High frequency mechanical ventilation affects respiratory system mechanics differently in C57BL/6J and BALB/c adult mice

2013 ◽  
Vol 185 (2) ◽  
pp. 472-476
Author(s):  
Hélène Hadden
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory System ◽  
High Frequency ◽  
Respiratory System Mechanics ◽  
Adult Mice

scholarly journals Effects of High Frequency Chest Compression on Respiratory System Mechanics in Normal Subjects and Cystic Fibrosis Patients

1995 ◽  
Vol 2 (1) ◽  
pp. 40-46 ◽  
Author(s):  
Richard L Jones ◽  
Richard T Lester ◽  
Neil E Brown
Keyword(s):  
Cystic Fibrosis ◽  
Airway Obstruction ◽  
Chest Compression ◽  
Respiratory System ◽  
High Frequency ◽  
Oscillation Frequency ◽  
Normal Subjects ◽  
Lung Mechanics ◽  
Normal Lung ◽  
Respiratory System Mechanics

OBJECTIVE: To investigate the short term effects of high frequency chest compression (HFCC) on several indices of respiratory system mechanics in normal subjects and patients with cystic fibrosis (CF).DESIGN: Comparative physiological approach. Subjects were blinded to 10 randomized HFCC settings (5, 10, 15, 20 and 25 Hz) with each applied at the lowest and at the highest background vest pressure.SETTING: Pulmonary function and lung mechanics laboratory, University of Alberta.PARTICIPANTS: Ten normal male volunteers (24.2±3.8 years) and 11 clinically stable CF patients (23.4±6.7 years). Normal subjects were nonsmokers who had normal lung function. The CF patients had a wide range of airway obstruction.INTERVENTIONS: HFCC was supplied by oscillating a pneumatic vest that covered the entire torso. Balloon tipped catheters were used to measure esophageal (Pes) and external chest wall (Pew) pressures. Changes in end-expiratory lung volume (EELV) during HFCC were measured from a spirogram and were compared with baseline functional residual capacity (FRC). The HFCC induced air movement al the mouth, oscillated tidal volume (Vosc), was measured by reverse plethysmography.RESULTS: Both normals and CF patients had similar changes in Pes and EELV. At the highest background vest pressure and at the higher oscillation frequencies, EELV decreased approximately 30% from the no-HFCC baseline FRC. Vosc decreased with increasing oscillation frequency but normals had higher Vosc than CF patients at each frequency. Conversion of Vose to flow (V˙osc) revealed that the highest Vosc occurred between 10 and 15 Hz for both normals and CF patients. Also, Vosc was dependent on the overall airway function. Low forced expired volume in 1 s resulted in low Vosc, especially when Vosc was measured during spontaneous expiration.CONCLUSIONS: CF patients with moderate or severe airway obstruction may gain maximal benefit from HFCC therapy when low vest pressure is used at an oscillation frequency of 10 to 15 Hz. The low vest pressure minimizes the decrease in EELV and 10 to 15 Hz maximizes Vosc.

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.

Assessment of respiratory system mechanics by artificial neural networks: an exploratory study

2001 ◽  
Vol 90 (5) ◽  
pp. 1817-1824 ◽  
Author(s):  
Gaetano Perchiazzi ◽  
Marieann Högman ◽  
Christian Rylander ◽  
Rocco Giuliani ◽  
Tommaso Fiore ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory System ◽  
Exploratory Study ◽  
Porcine Model ◽  
Regression Coefficient ◽  
Constant Flow ◽  
Respiratory System Mechanics ◽  
Respiratory System Resistance ◽  
Artificial Neural ◽  
Artificial Neural Network Ann

