Extracorporeal Membrane Oxygenation Therapy for Critically Ill Coronavirus Disease 2019 Patients in Wuhan, China: A Retrospective Multicenter Cohort Study

ESICM guidelines on acute respiratory distress syndrome: definition, phenotyping and respiratory support strategies

The aim of these guidelines is to update the 2017 clinical practice guideline (CPG) of the European Society of Intensive Care Medicine (ESICM). The scope of this CPG is limited to adult patients and to non-pharmacological respiratory support strategies across different aspects of acute respiratory distress syndrome (ARDS), including ARDS due to coronavirus disease 2019 (COVID-19). These guidelines were formulated by an international panel of clinical experts, one methodologist and patients' representatives on behalf of the ESICM. The review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement recommendations. We followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to assess the certainty of evidence and grade recommendations and the quality of reporting of each study based on the EQUATOR (Enhancing the QUAlity and Transparency Of health Research) network guidelines. The CPG addressed 21 questions and formulates 21 recommendations on the following domains: (1) definition; (2) phenotyping, and respiratory support strategies including (3) high-flow nasal cannula oxygen (HFNO); (4) non-invasive ventilation (NIV); (5) tidal volume setting; (6) positive end-expiratory pressure (PEEP) and recruitment maneuvers (RM); (7) prone positioning; (8) neuromuscular blockade, and (9) extracorporeal life support (ECLS). In addition, the CPG includes expert opinion on clinical practice and identifies the areas of future research.

Promoting self‐healing power and balancing immune response: a holistic, effective strategy of traditional Chinese medicine in treating COVID‐19

The COVID-19 pandemic is a serious challenge to human medicines. Modern medicine (MM) has been excellent in identifying the virus, sequencing its mutants, and monitoring the pandemic progress. However, due to lack of effective antivirals in the first two years of the pandemic, MM treated COVID-19 mainly by conventional supportive care with limited efficacy. In China, traditional Chinese medicine (TCM) has been actively participating the control of COVID-19, and the combination of TCM and conventional supportive care has shown better efficacies than the conventional care alone. Purpose: Clinical studies have shown that TCM treats COVID-19 through a holistic action, such as repairing organ injuries, anti-inflammation, immunoregulation and antiviral activities, etc. However, it is not clear how TCM is able to achieve these effects, and the scientific interpretation of TCM theories is lacking. This review aims to elucidate the scientific basis underlying TCM theories in the context of host-pathogen interaction and provide a working model for TCM in treating infectious diseases. Procedure: This review focuses on the essential components of host-pathogen interaction and performs an in-depth analysis of current literatures, including TCM theories and clinical studies as well as the most recent findings of tolerance (self-healing) mechanism in biomedical sciences. Conclusion: TCM treats COVID-19 through a holistic regulation of host responses, particularly by promoting patients’ self-healing power and balancing immune responses. Compared to the pathogen-centered MM, the host-centered TCM doesn't require specific antivirals and has less side-effects and drug resistance. This review provides a scientific insight into the mechanism of TCM and sheds a light on the prospective integration of TCM and MM for future challenges.

Improving Extracorporeal Membrane Oxygenation Survival in COVID-19. Effect of a Bundle of Care

Veno-venous extracorporeal membrane oxygenation (ECMO) support surged during the COVID-19 pandemic. Our program changed the model of care pursuing to protect the multidisciplinary team from the risk of infection and to serve as many patients as possible. Patient-healthcare interactions were restricted, and the ECMO bed capacity was increased by reducing the ECMO specialist-patient ratio to 1:4 with non-ECMO trained nurses support. The outcomes worsened and we paused while we evaluated and modified our model of care. The ECMO bed capacity was reduced to allow a nurse ECMO-specialist nurse ratio 2:1 with an ECMO trained nurse assistant's support. Intensivists, general practitioners, nurse assistants, and physical and respiratory therapists were trained on ECMO. Tracheostomy, bronchoscopy, and microbiological molecular diagnosis were done earlier, and family visits and rehabilitation were allowed in the first 48 hours of ECMO cannulation. There were 35 patients in the preintervention cohort and 66 in the postintervention cohort. Ninety days mortality was significantly lower after the intervention (62.9% vs. 31.8%, p = 0.003). Factors associated with increased risk of death were the need for cannulation or conversion to veno arterial or veno arterio venous ECMO, hemorrhagic stroke, and renal replacement therapy during ECMO. The interventions associated with a decrease in the risk of death were the following: early fiberoptic bronchoscopy and microbiological molecular diagnostic tests. Increasing the ECMO multidisciplinary team in relation to the number of patients and the earlier performance of diagnostic and therapeutic interventions, such as tracheostomy, fiberoptic bronchoscopy, molecular microbiological diagnosis of pneumonia, rehabilitation, and family support significantly decreased mortality of patients on ECMO due to COVID-19.

