Extracorporeal Membrane Oxygenation for COVID-19: Comparison of Outcomes to Non-COVID-19-Related Viral Acute Respiratory Distress Syndrome From the Extracorporeal Life Support Organization Registry.

To compare complications and mortality between patients that required extracorporeal membrane oxygenation (ECMO) support for acute respiratory distress syndrome (ARDS) due to COVID-19 and non-COVID-19 viral pathogens. DESIGN: Retrospective observational cohort study. SETTING: Adult patients in the Extracorporeal Life Support Organization registry. PATIENTS: Nine-thousand two-hundred ninety-one patients that required ECMO for viral mediated ARDS between January 2017 and December 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcomes of interest were mortality during ECMO support and prior to hospital discharge. Time-to-event analysis and logistic regression were used to compare outcomes between the groups. Among 9,291 included patients, 1,155 required ECMO for non-COVID-19 viral ARDS and 8,136 required ECMO for ARDS due to COVID-19. Patients with COVID-19 had longer duration of ECMO (19.6 d [interquartile range (IQR), 10.1-34.0 d] vs 10.7 d [IQR, 6.3-19.7 d]; p < 0.001), higher mortality during ECMO support (44.4% vs 27.5%; p < 0.001), and higher in-hospital mortality (50.2% vs 34.5%; p < 0.001). Further, patients with COVID-19 were more likely to experience mechanical and clinical complications (membrane lung failure, pneumothorax, intracranial hemorrhage, and superimposed infection). After adjusting for pre-ECMO disease severity, patients with COVID-19 were more than two times as likely to die in the hospital compared with patients with non-COVID-19 viral ARDS. CONCLUSIONS: Patients with COVID-19 that require ECMO have longer duration of ECMO, more complications, and higher in-hospital mortality compared with patients with non-COVID-19-related viral ARDS. Further study in patients with COVID-19 is critical to identify the patient phenotype most likely to benefit from ECMO and to better define the role of ECMO in the management of this disease process.

Extracorporeal Carbon Dioxide Removal With the Hemolung in Patients With Acute Respiratory Failure: A Multicenter Retrospective Cohort Study.

OBJECTIVES: Extracorporeal carbon dioxide removal (ECCO 2 R) devices are effective in reducing hypercapnia and mechanical ventilation support but have not been shown to reduce mortality. This may be due to case selection, device performance, familiarity, or the management. The objective of this study is to investigate the effectiveness and safety of a single ECCO 2 R device (Hemolung) in patients with acute respiratory failure and identify variables associated with survival that could help case selection in clinical practice as well as future research. DESIGN: Multicenter, multinational, retrospective review. SETTING: Data from the Hemolung Registry between April 2013 and June 2021, where 57 ICUs contributed deidentified data. PATIENTS: Patients with acute respiratory failure treated with the Hemolung. The characteristics of patients who survived to ICU discharge were compared with those who died. Multivariable logistical regression analysis was used to identify variables associated with ICU survival. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 159 patients included, 65 (41%) survived to ICU discharge. The survival was highest in status asthmaticus (86%), followed by acute respiratory distress syndrome (ARDS) (52%) and COVID-19 ARDS (31%). All patients had a significant reduction in Pa co2 and improvement in pH with reduction in mechanical ventilation support. Patients who died were older, had a lower Pa o2 :F io2 (P/F) and higher use of adjunctive therapies. There was no difference in the complications between patients who survived to those who died. Multivariable regression analysis showed non-COVID-19 ARDS, age less than 65 years, and P/F at initiation of ECCO 2 R to be independently associated with survival to ICU discharge (P/F 100-200 vs <100: odds ratio, 6.57; 95% CI, 2.03-21.33). CONCLUSIONS: Significant improvement in hypercapnic acidosis along with reduction in ventilation supports was noted within 4 hours of initiating ECCO 2 R. Non-COVID-19 ARDS, age, and P/F at commencement of ECCO 2 R were independently associated with survival.

