Extracorporeal Membrane Oxygenation for Respiratory Failure Related to COVID-19: A Nationwide Cohort Study

Outcomes of COVID-19 patients undergoing extracorporeal membrane oxygenation: A systematic review and meta-Analysis

BACKGROUND

The Coronavirus Disease 2019 (COVID-19) pandemic has been ongoing for over 3 years, during which numerous clinical and experimental studies have been conducted. The objective of this systematic review and meta-analysis was to assess the survival probability and complications of COVID-19 patients receiving extracorporeal membrane oxygenation (ECMO).

METHODS

We searched the databases by using Population-Intervention-Comparison-Outcome-Study Design (PICOS). We conducted a search of the PubMed, Web of Science, and EMBASE databases to retrieve studies published until December 10, 2022. A random-effects meta-analysis, subgroup analysis, and assessed the studies using the Newcastle-Ottawa Scale score. The results were presented as pooled morbidity with 95% confidence intervals.

RESULTS

The study was conducted on 19 studies that enrolled a total of 1494 patients, and the results showed a pooled survival probability of 66.0%. The pooled morbidity for intracranial hemorrhage was 8.7%, intracranial thrombosis 7.0%, pneumothorax 9.0%, pulmonary embolism 11.0%, pulmonary hemorrhage 9.0%, heart failure 14.0%, liver failure 13.0%, renal injury 44.0%, gastrointestinal hemorrhage 6.0%, gastrointestinal ischemia 6.0% and venous thrombosis 31.0%.

CONCLUSION

This systematic review and meta-analysis of observational studies focused on the survival probability and complications of COVID-19 patients undergoing ECMO, which are significant in evaluating the use of ECMO in COVID-19 patients and provide a basis for further research.

TRIAL REGISTRATION

Our study was registered on PROSPERO with registration number CRD42022382555.

In COVID-19 Patients Supported with Extracorporeal Membrane Oxygenation, Intensive Care Unit Mortality Is Associated with the Blood Transfusion Rate

Background: The COVID-19 pandemic markedly increased the number of patients with infection-related acute respiratory distress syndrome who required extracorporeal membrane oxygenation (ECMO) and multiple blood transfusions. This study aimed to assess a potential correlation between the daily rate of transfused blood products and the intensive care unit (ICU) outcome of ECMO-supported COVID-19 patients. Methods: Data were retrieved from the electronic databases of three Israeli tertiary care centers. All COVID-19 patients treated with ECMO for >3 days in these centers between July 2020 and November 2021 were included in the analysis. Results: The study incorporated 106 patients [median age 49 (17-73) years]. The median numbers of ECMO days and daily transfused packed red blood cell (PRBC) units were 20.5 (4-240) and 0.61 (0-2.82), respectively. In multivariate analysis, age ≥50 years was an independent factor for ICU mortality [odds ratio (OR) 4.47). In ECMO-supported patients for <38 days, transfusion of ≥0.85 units/day was associated with higher ICU mortality compared to that observed in patients transfused with <0.85 PRBC units/day (OR = 5.43; p < 0.004). Transfusion of ≥0.5 units/day combined with ECMO support of ≥38 days (OR = 17.9; p < 0.001) conferred the highest mortality risk. Conclusions: Three-quarters of patients <50 years old and half of patients ≥50 years were successfully discharged from ICU. Higher daily transfusion rates were associated with significantly increased ICU mortality, irrespective of ECMO duration. Reduced blood transfusion may improve the survival of these patients. This approach could also contribute to the measures taken to address the challenges of blood shortages occurring during pandemics and other global or national emergencies.

Developing a veno-venous extracorporeal membrane oxygenation program during the COVID-19 pandemic: don't forget to notify the blood bank

OBJECTIVES

During the SARS-CoV-2 pandemic, there has been significant increased use of vvECMO as rescue therapy. Patients with COVID-19 as anticoagulation is needed for vvECMO support, may develop bleeding complications requiring an increased number of RBC transfusions. We would like to report the RBC transfusion needs following the implementation of an ECMO program. Data on blood usage in this population is important in view of the decline in donations due to the pandemic.

STUDY DESIGN AND METHODS

We analyzed data on RBC transfusions in patients who required vvECMO for COVID-19 related ARDS in a Belgian ICU from March 2020 to March 2022. The primary end point was RBC transfusion requirements. and the relationship to outcome. We also analyzed the evolution of this requirement during the four waves.

RESULTS

We admitted 538 patients for hypoxemic ARDS due to COVID-19. Sixty patients (11%) required vvECMO, of whom 27 (45%) died. Forty-seven (78 %) of the vvECMO patients were transfused a total of 403 packed RBC units.. Sites of hemorrhagic complications were ECMO cannulation sites and lungs. RBC transfusion per patient per day on vvECMO was 0.50 [0.30-0.67] units. There were no differences in hemorrhagic complications in vvECMO survivors and non-survivors. The percentage of vvECMO patients receiving a RBC transfusion increased slightly during the last COVID-19 wave, with 92 % of patients transfused.

CONCLUSIONS

vvECMO program is associated with a major need for RBC transfusions. These data are important when blood availability is decreased due to a pandemic and illustrates the need for studies on optimizing blood management including therapeutic anticoagulation target, threshold for RBC transfusion or alternatives to RBC transfusion.

Specific and Non-specific Aspects and Future Challenges of ICU Care Among COVID-19 Patients with Obesity: A Narrative Review

PURPOSE OF REVIEW

Since the end of 2019, the coronavirus disease 2019 (COVID-19) pandemic has infected nearly 800 million people and caused almost seven million deaths. Obesity was quickly identified as a risk factor for severe COVID-19, ICU admission, acute respiratory distress syndrome, organ support including mechanical ventilation and prolonged length of stay. The relationship among obesity; COVID-19; and respiratory, thrombotic, and renal complications upon admission to the ICU is unclear.

