Extracorporeal Life Support Organization Coronavirus Disease 2019 Interim Guidelines: A Consensus Document from an International Group of Interdisciplinary Extracorporeal Membrane Oxygenation Providers

Insurance-based Disparities in Outcomes and Extracorporeal Membrane Oxygenation Utilization for Hospitalized COVID-19 Patients

BACKGROUND

The objective of this study was to examine insurance-based disparities in mortality, nonhome discharges, and extracorporeal membrane oxygenation utilization in patients hospitalized with COVID-19.

METHODS

Using a national database of U.S. academic medical centers and their affiliated hospitals, the risk-adjusted association between mortality, nonhome discharge, and extracorporeal membrane oxygenation utilization and (1) the type of insurance coverage (private insurance, Medicare, dual enrollment in Medicare and Medicaid, and no insurance) and (2) the weekly hospital COVID-19 burden (0 to 5.0%; 5.1 to 10%, 10.1 to 20%, 20.1 to 30%, and 30.1% and greater) was evaluated. Modeling was expanded to include an interaction between payer status and the weekly hospital COVID-19 burden to examine whether the lack of private insurance was associated with increases in disparities as the COVID-19 burden increased.

RESULTS

Among 760,846 patients hospitalized with COVID-19, 214,992 had private insurance, 318,624 had Medicare, 96,192 were dually enrolled in Medicare and Medicaid, 107,548 had Medicaid, and 23,560 had no insurance. Overall, 76,250 died, 211,702 had nonhome discharges, 75,703 were mechanically ventilated, and 2,642 underwent extracorporeal membrane oxygenation. The adjusted odds of death were higher in patients with Medicare (adjusted odds ratio, 1.28 [95% CI, 1.21 to 1.35]; P < 0.0005), dually enrolled (adjusted odds ratio, 1.39 [95% CI, 1.30 to 1.50]; P < 0.0005), Medicaid (adjusted odds ratio, 1.28 [95% CI, 1.20 to 1.36]; P < 0.0005), and no insurance (adjusted odds ratio, 1.43 [95% CI, 1.26 to 1.62]; P < 0.0005) compared to patients with private insurance. Patients with Medicare (adjusted odds ratio, 0.47; [95% CI, 0.39 to 0.58]; P < 0.0005), dually enrolled (adjusted odds ratio, 0.32 [95% CI, 0.24 to 0.43]; P < 0.0005), Medicaid (adjusted odds ratio, 0.70 [95% CI, 0.62 to 0.79]; P < 0.0005), and no insurance (adjusted odds ratio, 0.40 [95% CI, 0.29 to 0.56]; P < 0.001) were less likely to be placed on extracorporeal membrane oxygenation than patients with private insurance. Mortality, nonhome discharges, and extracorporeal membrane oxygenation utilization did not change significantly more in patients with private insurance compared to patients without private insurance as the COVID-19 burden increased.

CONCLUSIONS

Among patients with COVID-19, insurance-based disparities in mortality, nonhome discharges, and extracorporeal membrane oxygenation utilization were substantial, but these disparities did not increase as the hospital COVID-19 burden increased.

EDITOR’S PERSPECTIVE

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.

Changes in Therapy and Outcome of Patients Requiring Veno-Venous Extracorporeal Membrane Oxygenation for COVID-19

BACKGROUND

 Coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome requiring veno-venous extracorporeal membrane oxygenation (vv-ECMO) is related with poor outcome, especially in Germany. We aimed to analyze whether changes in vv-ECMO therapy during the pandemic were observed and lead to changes in the outcome of vv-ECMO patients.

METHODS

 All patients undergoing vv-ECMO support for COVID-19 between 2020 and 2021 in a single center (n = 75) were retrospectively analyzed. Weaning from vv-ECMO and in-hospital mortality were defined as primary and peri-interventional adverse events as secondary endpoints of the study.