We evaluated 1) the performance of an artificial neural network (ANN)-based technology in assessing the respiratory system resistance (Rrs) and compliance (Crs) in a porcine model of acute lung injury and 2) the possibility of using, for ANN training, signals coming from an electrical analog (EA) of the lung. Two differently experienced ANNs were compared. One ANN (ANNBIO) was trained on tracings recorded at different time points after the administration of oleic acid in 10 anesthetized and paralyzed pigs during constant-flow mechanical ventilation. A second ANN (ANNMOD) was trained on EA simulations. Both ANNs were evaluated prospectively on data coming from four different pigs. Linear regression between ANN output and manually computed mechanics showed a regression coefficient ( R) of 0.98 for both ANNs in assessing Crs. On Rrs, ANNBIO showed a performance expressed by R= 0.40 and ANNMOD by R = 0.61. These results suggest that ANNs can learn to assess the respiratory system mechanics during mechanical ventilation but that the assessment of resistance and compliance by ANNs may require different approaches.

scholarly journals Lung Mechanics in Type L CoVID-19 Pneumonia: A Pseudo-Normal ARDS.

2020 ◽  
Author(s):  
Lorenzo Viola ◽  
Emanuele Russo ◽  
Marco Benni ◽  
Emiliano Gamberini ◽  
Alessandro Circelli ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Acute Respiratory Distress Syndrome ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Respiratory System ◽  
Respiratory Insufficiency ◽  
Distress Syndrome ◽  
Lung Mechanics ◽  
Prone Positioning ◽  
Respiratory System Mechanics

Abstract Since its outbreak, in January, 2020, it has been clear that CoVID-19 pneumonia is atypical. Despite a full concordance to Berlin criteria for Acute Respiratory Distress Syndrome (ARDS), respiratory system mechanics is preserved [1]. Mechanical ventilation and muscular paralysis are recommended in worsening respiratory insufficiency [2]; in a substantial number of cases, prone positioning significantly improves oxygenation.

scholarly journals Hourly Analysis of Mechanical Ventilation Parameters in Critically Ill Adult Covid-19 Patients: Association with Mortality

2021 ◽  
Author(s):  
Tomás F. Fariña-González ◽  
Antonio Núñez-Reiz ◽  
Julieta Latorre ◽  
Maria Calle-Romero ◽  
Viktor Yordanov-Zlatkov ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory System ◽  
Time Course ◽  
Respiratory Mechanics ◽  
Invasive Mechanical Ventilation ◽  
Lung Mechanics ◽  
Icu Admission ◽  
Respiratory System Mechanics ◽  
Renal Replacement Therapies ◽  
Pressure Controlled

Abstract Objective: there exists controversy about the pathophysiology and lung mechanics of COVID-19 associated ARDS, because some report severe hypoxemia with preserved respiratory system mechanics, contrasting with “classic” ARDS. We performed a detailed hourly analysis of the characteristics and time course of lung mechanics and biochemical analysis of patients requiring invasive mechanical ventilation for COVID-19-associated ARDS, comparing survivors and non-survivors.Methods and measurements: retrospective analysis of the data stored in the ICU information system of patients admitted in our hospital ICU that required invasive mechanical ventilation due to confirmed SARS-CoV-2 pneumonia between March 5th and April 30th, 2020. We compare respiratory system mechanics and gas exchange during the first ten days of IMV, discriminating volume and pressure controlled modes, between ICU survivors and non-survivors.Results: 140 patients were analyzed, analyzing 11,138 respiratory mechanics recordings. Global mortality was 38.6%. Multivariate analysis showed that age (OR 1,092, 95% (CI 1,014-1,176)), previous use of ACEI/ARBs (OR 4,612, (95% CI 1,19-17,84)) and need of renal replacement therapies (OR 10,15, (95% CI 1,58-65,11)) were associated with higher mortality. Respiratory variables start to diverge significantly between survivors and non-survivors after the 96 to 120 hours from mechanical ventilation initiation, particularly respiratory system compliance. In non survivors, mechanical power at 24 and 96 hs was higher regardless ventilatory mode. Conclusions: in patients admitted for SARS-CoV-2 pneumonia and requiring mechanical ventilation, non survivors have different respiratory system mechanics than survivors in the first 10 days of ICU admission. We propose a checkpoint at 96-120 hs to assess patients` improvement or worsening in order to consider escalating to extracorporeal therapies.“TAKE HOME MESSAGE”: assessing respiratory mechanics in the first 96-120 hs from ICU admission could predict the outcome of Covid-19 patients under mechanical ventilation.