RECENT FINDINGS

The predominant effect of a hyperinflammatory status or a cytokine storm has been suggested in patients with obesity, but more recent studies have challenged this hypothesis. Numerous studies have also shown increased mortality among critically ill patients with obesity and COVID-19, casting doubt on the obesity paradox, with survival advantages with overweight and mild obesity being reported in other ICU syndromes. Finally, it is now clear that the increase in the global prevalence of overweight and obesity is a major public health issue that must be accompanied by a transformation of our ICUs, both in terms of equipment and human resources. Research must also focus more on these patients to improve their care. In this review, we focused on the central role of obesity in critically ill patients during this pandemic, highlighting its specificities during their stay in the ICU, identifying the lessons we have learned, and identifying areas for future research as well as the future challenges for ICU activity.

Veno-Arterial-Venous Extracorporeal Membrane Oxygenation in a Patient Undergoing Dialysis and Having Cardiopulmonary Failure Due to Coronavirus Disease: A Case Report

Coronavirus disease (COVID-19), a viral infection caused by severe acute respiratory syndrome coronavirus 2, was first reported in China in December 2019 and has since become a global pandemic. COVID-19 is a multisystem disease with respiratory symptoms as the main presentation. There is growing awareness of the adverse prognostic impact of cardiovascular involvement caused by COVID-19. We report a case of a patient on hemodialysis with COVID-19 who developed cardiopulmonary failure and was successfully weaned off veno-arterial-venous (VAV) extracorporeal membrane oxygenation (ECMO). A 54-year-old man was brought to our intensive care unit (ICU) with respiratory failure due to COVID-19, which had been diagnosed based on antigen testing results. Three days prior, he had started taking dexamethasone orally, but his respiratory distress had worsened two days prior, and he was referred to our hospital. He had a history of hypertension, atrial fibrillation, chronic heart failure, and end-stage renal disease. He was found to have circulatory shock and severe hypoxemia, and computed tomography (CT) showed ground-glass opacities throughout the lung fields. Hypoxemia persisted after ventilation. The ventilation settings for this patient were volume control ventilation, fraction of inspiratory oxygen 100%, tidal volume 360 ml, respiratory rate 22 breaths per minute, and positive end-expiratory pressure 15 mmHg. Therefore, veno-venous ECMO (VV-ECMO) was initiated. Echocardiography showed right ventricular free-wall motion disorder, which was judged to be a complication of cardiogenic shock due to septic cardiomyopathy. The patient was switched to VAV-ECMO, after which his circulatory and respiratory insufficiency gradually improved. He was switched to VV-ECMO on day 7 of hospitalization and weaned off ECMO on day 15 of hospitalization. The patient was fully weaned off the ventilator on day 37 of hospitalization and discharged from the ICU on day 38 of hospitalization. COVID-19 can cause cardiomyopathy, a rare cardiovascular disorder that can lead to cardiogenic shock; however, the cardiac and pulmonary symptoms may not occur simultaneously. Therefore, switching to VAV-ECMO after VV-ECMO was introduced; however, it is important to note that the mortality rate associated with this procedure is high.

Epidemiology of Seizures and Association With Mortality in Adult Patients Undergoing ECMO: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) provides lifesaving support to patients with cardiopulmonary failure. Although seizures increase mortality risks among critically ill patients broadly, studies specific to adult ECMO patients have largely been limited to single-center studies. Thus, we aimed to perform a systematic review and meta-analyses of seizure prevalence, mortality, and their associations in adult ECMO patients.

METHODS

PubMed, EMBASE, Cochrane trial registry, Web of Science, and SCOPUS were searched on August 5, 2023. Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, we included studies of adults undergoing venovenous ECMO (VV-ECMO), venoarterial ECMO (VA-ECMO), or extracorporeal cardiopulmonary resuscitation (ECPR) that reported seizures during ECMO. The extracted data included study characteristics, patient demographics, ECMO support, EEG monitoring, and seizures, organized by ECMO types. Forest plot and meta-regression analyses were performed. Bias assessment was performed with the Egger test and Newcastle-Ottawa Scale.

RESULTS

Twenty-three studies (n = 40,420, mean age = 51.8 years, male = 62%) were included. Data were extracted by ECMO type as follows: VV-ECMO (n = 16,633), non-ECPR VA-ECMO (n = 11,082), ECPR (n = 3,369), combination of VA-ECMO and ECPR (n = 240), and combination of all types (n = 9,096). The pooled seizure prevalence for all ECMO types was 3.0%, not significantly different across ECMO types (VV-ECMO = 2.0% [95% CI 0.8-4.5]; VA-ECMO = 3.5% [95% CI 1.7-7.0]; ECPR = 4.9% [95% CI 1.3-17.2]). The pooled mortality was lower for VV-ECMO (46.2% [95% CI 39.3-53.2]) than VA-ECMO (63.4% [95% CI 56.6-69.6]) and ECPR (61.5% [95% CI 57.3-65.6]). Specifically, for VV-ECMO, the pooled mortality of patients with and without seizures was 55.1% and 36.7%, respectively (relative risk = 1.5 [95% CI 1.3-1.7]). Similarly, for VA-ECMO, the pooled mortality of patients with and without seizures was 74.4% and 56.1%, respectively (relative risk = 1.3 [95% CI 1.2-1.5]). Meta-regression analyses demonstrated that seizure prevalence was not associated with prior neurologic comorbidities, adjusted for ECMO type and study year.

DISCUSSION

Seizures are infrequent during ECMO support. However, they were associated with increased mortality when present. Multi-institutional, larger-scale studies using standardized EEG monitoring are necessary to further understand the risk factors of specific classes of seizures for individual ECMO types, and their effects on mortality. Limitations of our study include missing data for details on seizure types, sedating/antiseizure medications used during ECMO, other ECMO-related complications, and EEG recording protocols.

