scholarly journals Effect of prone positioning on oxygenation and static respiratory system compliance in COVID-19 ARDS vs. non-COVID ARDS

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jimyung Park ◽  
Hong Yeul Lee ◽  
Jinwoo Lee ◽  
Sang-Min Lee
Keyword(s):  
Mechanical Ventilation ◽  
Clinical Outcome ◽  
Respiratory System ◽  
Therapeutic Option ◽  
Physiological Effect ◽  
Respiratory Physiology ◽  
Entire Group ◽  
Prone Positioning ◽  
Respiratory System Compliance ◽  
First Session

Abstract Background Prone positioning is recommended for patients with moderate-to-severe acute respiratory distress syndrome (ARDS) receiving mechanical ventilation. While the debate continues as to whether COVID-19 ARDS is clinically different from non-COVID ARDS, there is little data on whether the physiological effects of prone positioning differ between the two conditions. We aimed to compare the physiological effect of prone positioning between patients with COVID-19 ARDS and those with non-COVID ARDS. Methods We retrospectively compared 23 patients with COVID-19 ARDS and 145 patients with non-COVID ARDS treated using prone positioning while on mechanical ventilation. Changes in PaO2/FiO2 ratio and static respiratory system compliance (Crs) after the first session of prone positioning were compared between the two groups: first, using all patients with non-COVID ARDS, and second, using subgroups of patients with non-COVID ARDS matched 1:1 with patients with COVID-19 ARDS for baseline PaO2/FiO2 ratio and static Crs. We also evaluated whether the response to the first prone positioning session was associated with the clinical outcome. Results When compared with the entire group of patients with non-COVID ARDS, patients with COVID-19 ARDS showed more pronounced improvement in PaO2/FiO2 ratio [adjusted difference 39.3 (95% CI 5.2–73.5) mmHg] and static Crs [adjusted difference 3.4 (95% CI 1.1–5.6) mL/cmH2O]. However, these between-group differences were not significant when the matched samples (either PaO2/FiO2-matched or compliance-matched) were analyzed. Patients who successfully discontinued mechanical ventilation showed more remarkable improvement in PaO2/FiO2 ratio [median 112 (IQR 85–144) vs. 35 (IQR 6–52) mmHg, P = 0.003] and static compliance [median 5.7 (IQR 3.3–7.7) vs. − 1.0 (IQR − 3.7–3.0) mL/cmH2O, P = 0.006] after prone positioning compared with patients who did not. The association between oxygenation and Crs responses to prone positioning and clinical outcome was also evident in the adjusted competing risk regression. Conclusions In patients with COVID-19 ARDS, prone positioning was as effective in improving respiratory physiology as in patients with non-COVID ARDS. Thus, it should be actively considered as a therapeutic option. The physiological response to the first session of prone positioning was predictive of the clinical outcome of patients with COVID-19 ARDS.

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

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 problems

2017 ◽  
Author(s):  
Sheila Adam ◽  
Sue Osborne ◽  
John Welch
Keyword(s):  
Nitric Oxide ◽  
Mechanical Ventilation ◽  
Respiratory Physiology ◽  
Respiratory Support ◽  
Holistic Care ◽  
Prone Positioning ◽  
Respiratory Problems ◽  
Anatomy And Physiology ◽  
Effective Care ◽  
Critical Care Admission

A requirement for respiratory support is the most frequent cause of critical care admission. Effective care requires an appreciation of the relevant anatomy and physiology, skills of physical assessment and use of monitoring, knowledge of a range of airway and breathing problems and the different challenges they present, and an understanding of the most appropriate means of airway management and respiratory support. This chapter details essential respiratory physiology and the advantages, disadvantages, and potential complications of different methods of monitoring and respiratory support, including holistic care of patients with artificial airways and various modes of mechanical ventilation, the use of nitric oxide, prone positioning and extra-corporeal devices, and management of the weaning patient.

Perioperative Respiratory Care and Complications

2015 ◽  
pp. 378-422
Author(s):  
Peter Burrage ◽  
Zinaida Wadhwani ◽  
Michael Nurok
Keyword(s):  
Mechanical Ventilation ◽  
Gas Exchange ◽  
Pulmonary Disease ◽  
Critically Ill ◽  
Respiratory System ◽  
Management Strategies ◽  
Respiratory Physiology ◽  
Respiratory Care ◽  
Pulmonary Mechanics ◽  
Contemporary Management

Clinicians caring for patients with cardio-pulmonary disease invariably must manage the respiratory system. Doing so requires a basic understanding of physiology and the interaction of the heart and lung. The present chapter begins with rudimentary concepts of respiratory physiology, focusing on, gas exchange, pulmonary mechanics, and cardio-pulmonary interactions. These are used to develop an approach to mechanical ventilation and routine perioperative respiratory care of the patient having undergone a cardio-pulmonary procedure. The final section of this chapter addresses specific respiratory challenges encountered in caring for the critically ill cardiothoracic patient in addition to contemporary management strategies.

scholarly journals Ventilated Patients With COVID-19 Show Airflow Obstruction

2021 ◽  
pp. 088506662110006
Author(s):  
Vikas S. Koppurapu ◽  
Maksym Puliaiev ◽  
Kevin C. Doerschug ◽  
Gregory A. Schmidt
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory System ◽  
Invasive Mechanical Ventilation ◽  
Airflow Obstruction ◽  
Plateau Pressure ◽  
Control Mode ◽  
Volume Control ◽  
Respiratory System Compliance ◽  
University Of Iowa ◽  
The University