Evolving outcomes of extracorporeal membrane oxygenation during the first 2 years of the COVID-19 pandemic: a systematic review and meta-analysis

Background

Extracorporeal membrane oxygenation (ECMO) has been used extensively for coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome (ARDS). Reports early in the pandemic suggested that mortality in patients with COVID-19 receiving ECMO was comparable to non-COVID-19-related ARDS. However, subsequent reports suggested that mortality appeared to be increasing over time. Therefore, we conducted an updated systematic review and meta-analysis, to characterise changes in mortality over time and elucidate risk factors for poor outcomes.

Methods

We conducted a meta-analysis (CRD42021271202), searching MEDLINE, Embase, Cochrane, and Scopus databases, from 1 December 2019 to 26 January 2022, for studies reporting on mortality among adults with COVID-19 receiving ECMO. We also captured hospital and intensive care unit lengths of stay, duration of mechanical ventilation and ECMO, as well as complications of ECMO. We conducted random-effects meta-analyses, assessed risk of bias of included studies using the Joanna Briggs Institute checklist and evaluated certainty of pooled estimates using GRADE methodology.

Results

Of 4522 citations, we included 52 studies comprising 18,211 patients in the meta-analysis. The pooled mortality rate among patients with COVID-19 requiring ECMO was 48.8% (95% confidence interval 44.8–52.9%, high certainty). Mortality was higher among studies which enrolled patients later in the pandemic as opposed to earlier (1st half 2020: 41.2%, 2nd half 2020: 46.4%, 1st half 2021: 62.0%, 2nd half 2021: 46.5%, interaction p value = 0.0014). Predictors of increased mortality included age, the time of final patient enrolment from 1 January 2020, and the proportion of patients receiving corticosteroids, and reduced duration of ECMO run.

Conclusions

The mortality rate for patients receiving ECMO for COVID-19-related ARDS has increased as the pandemic has progressed. The reasons for this are likely multifactorial; however, as outcomes for these patients evolve, the decision to initiate ECMO should include the best contextual estimate of mortality at the time of ECMO initiation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04011-2.

Temporary mechanical circulatory support for COVID‐19 patients: A systematic review of literature

Objective

Myocardial damage occurs in up to 25% of coronavirus disease 2019 (COVID‐19) cases. While veno‐venous extracorporeal life support (V‐V ECLS) is used as respiratory support, mechanical circulatory support (MCS) may be required for severe cardiac dysfunction. This systematic review summarizes the available literature regarding MCS use rates, disease drivers for MCS initiation, and MCS outcomes in COVID‐19 patients.

Methods

PubMed/EMBASE were searched until October 14, 2021. Articles including adults receiving ECLS for COVID‐19 were included. The primary outcome was the rate of MCS use. Secondary outcomes included mortality at follow‐up, ECLS conversion rate, intubation‐to‐cannulation time, time on ECLS, cardiac diseases, use of inotropes, and vasopressors.

Results

Twenty‐eight observational studies (comprising both ECLS‐only populations and ECLS patients as part of larger populations) included 4218 COVID‐19 patients (females: 28.8%; median age: 54.3 years, 95%CI: 50.7–57.8) of whom 2774 (65.8%) required ECLS with the majority (92.7%) on V‐V ECLS, 4.7% on veno‐arterial ECLS and/or Impella, and 2.6% on other ECLS. Acute heart failure, cardiogenic shock, and cardiac arrest were reported in 7.8%, 9.7%, and 6.6% of patients, respectively. Vasopressors were used in 37.2%. Overall, 3.1% of patients required an ECLS change from V‐V ECLS to MCS for heart failure, myocarditis, or myocardial infarction. The median ECLS duration was 15.9 days (95%CI: 13.9–16.3), with an overall survival of 54.6% and 28.1% in V‐V ECLS and MCS patients. One study reported 61.1% survival with oxy‐right ventricular assist device.

Conclusion

MCS use for cardiocirculatory compromise has been reported in 7.3% of COVID‐19 patients requiring ECLS, which is a lower percentage compared to the incidence of any severe cardiocirculatory complication. Based on the poor survival rates, further investigations are warranted to establish the most appropriated indications and timing for MCS in COVID‐19.

Survival benefit of extracorporeal membrane oxygenation in severe COVID-19: a multi-centre-matched cohort study

Purpose

Extracorporeal membrane oxygenation (ECMO) has become an established therapy for severe respiratory failure in coronavirus disease 2019 (COVID-19). The added benefit of receiving ECMO in COVID-19 remains uncertain. The aim of this study is to analyse the impact of receiving ECMO at specialist centres on hospital mortality.