Extracorporeal Membrane Oxygenation for COVID-19: Comparison of Outcomes to Non-COVID-19–Related Viral Acute Respiratory Distress Syndrome From the Extracorporeal Life Support Organization Registry

OBJECTIVES: To compare complications and mortality between patients that required extracorporeal membrane oxygenation (ECMO) support for acute respiratory distress syndrome (ARDS) due to COVID-19 and non-COVID-19 viral pathogens. DESIGN: Retrospective observational cohort study. SETTING: Adult patients in the Extracorporeal Life Support Organization registry. PATIENTS: Nine-thousand two-hundred ninety-one patients that required ECMO for viral mediated ARDS between January 2017 and December 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcomes of interest were mortality during ECMO support and prior to hospital discharge. Time-to-event analysis and logistic regression were used to compare outcomes between the groups. Among 9,291 included patients, 1,155 required ECMO for non-COVID-19 viral ARDS and 8,136 required ECMO for ARDS due to COVID-19. Patients with COVID-19 had longer duration of ECMO (19.6 d [interquartile range (IQR), 10.1–34.0 d] vs 10.7 d [IQR, 6.3–19.7 d];p < 0.001), higher mortality during ECMO support (44.4% vs 27.5%;p < 0.001), and higher in-hospital mortality (50.2% vs 34.5%;p < 0.001). Further, patients with COVID-19 were more likely to experience mechanical and clinical complications (membrane lung failure, pneumothorax, intracranial hemorrhage, and superimposed infection). After adjusting for pre-ECMO disease severity, patients with COVID-19 were more than two times as likely to die in the hospital compared with patients with non-COVID-19 viral ARDS. CONCLUSIONS: Patients with COVID-19 that require ECMO have longer duration of ECMO, more complications, and higher in-hospital mortality compared with patients with non-COVID-19–related viral ARDS. Further study in patients with COVID-19 is critical to identify the patient phenotype most likely to benefit from ECMO and to better define the role of ECMO in the management of this disease process.

Efficacy and safety testing of a COVID-19 era emergency ventilator in a healthy rabbit lung model.

BACKGROUND: The COVID-19 pandemic revealed a substantial and unmet need for low-cost, easily accessible mechanical ventilation strategies for use in medical resource-challenged areas. Internationally, several groups developed non-conventional COVID-19 era emergency ventilator strategies as a stopgap measure when conventional ventilators were unavailable. Here, we compared our FALCON emergency ventilator in a rabbit model and compared its safety and functionality to conventional mechanical ventilation. METHODS: New Zealand white rabbits (n = 5) received mechanical ventilation from both the FALCON and a conventional mechanical ventilator (Engström Carestation™) for 1 h each. Airflow and pressure, blood O2 saturation, end tidal CO2, and arterial blood gas measurements were measured. Additionally, gross and histological lung samples were compared to spontaneously breathing rabbits (n = 3) to assess signs of ventilator induced lung injury. RESULTS: All rabbits were successfully ventilated with the FALCON. At identical ventilator settings, tidal volumes, pressures, and respiratory rates were similar between both ventilators, but the inspiratory to expiratory ratio was lower using the FALCON. End tidal CO2 was significantly higher on the FALCON, and arterial blood gas measurements demonstrated lower arterial partial pressure of O2 at 30 min and higher arterial partial pressure of CO2 at 30 and 60 min using the FALCON. However, when ventilated at higher respiratory rates, we observed a stepwise decrease in end tidal CO2. Poincaré plot analysis demonstrated small but significant increases in short-term and long-term variation of peak inspiratory pressure generation from the FALCON. Wet to dry lung weight and lung injury scoring between the mechanically ventilated and spontaneously breathing rabbits were similar. CONCLUSIONS: Although conventional ventilators are always preferable outside of emergency use, the FALCON ventilator safely and effectively ventilated healthy rabbits without lung injury. Emergency ventilation using accessible and inexpensive strategies like the FALCON may be useful for communities with low access to medical resources and as a backup form of emergency ventilation.

Construction and Performance Testing of a Fast-Assembly COVID-19 (FALCON) Emergency Ventilator in a Model of Normal and Low-Pulmonary Compliance Conditions.

