Respiratory System and Mechanical Ventilation in Patients with CHD

2018 ◽  
pp. 163-175
Author(s):  
Giuseppe Isgrò ◽  
Simona Silvetti
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory System

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

Mucormycosis: A Black Fungus- Post Covid Complications

2021 ◽  
Author(s):  
Prithiv Kumar KR
Keyword(s):  
Mechanical Ventilation ◽  
T Cells ◽  
Intensive Care ◽  
Fungal Infection ◽  
Intensive Care Units ◽  
Respiratory System ◽  
Cd8 T Cells ◽  
Transmitted Disease ◽  
Global Pandemic

Human to human transmitted disease is the game of coronavirus disease (COVID-19) transmission and it had been declared an emergency global pandemic that caused major disastrous in the respiratory system to more than five million people and killing more than half a billion deaths across the globe. Besides lower acute respiratory syndrome, there is damage to the alveolar with severe inflammatory exudation. COVID-19 patients often have lower immunosuppressive CD4+ T and CD8+ T cells and most patients in intensive care units (ICU) need mechanical ventilation, hence longer stay in hospitals. These patients have been discovered to develop fungal co-infections. COVID-19 patients develop what is known as mucormycosis a black fungal infection that is deadly leading to loss of sight and hearing and eventually death. This chapter will focus on mucormycosis, a black fungus caused during post covid complications.

scholarly journals The correlation of respiratory system compliance and mortality in COVID-19 acute respiratory distress syndrome: do phenotypes really exist?

2021 ◽  
Vol 8 (2) ◽  
pp. 67-74
Author(s):  
Rachel L. Choron ◽  
Stephen A. Iacono ◽  
Alexander Cong ◽  
Christopher G. Bargoud ◽  
Amanda L. Teichman ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory System ◽  
Management Strategies ◽  
Respiratory System Compliance ◽  
Risk Of Death ◽  
Mortality Difference ◽  
Ventilator Management ◽  
Observational Cohort ◽  
Multivariable Regression ◽  
The Mean

Background: Recent literature suggests respiratory system compliance (Crs) based phenotypes exist among COVID-19 ARDS patients. We sought to determine whether these phenotypes exist and whether Crs predicts mortality. Methods: A retrospective observational cohort study of 111 COVID-19 ARDS patients admitted March 11-July 8, 2020. Crs was averaged for the first 72-hours of mechanical ventilation. Crs<30ml/cmH2O was defined as poor Crs(phenotype-H) whereas Crs≥30ml/cmH2O as preserved Crs(phenotype-L). Results: 111 COVID-19 ARDS patients were included, 40 phenotype-H and 71 phenotype-L. Both the mean PaO2/FiO2 ratio for the first 72-hours of mechanical ventilation and the PaO2/FiO2 ratio hospital nadir were lower in phenotype-H than L(115[IQR87] vs 165[87], p=0.016), (63[32] vs 75[59], p=0.026). There were no difference in characteristics, diagnostic studies, or complications between groups. Twenty-seven (67.5%) phenotype-H patients died vs 37(52.1%) phenotype-L(p=0.115). Multivariable regression did not reveal a mortality difference between phenotypes; however, a 2-fold mortality increase was noted in Crs<20 vs >50ml/cmH2O when analyzing ordinal Crs groups. Moving up one group level (ex. Crs30-39.9ml/cmH2O to 40-49.9ml/cmH2O), was marginally associated with 14% lower risk of death(RR=0.86, 95%CI 0.72, 1.01, p=0.065). This attenuated (RR=0.94, 95%CI 0.80, 1.11) when adjusting for pH nadir and PaO2/FiO2 ratio nadir. Conclusion: We identified a spectrum of Crs in COVID-19 ARDS similar to Crs distribution in non-COVID-19 ARDS. While we identified increasing mortality as Crs decreased, there was no specific threshold marking significantly different mortality based on phenotype. We therefore would not define COVID-19 ARDS patients by phenotypes-H or L and would not stray from traditional ARDS ventilator management strategies.