Methods

A multi-centre retrospective study was conducted in COVID-19 patients from 111 hospitals, referred to two specialist ECMO centres in the United Kingdom (UK) (March 2020 to February 2021). Detailed covariate data were contemporaneously curated from electronic referral systems. We analysed added benefit of ECMO treatment in specialist centres using propensity score matching techniques.

Results

1363 patients, 243 receiving ECMO, were analysed. The best matching technique generated 209 matches, with a marginal odds ratio (OR) for mortality of 0.44 (95% CI 0.29–0.68, p < 0.001) and absolute mortality reduction of 18.2% (44% vs 25.8%, p < 0.001) for treatment with ECMO in a specialist centre.

Conclusion

We found ECMO provided at specialist centres conferred significant survival benefit. Where resources and specialism allow, ECMO should be widely offered.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-022-06645-w.

Acute Kidney Injury in Patients with Severe ARDS Requiring Extracorporeal Membrane Oxygenation: Incidence, Prognostic Impact and Risk Factors

(1) Background: Acute kidney injury (AKI) is a common but under-investigated complication in patients receiving extracorporeal membrane oxygenation (ECMO). We aimed to define the incidence and clinical course, as well as the predictors of AKI in adults receiving ECMO support. (2) Materials and Methods: This is a retrospective analysis of all patients undergoing veno-venous ECMO treatment in a tertiary care center between December 2008 and December 2017. The primary endpoint was the new occurrence of an AKI of stage 2 or 3 according to the Kidney Disease: Improving Global Outcomes (KDIGO) classification after ECMO implantation. (3) Results: During the observation period, 103 patients underwent veno-venous ECMO implantation. In total, 59 patients (57.3%) met the primary endpoint with an AKI of stage 2 or 3 and 55 patients (53.4%) required renal replacement therapy. Patients with an AKI of 2 or 3 suffered from more bleeding and infectious complications. Whereas weaning failure from ECMO (30/59 (50.8%) vs. 15/44 (34.1%), p = 0.08) and 30-day mortality (35/59 (59.3%) vs. 17/44 (38.6%), p = 0.06) only tended to be higher in the group with an AKI of stage 2 or 3, long-term survival of up to five years was significantly lower in the group with an AKI of stage 2 or 3 (p = 0.015). High lactate, serum creatinine, and ECMO pump-speed levels, and low platelets, a low base excess, and a low hematocrit level before ECMO were independent predictors of moderate to severe AKI. Primary hypercapnic acidosis was more common in AKI non-survivors (12 (32.4%) vs. 0 (0.0%), p < 0.01). Accordingly, pCO2-levels prior to ECMO implantation tended to be higher in AKI non-survivors (76.12 ± 27.90 mmHg vs. 64.44 ± 44.31 mmHg, p = 0.08). In addition, the duration of mechanical ventilation prior to ECMO-implantation tended to be longer (91.14 ± 108.16 h vs. 75.90 ± 86.81 h, p = 0.078), while serum creatinine (180.92 ± 115.72 mmol/L vs. 124.95 ± 77.77 mmol/L, p = 0.03) and bicarbonate levels were significantly higher in non-survivors (28.22 ± 8.44 mmol/L vs. 23.36 ± 4.19 mmol/L, p = 0.04). (4) Conclusion: Two-thirds of adult patients receiving ECMO suffered from moderate to severe AKI, with a significantly increased morbidity and long-term mortality.

Transition from Simple V-V to V-A and Hybrid ECMO Configurations in COVID-19 ARDS

In SARS-CoV-2 patients with severe acute respiratory distress syndrome (ARDS), Veno-Venous Extracorporeal Membrane Oxygenation (V-V ECMO) was shown to provide valuable treatment with reasonable survival in large multi-centre investigations. However, in some patients, conversion to modified ECMO support forms may be needed. In this single-centre retrospective registry, all consecutive patients receiving V-V ECMO between 1 March 2020 to 1 May 2021 were included and analysed. The patient cohort was divided into two groups: those who remained on V-V ECMO and those who required conversion to other modalities. Seventy-eight patients were included, with fourteen cases (18%) requiring conversions to veno-arterial (V-A) or hybrid ECMO. The reasons for the ECMO mode configuration change were inadequate drainage (35.7%), inadequate perfusion (14.3%), myocardial infarction (7.1%), hypovolemic shock (14.3%), cardiogenic shock (14.3%) and septic shock (7.1%). In multivariable analysis, the use of dobutamine (p = 0.007) and a shorter ICU duration (p = 0.047) predicted the conversion. The 30-day mortality was higher in converted patients (log-rank p = 0.029). Overall, only 19 patients (24.4%) survived to discharge or lung transplantation. Adverse events were more common after conversion and included renal, cardiovascular and ECMO-circuit complications. Conversion itself was not associated with mortality in the multivariable analysis. In conclusion, as many as 18% of patients undergoing V-V ECMO for COVID-19 ARDS may require conversion to advanced ECMO support.