scholarly journals Evaluation of Respiratory Dynamics in an Asymmetric Lung Compliance Model

2017 ◽  
Vol 32 (2) ◽  
pp. 174-181 ◽  
Author(s):  
So Hui Yun ◽  
Ho-Jin Lee ◽  
Yong-Hun Lee ◽  
Jong Cook Park
Keyword(s):  
Lung Compliance ◽  
Respiratory Dynamics ◽  
Compliance Model

scholarly journals The BathRC model: a method to estimate flow restrictor size for dual ventilation of dissimilar patients

2020 ◽  
Author(s):  
Andrew Plummer ◽  
Jon du Bois ◽  
Siu Man Lee ◽  
Patrick Magee ◽  
Jens Roesner ◽  
...  
Keyword(s):  
Large Range ◽  
Breathing Circuit ◽  
Direct Calculation ◽  
Lung Compliance ◽  
Lower Tidal Volume ◽  
Short Supply ◽  
Flow Restriction ◽  
Linear Resistance ◽  
Large Numbers ◽  
Compliance Model

AbstractWith large numbers of COVID-19 patients requiring mechanical ventilation and ventilators being in short supply, in extremis two patients are having to share one ventilator. This possibility has been discussed for at least two decades, and careful matching of patient ventilation requirements is advised. However, with a large range of lung compliance and other characteristics, which may also vary with time, good matching is difficult to achieve. Adjusting the impedance of the flow path between ventilator and patient gives the opportunity to control the airway pressure and hence flow and volume individually for each patient. Several groups are now investigating this, in particular the addition of a flow restrictor in the inspiration tube for the patient who is more compliant, or requires a lower tidal volume. In this paper, we show that a simple linear resistance-compliance model, termed the BathRC model, of the ventilator tubing system and lung allows direct calculation of the relationships between pressures, volumes, and required flow restriction. The BathRC model is experimentally validated using a GE Aisys CS2 ventilator connected to two test lungs. The pressure-flow relationships for two restrictors are experimentally determined, and despite the need to approximate them with a linear resistance characteristic, their effect in the breathing circuit is accurately predicted by the simple model. The BathRC model is freely available for download; we do not condone dual ventilation, but this tool is provided to demonstrate that flow restriction can be readily estimated. This research is part of a larger test, simulation and design investigation on dual ventilation being undertaken at the UoB and RUH.

On-Line Calculation of Pulmonary Mechanics by Digital Computer

1978 ◽  
Vol 17 (04) ◽  
pp. 261-272 ◽  
Author(s):  
Y. Brault ◽  
G. Atlan ◽  
H. Lorino ◽  
A. Harf ◽  
A.-M. Lorino ◽  
...  
Keyword(s):  
Time Pressure ◽  
Lung Compliance ◽  
Pulmonary Mechanics ◽  
Close Correspondence ◽  
Standard Equipment ◽  
On Demand ◽  
On Line ◽  
The Subject ◽  
Ventilatory Mechanics ◽  
Computerized System

A system was built up around a minicomputer to process in real time pressure and flow signals collected during the course of three ventilatory mechanics tests: the calculation of the lung volume, the evaluation of the static lung compliance, the analysis of the forced expiratory performance. The subject is seated in an open body Plethysmograph, which allows for the instantaneous calculation of changes in the volume of his thorax and abdomen. The system is controlled through a graphics console which displays the sampled curves and the results of data processing. In addition, the signals can be stored on demand onto a magnetic tape so that the method can be tested and improved off line. The results obtained in healthy volunteers are highly reproducible. A close correspondence is found both in patients and volunteers between computer-derived and hand-calculated results. The computerized system has become a standard equipment of our Lung Function Department, where it allows for a rapid quantitative analysis of lung volumes, lung elasticity and bronchial airflow.