Respiratory Mechanics

2017 ◽  
Author(s):  
John W. Kreit
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory System ◽  
Respiratory Mechanics ◽  
Pressure Change ◽  
Equation Of Motion ◽  
Positive End Expiratory Pressure ◽  
Elastic Recoil ◽  
Viscous Forces ◽  
Equilibrium Volume ◽  
Complex Process

Ventilation can occur only when the respiratory system expands above and then returns to its resting or equilibrium volume. This is just another way of saying that ventilation depends on our ability to breathe. Although breathing requires very little effort and even less thought, it’s nevertheless a fairly complex process. Respiratory Mechanics reviews the interaction between applied and opposing forces during spontaneous and mechanical ventilation. It discusses elastic recoil, viscous forces, compliance, resistance, and the equation of motion and the time constant of the respiratory system. It also describes how and why pleural, alveolar, lung transmural, intra-abdominal, and airway pressure change during spontaneous and mechanical ventilation, and the effect of applied positive end-expiratory pressure (PEEP).

Techniques for measuring respiratory mechanics: an analytic approach with a viscoelastic model

1993 ◽  
Vol 74 (5) ◽  
pp. 2373-2379 ◽  
Author(s):  
A. M. Lorino ◽  
A. Harf
Keyword(s):  
Mechanical Ventilation ◽  
Mechanical Behavior ◽  
Respiratory System ◽  
Respiratory Mechanics ◽  
Homogeneous Model ◽  
Viscoelastic Model ◽  
Normal Subjects ◽  
Inspiratory Time ◽  
Airway Occlusion ◽  
Analytic Expressions

A homogeneous model with stress relaxation that is described by a pure viscoelastic component was recently proposed to describe the mechanical behavior of the respiratory system during mechanical ventilation (Bates et al. J. Appl. Physiol. 67: 2276–2285, 1989). With the use of this model, analytic expressions of the pressure in response to typical volume inputs are developed, and the recently published studies relating to the influence of the ventilatory pattern on respiratory mechanics are reviewed and analyzed. The analytic expression of pressure responses to rapid airway occlusion following constant-flow inflation and to sinusoidal volume oscillations allows prediction of most of the reported results. The theoretical analysis suggests that in normal subjects the observed flow and volume dependencies of respiratory mechanics are, in fact, illustrations of the dependence of the viscoelastic resistance on inspiratory time and respiratory frequency. Thus the homogeneous viscoelastic model appears suitable to describe respiratory system mechanical behavior under mechanical ventilation.

scholarly journals Mild hypothermia attenuates changes in respiratory system mechanics and modifies cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation

2010 ◽  
pp. 937-944
Author(s):  
P Dostál ◽  
M Šenkeřík ◽  
R Pařízková ◽  
D Bareš ◽  
P Živný ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Lung Injury ◽  
Bronchoalveolar Lavage ◽  
Respiratory System ◽  
Bronchoalveolar Lavage Fluid ◽  
Mild Hypothermia ◽  
Lavage Fluid ◽  
Cytokine Concentration ◽  
Volume Ventilation ◽  
Hypothermia Group

Hypothermia was shown to attenuate ventilator-induced lung injury due to large tidal volumes. It is unclear if the protective effect of hypothermia is maintained under less injurious mechanical ventilation in animals without previous lung injury. Tracheostomized rats were randomly allocated to non-ventilated group (group C) or ventilated groups of normothermia (group N) and mild hypothermia (group H). After two hours of mechanical ventilation with inspiratory fraction of oxygen 1.0, respiratory rate 60 min-1, tidal volume 10 ml·kg-1, positive end-expiratory pressure (PEEP) 2 cm H2O or immediately after tracheostomy in non-ventilated animals inspiratory pressures were recorded, rats were sacrificed, pressure-volume (PV) curve of respiratory system constructed, bronchoalveolar lavage (BAL) fluid and aortic blood samples obtained. Group N animals exhibited a higher rise in peak inspiratory pressures in comparison to group H animals. Shift of the PV curve to right, higher total protein and interleukin6 levels in BAL fluid were observed in normothermia animals in comparison with hypothermia animals and non-ventilated controls. Tumor necrosis factor-α was lower in the hypothermia group in comparison with normothermia and non-ventilated groups. Mild hypothermia attenuated changes in respiratory system mechanics and modified cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation in animals without previous lung injury.

