scholarly journals Effects on Lung Gas Volume, Respiratory Mechanics and Gas Exchange of a Closed-Circuit Suctioning System during Volume- and Pressure-Controlled Ventilation in ARDS Patients

2021 ◽  
Vol 10 (23) ◽  
pp. 5657
Author(s):  
Davide Chiumello ◽  
Luca Bolgiaghi ◽  
Paolo Formenti ◽  
Tommaso Pozzi ◽  
Manuela Lucenteforte ◽  
...  

Mechanically ventilated patients periodically require endotracheal suctioning. There are conflicting data regarding the loss of lung gas volume caused by the application of a negative pressure by closed-circuit suctioning. The aim of this study was to evaluate the effects of suctioning performed by a closed-circuit system in ARDS patients during volume- or pressure-controlled ventilation. In this prospective crossover-design study, 18 ARDS patients were ventilated under volume and pressure control applied in random order. Gas exchange, respiratory mechanics and EIT-derived end-expiratory lung volume (EELV) before the suctioning manoeuvre and after 5, 15 and 30 min were recorded. The tidal volume and respiratory rate were similar in both ventilation modes; in volume control, the EELV decreased by 31 ± 23 mL, 5 min after the suctioning, but it remained similar after 15 and 30 min; the oxygenation, PaCO2 and respiratory system elastance did not change. In the pressure control, 5 min after suctioning, EELV decreased by 35 (26–46) mL, the PaO2/FiO2 did not change, while PaCO2 increased by 5 and 30 min after suctioning (45 (40–51) vs. 48 (43–52) and 47 (42–54) mmHg, respectively). Our results suggest minimal clinical advantages when a closed system is used in volume-controlled compared to pressure-controlled ventilation.

2011 ◽  
Vol 110 (5) ◽  
pp. 1374-1383 ◽  
Author(s):  
Gaetano Perchiazzi ◽  
Christian Rylander ◽  
Antonio Vena ◽  
Savino Derosa ◽  
Debora Polieri ◽  
...  

During positive-pressure ventilation parenchymal deformation can be assessed as strain (volume increase above functional residual capacity) in response to stress (transpulmonary pressure). The aim of this study was to explore the relationship between stress and strain on the regional level using computed tomography in anesthetized healthy pigs in two postures and two patterns of breathing. Airway opening and esophageal pressures were used to calculate stress; change of gas content as assessed from computed tomography was used to calculate strain. Static stress-strain curves and dynamic strain-time curves were constructed, the latter during the inspiratory phase of volume and pressure-controlled ventilation, both in supine and prone position. The lung was divided into nondependent, intermediate, dependent, and central regions: their curves were modeled by exponential regression and examined for statistically significant differences. In all the examined regions, there were strong but different exponential relations between stress and strain. During mechanical ventilation, the end-inspiratory strain was higher in the dependent than in the nondependent regions. No differences between volume- and pressure-controlled ventilation were found. However, during volume control ventilation, prone positioning decreased the end-inspiratory strain of dependent regions and increased it in nondependent regions, resulting in reduced strain gradient. Strain is inhomogeneously distributed within the healthy lung. Prone positioning attenuates differences between dependent and nondependent regions. The regional effects of ventilatory mode and body positioning should be further explored in patients with acute lung injury.


Author(s):  
Alex Brito ◽  
Evan Fontaine ◽  
S. James El Haddi ◽  
Albert Chi MD FACS

Abstract During the Coronavirus-19, or COVID-19, pandemic there was an early shortage of available ventilators. Domestic production was limited by dependence on overseas sources of raw materials despite partnering with automotive manufacturers. Our group has developed a 3D printed alternative called the CRISIS ventilator. Its design is similar to existing resuscitator devices on the market and uses a modified Pressure-Control ventilation. Here we compare the performance of the device on a simulated ARDS lung and handling of different clinical scenarios included tension pneumothorax and bronchospasm.


2007 ◽  
Vol 18 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Gregory A. Hans ◽  
Audrey A. Prégaldien ◽  
Abdourahamane Kaba ◽  
Thierry M. Sottiaux ◽  
Arnaud DeRoover ◽  
...  

2021 ◽  
Vol 11 ◽  
Author(s):  
Andre Dos Santos Rocha ◽  
Roberta Südy ◽  
Davide Bizzotto ◽  
Miklos Kassai ◽  
Tania Carvalho ◽  
...  