Duration of Invasive Mechanical Ventilation before Veno-Venous ExtraCorporeal Membrane Oxygenation for Covid-19 related Acute Respiratory Distress Syndrome: The experience of a tertiary care center

Background

Veno-Venous Extracorporeal Membrane Oxygenation (VV-ECMO) is an efficient ventilatory support in patients with refractory Covid-19-related Acute Respiratory Distress Syndrome (ARDS), however the duration of invasive mechanical ventilation (IMV) before ECMO initiation as a contraindication is still controversial. The aim of this study was to investigate the impact of prolonged IMV prior to VV-ECMO in patients suffering from refractory Covid-19-related ARDS.

Methods

This single-center retrospective study included all patients treated with VV-ECMO for refractory Covid-19-related ARDS between January 1, 2020 and May 31, 2022. The impact of IMV duration was investigated by comparing patients on VV-ECMO during the 7 days (and 10 days) following IMV with those assisted after 7 days (and 10 days). The primary endpoint was in-hospital mortality.

Results

Sixty-four patients were hospitalized in the ICU for Covid-19-related refractory ARDS requiring VV-ECMO. Global in-hospital mortality was 55 %. Median duration of IMV was 4 [2; 8] days before VV-ECMO initiation. There was no significant difference in in-hospital mortality between patients assisted with IMV pre-VV-ECMO for a duration of ≤7 days (≤10 days) and those assisted after 7 days (and 10 days) ((p = 0.59 and p = 0.45).

Conclusion

This study suggests that patients assisted with VV-ECMO after prolonged IMV had the same prognosis than those assisted earlier in refractory Covid-19-related ARDS. Therefore, prolonged mechanical ventilation of more than 7-10 days should not contraindicate VV-ECMO support. An individual approach is necessary to balance the risks and benefits of ECMO in this population.

Status of COVID-19 Patients Treated With Extracorporeal Membrane Oxygenation in Japan: Nationwide Database Analysis

Background The report of epidemiological data on coronavirus disease 2019 (COVID-19) patients treated using extracorporeal membrane oxygenation (ECMO) in Japan has been limited. Our study seeks to fill the existing gap in knowledge by providing an in-depth analysis of the clinical epidemiological characteristics and diverse medical outcomes of COVID-19 patients treated with ECMO in Japan. Methods This study used the COVID-19 Registry Japan nationwide database. We included patients aged 18 years or older enrolled between March 17, 2020, and February 1, 2022, with traceable ECMO data. The items on clinical epidemiological characteristics and various medical outcomes were collected. Statistical analysis included a median and interquartile range (IQR) for continuous variables and frequencies for categorical variables. Results The number of participating hospitals was 731, and the number of patients enrolled for analysis was 49,590. Of these, 196 (0.4%) patients received ECMO. Hospital mortality was 33.2%, and discharge to home was 23.0% in the ECMO group. The complications during hospitalization included pneumothorax (9.7%), seizures (4.1%), stroke (4.6%), and pulmonary thromboembolism (2.0%). At discharge, 38.3% had worsened self-care ability, and 38.8% had worsened ambulatory function. Conclusions The results of ECMO treatment in Japan showed that the mortality and complication rates were well-controlled compared with those worldwide.

Delta Variant in the COVID-19 Pandemic: A Comparative Study on Clinical Outcomes Based on Vaccination Status

BACKGROUND

As the global battle against the COVID-19 pandemic endures, the spread of the Delta variant has introduced nuanced challenges, prompting a nuanced examination.

MATERIALS AND METHODS

We performed a multilevel logistic regression analysis encompassing 197 patients, comprising 44 vaccinated individuals (V group) and 153 unvaccinated counterparts (UV). These patients, afflicted with the Delta variant of SARS-CoV-2, were hospitalized between October 2021 and February 2022 at the COVID-19 department of a University Centre in Cluj-Napoca, Romania. We compared patient characteristics, CT lung involvement, Padua score, oxygen saturation (O2 saturation), ventilation requirements, dynamics of arterial blood gas (ABG) parameters, ICU admission rates, and mortality rates between the two groups.

RESULTS

The UV group exhibited a statistically significant (p < 0.05) proclivity toward developing a more severe form of infection, marked by elevated rates of lung involvement, oxygen requirement, ICU admission, and mortality.

CONCLUSION

Our findings underscore the substantial efficacy of the vaccine in diminishing the incidence of severe disease, lowering the rates of ICU admissions, and mitigating mortality among hospitalized patients.

The Respiratory Mechanics of COVID-19 Acute Respiratory Distress Syndrome-Lessons Learned?

Acute respiratory distress syndrome (ARDS) is a well-defined clinical entity characterized by the acute onset of diffuse pulmonary injury and hypoxemia not explained by fluid overload. The COVID-19 pandemic brought about an unprecedented volume of patients with ARDS and challenged our understanding and clinical approach to treatment of this clinical syndrome. Unique to COVID-19 ARDS is the disruption and dysregulation of the pulmonary vascular compartment caused by the SARS-CoV-2 virus, which is a significant cause of hypoxemia in these patients. As a result, gas exchange does not necessarily correlate with respiratory system compliance and mechanics in COVID-19 ARDS as it does with other etiologies. The purpose of this review is to relate the mechanics of COVID-19 ARDS to its underlying pathophysiologic mechanisms and outline the lessons we have learned in the management of this clinic syndrome.

Healthcare-associated infections in patients with severe COVID-19 supported with extracorporeal membrane oxygenation: a nationwide cohort study

BACKGROUND

Both critically ill patients with coronavirus disease 2019 (COVID-19) and patients receiving extracorporeal membrane oxygenation (ECMO) support exhibit a high incidence of healthcare-associated infections (HAI). However, data on incidence, microbiology, resistance patterns, and the impact of HAI on outcomes in patients receiving ECMO for severe COVID-19 remain limited. We aimed to report HAI incidence and microbiology in patients receiving ECMO for severe COVID-19 and to evaluate the impact of ECMO-associated infections (ECMO-AI) on in-hospital mortality.