RESULTS

 During the study period, four infective waves were observed in Germany. Patients were assigned correspondingly to four study groups: ECMO implantation between March 2020 and September 2020: first wave (n = 11); October 2020 to February 2021: second wave (n = 23); March 2021 to July 2021: third wave (n = 25); and August 2021 to December 2021: fourth wave (n = 20). Preferred cannulation technique changed within the second wave from femoro-femoral to femoro-jugular access (p < 0.01) and awake ECMO was implemented. Mean ECMO run time increased by more than 300% from 10.9 ± 9.6 (first wave) to 44.9 ± 47.0 days (fourth wave). Weaning of patients was achieved in less than 20% in the first wave but increased to approximately 40% since the second one. Furthermore, we observed a continuous numerically decrease of in-hospital mortality from 81.8 to 57.9% (p = 0.61).

CONCLUSION

 Preference for femoro-jugular cannulation and awake ECMO combined with preexisting expertise and patient selection are considered to be associated with increased duration of ECMO support and numerically improved ECMO weaning and in-hospital mortality.

Triage of V-V ECMO referrals for COVID-19 respiratory failure

BACKGROUND

As the pandemic progressed, the use of extracorporeal membrane oxygenation (ECMO) for COVID-19-related acute respiratory distress syndrome increased, and patient triage and transfer to ECMO centers became important to optimize patient outcomes. Our objectives are to identify predictors of patient transfer for veno-venous extracorporeal membrane oxygenation (V-V ECMO) evaluation as well as to describe the outcomes of accepted patients.

METHODS

This is a single-center, retrospective analysis of V-V ECMO transfer requests for adult patients with known or suspected COVID-19 and respiratory failure from March 2020 until March 2021. Data were collected prospectively during the triage process for transfer requests as part of clinical patient care at our institution.

RESULTS

Of 341 referred patients, 112 (33%) were accepted for transfer to our facility, whereas 229 (67%) patients were declined for transfer. The Classification and Regression Tree analysis showed that patients' high pressure during airway pressure release ventilation (APRV) and age were the variables most significantly associated with the decision to accept or decline patients for transfer.

CONCLUSIONS

Our triage process enabled one-third of referred patients to be transferred for evaluation, with nearly 70% of those patients ultimately receiving ECMO support. High ventilator settings on APRV and young age were associated with acceptance for transfer. Accepted patients also had a higher incidence of adjunctive therapies (proning and paralysis) prior to transfer request, less cardiac or renal dysfunction, and a shorter duration of mechanical ventilation. Further research is warranted to investigate the outcomes of nontransferred patients.

Predictors associated with successful weaning of veno-venous extracorporeal membrane oxygenation and mortality in adult patients with severe acute lung failure: Protocol of a pooled data analysis of cohort studies

BACKGROUND

Severe acute lung failure (ALF) often necessitates veno-venous extracorporeal membrane oxygenation (VV-ECMO), where identifying predictors of weaning success and mortality remains crucial yet challenging. The study aims to identify predictors of weaning success and mortality in adults undergoing VV-ECMO for severe ALF, a gap in current clinical knowledge.

METHODS AND ANALYSIS

PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials will be searched for cohort studies examining the predictive factors of successful weaning and mortality in adult patients on VV-ECMO due to severe ALF. Risk of bias assessment will be conducted using the Newcastle-Ottawa scale for each included study. The primary outcomes will be successful weaning from VV-ECMO and all-cause mortality. Between-study heterogeneity will be evaluated using the I2 statistic. Sensitivity, subgroup, and meta-regression analyses will be performed to ascertain potential sources of heterogeneity and assess the robustness of our results. We will use the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) tool to recommend the level of evidence.

DISCUSSION

This study seeks to provide clinically significant insights into predictors for weaning and mortality during VV-ECMO treatment for ALF, aiming to support clinical decisions and potentially influence health policy, thereby improving patient outcomes.

