The effect of lung mechanics on gas transport during high-frequency oscillation

1991 ◽  
Vol 11 (4) ◽  
pp. 335-339 ◽  
Author(s):  
Margrid Schindler ◽  
Michael Seear
Keyword(s):  
High Frequency ◽  
Gas Transport ◽  
Lung Mechanics ◽  
High Frequency Oscillation ◽  
Frequency Oscillation

Gas transport enhancement in high-frequency oscillation

1990 ◽  
Vol 82 (1) ◽  
pp. 29-37 ◽  
Author(s):  
R. Spahn ◽  
R. Leuthold ◽  
E.R. Schmid ◽  
P.F. Niederer
Keyword(s):  
High Frequency ◽  
Gas Transport ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Transport Enhancement

Mechanisms of gas transport during ventilation by high-frequency oscillation

1984 ◽  
Vol 56 (3) ◽  
pp. 553-563 ◽  
Author(s):  
H. K. Chang
Keyword(s):  
High Frequency ◽  
Molecular Diffusion ◽  
Gas Transport ◽  
Tracheobronchial Tree ◽  
Convective Transport ◽  
High Frequency Oscillation ◽  
Future Research ◽  
Frequency Oscillation ◽  
Airway Opening ◽  
Mode Of Transport

Ventilation by high-frequency oscillation (HFO) presents some difficulties in understanding exactly how gas is transported in the lung. However, at a qualitative level, five modes of transport may be identified: 1) direct alveolar ventilation in the lung units situated near the airway opening; 2) bulk convective mixing in the conducting airways as a result of recirculation of air among units of inhomogeneous time constants; 3) convective transport of gases as a result of the asymmetry between inspiratory and expiratory velocity profiles; 4) longitudinal dispersion caused by the interaction between axial velocities and radial transports due to turbulent eddies and/or secondary swirling motions; and 5) molecular diffusion near the alveolocapillary membrane. These modes of transport are not mutually exclusive and certainly interact. It is therefore difficult to make quantitative predictions about the overall rate of transport. Qualitatively, it may now be stated with confidence that convective transport in the tracheobronchial tree is very important during HFO as in normal breathing and that increasing tidal volume is more effective than increasing frequency in improving gas exchange during HFO. To optimize the gas transport efficiency of HFO, future research should focus on identifying the rate-limiting mode of transport for a given set of geometric and dynamic conditions.

Open-lung Protective Ventilation with Pressure Control Ventilation, High-frequency Oscillation, and Intratracheal Pulmonary Ventilation Results in Similar Gas Exchange, Hemodynamics, and Lung Mechanics

2003 ◽  
Vol 99 (5) ◽  
pp. 1102-1111 ◽  
Author(s):  
Khaled A. Sedeek ◽  
Muneyuki Takeuchi ◽  
Klaudiusz Suchodolski ◽  
Sara O. Vargas ◽  
Motomu Shimaoka ◽  
...  
Keyword(s):  
Gas Exchange ◽  
High Frequency ◽  
Distress Syndrome ◽  
Pulmonary Ventilation ◽  
Pressure Control ◽  
Control Ventilation ◽  
Lung Mechanics ◽  
High Frequency Oscillation ◽  
Lung Protective Ventilation ◽  
Frequency Oscillation

Background Pressure control ventilation (PCV), high-frequency oscillation (HFO), and intratracheal pulmonary ventilation (ITPV) may all be used to provide lung protective ventilation in acute respiratory distress syndrome, but the specific approach that is optimal remains controversial. Methods Saline lavage was used to produce acute respiratory distress syndrome in 21 sheep randomly assigned to receive PCV, HFO, or ITPV as follows: positive end-expiratory pressure (PCV and ITPV) and mean airway pressure (HFO) were set in a pressure-decreasing manner after lung recruitment that achieved a ratio of Pao2/Fio2 > 400 mmHg. Respiratory rates were 30 breaths/min, 120 breaths/min, and 8 Hz, respectively, for PCV, ITPV, and HFO. Eucapnia was targeted with peak carinal pressure of no more than 35 cm H2O. Animals were then ventilated for 4 h. Results There were no differences among groups in gas exchange, lung mechanics, or hemodynamics. Tidal volume (PCV, 8.9 +/- 2.1 ml/kg; ITPV, 2.7 +/- 0.8 ml/kg; HFO, approximately 2.0 ml/kg) and peak carinal pressure (PCV, 30.6 +/- 2.6 cm H2O; ITPV, 22.3 +/- 4.8 cm H2O; HFO, approximately 24.3 cm H2O) were higher in PCV. Pilot histologic data showed greater interstitial hemorrhage and alveolar septal expansion in PCV than in HFO or ITPV. Conclusion These data indicate that HFO, ITPV, and PCV when applied with an open-lung protective ventilatory strategy results in the same gas exchange, lung mechanics, and hemodynamic response, but pilot data indicate that lung injury may be greater with PCV.

High-Frequency Oscillation and Chronic Lung Disease in Very Low Birth Weight Infants

PEDIATRICS ◽  
2001 ◽  
Vol 108 (1) ◽  
pp. 212-214
Author(s):  
J. P. Shenai; ◽  
P. Rimensberger; ◽  
U. Thome ◽  
F. Pohlandt; ◽  
P. Rimensberger
Keyword(s):  
Birth Weight ◽  
Low Birth Weight ◽  
Lung Disease ◽  
Chronic Lung Disease ◽  
High Frequency ◽  
Very Low Birth Weight ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Low Birth Weight Infants

scholarly journals A Comprehensive Investigation on High-Frequency Oscillation in DC Microgrid

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Mohammad Habibullah ◽  
Nadarajah Mithulananthan ◽  
Krischonme Bhumkittipich ◽  
Mohammad Amin
Keyword(s):  
High Frequency ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Comprehensive Investigation ◽  
Dc Microgrid
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