INTRODUCTION: The COVID-19 pandemic has revealed an immense, unmet and international need for available ventilators. Both clinical and engineering groups around the globe have responded through the development of "homemade" or do-it-yourself (DIY) ventilators. Several designs have been prototyped, tested, and shared over the internet. However, many open source DIY ventilators require extensive familiarity with microcontroller programming and electronics assembly, which many healthcare providers may lack. In light of this, we designed and bench tested a low-cost, pressure-controlled mechanical ventilator that is "plug and play" by design, where no end-user microcontroller programming is required. This Fast-AssembLy COVID-Nineteen (FALCON) emergency prototype ventilator can be rapidly assembled and could be readily modified and improved upon to potentially provide a ventilatory option when no other is present, especially in low- and middle-income countries. HYPOTHESIS: We anticipated that a minimal component prototype ventilator could be easily assembled that could reproduce pressure/flow waveforms and tidal volumes similar to a hospital grade ventilator (Engström CarestationTM). MATERIALS AND METHODS: We benched-tested our prototype ventilator using an artificial test lung under 36 test conditions with varying respiratory rates, peak inspiratory pressures (PIP), positive end expiratory pressures (PEEP), and artificial lung compliances. Pressure and flow waveforms were recorded, and tidal volumes calculated with prototype ventilator performance compared to a hospital-grade ventilator (Engström CarestationTM) under identical test conditions. RESULTS: Pressure and flow waveforms produced by the prototype ventilator were highly similar to the CarestationTM. The ventilator generated consistent PIP/PEEP, with tidal volume ranges similar to the CarestationTM. The FALCON prototype was tested continuously for a 5-day period without failure or significant changes in delivered PIP/PEEP. CONCLUSION: The FALCON prototype ventilator is an inexpensive and easily-assembled "plug and play" emergency ventilator design. The FALCON ventilator is currently a non-certified prototype that, following further appropriate validation and testing, might eventually be used as a life-saving emergency device in extraordinary circumstances when more sophisticated forms of ventilation are unavailable.

Physiologic Improvement in Respiratory Acidosis Using Extracorporeal Co2 Removal With Hemolung Respiratory Assist System in the Management of Severe Respiratory Failure From Coronavirus Disease 2019.

OBJECTIVES: About 15% of hospitalized coronavirus disease 2019 patients require ICU admission, and most (80%) of these require invasive mechanical ventilation. Lung-protective ventilation in coronavirus disease 2019 acute respiratory failure may result in severe respiratory acidosis without significant hypoxemia. Low-flow extracorporeal Co2 removal can facilitate lung-protective ventilation and avoid the adverse effects of severe respiratory acidosis. The objective was to evaluate the efficacy of extracorporeal Co2 removal using the Hemolung Respiratory Assist System in correcting severe respiratory acidosis in mechanically ventilated coronavirus disease 2019 patients with severe acute respiratory failure. DESIGN: Retrospective cohort analysis of patients with coronavirus disease 2019 mechanically ventilated with severe hypercapnia and respiratory acidosis and treated with low-flow extracorporeal Co2 removal. SETTING: Eight tertiary ICUs in the United States. PATIENTS: Adult patients supported with the Hemolung Respiratory Assist System from March 1, to September 30, 2020. INTERVENTIONS: Extracorporeal Co2 removal with Hemolung Respiratory Assist System under a Food and Drug Administration emergency use authorization for coronavirus disease 2019. MEASUREMENTS AND MAIN RESULTS: The primary outcome was improvement in pH and Paco2 from baseline. Secondary outcomes included survival to decannulation, mortality, time on ventilator, and adverse events. Thirty-one patients were treated with Hemolung Respiratory Assist System with significant improvement in pH and Pco2 in this cohort. Two patients experienced complications that prevented treatment. Of the 29 treated patients, 58% survived to 48 hours post treatment and 38% to hospital discharge. No difference in age or comorbidities were noted between survivors and nonsurvivors. There was significant improvement in pH (7.24 ± 0.12 to 7.35 ± 0.07; p < 0.0001) and Paco2 (79 ± 23 to 58 ± 14; p < 0.0001) from baseline to 24 hours. CONCLUSIONS: In this retrospective case series of 29 patients, we have demonstrated efficacy of extracorporeal Co2 removal using the Hemolung Respiratory Assist System to improve respiratory acidosis in patients with severe hypercapnic respiratory failure due to coronavirus disease 2019.