ETHICS AND DISSEMINATION

Given the absence of direct engagement with human subjects or access to personal medical records, ethical approval for this study is deemed unnecessary. The study findings will be shared at a scientific conference either at the global or national level. Alternatively, the results will be presented for publication in a rigorously peer-reviewed journal regarding critical care medicine.

Association between ICU quality and in-hospital mortality of V-V ECMO-supported patients-the ECMO quality improvement action (EQIA) study: a national cohort study in China from 2017 to 2019

This cohort study was performed to explore the influence of intensive care unit (ICU) quality on in-hospital mortality of veno-venous (V-V) extracorporeal membrane oxygenation (ECMO)-supported patients in China. The study involved all V-V ECMO-supported patients in 318 of 1700 tertiary hospitals from 2017 to 2019, using data from the National Clinical Improvement System and China National Critical Care Quality Control Center. ICU quality was assessed by quality control indicators and capacity parameters. Among the 2563 V-V ECMO-supported patients in 318 hospitals, a significant correlation was found between ECMO-related complications and prognosis. The reintubation rate within 48 hours after extubation and the total ICU mortality rate were independent risk factors for higher in-hospital mortality of V-V ECMO-supported patients (cutoff: 1.5% and 7.0%; 95% confidence interval: 1.05-1.48 and 1.04-1.45; odds ratios: 1.25 and 1.23; P = 0.012 and P = 0.015, respectively). Meanwhile, the V-V ECMO center volume was a protective factor (cutoff of ≥ 50 cases within the 3-year study period; 95% confidence interval: 0.57-0.83, odds ratio: 0.69, P = 0.0001). The subgroup analysis of 864 patients in 11 high-volume centers further strengthened these findings. Thus, ICU quality may play an important role in improving the prognosis of V-V ECMO-supported patients.

Refractory circulatory failure in COVID-19 patients treated with veno-arterial ECMO a retrospective single-center experience

OBJECTIVE

In this retrospective case series, survival rates in different indications for veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and differential diagnoses of COVID-19 associated refractory circulatory failure are investigated.

METHODS

Retrospective analysis of 28 consecutive COVID-19 patients requiring VA-ECMO. All VA-ECMO's were cannulated peripherally, using a femoro-femoral cannulation.

RESULTS

At VA-ECMO initiation, median age was 57 years (IQR: 51-62), SOFA score 16 (IQR: 13-17) and norepinephrine dosing 0.53μg/kg/min (IQR: 0.35-0.87). Virus-variants were: 61% wild-type, 14% Alpha, 18% Delta and 7% Omicron. Indications for VA-ECMO support were pulmonary embolism (PE) (n = 5, survival 80%), right heart failure due to secondary pulmonary hypertension (n = 5, survival 20%), cardiac arrest (n = 4, survival 25%), acute heart failure (AHF) (n = 10, survival 40%) and refractory vasoplegia (n = 4, survival 0%). Among the patients with AHF, 4 patients suffered from COVID-19 associated heart failure (CovHF) (survival 100%) and 6 patients from sepsis associated heart failure (SHF) (survival 0%). Main Complications were acute kidney injury (AKI) 93%, renal replacement therapy was needed in 79%, intracranial hemorrhage occurred in 18%. Overall survival to hospital discharge was 39%.

CONCLUSION

Survival on VA-ECMO in COVID-19 depends on VA-ECMO indication, which should be considered in further studies and clinical decision making. A subgroup of patients suffers from acute heart failure due to inflammation, which has to be differentiated into septic or COVID-19 associated. Novel biomarkers are required to ensure reliable differentiation between these entities; a candidate might be soluble interleukin 2 receptor.