IntroductionThe advantages of physiologically variable ventilation (PVV) based on a spontaneous breathing pattern have been demonstrated in several respiratory conditions. However, its potential benefits in chronic obstructive pulmonary disease (COPD) have not yet been characterized. We used an experimental model of COPD to compare respiratory function outcomes after 6 h of PVV versus conventional pressure-controlled ventilation (PCV).Materials and MethodsRabbits received nebulized elastase and lipopolysaccharide throughout 4 weeks. After 30 days, animals were anesthetized, tracheotomized, and randomized to receive 6 h of physiologically variable (n = 8) or conventional PCV (n = 7). Blood gases, respiratory mechanics, and chest fluoroscopy were assessed hourly.ResultsAfter 6 h of ventilation, animals receiving variable ventilation demonstrated significantly higher oxygenation index (PaO2/FiO2 441 ± 37 (mean ± standard deviation) versus 354 ± 61 mmHg, p < 0.001) and lower respiratory elastance (359 ± 36 versus 463 ± 81 cmH2O/L, p < 0.01) than animals receiving PCV. Animals ventilated with the variable mode also presented less lung derecruitment (decrease in lung aerated area, –3.4 ± 9.9 versus –17.9 ± 6.7%, p < 0.01) and intrapulmonary shunt fraction (9.6 ± 4.1 versus 17.0 ± 5.8%, p < 0.01).ConclusionPVV applied to a model of COPD improved oxygenation, respiratory mechanics, lung aeration, and intrapulmonary shunt fraction compared to conventional ventilation. A reduction in alveolar derecruitment and lung tissue stress leading to better aeration and gas exchange may explain the benefits of PVV.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Xiao-Wei Liu ◽  
Yan Jin ◽  
Tao Ma ◽  
Bo Qu ◽  
Zhi Liu

This study was conducted to evaluate the effects of open endotracheal suctioning on gas exchange and respiratory mechanics in ARF patients under the modes of PCV or VCV. Ninety-six ARF patients were treated with open endotracheal suctioning and their variations in respiratory mechanics and gas exchange after the suctions were compared. Under PCV mode, compared with the initial level of tidal volume (VT), ARF patients showed 30.0% and 27.8% decrease at 1 min and 10 min, respectively. Furthermore, the initial respiratory system compliance (Crs) decreased by 29.6% and 28.5% at 1 min and 10 min, respectively. Under VCV mode, compared with the initial level, 38.6% and 37.5% increase in peak airway pressure (PAP) were found at 1 min and 10 min, respectively. Under PCV mode, the initial PaO2increased by 6.4% and 10.2 % at 3 min and 10 min, respectively, while 18.9% and 30.6% increase of the initial PaO2were observed under VCV mode. Summarily, endotracheal suctioning may impair gas exchange and decrease lung compliance in ARF patients receiving mechanical ventilation under both PCV and VCV modes, but endotracheal suctioning effects on gas exchange were more severe and longer-lasting under PCV mode than VCV.


2020 ◽  
Author(s):  
Alcendino Cândido Jardim-Neto ◽  
Carrie E. Perlman

AbstractIn a major health crisis, demand for mechanical ventilators may exceed supply. This scenario has led to the idea of connecting ventilation circuits in parallel to ventilate multiple patients simultaneously with the same machine. However, simple parallel connection may be harmful when the patients’ respiratory system mechanics differ. The aim of this work was to develop and test a low-cost, multi-patient, pressure-controlled ventilation system in which parameter settings could be individualized. Two types of circuits were built from polyvinyl chloride plumbing tubes and connectors, with ball valves and water columns used to control pressures. The circuits were connected to test lungs of differing compliances, ventilated in parallel at 20 cycles per minute and assessed for control error, variability and interdependency during peak inspiratory (20 to 35 cmH2O, in 5 cmH2O steps) and positive end-expiratory (5 to 20 to 5 cmH2O, in 5 cmH2O steps) pressure changes in one of the circuits. Results showed control errors lower than 1 cmH2O, a maximum standard deviation in pressure of 1.4 cmH2O and no dependency between the parallel circuits during the pressure maneuvers or a controlled disconnection/reconnection. This pressure-control system might be used to expand a commercial ventilator or, with constant gas inflow and an automated outlet valve, as a stand-alone ventilator with individually-controlled settings for multiple patients. In conclusion, the proposed solution is presented as a potentially reliable strategy for safely individualizing pressure-control parameters in a multi-patient ventilation system during a major health crisis.


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