Impact of COVID 19 Pandemic on Tuerculosis

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 1084-1088
Author(s):  
Deepanshu Chawla ◽  
Pankaj Wagh ◽  
Saood Ali ◽  
Ulhas Jadhav ◽  
Babaji Ghewade
Keyword(s):  
Hand Hygiene Compliance ◽  
Adverse Outcome ◽  
Central India ◽  
Lung Compliance ◽  
Significant Loss ◽  
Tuberculosis Control ◽  
Mortality And Morbidity ◽  
Airborne Infection ◽  
Hygiene Compliance ◽  
Economic Constraints

Covid19 or SARS COV 2 is the most dreaded pandemic of the century, causing widespread mortality and morbidity. On the other hand, tuberculosis is an age-old disease killing billions around the globe every year. Both the diseases have caused a significant loss of human lives along with socio-economic constraints. While SARS Cov 2 is a very new disease, tuberculosis is known to humanity for thousands of years. Tuberculosis is an airborne infection while Covid spreads via droplet spread and through fomite as well. Tuberculosis and complications related to it may lead to increased mortality due to poor lung compliance. Moreover, Tuberculosis control programmed may get affected due to the ongoing pandemic. To decrease the adverse outcome of Covid19 on Tb strict measures like proper social distancing, hand hygiene, compliance to Anti Tubercular drugs, domiciliary Tb care and strengthening immune system may prove important. Measures like the use of masks, proper cough hygiene and repeated washing of hands may play a role in decreasing the spread of tuberculosis as well and might also play a role in the elimination of tuberculosis. The article also highlights the measures taken in a rural hospital in central India for the management of COVID 19 and Tuberculosis and the possible difficulties faced in the management of tuberculosis during the Covid pandemic.

scholarly journals ECMO in COVID-19—prolonged therapy needed? A retrospective analysis of outcome and prognostic factors

Perfusion ◽  
2021 ◽  
pp. 026765912199599
Author(s):  
Esther Dreier ◽  
Maximilian Valentin Malfertheiner ◽  
Thomas Dienemann ◽  
Christoph Fisser ◽  
Maik Foltan ◽  
...  
Keyword(s):  
Lung Compliance ◽  
Ecmo Support ◽  
Short Term ◽  
Single Center Study ◽  
Venovenous Extracorporeal Membrane Oxygenation ◽  
Baseline Characteristics ◽  
Ecmo Therapy ◽  
Vv Ecmo

Background: The role of venovenous extracorporeal membrane oxygenation (VV ECMO) in patients with COVID-19-induced acute respiratory distress syndrome (ARDS) still remains unclear. Our aim was to investigate the clinical course and outcome of those patients and to identify factors associated with the need for prolonged ECMO therapy. Methods: A retrospective single-center study on patients with VV ECMO for COVID-19-associated ARDS was performed. Baseline characteristics, ventilatory and ECMO parameters, and laboratory and virological results were evaluated over time. Six months follow-up was assessed. Results: Eleven of 16 patients (68.8%) survived to 6 months follow-up with four patients requiring short-term (<28 days) and seven requiring prolonged (⩾28 days) ECMO support. Lung compliance before ECMO was higher in the prolonged than in the short-term group (28.1 (28.8–32.1) ml/cmH2O vs 18.7 (17.7–25.0) ml/cmH2O, p = 0.030). Mechanical ventilation before ECMO was longer (19 (16–23) days vs 5 (5–9) days, p = 0.002) and SOFA score was higher (12.0 (10.5–17.0) vs 10.0 (9.0–10.0), p = 0.002) in non-survivors compared to survivors. Low viral load during the first days on ECMO tended to indicate worse outcomes. Seroconversion against SARS-CoV-2 occurred in all patients, but did not affect outcome. Conclusions: VV ECMO support for COVID-19-induced ARDS is justified if initiated early and at an experienced ECMO center. Prolonged ECMO therapy might be required in those patients. Although no relevant predictive factors for the duration of ECMO support were found, the decision to stop therapy should not be made dependent of the length of ECMO treatment.