METHODS

For this study, we analyzed data from 701 patients included in the ECMOSARS registry which included COVID-19 patients supported by ECMO in France.

RESULTS

Among 602 analyzed patients for whom HAI and hospital mortality data were available, 214 (36%) had ECMO-AI, resulting in an incidence rate of 27 ECMO-AI per 1000 ECMO days at risk. Of these, 154 patients had bloodstream infection (BSI) and 117 patients had ventilator-associated pneumonia (VAP). The responsible microorganisms were Enterobacteriaceae (34% for BSI and 48% for VAP), Enterococcus species (25% and 6%, respectively) and non-fermenting Gram-negative bacilli (13% and 20%, respectively). Fungal infections were also observed (10% for BSI and 3% for VAP), as were multidrug-resistant organisms (21% and 15%, respectively). Using a Cox multistate model, ECMO-AI were not found associated with hospital death (HR = 1.00 95% CI [0.79-1.26], p = 0.986).

CONCLUSIONS

In a nationwide cohort of COVID-19 patients receiving ECMO support, we observed a high incidence of ECMO-AI. ECMO-AI were not found associated with hospital death. Trial registration number NCT04397588 (May 21, 2020).

Relationship between the Pre-ECMO and ECMO Time and Survival of Severe COVID-19 Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Coronavirus disease 2019 (COVID-19) is the etiology of acute respiratory distress syndrome (ARDS). Extracorporeal membrane oxygenation (ECMO) is used to support gas exchange in patients who have failed conventional mechanical ventilation. However, there is no clear consensus on the timing of ECMO use in severe COVID-19 patients.

OBJECTIVE

The aim of this study is to compare the differences in pre-ECMO time and ECMO duration between COVID-19 survivors and non-survivors and to explore the association between them.

METHODS

PubMed, the Cochrane Library, Embase, and other sources were searched until 21 October 2022. Studies reporting the relationship between ECMO-related time and COVID-19 survival were included. All available data were pooled using random-effects methods. Linear regression analysis was used to determine the correlation between pre-ECMO time and ECMO duration. The meta-analysis was registered with PROSPERO under registration number CRD42023403236.

RESULTS

Out of the initial 2473 citations, we analyzed 318 full-text articles, and 54 studies were included, involving 13,691 patients. There were significant differences between survivors and non-survivors in the time from COVID-19 diagnosis (standardized mean difference (SMD) = -0.41, 95% confidence interval (CI): [-0.53, -0.29], p < 0.00001), hospital (SMD = -0.53, 95% CI: [-0.97, -0.09], p = 0.02) and intensive care unit (ICU) admission (SMD = -0.28, 95% CI: [-0.49, -0.08], p = 0.007), intubation or mechanical ventilation to ECMO (SMD = -0.21, 95% CI: [-0.32, -0.09], p = 0.0003) and ECMO duration (SMD = -0.18, 95% CI: [-0.30, -0.06], p = 0.003). There was no statistical association between a longer time from symptom onset to ECMO (hazard ratio (HR) = 1.05, 95% CI: [0.99, 1.12], p = 0.11) or time from intubation or mechanical ventilation (MV) and the risk of mortality (highest vs. lowest time groups odds ratio (OR) = 1.18, 95% CI: [0.78, 1.78], p = 0.42; per one-day increase OR = 1.14, 95% CI: [0.86, 1.52], p = 0.36; HR = 0.99, 95% CI: [0.95, 1.02], p = 0.39). There was no linear relationship between pre-ECMO time and ECMO duration.

CONCLUSION

There are differences in pre-ECMO time between COVID-19 survivors and non-survivors, and there is insufficient evidence to conclude that longer pre-ECMO time is responsible for reduced survival in COVID-19 patients. ECMO duration differed between survivors and non-survivors, and the timing of pre-ECMO does not have an impact on ECMO duration. Further studies are needed to explore the association between pre-ECMO and ECMO time in the survival of COVID-19 patients.

Prone Positioning During Venovenous Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome With COVID-19: A Meta-Analysis

The available literature has furnished substantial evidence indicating the favorable outcomes of prone positioning (PP) on oxygenation parameters among patients afflicted with coronavirus disease 2019 (COVID-19). However, there is a notable disparity in the reported influence of PP on the overall outcomes of COVID-19 patients undergoing venovenous extracorporeal membrane oxygenation (V-V ECMO) for acute respiratory distress syndrome (ARDS) across studies. This article has been prepared in adherence with Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. MEDLINE, Embase, and Cochrane databases were utilized for data retrieval. The primary endpoint was to evaluate the cumulative survival rate among COVID-19 patients receiving V-V ECMO, comparing those who received PP to those who did not. Secondary endpoints included the duration of intensive care unit (ICU) stay, ECMO duration, and mechanical ventilation duration. A total of 15 studies involving 2286 patients were analyzed in the meta-analysis. PP significantly improved the cumulative survival rate (0.48, 95% CI: 0.40-0.55); risk ratio (RR) of 1.24 (95% CI: 1.11-1.38).PP during ECMO for COVID-19 patients yielded favorable outcomes in terms of 60-day survival, 90-day survival, ICU survival, and hospital survival. In contrast, patients who underwent PP had longer ECMO duration (8.1 days, 95% CI: 6.2-9.9, p<0.001) and mechanical ventilation duration (9.6 days, 95% CI: 8.0-11.2, p<0.001). PP demonstrated improved survival in COVID-19 patients with ARDS receiving V-V ECMO. However, additional well-designed prospective trials are warranted to further explore the effects of this combination on survival outcomes in COVID-19 patients.