Obesity and Extracorporeal Membrane Oxygenation

Obesity is increasing in prevalence worldwide and carries a theoretical increased risk of morbidity and mortality in critical illness, including hypercoagulability, thrombosis, and renal dysfunction. Obesity has historically been considered a relative contraindication to candidacy for extracorporeal membrane oxygenation (ECMO); however, recent research has suggested that obesity may be associated with improved outcomes in ECMO. This review was conducted to assess and synthesize the existing literature on ECMO outcomes in the obese population. We searched PubMed, Scopus, and CENTRAL databases for obesity and ECMO outcomes, and articles were screened independently by 2 authors. The selection process yielded 29 articles, with one ambispective and 28 retrospective cohort studies. Analyses of these studies show no evidence of globally increased mortality or complications in obesity. Prospective evaluation is needed to further investigate this relationship, but there is currently no evidence to support using body mass index as exclusionary criteria for ECMO.

Risk Factors for the Mortality of Patients With Coronavirus Disease 2019 Requiring Extracorporeal Membrane Oxygenation in a Non-Centralized Setting: A Nationwide Study

BACKGROUND

Limited data are available on the mortality rates of patients receiving extracorporeal membrane oxygenation (ECMO) support for coronavirus disease 2019 (COVID-19). We aimed to analyze the relationship between COVID-19 and clinical outcomes for patients receiving ECMO.

METHODS

We retrospectively investigated patients with COVID-19 pneumonia requiring ECMO in 19 hospitals across Korea from January 1, 2020 to August 31, 2021. The primary outcome was the 90-day mortality after ECMO initiation. We performed multivariate analysis using a logistic regression model to estimate the odds ratio (OR) of 90-day mortality. Survival differences were analyzed using the Kaplan-Meier (KM) method.

RESULTS

Of 127 patients with COVID-19 pneumonia who received ECMO, 70 patients (55.1%) died within 90 days of ECMO initiation. The median age was 64 years, and 63% of patients were male. The incidence of ECMO was increased with age but was decreased after 70 years of age. However, the survival rate was decreased linearly with age. In multivariate analysis, age (OR, 1.048; 95% confidence interval [CI], 1.010-1.089; P = 0.014) and receipt of continuous renal replacement therapy (CRRT) (OR, 3.069; 95% CI, 1.312-7.180; P = 0.010) were significantly associated with an increased risk of 90-day mortality. KM curves showed significant differences in survival between groups according to age (65 years) (log-rank P = 0.021) and receipt of CRRT (log-rank P = 0.004).

CONCLUSION

Older age and receipt of CRRT were associated with higher mortality rates among patients with COVID-19 who received ECMO.

Analysis of adverse events related to extracorporeal membrane oxygenation from a nationwide database of patient-safety accidents in Japan

Although adverse events related to extracorporeal membrane oxygenation have been reported, epidemiological data on life-threatening events are insufficient to study the causes of such adverse events. Data from the Japan Council for Quality Health Care database were retrospectively analyzed. The adverse events extracted from this national database included events associated with extracorporeal membrane oxygenation reported between January 2010 and December 2021. We identified 178 adverse events related to extracorporeal membrane oxygenation. At least 41 (23%) and 47 (26%) accidents resulted in death and residual disability, respectively. The most common adverse events were cannula malposition (28%), decannulation (19%), and bleeding (15%). Among patients with cannula malposition, 38% did not undergo fluoroscopy-guided or ultrasound-guided cannulation, 54% required surgical treatment, and 18% required trans-arterial embolization. In this epidemiological study in Japan, 23% of the adverse events related to extracorporeal membrane oxygenation had fatal outcomes. Our findings suggest that a training system for cannulation techniques may be needed, and hospitals offering extracorporeal membrane oxygenation should perform emergency surgeries.

Venovenous Extracorporeal Membrane Oxygenation Candidacy Decision-Making: Lessons and Hypotheses From a Single-Center Observational Analysis

BACKGROUND

Use of venovenous extracorporeal membrane oxygenation (ECMO) is increasing, but candidacy selection processes are variable and subject to bias.

RESEARCH QUESTION

What are the reasons behind venovenous ECMO candidacy decisions, and are decisions made consistently across patients?