Objective: Many patients with coronavirus disease 2019 (COVID-19) need mechanical ventilation secondary to acute respiratory distress syndrome. Information on the respiratory system mechanical characteristics of this disease is limited. The aim of this study is to describe the respiratory system mechanical properties of ventilated COVID-19 patients. Design, Setting, and Patients: Patients consecutively admitted to the medical intensive care unit at the University of Iowa Hospitals and Clinics in Iowa City, USA, from April 19 to May 1, 2020, were prospectively studied; final date of follow-up was May 1, 2020. Measurements: At the time of first patient contact, ventilator information was collected including mode, settings, peak airway pressure, plateau pressure, and total positive end expiratory pressure. Indices of airflow resistance and respiratory system compliance were calculated and analyzed. Main Results: The mean age of the patients was 58 years. 6 out of 12 (50%) patients were female. Of the 21 laboratory-confirmed COVID-19 patients on invasive mechanical ventilation, 9 patients who were actively breathing on the ventilator were excluded. All the patients included were on volume-control mode. Mean [±standard deviation] ventilator indices were: resistive pressure 19 [±4] cmH2O, airway resistance 20 [±4] cmH2O/L/s, and respiratory system static compliance 39 [±16] ml/cmH2O. These values are consistent with abnormally elevated resistance to airflow and reduced respiratory system compliance. Analysis of flow waveform graphics revealed a pattern consistent with airflow obstruction in all patients. Conclusions: Severe respiratory failure due to COVID-19 is regularly associated with airflow obstruction.

Tert-butylhydroquinone augments Nrf2-dependent resilience against oxidative stress and improves survival of ventilator-induced lung injury in mice

2021 ◽  
Vol 320 (1) ◽  
pp. L17-L28
Author(s):  
Lilly Veskemaa ◽  
Jan A. Graw ◽  
Philipp A. Pickerodt ◽  
Mahdi Taher ◽  
Willehad Boemke ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Mechanical Ventilation ◽  
Lung Injury ◽  
Respiratory System ◽  
Arterial Oxygenation ◽  
Respiratory System Compliance ◽  
Proinflammatory Response ◽  
Ventilator Induced Lung Injury ◽  
Redox Capacity

Oxidative stress caused by mechanical ventilation contributes to the pathophysiology of ventilator-induced lung injury (VILI). A key mechanism maintaining redox balance is the upregulation of nuclear factor-erythroid-2-related factor 2 (Nrf2)-dependent antioxidant gene expression. We tested whether pretreatment with an Nrf2-antioxidant response element (ARE) pathway activator tert-butylhydroquinone (tBHQ) protects against VILI. Male C57BL/6J mice were pretreated with an intraperitoneal injection of tBHQ ( n = 10), an equivalent volume of 3% ethanol (EtOH3%, vehicle, n = 13), or phosphate-buffered saline (controls, n = 10) and were then subjected to high tidal volume (HVT) ventilation for a maximum of 4 h. HVT ventilation severely impaired arterial oxygenation ([Formula: see text] = 49 ± 7 mmHg, means ± SD) and respiratory system compliance, resulting in a 100% mortality among controls. Compared with controls, tBHQ improved arterial oxygenation ([Formula: see text] = 90 ± 41 mmHg) and respiratory system compliance after HVT ventilation. In addition, tBHQ attenuated the HVT ventilation-induced development of lung edema and proinflammatory response, evidenced by lower concentrations of protein and proinflammatory cytokines (IL-1β and TNF-α) in the bronchoalveolar lavage fluid, respectively. Moreover, tBHQ enhanced the pulmonary redox capacity, indicated by enhanced Nrf2-depentent gene expression at baseline and by the highest total glutathione concentration after HVT ventilation among all groups. Overall, tBHQ pretreatment resulted in 60% survival ( P < 0.001 vs. controls). Interestingly, compared with controls, EtOH3% reduced the proinflammatory response to HVT ventilation in the lung, resulting in 38.5% survival ( P = 0.0054 vs. controls). In this murine model of VILI, tBHQ increases the pulmonary redox capacity by activating the Nrf2-ARE pathway and protects against VILI. These findings support the efficacy of pharmacological Nrf2-ARE pathway activation to increase resilience against oxidative stress during injurious mechanical ventilation.

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 The Correlation of Respiratory System Compliance and Mortality in COVID-19 Acute Respiratory Distress Syndrome: Do Phenotypes Really Exist?

2021 ◽  
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

Abstract 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.

Prone positioning in the ICU

2016 ◽  
Author(s):  
Paolo Taccone ◽  
Davide Chiumello
Keyword(s):  
Mechanical Ventilation ◽  
Gas Exchange ◽  
Pulmonary Blood Flow ◽  
Distress Syndrome ◽  
Patient Survival ◽  
Physiological Effect ◽  
Arterial Oxygenation ◽  
Prone Positioning ◽  
Recumbent Position ◽  
Physiological Research

Prone positioning (also known as ‘proning’, ‘prone manoeuvre’ or ‘prone ventilation’) refers to mechanical ventilation with patients positioned in prone position in contrast of standard supine (flat or semi-recumbent) position. The use of the prone positioning was proposed over 30 years ago as a means to improve arterial oxygenation in patients with acute respiratory distress syndrome (ARDS). Since then, extensive physiological research has been conducted to explore the possible mechanisms underlying the observed improvement in gas exchange, which involve changes in the distribution of both ventilation and pulmonary blood flow. Furthermore, it has been shown that, independently of gas exchange, prone positioning may reduce the harm of mechanical ventilation, which is known to adversely impact patient survival. In this chapter we will summarize the physiological effect of prone positioning, as well as the clinical evidences supporting its use to reduce mortality in patients with ARDS.

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