[Ventilatory management of SARS-CoV-2 acute respiratory failure]

COVID-19 pneumonia presents several particularities in its clinical presentation (cytokine storm, silent hypoxemia, thrombo-embolic risk) and may lead to a number of acute respiratory distress syndrome (ARDS) phenotypes. While the optimal oxygenation strategy in cases of hypoxemic acute respiratory failure (ARF) is still under debate, ventilatory management of COVID-19-related ARF has confirmed the efficacy of high-flow oxygen therapy and restored interest in other ventilatory approaches such as continuous positive airway pressure (CPAP) and noninvasive ventilation involving a helmet, which due to patient overflow are sometimes implemented outside of critical care units. However, further studies are still needed to determine which patients should be given which oxygenation technique, and under which conditions they require invasive mechanical ventilation, given that delayed initiation potentially burdens prognosis. During invasive mechanical ventilation, ventral decubitus and extracorporeal membrane oxygenation have become increasingly prevalent. While innovative therapies such as awake prone position or lung transplantation have likewise been developed, their indications, modalities and efficacy remain to be determined.

Functional Status and Quality of Life 6 Months After Extracorporeal Membrane Oxygenation Therapy for COVID-19-Related Pulmonary Failure

Extracorporeal membrane oxygenation (ECMO) is increasingly used in COVID-19-related pulmonary failure and the number of patients recovering from COVID-19 is growing. Here, we assess survival and recovery 6 months after ECMO for COVID-19. From April 2020 to September 2021, n = 60 (60.5 [51.0-65.0] years, 23.3% female) were treated with venovenous/venoarterial ECMO for COVID-19. 41.7% were weaned off ECMO, survival-to-discharge was 40.0% (n = 24). Age (63.0 [60.0-66.8] vs. 55.0 [43.8-60.0] years, p < 0.001), vasoactive support (97.2% vs . 75.0%, p = 0.013), and pre-ECMO SOFA scores (13.0 [12.0-14.8] vs. 12.0 [10.0-13.8] p = 0.036) correlated with nonsurvival. All patients aged >65 years, with histories of neoplasia, immunocompromise, chronic renal failure, or frailty died. After 6 months, 20 were alive (6-month survival 33.3%, survival conditioned on survival-to-discharge 83.3%), with follow-up in 19. 57.9% showed no relevant, 26.3% moderate, 15.8% severe deficits. Cardiopulmonary status was satisfactory (mMRC level: 84.2% ≤2). 73.7% were independent in daily life. Cognitive impairments were frequent (52.6%). 26.3% showed moderate depression, 15.8% posttraumatic stress disorder. Social and work life were considerably affected. Extracorporeal membrane oxygenation thus can serve as salvage therapy in COVID-19, but advanced age, immunocompromise, histories of neoplasia, and frailty must be considered as relative contraindications. Age, vasoactive support, and SOFA scores assist discriminating in daily practice. Deficits after 6 months are substantial, and efforts need to focus on long-term recovery.

Veno-arterial extracorporeal membrane oxygenation for circulatory failure in COVID-19 patients: insights from the ECMOSARS registry

OBJECTIVES

The clinical profile and outcomes of patients with Coronavirus Disease 2019 (COVID-19) who require veno-arterial extracorporeal membrane oxygenation (VA-ECMO) or veno-arterial-venous extracorporeal membrane oxygenation (VAV-ECMO) are poorly understood. We aimed to describe the characteristics and outcomes of these patients and to identify predictors of both favourable and unfavourable outcomes.

METHODS

ECMOSARS is a multicentre, prospective, nationwide French registry enrolling patients who require veno-venous extracorporeal membrane oxygenation (ECMO)/VA-ECMO in the context of COVID-19 infection (652 patients at 41 centres). We focused on 47 patients supported with VA- or VAV-ECMO for refractory cardiogenic shock.

RESULTS

The median age was 49. Fourteen percent of patients had a prior diagnosis of heart failure. The most common aetiologies of cardiogenic shock were acute pulmonary embolism (30%), myocarditis (28%) and acute coronary syndrome (4%). Extracorporeal cardiopulmonary resuscitation (E-CPR) occurred in 38%. In-hospital survival was 28% in the whole cohort, and 43% when E-CPR patients were excluded. ECMO cannulation was associated with significant improvements in pH and FiO2 on day 1, but non-survivors showed significantly more severe acidosis and higher FiO2 than survivors at this point (P = 0.030 and P = 0.006). Other factors associated with death were greater age (P = 0.02), higher body mass index (P = 0.03), E-CPR (P = 0.001), non-myocarditis aetiology (P = 0.02), higher serum lactates (P = 0.004), epinephrine (but not noradrenaline) use before initiation of ECMO (P = 0.003), haemorrhagic complications (P = 0.001), greater transfusion requirements (P = 0.001) and more severe Survival after Veno-Arterial ECMO (SAVE) and Sonographic Assessment of Intravascular Fluid Estimate (SAFE) scores (P = 0.01 and P = 0.03).

CONCLUSIONS

We report the largest focused analysis of VA- and VAV-ECMO recipients in COVID-19. Although relatively rare, the need for temporary mechanical circulatory support in these patients is associated with poor prognosis. However, VA-ECMO remains a viable solution to rescue carefully selected patients. We identified factors associated with poor prognosis and suggest that E-CPR is not a reasonable indication for VA-ECMO in this population.

Prognostic value of respiratory compliance course on mortality in COVID-19 patients with vv-ECMO

BACKGROUND

COVID-19-associated acute respiratory distress syndrome (ARDS) supported by veno-venous extra-corporal membrane oxygenation (vv-ECMO) results in a high in-hospital mortality rate of more than 35%. However, after cannulation, no prognostic factor has been described to guide the management of these patients. The objective was to assess the association between static respiratory compliance over the first 10 days post-vv-ECMO implantation on 180-day mortality.