scholarly journals A Public Safety Compliance Model of Safety Behaviors in the Age of the COVID-19 Pandemic

2021 ◽  
Vol 58 ◽  
pp. 004695802110313
Author(s):  
Mohammad Al-Bsheish ◽  
Mu’taman Jarrar ◽  
Amanda Scarbrough
Keyword(s):  
Public Safety ◽  
The Other ◽  
Safety Behaviors ◽  
Economic Sectors ◽  
The Public ◽  
Safety Compliance ◽  
Heavy Burden ◽  
Compliance Model ◽  
Entire World ◽  
The One

The outbreak of COVID-19 has placed a heavy burden on society, threatening the future of the entire world as the pandemic has hit health systems and economic sectors hard. Where time moves fast, continuing curfews and lockdown is impossible. This paper assembles three main safety behaviors, social distancing, wearing a facemask, and hygiene in one model (PSC Triangle) to be practiced by the public. Integrating public safety compliance with these behaviors is the main recommendation to slow the spread of COVID-19. Although some concerns and challenges face these practices, the shifting of public behaviors to be more safety-centered is appropriate and available as an urgent desire exists to return to normal life on the one hand and the medical effort to find effective cure or vaccine that has not yet succeeded on the other hand. Recommendations to enhance public safety compliance are provided.

scholarly journals K2P2.1 (TREK-1) potassium channel activation protects against hyperoxia-induced lung injury

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tatiana Zyrianova ◽  
Benjamin Lopez ◽  
Riccardo Olcese ◽  
John Belperio ◽  
Christopher M. Waters ◽  
...  
Keyword(s):  
Lung Injury ◽  
Lung Compliance ◽  
Alveolar Epithelial Cells ◽  
Pharmacological Intervention ◽  
Alveolar Epithelial ◽  
Protein Levels ◽  
Cell Counts ◽  
Novel Approach ◽  
Intracellular Ca ◽  
Cell Depolarization

AbstractNo targeted therapies exist to counteract Hyperoxia (HO)-induced Acute Lung Injury (HALI). We previously found that HO downregulates alveolar K2P2.1 (TREK-1) K+ channels, which results in worsening lung injury. This decrease in TREK-1 levels leaves a subset of channels amendable to pharmacological intervention. Therefore, we hypothesized that TREK-1 activation protects against HALI. We treated HO-exposed mice and primary alveolar epithelial cells (AECs) with the novel TREK-1 activators ML335 and BL1249, and quantified physiological, histological, and biochemical lung injury markers. We determined the effects of these drugs on epithelial TREK-1 currents, plasma membrane potential (Em), and intracellular Ca2+ (iCa) concentrations using fluorometric assays, and blocked voltage-gated Ca2+ channels (CaV) as a downstream mechanism of cytokine secretion. Once-daily, intra-tracheal injections of HO-exposed mice with ML335 or BL1249 improved lung compliance, histological lung injury scores, broncho-alveolar lavage protein levels and cell counts, and IL-6 and IP-10 concentrations. TREK-1 activation also decreased IL-6, IP-10, and CCL-2 secretion from primary AECs. Mechanistically, ML335 and BL1249 induced TREK-1 currents in AECs, counteracted HO-induced cell depolarization, and lowered iCa2+ concentrations. In addition, CCL-2 secretion was decreased after L-type CaV inhibition. Therefore, Em stabilization with TREK-1 activators may represent a novel approach to counteract HALI.

scholarly journals Surgical tracheostomy in a cohort of COVID-19 patients

HNO ◽  
2021 ◽  
Author(s):  
Patrick J. Schuler ◽  
Jens Greve ◽  
Thomas K. Hoffmann ◽  
Janina Hahn ◽  
Felix Boehm ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory Failure ◽  
Prolonged Mechanical Ventilation ◽  
Tertiary Care ◽  
Lung Compliance ◽  
Hypoxemic Respiratory Failure ◽  
Surgical Tracheostomy ◽  
Increased Risk ◽  
Open Surgical Tracheostomy ◽  
Sedative Drugs