STUDY DESIGN AND METHODS

Prospective observational study of all patients, admitted or outside hospital referrals, considered for venovenous ECMO at a tertiary referral center. Relevant clinical data and reasons for candidacy determination were cross-referenced with other noncandidates and candidates and were assessed qualitatively.

RESULTS

Eighty-one consultations resulted in 44 noncandidates (54%), 29 candidates (36%; nine of whom subsequently underwent cannulation), and eight deferred decisions (10%). Fifteen unique contraindications were identified, variably present across all patients. Five contraindications were invoked as the sole reason to deny ECMO to a patient. In patients with three or more contraindications, additional contraindications were cited even if the severity was relatively minor. All but four contraindications invoked to deny ECMO to a patient were nonprohibitive for at least one other candidate. Contraindications documented in noncandidates were present but not mentioned in 21 other noncandidates (47%). Twenty-six candidates (90%) had at least one contraindication that was prohibitive in a noncandidate, including a contraindication that was the sole reason to deny ECMO. Contraindications were proposed as informing three prognostic domains, through which patterns of inconsistency could be understood better: (1) irreversible underlying pulmonary process, (2) unsurvivable critical illness, and (3) clinical condition too compromised for meaningful recovery.

INTERPRETATION

ECMO candidacy decisions are inconsistent. We identified four patterns of inconsistency in our center and propose a three-domain model for understanding and categorizing contraindications, yielding five lessons that may improve candidacy decision processes until further research can guide practice more definitively.

Development and evaluation of extracorporeal membrane oxygenation nursing education program for nursing students using virtual reality

BACKGROUND

This study aims to improve nursing students' ability to care for critically ill patients through education in extracorporeal membrane oxygenation (ECMO) nursing.

METHODS

This study developed a virtual reality (VR) simulation program for the five-step ECMO nursing of the Analysis, Design, Development, Implement, and Evaluation (ADDIE) model and used an equivalent control group pre-test and post-test no-synchronized design to verify the effect. The participants of this study were fourth-year nursing students enrolled in nursing departments at three universities in Seoul, Gangwon, and Gyeonggi in South Korea; it included 66 participants, 33 in each of the experimental and control groups. The program consisted of pre-training, orientation, VR simulation, and debriefing.

RESULTS

The interaction effect of the intervention and control groups with time points using the ECMO nursing VR simulation program was rejected due to no statistically significant difference in knowledge (F = 1.41, p = .251), confidence (F = 1.97, p = .144), and clinical reasoning capacity (F = 2.85, p = .061). However, learning immersion (t = 3.97, p < .001) and learning satisfaction (t = 4.25, p < .001) were statistically significantly higher in the experimental group than in the control group.

CONCLUSION

VR simulation program for ECMO nursing developed in this study is a potential educational method that positively affects the learning immersion and learning satisfaction of nursing students.

Obesity and Extracorporeal Membrane Oxygenation (ECMO): Analysis of Outcomes

Traditionally, patients with obesity have been deemed ineligible for extracorporeal life support (ELS) therapies such as extracorporeal membrane oxygenation (ECMO), given the association of obesity with chronic health conditions that contribute to increased morbidity and mortality. Nevertheless, a growing body of literature suggests the feasibility, efficacy, and safety of ECMO in the obese population. This review provides an in-depth analysis of the current literature assessing the effects of obesity on outcomes among patients supported with ECMO (venovenous [VV] ECMO in noncoronavirus disease 2019 and coronavirus disease 2019 acute respiratory distress syndrome, venoarterial [VA] ECMO, and combined VV and VA ECMO), offer a possible explanation of the current findings on the basis of the obesity paradox phenomenon, provides a framework for future studies addressing the use of ELS therapies in the obese patient population, and provides guidance from the literature for many of the challenges related to initiating, maintaining, and weaning ELS therapy in patients with obesity.