scholarly journals Quantification of Alveolar Recruitment for the Optimization of Mechanical Ventilation Using Quasi-Static Pressure Volume Curve

2018 ◽  
Author(s):  
Mohsen Nabian ◽  
Uichiro Narusawa
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory System ◽  
Distress Syndrome ◽  
Alveolar Recruitment ◽  
System Optimum ◽  
Quantitative Characterization ◽  
Volume Curve ◽  
Pressure Volume Curve ◽  
Ventilation Setting

Quasi-static, pulmonary pressure-volume (P-V) curves over an inflation-deflation cycle are analyzed using a respiratory system model (RSM), which had been developed for quantitative characterization of the mechanical behavior of the total respiratory system. Optimum mechanical ventilation setting of Positive End Expiratory Pressure (PEEP) for total alveolar recruitment is quantified based on the existing P-V curves of healthy and injured animal models. Our analytical predictions may contribute to the optimization of mechanical ventilation settings for the Acute Respiratory Distress Syndrome (ARDS) patients.

scholarly journals Mechanical power normalized to lung-thorax compliance indicates weaning readiness in prolonged ventilated patients

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Alessandro Ghiani ◽  
Joanna Paderewska ◽  
Swenja Walcher ◽  
Konstantinos Tsitouras ◽  
Claus Neurohr ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Logistic Regression ◽  
Respiratory System ◽  
Spontaneous Breathing ◽  
Characteristic Curve ◽  
Spontaneous Breathing Trial ◽  
Mechanical Power ◽  
Binary Logistic Regression Model ◽  
Weaning Failure ◽  
Ventilated Patients

AbstractSince critical respiratory muscle workload is a significant determinant of weaning failure, applied mechanical power (MP) during artificial ventilation may serve for readiness testing before proceeding on a spontaneous breathing trial (SBT). Secondary analysis of a prospective, observational study in 130 prolonged ventilated, tracheotomized patients. Calculated MP’s predictive SBT outcome performance was determined using the area under receiver operating characteristic curve (AUROC), measures derived from k-fold cross-validation (likelihood ratios, Matthew's correlation coefficient [MCC]), and a multivariable binary logistic regression model. Thirty (23.1%) patients failed the SBT, with absolute MP presenting poor discriminatory ability (MCC 0.26; AUROC 0.68, 95%CI [0.59‒0.75], p = 0.002), considerably improved when normalized to lung-thorax compliance (LTCdyn-MP, MCC 0.37; AUROC 0.76, 95%CI [0.68‒0.83], p < 0.001) and mechanical ventilation PaCO2 (so-called power index of the respiratory system [PIrs]: MCC 0.42; AUROC 0.81 [0.73‒0.87], p < 0.001). In the logistic regression analysis, PIrs (OR 1.48 per 1000 cmH2O2/min, 95%CI [1.24‒1.76], p < 0.001) and its components LTCdyn-MP (1.25 per 1000 cmH2O2/min, [1.06‒1.46], p < 0.001) and mechanical ventilation PaCO2 (1.17 [1.06‒1.28], p < 0.001) were independently related to SBT failure. MP normalized to respiratory system compliance may help identify prolonged mechanically ventilated patients ready for spontaneous breathing.

Lung Ventilation: Natural and Mechanical

2017 ◽  
Author(s):  
Yuan Lei
Keyword(s):  
Mechanical Ventilation ◽  
Critical Care ◽  
Respiratory System ◽  
Positive Pressure Ventilation ◽  
Lung Ventilation ◽  
Intermittent Positive Pressure Ventilation ◽  
Artificial Lung ◽  
Positive Pressure ◽  
Anatomy And Physiology ◽  
Artificial Lung Ventilation

‘Lung Ventilation: Natural and Mechanical’ describes the processes of respiration and lung ventilation, focusing on those issues related directly to mechanical ventilation. The chapter starts by discussing the anatomy and physiology of respiration, and the involvement of the lungs and the entire respiratory system. It continues by introducing the three operating principles of mechanical ventilation. It then narrows its focus to intermittent positive pressure ventilation (IPPV), the operating principle of most modern critical care ventilators, explaining the pneumatic process of IPPV. The chapter ends by comparing natural and mechanical/artificial lung ventilation.

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