Nasal High-Frequency Oscillatory Ventilation in Preterm Infants with Moderate Respiratory Distress Syndrome: A Multicenter Randomized Clinical Trial

Neonatology ◽  
2021 ◽  
pp. 1-7
Author(s):  
Xingwang Zhu ◽  
Zhichun Feng ◽  
Chengjun Liu ◽  
Liping Shi ◽  
Yuan Shi ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory Distress Syndrome ◽  
Preterm Infants ◽  
High Frequency ◽  
Primary Outcome ◽  
Distress Syndrome ◽  
Invasive Mechanical Ventilation ◽  
Risk Difference ◽  
High Frequency Oscillatory Ventilation ◽  
High Frequency Oscillatory

<b><i>Objective:</i></b> To determine whether nasal high-frequency oscillatory ventilation (NHFOV) as a primary mode of respiratory support as compared with nasal continuous airway pressure (NCPAP) will reduce the need for invasive mechanical ventilation in preterm infants (26<sup>0/7</sup>–33<sup>6/7</sup> weeks of gestational age [GA]) with respiratory distress syndrome (RDS). <b><i>Methods:</i></b> This multicenter randomized controlled trial was conducted in 18 tertiary neonatal intensive care units in China. A total of 302 preterm infants born at a GA of 26<sup>0/7</sup>–33<sup>6/7</sup> weeks with a diagnosis of RDS were randomly assigned to either the NCPAP (<i>n</i> = 150) or the NHFOV (<i>n</i> = 152) group. The primary outcome was the need for invasive mechanical ventilation during the first 7 days after birth. <b><i>Results:</i></b> Treatment failure occurred in 15 of 152 infants (9.9%) in the ­NHFOV group and in 26 of 150 infants (17.3%) in the NCPAP group (95% CI of risk difference: −15.2 to 0.4, <i>p =</i> 0.06). In the subgroup analysis, NHFOV resulted in a significantly lower rate of treatment failure than did NCPAP in the strata of 26<sup>+0/7</sup>–29<sup>+6/7</sup>weeks of GA (11.9 vs. 32.4%, 95% CI of risk difference: −39.3 to −1.7, <i>p =</i> 0.03) and birth weight &#x3c;1,500 g (10.4 vs. 29.6%, 95% CI of risk difference: −33.8 to −4.6, <i>p =</i> 0.01). The rate of thick secretions causing an airway obstruction was higher in the NHFOV group than in the NCPAP group (13.8 vs. 5.3%, 95% CI of risk difference: 1.9–15.1, <i>p =</i> 0.01). No significant differences in other secondary outcomes were found between the NHFOV and NCPAP groups. <b><i>Conclusions:</i></b> NHFOV was not superior to NCPAP with regard to the primary outcome when applied as the primary respiratory support for RDS in infants between 26<sup>+0/7</sup> and 33<sup>+6/7</sup> weeks of GA. In the subgroup analysis, NHFOV seemed to improve effectiveness than NCPAP in preterm infants &#x3c;30 weeks of GA.

scholarly journals Robustness of two different methods of monitoring respiratory system compliance during mechanical ventilation

2017 ◽  
Vol 55 (10) ◽  
pp. 1819-1828 ◽  
Author(s):  
Gaetano Perchiazzi ◽  
Christian Rylander ◽  
Mariangela Pellegrini ◽  
Anders Larsson ◽  
Göran Hedenstierna
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory System ◽  
Respiratory System Compliance
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