Prevalence and Risk Factors for Weaning Failure From Venovenous Extracorporeal Membrane Oxygenation in Patients With Severe Acute Respiratory Insufficiency

OBJECTIVE

Analysis of the prevalence and risk factors for weaning failure from venovenous extracorporeal membrane oxygenation (VV-ECMO) in patients with severe acute respiratory insufficiency.

DESIGN

Single-center retrospective observational study.

SETTING

Sixteen beds medical ICU at the University Hospital Regensburg.

PATIENTS

Two hundred twenty-seven patients with severe acute respiratory insufficiency requiring VV-ECMO support between October 2011 and December 2017.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients meeting our ECMO weaning criteria (Sp o2 ≥ 90% with F io2 ≤ 0.4 or Pa o2 /F io2 > 150 mm Hg, pH = 7.35-7.45, positive end-expiratory pressure ≤ 10 cm H 2 O, driving pressure < 15 cm H 2 O, respiratory rate < 30/min, tidal volume > 5 mL/kg, ECMO bloodflow ≈ 1. 5 L/min, sweep gas flow ≈ 1 L/min, heart rate < 120/min, systolic blood pressure 90-160 mm Hg, norepinephrine < 0.2 µg/[kg*min]) underwent an ECMO weaning trial (EWT) with pausing sweep gas flow. Arterial blood gas analysis, respiratory and ventilator parameters were recorded prior, during, and after EWTs. Baseline data, including demographics, vitals, respiratory, ventilator, and laboratory parameters were recorded at the time of cannulation. One hundred seventy-nine of 227 (79%) patients were successfully decannulated. Ten patients (4%) underwent prolonged weaning of at least three failed EWTs before successful decannulation. The respiratory rate (19/min vs 16/min, p = 0.002) and Pa co2 (44 mm Hg vs 40 mm Hg, p = 0.003) were higher before failed than successful EWTs. Both parameters were risk factors for ECMO weaning failure (Pa co2 : odds ratio [OR] 1.05; 95% CI, 1.001-1.10; p = 0.045; respiratory rate: OR 1.10; 95% CI, 1.04-1.15; p < 0.001) in multivariable analysis. The rapid shallow breathing index [42 (1/L*min), vs 35 (1/L*min), p = 0.052) was higher before failed than successful EWTs. The decline of Sa o2 and Pa o2 /F io2 during EWTs was higher in failed than successful trials.

CONCLUSIONS

Seventy-nine percent of patients were successfully decannulated with only 4% needing prolonged ECMO weaning. Before EWT only parameters of impaired ventilation (insufficient decarboxylation, higher respiratory rate) but not of oxygenation were predictive for weaning failure, whereas during EWT-impaired oxygenation was associated with weaning failure.

In-hospital care of children with COVID-19

Children have been reported to be less affected and to have milder severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection than adults during the coronavirus disease 2019 (COVID-19) pandemic. However, children, and particularly those with underlying disorders, are still likely to develop critical illnesses. In the case of SARS-CoV-2 infection, most previous studies have focused on adult patients. To aid in the knowledge of in-hospital care of children with COVID-19, this study presents an expert review of the literature, including the management of respiratory distress or failure, extracorporeal membrane oxygenation (ECMO), multisystem inflammatory syndrome in children (MIS-C), hemodynamic and other organ support, pharmaceutical therapies (anti-viral drugs, anti-inflammatory or antithrombotic therapies) and management of cardiopulmonary arrest.

Predictors of poor outcome in critically ill patients with COVID-19 pneumonia treated with extracorporeal membrane oxygenation

INTRODUCTION

We aimed to identify risk factors associated with ICU mortality in critically ill patients with COVID-19 pneumonia treated with Extracorporeal membrane oxygenation (ECMO). We also aimed to assess protocol violations of the local eligibility criteria of ECMO initiation.

