM; Murdoch, IA

doi:10.1093/bja/88.5.708

Cited by 9 publications

(3 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With active expiration, the lung volume can be controlled to avoid over-extension of the lung tissue, reducing the risks of lung injuries. HFOV has been used extensively both on neonates25 and adults 2,6,27,28. HFV has attracted much research interest; a comprehensive review of this area of study can be found in Chang 3.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study of High-Frequency Oscillatory Air Flow and Convective Mixing in a CT-Based Human Airway Model

et al. 2010

View full text Add to dashboard Cite

High frequency oscillatory ventilation (HFOV) is considered an efficient and safe respiratory technique to ventilate neonates and patients with acute respiratory distress syndrome. HFOV has very different characteristics from normal breathing physiology, with a much smaller tidal volume and a higher breathing frequency. In this work, the high frequency oscillatory flow is studied using a computational fluid dynamics (CFD) analysis in three different geometrical models with increasing complexity: a straight tube, a single-bifurcation tube model, and a computedtomography (CT)-based human airway model of up to seven generations. We aim to understand the counter-flow phenomenon at flow reversal and its role in convective mixing in these models using sinusoidal waveforms of different frequencies and Reynolds numbers. Mixing is quantified by the stretch rate analysis. In the straight-tube model, coaxial counter flow with opposing fluid streams is formed around flow reversal, agreeing with an analytical Womersley solution. However, counter flow yields no net convective mixing at end cycle. In the single-bifurcation model, counter flow at high Re is intervened with secondary vortices in the parent (child) branch at end expiration (inspiration), resulting in an irreversible mixing process. For the CT-based airway model three cases are considered, consisting of the normal breathing case, the highfrequency-normal-Re case, and the HFOV case. The counter-flow structure is more evident in the high-frequency-normal-Re case than the HFOV case. The instantaneous and time-averaged stretch rates at the end of two breathing cycles and in the vicinity of flow reversal are computed. It is found that counter flow contributes about 20% to mixing in HFOV.

show abstract

Section: Introductionmentioning

confidence: 99%

Numerical Study of High-Frequency Oscillatory Air Flow and Convective Mixing in a CT-Based Human Airway Model

et al. 2010

View full text Add to dashboard Cite

show abstract

“…HFOV is a shallow, fast mode of mechanical ventilation which can avoid the risk of lung injury associated with cyclic opening and closing of alveolar units in conventional ventilation. 16 HFOV has been successfully applied to neonates since 1981, 18 and more recently to adolescents 20 and adults. 1,6,19 HFOV results in better pulmonary outcomes than conventional mechanical ventilation for very low birth weight infants suffering with respiratory distress syndrome.…”

Section: Introductionmentioning

confidence: 99%

Fluid Dynamics of Gas Exchange in High-Frequency Oscillatory Ventilation: In Vitro Investigations in Idealized and Anatomically Realistic Airway Bifurcation Models

2008

View full text Add to dashboard Cite

“…For these patients, HFOV is an effective therapeutical alternative, especially for non‐responders to conventional ventilation (4).…”

mentioning

confidence: 99%

Visualization of inert gas wash‐out during high‐frequency oscillatory ventilation using fluorine‐19 MRI

Wolf

Scholz

Terekhov

et al. 2010

Magnetic Resonance in Med

View full text Add to dashboard Cite

High-frequency oscillatory ventilation is looked upon as a lung-protective ventilation strategy. For a further clarification of the physical processes promoting gas transport, a visualization of gas flow and the distribution of ventilation are of considerable interest. Therefore, fluorine-19 magnetic resonance imaging of the imaging gas octafluorocyclobutane (C 4 F 8 ) during high-frequency oscillatory ventilation was performed in five healthy pigs. For that, a mutually compatible ventilation-imaging system was set up and transverse images were acquired every 5 sec using FLASH sequences on a 1.5 T scanner. Despite a drop in signal-to-noise ratio after the onset of high-frequency oscillatory ventilation, for each pig, the four experiments could be analyzed. A mean wash-out time (t) at 5 Hz of 52.7 6 18 sec and 125.9 6 39 sec at 10 Hz, respectively, were found for regions of interest including the whole lung. This is in agreement with the clinical findings, in that washout of respiratory gases is significantly prolonged for increased high-frequency oscillatory ventilation frequencies. Our study could be a good starting-point for a further optimization of high-frequency oscillatory ventilation. Magn Reson Med 64:1479-1483,

show abstract

High-frequency oscillation in adolescents

Cited by 9 publications

References 10 publications

Numerical Study of High-Frequency Oscillatory Air Flow and Convective Mixing in a CT-Based Human Airway Model

Numerical Study of High-Frequency Oscillatory Air Flow and Convective Mixing in a CT-Based Human Airway Model

Fluid Dynamics of Gas Exchange in High-Frequency Oscillatory Ventilation: In Vitro Investigations in Idealized and Anatomically Realistic Airway Bifurcation Models

Visualization of inert gas wash‐out during high‐frequency oscillatory ventilation using fluorine‐19 MRI

Contact Info

Product

Resources

About