High frequency oscillatory ventilation near resonant frequency of the respiratory system in rabbits with normal and surfactant depleted lungs

1991 ◽  
Vol 150 (9) ◽  
pp. 671-675 ◽  
Author(s):  
A. Schulze ◽  
P. Schaller ◽  
J. Dinger ◽  
U. Winkler ◽  
D. Gmyrek
Keyword(s):  
Resonant Frequency ◽  
Respiratory System ◽  
High Frequency ◽  
High Frequency Oscillatory Ventilation ◽  
Oscillatory Ventilation ◽  
High Frequency Oscillatory

scholarly journals In Vitro Estimation of Relative Compliance during High-Frequency Oscillatory Ventilation

2021 ◽  
Vol 11 (3) ◽  
pp. 899
Author(s):  
Jan Matejka ◽  
Martin Rozanek ◽  
Jakub Rafl ◽  
Petr Kudrna ◽  
Karel Roubik
Keyword(s):  
Physical Model ◽  
Respiratory System ◽  
High Frequency ◽  
High Frequency Oscillatory Ventilation ◽  
Opening Pressure ◽  
Respiratory System Mechanics ◽  
Oscillatory Ventilation ◽  
Airway Opening ◽  
High Frequency Oscillatory

High-frequency oscillatory ventilation (HFOV), which uses a small tidal volume and a high respiratory rate, is considered a type of protective lung ventilation that can be beneficial for certain patients. A disadvantage of HFOV is its limited monitoring of lung mechanics, which complicates its settings and optimal adjustment. Recent studies have shown that respiratory system reactance (Xrs) could be a promising parameter in the evaluation of respiratory system mechanics in HFOV. The aim of this study was to verify in vitro that a change in respiratory system mechanics during HFOV can be monitored by evaluating Xrs. We built an experimental system consisting of a 3100B high-frequency oscillatory ventilator, a physical model of the respiratory system with constant compliance, and a system for pressure and flow measurements. During the experiment, models of different constant compliance were connected to HFOV, and Xrs was derived from the impedance of the physical model that was calculated from the spectral density of airway opening pressure and spectral cross-power density of gas flow and airway opening pressure. The calculated Xrs changed with the change of compliance of the physical model of the respiratory system. This method enabled monitoring of the trend in the respiratory system compliance during HFOV, and has the potential to optimize the mean pressure setting in HFOV in clinical practice.

scholarly journals High-frequency oscillatory ventilation in neonatal RDS: initial volume optimization and respiratory mechanics

1998 ◽  
Vol 84 (4) ◽  
pp. 1174-1177 ◽  
Author(s):  
Masendu Kalenga ◽  
Oreste Battisti ◽  
Anne François ◽  
Jean-Paul Langhendries ◽  
Dale R. Gerstmann ◽  
...  
Keyword(s):  
Respiratory System ◽  
Lung Volume ◽  
High Frequency ◽  
Distress Syndrome ◽  
Respiratory Mechanics ◽  
High Frequency Oscillatory Ventilation ◽  
Oscillatory Ventilation ◽  
Respiratory System Resistance ◽  
High Frequency Oscillatory ◽  
Good Oxygenation

To determine whether initial lung volume optimization influences respiratory mechanics, which could indicate the achievement of optimal volume, we studied 17 premature infants with respiratory distress syndrome (RDS) assisted by high-frequency oscillatory ventilation. The continuous distending pressure (CDP) was increased stepwise from 6–8 cmH2O up to optimal CDP (OCDP), i.e., that allowing good oxygenation with the lowest inspired O2 fraction. Respiratory system compliance (Crs) and resistance were concomitantly measured. Mean OCDP was 16.5 ± 1.2 cmH2O. Inspired O2 fraction could be reduced from an initial level of 0.73 ± 0.17 to 0.33 ± 0.07. However, Crs (0.45 ± 0.14 ml ⋅ cmH2O−1 ⋅ kg−1at starting CDP point) remained unchanged through lung volume optimization but appeared inversely related to OCDP. Similarly, respiratory system resistance was not affected. We conclude that there is a marked dissociation between oxygenation improvement and Crs profile during the initial phase of lung recruitment by early high-frequency oscillatory ventilation in infants with RDS. Thus optimal lung volume cannot be defined by serial Crs measurement. At the most, low initial Crs suggests that higher CDP will be needed.

scholarly journals Optimal mean airway pressure during high-frequency oscillatory ventilation determined by measurement of respiratory system reactance

2013 ◽  
Vol 75 (4) ◽  
pp. 493-499 ◽  
Author(s):  
Emanuela Zannin ◽  
Maria Luisa Ventura ◽  
Raffaele L. Dellacà ◽  
Miria Natile ◽  
Paolo Tagliabue ◽  
...  
Keyword(s):  
Respiratory System ◽  
High Frequency ◽  
Airway Pressure ◽  
High Frequency Oscillatory Ventilation ◽  
Mean Airway Pressure ◽  
Oscillatory Ventilation ◽  
High Frequency Oscillatory

scholarly journals Assessment of Respiratory System Resistance during High-Frequency Oscillatory Ventilation Based on In Vitro Experiment

2021 ◽  
Vol 11 (23) ◽  
pp. 11279
Author(s):  
Jan Matejka ◽  
Martin Rozanek ◽  
Jakub Rafl
Keyword(s):  
Physical Model ◽  
Respiratory System ◽  
High Frequency ◽  
Gas Flow ◽  
High Frequency Oscillatory Ventilation ◽  
Oscillatory Ventilation ◽  
Airway Opening ◽  
Respiratory System Resistance ◽  
High Frequency Oscillatory

High-frequency oscillatory ventilation (HFOV) is a type of mechanical ventilation with a protective potential characterized by a small tidal volume. Unfortunately, HFOV has limited monitoring of ventilation parameters and mechanical parameters of the respiratory system, which makes it difficult to adjust the continuous distension pressure (CDP) according to the individual patient’s airway status. Airway resistance Raw is one of the important parameters describing the mechanics of the respiratory system. The aim of the presented study was to verify in vitro whether the resistance of the respiratory system Rrs can be reliably determined during HFOV to evaluate Raw in pediatric and adult patients. An experiment was performed with a 3100B high-frequency oscillator, a physical model of the respiratory system, and a pressure and flow measurement system. The physical model with different combinations of resistance and compliance was ventilated during the experiment. The resistance Rrs was calculated from the impedance of the physical model, which was determined from the spectral density of the pressure at airway opening and the spectral cross-density of the gas flow and pressure at airway opening. Rrs of the model increased with an added resistor and did not change significantly with a change in compliance. The method is feasible for monitoring respiratory system resistance during HFOV and has the potential to optimize CDP settings during HFOV in clinical practice.

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