METHODS

All 31 consecutive adult patients with confirmed COVID-19 pneumonia admitted to ICU and treated with ECMO from March 13th 2020 to 8 December 2021 were enrolled. Eligibility criteria for ECMO initiation were: P/F-ratio<50 mmHg >3 hours, P/F-ratio<80 mmHg >6 hours or pH<7.25 + PaCO2>60 mmHg >6 hours, despite maximal protective invasive ventilation. Primary outcome was ICU mortality. Univariate logistic regression analyses were performed to identify predictors of ICU mortality.

RESULTS

12 out of 31 patients (38.7%) did not survive ECMO treatment in ICU. Half of the non-survivors suffered from acute kidney failure compared to 3 out of 19 survivors (15.79%) (p = .04). Half of the non-survivors required CRRT treatment versus 1 patient in the survivor group (5.3%) (p < .01). Higher age (2.45 (0.97-6.18), p = .05), the development of AKI (5.33 (1.00-28.43), p = .05), need of CRRT during ICU stay (18.00 (1.79-181.31), p = .01) and major bleeding during ECMO therapy (0.51 (0.19-0.89), p < .01) were identified to be predictors of ICU mortality.

CONCLUSION

Almost 60% of patients could be treated successfully with ECMO with sustained results at 3 months. Predictors for ICU mortality were development of AKI and need of CRRT during ICU stay, higher age category and major bleeding. Inadvertent ECMO allocation was noted in almost one in five patients.

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.

Tracheostomy in Critically Ill COVID-19 Patients on Extracorporeal Membrane Oxygenation: A Single-Center Experience

OBJECTIVES

Novel coronavirus-19 (COVID-19) has led to over 6 million fatalities globally. An estimated 75% of COVID-19 patients who require critical care admission develop acute respiratory distress syndrome (ARDS) needing invasive mechanical ventilation (IMV) and/or extracorporeal membrane oxygenation (ECMO). Due to prolonged ventilation requirements, these patients often also require tracheostomy. We performed a review of clinical outcomes in COVID-19 patients on ECMO at a high-volume tertiary care center in Hamilton, Ontario, Canada.

METHODOLOGY

We performed a retrospective case series, including 24 adult patients diagnosed with COVID-19 who required IMV, veno-venous (ECMO), and tracheostomy. All patients were included from April to December 2021. We extracted demographic and clinical variables pertaining to the tracheostomy procedure and ECMO therapy. We performed descriptive statistical analyses. This study was approved by the Hamilton Integrated Research Ethics Board (14217-C).

RESULTS

We included 24 consecutive patients with COVID-19 who required tracheostomy while undergoing ECMO therapy. The mean age was 49.4 years [standard deviation (SD): 7.33], the majority of patients were male (75%), with mean body mass index of 32 (SD: 8.81). Overall mortality rate was 33.3%. Percutaneous tracheostomy was performed most frequently (83.3%) and, similar to open tracheostomy, was associated with a low rate of perioperative bleeding complications. Within surviving patients, the mean time to IMV weaning and decannulation was 60.2 (SD: 24.6) and 49.4 days (SD: 21.8), respectively.

CONCLUSION

Percutaneous tracheostomy appears to be safe in COVID-19 patients on ECMO and holding anticoagulation 24 hours prior to and after tracheostomy may limit bleeding events in these patients.

Decreased PRESET-Score corresponds with improved survival in COVID-19 veno-venous extracorporeal membrane oxygenation

INTRODUCTION

The PREdiction of Survival on ECMO Therapy Score (PRESET-Score) predicts mortality while on veno-venous extracorporeal membrane oxygenation (VV ECMO) for acute respiratory distress syndrome. The aim of our study was to assess the association between PRESET-Score and survival in a large COVID-19 VV ECMO cohort.

METHODS

This was a single-center retrospective study of COVID-19 VV ECMO patients from 15 March 2020, to 30 November 2021. Univariable and Multivariable analyses were performed to assess patient survival and score differences.