RESULTS

In this multicentric retrospective study in three ECMO referral centers, all patients with COVID-19-associated ARDS supported by vv-ECMO were included from 03/01/2020 to 12/31/2021. Patients were ventilated with ultra-protective settings targeting a driving pressure lower than 15 cmH₂O. 122 patients were included. Median age was 59 IQR (52-64), 83 (68%) were male, with a median body mass index of 33 (28-37) kg/m². Delay between first symptoms to vv-ECMO implantation was 16 (10-21) days. Six-month death was 48%. Over the first ten days, compliance increased in 180 day survivors [from 18 (12-25) to 20 (15-27) mL/cmH₂O] compared to non-survivors [from 12 (9-20) to 10 (8-14) mL/cmH₂O, p interaction < 0.0001]. A time varying multivariable Cox model found age, history of chronic lung disease, compliance from day one to day ten and sweep gas flow from day one to day ten as independent factors associated with 180-day mortality.

CONCLUSIONS

In COVID-19-associated ARDS, static respiratory compliance course over the first ten days post-vv-ECMO implantation is associated with 180-day mortality. This new information may provide crucial information on the patient's prognosis for intensivists.

Response to Prone Position in COVID-19 and Non-COVID-19 Patients with Severe ARDS Supported by vvECMO

BACKGROUND

For moderate to severe acute respiratory distress syndrome (ARDS), lung-protective ventilation combined with prolonged and repeated prone position (PP) is recommended. For the most severe patients for whom this strategy failed, venovenous extracorporeal membrane oxygenation (vv-ECMO) allows a reduction in ventilation-induced lung injury and improves survival. Some aggregated data have suggested a benefit regarding survival in pursuing PP during vv-ECMO. The combination of PP and vv-ECMO has been also documented in COVID-19 studies, although there is scarce evidence concerning respiratory mechanics and gas exchange response. The main objective was to compare the physiological response of the first PP during vv-ECMO in two cohorts of patients (COVID-19-related ARDS and non-COVID-19 ARDS) regarding respiratory system compliance (C_RS) and oxygenation changes.

METHODS

This was a single-center, retrospective, and ambispective cohort study in the ECMO center of Marseille, France. ECMO was indicated according to the EOLIA trial criteria.

RESULTS

A total of 85 patients were included, 60 in the non-COVID-19 ARDS group and 25 in the COVID-19-related ARDS group. Lung injuries of the COVID-19 cohort exhibited significantly higher severity with a lower C_RS at baseline. Concerning the main objective, the first PP during vv-ECMO was not associated with a change in C_RS or other variation in respiratory mechanic variables in both cohorts. By contrast, oxygenation was improved only in the non-COVID-19 ARDS group after a return to the supine position. Mean arterial pressure was higher during PP as compared with a return to the supine position in the COVID-19 group.

CONCLUSION

We found distinct physiological responses to the first PP in vv-ECMO-supported ARDS patients according to the COVID-19 etiology. This could be due to higher severity at baseline or specificity of the disease. Further investigations are warranted.

Multiple-site decontamination to prevent acquired infection in patients with veno-venous ECMO support

BACKGROUND

Acute distress respiratory syndrome (ARDS) patients with veno-venous extra corporeal membrane oxygenation (ECMO) support are particularly exposed to ECMO-associated infection (ECMO-AI). Unfortunately, data regarding AI prophylaxis in this setting are lacking. Selective decontamination regimens decrease AI incidence, including ventilator-associated pneumonia (VAP) and bloodstream infection (BSI) in critically ill patients. We hypothesized that a multiple-site decontamination (MSD) regimen is associated with a reduction in the incidence of AI among VV-ECMO patients.

METHODS

We conducted a retrospective observational study in three French ECMO referral centers from January 2010 to December 2021. All adult patients (> 18 years old) who received VV-ECMO support for ARDS were eligible. In addition to standard care (SC), 2 ICUs used MSD, which consists of the administration of topical antibiotics four times daily in the oropharynx and the gastric tube, once daily chlorhexidine body-wash and a 5-day nasal mupirocin course. AIs were compared between the 2 ICUs using MSD (MSD group) and the last ICU using SC.

RESULTS

They were 241 patients available for the study. Sixty-nine were admitted in an ICU that applied MSD while the 172 others received standard care and constituted the SC group. There were 19 ECMO-AIs (12 VAP, 7 BSI) in the MSD group (1162 ECMO-days) compared to 143 AIs (104 VAP, 39 BSI) in the SC group (2376 ECMO-days), (p < 0.05 for all infection site). In a Poisson regression model, MSD was independently associated with a lower incidence of ECMO-AI (IRR = 0.42, 95% CI [0.23-0.60] p < 0.001). There were 30 multidrug resistant microorganisms (MDRO) acquisition in the SC group as compared with two in the MSD group (IRR = 0.13, 95% CI [0.03-0.56] p = 0.001). Mortality in ICU was similar in both groups (43% in the SC group vs 45% in the MSD group p = 0.90). Results were similar after propensity-score matching.

CONCLUSION

In this cohort of patients from different hospitals, MSD appeared to be safe in ECMO patients and may be associated with improved outcomes including lower ECMO-AI and MDRO acquisition incidences. Since residual confounders may persist, these promising results deserve confirmation by randomized controlled trials.

Prognostic factors associated with mortality among patients receiving venovenous extracorporeal membrane oxygenation for COVID-19: a systematic review and meta-analysis

BACKGROUND

Venovenous extracorporeal membrane oxygenation (ECMO) can be considered for patients with COVID-19-associated acute respiratory distress syndrome (ARDS) who continue to deteriorate despite evidence-based therapies and lung-protective ventilation. The Extracorporeal Life Support Organization has emphasised the importance of patient selection; however, to better inform these decisions, a comprehensive and evidence-based understanding of the risk factors associated with poor outcomes is necessary. We aimed to summarise the association between pre-cannulation prognostic factors and risk of mortality in adult patients requiring venovenous ECMO for the treatment of COVID-19.

