A Simulated Single Ventilator / Dual Patient Ventilation Strategy for Acute Respiratory Distress Syndrome During the COVID-19 Pandemic

AbstractThe potential for acute shortages of ventilators at the peak of the Covid-19 pandemic has raised the possibility of needing to support two patients from a single ventilator. To provide a system for understanding and prototyping designs we have developed a mathematical model of two patients supported by a mechanical ventilator. We propose a standard setup where we simulate the introduction of T-splitters to supply air to two patients and a modified setup where we introduce a variable resistance in each inhalation pathway and one-way valves in each exhalation pathway. Using the standard setup, we demonstrate that ventilating two patients with mismatched lung compliances from a single ventilator will lead to clinically-significant reductions in tidal volume in the patient with the lowest respiratory compliance. Using the modified setup, we demonstrate that it could be possible to achieve the same tidal volumes in two patients with mismatched lung compliances, and we show that the tidal volume of one patient can be manipulated independently of the other. The results indicate that, with appropriate modifications, two patients could be supported from a single ventilator with independent control of tidal volumes.

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A simulated single ventilator/dual patient ventilation strategy for acute respiratory distress syndrome during the COVID-19 pandemic

Royal Society Open Science ◽

10.1098/rsos.200585 ◽

2020 ◽

Vol 7 (8) ◽

pp. 200585 ◽

Cited By ~ 1

Author(s):

José A. Solís-Lemus ◽

Edward Costar ◽

Denis Doorly ◽

Eric C. Kerrigan ◽

Caroline H. Kennedy ◽

...

Keyword(s):

Mathematical Model ◽

Tidal Volume ◽

Distress Syndrome ◽

The Other ◽

Mechanical Ventilator ◽

Ventilation Strategy ◽

Respiratory Compliance ◽

Standard Set ◽

Clinically Significant ◽

Set Up

The potential for acute shortages of ventilators at the peak of the COVID-19 pandemic has raised the possibility of needing to support two patients from a single ventilator. To provide a system for understanding and prototyping designs, we have developed a mathematical model of two patients supported by a mechanical ventilator. We propose a standard set-up where we simulate the introduction of T-splitters to supply air to two patients and a modified set-up where we introduce a variable resistance in each inhalation pathway and one-way valves in each exhalation pathway. Using the standard set-up, we demonstrate that ventilating two patients with mismatched lung compliances from a single ventilator will lead to clinically significant reductions in tidal volume in the patient with the lowest respiratory compliance. Using the modified set-up, we demonstrate that it could be possible to achieve the same tidal volumes in two patients with mismatched lung compliances, and we show that the tidal volume of one patient can be manipulated independently of the other. The results indicate that, with appropriate modifications, two patients could be supported from a single ventilator with independent control of tidal volumes.

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Improvements In Dynamic Pulmonary Compliance With A Very Low Tidal Volume Ventilation Strategy And Extracorporeal Membrane Oxygenation For Severe Acute Respiratory Distress Syndrome

10.1164/ajrccm-conference.2011.183.1_meetingabstracts.a1648 ◽

2011 ◽

Author(s):

Keith Brenner ◽

Matthew R. Baldwin ◽

Cara L. Agerstrand ◽

Kristin M. Burkart ◽

William A. Bulman ◽

...

Keyword(s):

Acute Respiratory Distress Syndrome ◽

Extracorporeal Membrane Oxygenation ◽

Respiratory Distress Syndrome ◽

Respiratory Distress ◽

Tidal Volume ◽

Distress Syndrome ◽

Ventilation Strategy ◽

Low Tidal Volume ◽

Pulmonary Compliance ◽

Volume Ventilation

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Faculty Opinions recommendation of A Quasi-Experimental, Before-After Trial Examining the Impact of an Emergency Department Mechanical Ventilator Protocol on Clinical Outcomes and Lung-Protective Ventilation in Acute Respiratory Distress Syndrome.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.727274417.793538975 ◽

2017 ◽

Author(s):

Ary Serpa Neto

Keyword(s):

Emergency Department ◽

Acute Respiratory Distress Syndrome ◽

Respiratory Distress Syndrome ◽

Respiratory Distress ◽

Distress Syndrome ◽

Protective Ventilation ◽

Lung Protective Ventilation ◽

Mechanical Ventilator ◽

Quasi Experimental ◽

The Impact

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Ultraprotective ventilation allowed by extracorporeal CO2 removal improves the right ventricular function in acute respiratory distress syndrome patients: a quasi-experimental pilot study

Annals of Intensive Care ◽

10.1186/s13613-020-00784-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Suzanne Goursaud ◽

Xavier Valette ◽

Julien Dupeyrat ◽

Cédric Daubin ◽

Damien du Cheyron

Keyword(s):

Acute Respiratory Distress Syndrome ◽

Pilot Study ◽

Respiratory Distress Syndrome ◽

Respiratory Distress ◽

Distress Syndrome ◽

Low Flow ◽

Ventilation Strategy ◽

Quasi Experimental ◽

Rv Function ◽

Ultraprotective Ventilation

Abstract Background Right ventricular (RV) failure is a common complication in moderate-to-severe acute respiratory distress syndrome (ARDS). RV failure is exacerbated by hypercapnic acidosis and overdistension induced by mechanical ventilation. Veno-venous extracorporeal CO2 removal (ECCO2R) might allow ultraprotective ventilation with lower tidal volume (VT) and plateau pressure (Pplat). This study investigated whether ECCO2R therapy could affect RV function. Methods This was a quasi-experimental prospective observational pilot study performed in a French medical ICU. Patients with moderate-to-severe ARDS with PaO2/FiO2 ratio between 80 and 150 mmHg were enrolled. An ultraprotective ventilation strategy was used with VT at 4 mL/kg of predicted body weight during the 24 h following the start of a low-flow ECCO2R device. RV function was assessed by transthoracic echocardiography (TTE) during the study protocol. Results The efficacy of ECCO2R facilitated an ultraprotective strategy in all 18 patients included. We observed a significant improvement in RV systolic function parameters. Tricuspid annular plane systolic excursion (TAPSE) increased significantly under ultraprotective ventilation compared to baseline (from 22.8 to 25.4 mm; p < 0.05). Systolic excursion velocity (S’ wave) also increased after the 1-day protocol (from 13.8 m/s to 15.1 m/s; p < 0.05). A significant improvement in the aortic velocity time integral (VTIAo) under ultraprotective ventilation settings was observed (p = 0.05). There were no significant differences in the values of systolic pulmonary arterial pressure (sPAP) and RV preload. Conclusion Low-flow ECCO2R facilitates an ultraprotective ventilation strategy thatwould improve RV function in moderate-to-severe ARDS patients. Improvement in RV contractility appears to be mainly due to a decrease in intrathoracic pressure allowed by ultraprotective ventilation, rather than a reduction of PaCO2.

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