Abstract Background One of the main symptoms of severe infection with the new coronavirus‑2 (SARS-CoV-2) is hypoxemic respiratory failure because of viral pneumonia with the need for mechanical ventilation. Prolonged mechanical ventilation may require a tracheostomy, but the increased risk for contamination is a matter of considerable debate. Objective Evaluation of safety and effects of surgical tracheostomy on ventilation parameters and outcome in patients with COVID-19. Study design Retrospective observational study between March 27 and May 18, 2020, in a single-center coronavirus disease-designated ICU at a tertiary care German hospital. Patients Patients with COVID-19 were treated with open surgical tracheostomy due to severe hypoxemic respiratory failure requiring mechanical ventilation. Measurements Clinical and ventilation data were obtained from medical records in a retrospective manner. Results A total of 18 patients with confirmed SARS-CoV‑2 infection and surgical tracheostomy were analyzed. The age range was 42–87 years. All patients received open tracheostomy between 2–16 days after admission. Ventilation after tracheostomy was less invasive (reduction in PEAK and positive end-expiratory pressure [PEEP]) and lung compliance increased over time after tracheostomy. Also, sedative drugs could be reduced, and patients had a reduced need of norepinephrine to maintain hemodynamic stability. Six of 18 patients died. All surgical staff were equipped with N99-masks and facial shields or with powered air-purifying respirators (PAPR). Conclusion Our data suggest that open surgical tracheostomy can be performed without severe complications in patients with COVID-19. Tracheostomy may reduce invasiveness of mechanical ventilation and the need for sedative drugs and norepinehprine. Recommendations for personal protective equipment (PPE) for surgical staff should be followed when PPE is available to avoid contamination of the personnel.

Negative impact of tissue inhibitor of metalloproteinase-3 null mutation on lung structure and function in response to sepsis

2003 ◽  
Vol 285 (6) ◽  
pp. L1222-L1232 ◽  
Author(s):  
Erica L. Martin ◽  
Brent Z. Moyer ◽  
M. Cynthia Pape ◽  
Barry Starcher ◽  
Kevin J. Leco ◽  
...  
Keyword(s):  
Negative Impact ◽  
Cecal Ligation ◽  
Lung Compliance ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Tissue Inhibitors Of Metalloproteinases ◽  
Wild Type ◽  
Gelatinase Activity ◽  
Lung Structure ◽  
And Function ◽  
Knockout Animals

Matrix metalloproteinases (MMPs) are degradative enzymes, which act to remodel tissue. Their activity is regulated by the tissue inhibitors of metalloproteinases (TIMPs). An imbalance in the degradation/inhibition activities has been associated with many diseases, including sepsis. We have previously shown that TIMP-3 knockout animals develop spontaneous, progressive air space enlargement. The objectives of this study were to determine the effects of a septic lung stress induced by cecal ligation and perforation (CLP) on lung function, structure, pulmonary surfactant, and inflammation in TIMP-3 null mice. Knockout and wild-type animals were randomized to either sham or CLP surgery, allowed to recover for 6 h, and then euthanized. TIMP-3 null animals exposed to sham surgery had a significant increase in lung compliance when compared with sham wild-type mice. Additionally, the TIMP-3 knockout mice showed a significant increase in compliance following CLP. Rapid compliance changes were accompanied by significantly decreased collagen and fibronectin levels and increased gelatinase (MMP-2 and -9) abundance and activation. Additionally, in situ zymography showed increased airway-associated gelatinase activity in the knockout animals enhanced following CLP. In conclusion, exposing TIMP-3 null animals to sepsis rapidly enhances the phenotypic abnormalities of these mice, due to increased MMP activity induced by CLP.

Sign in / Sign up

Export Citation Format

Share Document