METHODS

In this systematic review and meta-analysis, we searched MEDLINE and Embase from Dec 1, 2019, to April 14, 2022, for randomised controlled trials and observational studies involving adult patients who required ECMO for COVID-19-associated ARDS and for whom pre-cannulation prognostic factors associated with in-hospital mortality were evaluated. We conducted separate meta-analyses of unadjusted and adjusted odds ratios (uORs), adjusted hazard ratios (aHRs), and mean differences, and excluded studies if these data could not be extracted. We assessed the risk of bias using the Quality in Prognosis Studies tool and certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. Our protocol was registered with the Open Science Framework registry, osf.io/6gcy2.

FINDINGS

Our search identified 2888 studies, of which 42 observational cohort studies involving 17 449 patients were included. Factors that had moderate or high certainty of association with increased mortality included patient factors, such as older age (adjusted hazard ratio [aHR] 2·27 [95% CI 1·63-3·16]), male sex (unadjusted odds ratio [uOR] 1·34 [1·20-1·49]), and chronic lung disease (aHR 1·55 [1·20-2·00]); pre-cannulation disease factors, such as longer duration of symptoms (mean difference 1·51 days [95% CI 0·36-2·65]), longer duration of invasive mechanical ventilation (uOR 1·94 [1·40-2·67]), higher partial pressure of arterial carbon dioxide (mean difference 4·04 mm Hg [1·64-6·44]), and higher driving pressure (aHR 2·36 [1·40-3·97]); and centre factors, such as less previous experience with ECMO (aOR 2·27 [1·28-4·05].

INTERPRETATION

The prognostic factors identified highlight the importance of patient selection, the effect of injurious lung ventilation, and the potential opportunity for greater centralisation and collaboration in the use of ECMO for the treatment of COVID-19-associated ARDS. These factors should be carefully considered as part of a risk stratification framework when evaluating a patient for potential treatment with venovenous ECMO.

FUNDING

None.

Impact of Prone Position in COVID-19 Patients on Extracorporeal Membrane Oxygenation

OBJECTIVES

Prone positioning and venovenous extracorporeal membrane oxygenation (ECMO) are both useful interventions in acute respiratory distress syndrome (ARDS). Combining the two therapies is feasible and safe, but the effectiveness is not known. Our objective was to evaluate the potential survival benefit of prone positioning in venovenous ECMO patients cannulated for COVID-19-related ARDS.

DESIGN

Retrospective analysis of a multicenter cohort.

PATIENTS

Patients on venovenous ECMO who tested positive for severe acute respiratory syndrome coronavirus 2 by reverse transcriptase polymerase chain reaction or with a diagnosis on chest CT were eligible.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All patients on venovenous ECMO for respiratory failure in whom prone position status while on ECMO and in-hospital mortality were known were included. Of 647 patients in 41 centers, 517 were included. Median age was 55 (47-61), 78% were male and 95% were proned before cannulation. After cannulation, 364 patients (70%) were proned and 153 (30%) remained in the supine position for the whole ECMO run. There were 194 (53%) and 92 (60%) deaths in the prone and the supine groups, respectively. Prone position on ECMO was independently associated with lower in-hospital mortality (odds ratio = 0.49 [0.29-0.84]; p = 0.010). In 153 propensity score-matched pairs, mortality rate was 49.7% in the prone position group versus 60.1% in the supine position group (p = 0.085). Considering only patients alive at decannulation, propensity-matched proned patients had a significantly lower mortality rate (22.4% vs 37.8%; p = 0.029) than nonproned patients.

CONCLUSIONS

Prone position may be beneficial in patients supported by venovenous ECMO for COVID-19-related ARDS but more data are needed to draw definitive conclusions.

Impact of Prone Position in COVID-19 Patients on Extracorporeal Membrane Oxygenation

OBJECTIVES

Prone positioning and venovenous extracorporeal membrane oxygenation (ECMO) are both useful interventions in acute respiratory distress syndrome (ARDS). Combining the two therapies is feasible and safe, but the effectiveness is not known. Our objective was to evaluate the potential survival benefit of prone positioning in venovenous ECMO patients cannulated for COVID-19-related ARDS.

DESIGN

Retrospective analysis of a multicenter cohort.

PATIENTS

Patients on venovenous ECMO who tested positive for severe acute respiratory syndrome coronavirus 2 by reverse transcriptase polymerase chain reaction or with a diagnosis on chest CT were eligible.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All patients on venovenous ECMO for respiratory failure in whom prone position status while on ECMO and in-hospital mortality were known were included. Of 647 patients in 41 centers, 517 were included. Median age was 55 (47-61), 78% were male and 95% were proned before cannulation. After cannulation, 364 patients (70%) were proned and 153 (30%) remained in the supine position for the whole ECMO run. There were 194 (53%) and 92 (60%) deaths in the prone and the supine groups, respectively. Prone position on ECMO was independently associated with lower in-hospital mortality (odds ratio = 0.49 [0.29-0.84]; p = 0.010). In 153 propensity score-matched pairs, mortality rate was 49.7% in the prone position group versus 60.1% in the supine position group (p = 0.085). Considering only patients alive at decannulation, propensity-matched proned patients had a significantly lower mortality rate (22.4% vs 37.8%; p = 0.029) than nonproned patients.

CONCLUSIONS

Prone position may be beneficial in patients supported by venovenous ECMO for COVID-19-related ARDS but more data are needed to draw definitive conclusions.

Critical role of diagnostic SARS-CoV-2 T cell assays for immunodeficient patients

After almost 3 years of intense study, the immunological basis of COVID-19 is better understood. Patients who suffer severe disease have a chaotic, destructive immune response. Many patients with severe COVID-19 produce high titres of non-neutralising antibodies, which are unable to sterilise the infection. In contrast, there is increasing evidence that a rapid, balanced cellular immune response is required to eliminate the virus and mitigate disease severity. In the longer term, memory T cell responses, following infection or vaccination, play a critical role in protection against SARS-CoV-2.Given the pivotal role of cellular immunity in the response to COVID-19, diagnostic T cell assays for SARS-CoV-2 may be of particular value for immunodeficient patients. A diagnostic SARS-CoV-2 T cell assay would be of utility for immunocompromised patients who are unable to produce antibodies or have passively acquired antibodies from subcutaneous or intravenous immunoglobulin (SCIG/IVIG) replacement. In many antibody-deficient patients, cellular responses are preserved. SARS-CoV-2 T cell assays may identify breakthrough infections if reverse transcriptase quantitative PCR (RT-qPCR) or rapid antigen tests (RATs) are not undertaken during the window of viral shedding. In addition to utility in patients with immunodeficiency, memory T cell responses could also identify chronically symptomatic patients with long COVID-19 who were infected early in the pandemic. These individuals may have been infected before the availability of reliable RT-qPCR and RAT tests and their antibodies may have waned. T cell responses to SARS-CoV-2 have greater durability than antibodies and can also distinguish patients with infection from vaccinated individuals.

COVID-19-Related ARDS: Key Mechanistic Features and Treatments

Acute respiratory distress syndrome (ARDS) is a heterogeneous syndrome historically characterized by the presence of severe hypoxemia, high-permeability pulmonary edema manifesting as diffuse alveolar infiltrate on chest radiograph, and reduced compliance of the integrated respiratory system as a result of widespread compressive atelectasis and fluid-filled alveoli. Coronavirus disease 19 (COVID-19)-associated ARDS (C-ARDS) is a novel etiology caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that may present with distinct clinical features as a result of the viral pathobiology unique to SARS-CoV-2. In particular, severe injury to the pulmonary vascular endothelium, accompanied by the presence of diffuse microthrombi in the pulmonary microcirculation, can lead to a clinical presentation in which the severity of impaired gas exchange becomes uncoupled from lung capacity and respiratory mechanics. The purpose of this review is to highlight the key mechanistic features of C-ARDS and to discuss the implications these features have on its treatment. In some patients with C-ARDS, rigid adherence to guidelines derived from clinical trials in the pre-COVID era may not be appropriate.

Soluble RAGE as a Prognostic Marker of Worsening in Patients Admitted to the ICU for COVID-19 Pneumonia: A Prospective Cohort Study

Background: The different waves of SARS-CoV-2 infection have strained hospital resources and, notably, intensive care units (ICUs). Identifying patients at risk of developing a critical condition is essential to correctly refer patients to the appropriate structure and to spare limited resources. The soluble form of RAGE (sRAGE), the endoplasmic stress response and its surrogates, GRP78 and VEGF-A, may be interesting markers. Methods: This was a prospective monocenter cohort study of adult patients admitted to the ICU for severe COVID-19 pneumonia. The plasma levels of sRAGE, GRP78 and VEGF-A were measured within the first 24 h. Patients were classified as critical if they further needed vasopressor therapy, renal replacement therapy, or invasive mechanical ventilation, or died during their ICU stay, and were otherwise classified as not critical. Results: A total of 98 patients were included and 39 developed a critical condition. Critical patients presented higher sRAGE (626 [450−1043] vs. 227 [137−404] pg/mL, p < 0.0001), interleukin-6 (43 [15−112] vs. 11 [5−20] pg/mL, p < 0.0001), troponin T (17 [9−39] vs. 10 [6−18] pg/mL, p = 0.003) and NT-pro-BNP (321 [118−446] vs. 169 [63−366] pg/mL, p = 0.009) plasma levels. No difference was observed for VEGF-A and GRP78. The variables independently associated with worsening in the ICU were sRAGE (1.03 [1.01−1.05] per 10 pg/mL) and age (1.7 [1.2−2.4] per 5 years). An sRAGE value of 449.5 pg/mL predicted worsening with a sensitivity of 77% and a specificity of 80%. Conclusion: sRAGE may allow the identification of patients at risk of developing a critical form of COVID-19 pneumonia, and thus may be useful to correctly refer patients to the appropriate structure of care.

Bleeding and thrombotic events in patients with severe COVID-19 supported with extracorporeal membrane oxygenation: a nationwide cohort study

PURPOSE

To describe bleeding and thrombotic events and their risk factors in patients receiving extracorporeal membrane oxygenation (ECMO) for severe coronavirus disease 2019 (COVID-19) and to evaluate their impact on in-hospital mortality.

METHODS

The ECMOSARS registry included COVID-19 patients supported by ECMO in France. We analyzed all patients included up to March 31, 2022 without missing data regarding bleeding and thrombotic events. The association of bleeding and thrombotic events with in-hospital mortality and pre-ECMO variables was assessed using multivariable logistic regression models.

RESULTS

Among 620 patients supported by ECMO, 29% had only bleeding events, 16% only thrombotic events and 20% both bleeding and thrombosis. Cannulation site (18% of patients), ear nose and throat (12%), pulmonary bleeding (9%) and intracranial hemorrhage (8%) were the most frequent bleeding types. Device-related thrombosis and pulmonary embolism/thrombosis accounted for most of thrombotic events. In-hospital mortality was 55.7%. Bleeding events were associated with in-hospital mortality (adjusted odds ratio (adjOR) = 2.91[1.94-4.4]) but not thrombotic events (adjOR = 1.02[0.68-1.53]). Intracranial hemorrhage was strongly associated with in-hospital mortality (adjOR = 13.5[4.4-41.5]). Ventilation duration before ECMO ≥ 7 days and length of ECMO support were associated with bleeding. Thrombosis-associated factors were fibrinogen ≥ 6 g/L and length of ECMO support.

CONCLUSIONS

In a nationwide cohort of COVID-19 patients supported by ECMO, bleeding incidence was high and associated with mortality. Intracranial hemorrhage incidence was higher than reported for non-COVID patients and carried the highest risk of death. Thrombotic events were less frequent and not associated with mortality. Length of ECMO support was associated with a higher risk of both bleeding and thrombosis, supporting the development of strategies to minimize ECMO duration.