RESULTS

A total of 105 patients were included in our analysis with a mean PRESET-Score of 6.74. Overall survival was 65.71%. The mean PRESET-Score was significantly lower in the survivor group (6.03 vs 8.11, p < 0.001). Patients with a PRESET-Score less than or equal to six had improved survival compared to those with a PRESET-Score greater than or equal to 8 (97.7% vs. 32.5%, p < 0.001). In a multivariable logistic regression, a lower PRESET-Score was also predictive of survival (OR 2.84, 95% CI 1.75, 4.63, p < 0.001).

CONCLUSION

We demonstrate that lower PRESET scores are associated with improved survival. The utilization of this validated, quantifiable, and objective scoring system to help identify COVID-19 patients with the greatest potential to benefit from VV-ECMO appears feasible. The incorporation of the PRESET-Score into institutional ECMO candidacy guidelines can help insure and improve access of this limited healthcare resource to all critically ill patients.

Bloodstream infections in COVID-19 patients undergoing extracorporeal membrane oxygenation in ICU: An observational cohort study

BACKGROUND

COVID-19 patients undergoing ECMO are at highly increased risk of nosocomial infections.

OBJECTIVES

To study incidence, clinical outcomes and microbiological features of bloodstream infections (BSI) occurring during ECMO in COVID-19 patients.

METHODS

Observational prospective cohort study enrolling consecutive COVID-19 patients undergoing veno-venous-ECMO in an Italian ICU from March 2020 to March 2022.

RESULTS

In the study population of 68 patients (age 53 [49-60] years, 82% males), 30 (44%) developed bloodstream infections (BSI group) while 38 did not (N-BSI group) with an incidence of 32 events/1000 days of ECMO. In BSI group pre-ECMO respiratory support was shorter (6 [4-9] vs 9 [5-12] days, p = 0.02) and ECMO treatment was longer (18 [10-29] vs 11 [7-18] days, p = 0.03) than in N-BSI group. The overall ECMO and ICU mortality were 50% and 59%, respectively, without any inter-group difference (p = 1.00). A longer ECMO treatment was independently correlated with higher rate of BSI (p = 0.04, OR [95% CI] 1.06 [1.02-1.11]). Sixteen primary and 14 secondary infectious events were documented. Gram-positive pathogens were more common in primary than secondary BSI (88% vs 43%, p = 0.02) and Enterococcus faecalis (56%) was the most frequent one. Conversely, Gram-negative microorganisms were more often isolated in secondary rather than primary BSI (57% vs 13%, p = 0.02), with Acinetobacter baumannii (21%) and Pseudomonas aeruginosa (21%) as most represented species. The administration of Sars-CoV-2 antiviral drug showed independent correlation with a reduced rate of ICU mortality (p = 0.01, OR [95% CI] 0.22 [0.07-0.73]).

CONCLUSIONS

Bloodstream infections represented a frequent complication without worsening clinical outcomes in our COVID-19 patients undergoing ECMO. Primary and secondary BSI events showed peculiar microbiological profiles.

Risk Factors for Bleeding in Coronavirus Disease 2019 Patients on Extracorporeal Membrane Oxygenation and Effects of Transcatheter Arterial Embolization for Hemostasis

Purpose

To evaluate risk factors for bleeding events in coronavirus disease 2019 (COVID-19) patients on extracorporeal membrane oxygenation (ECMO) and to share the initial results of transcatheter arterial embolization (TAE) for hemostasis.

Material and Methods

Forty-three COVID-19 patients who received ECMO from May 2020 to September 2021 were enrolled in this study. Patients with sudden onset anemia immediately underwent computed tomography to assess bleeding. We compared laboratory data, duration of ECMO, hospitalization period, and fatality of patients' groups with and without significant hemorrhagic events using the chi-square test and Mann-Whitney U test. We also assessed the results of TAE in patients who received hemostasis.

Results

A total of 25 bleeding events occurred in 24 of the 43 patients. Age was a risk factor for bleeding events and fatality. The average duration of ECMO and hospitalization period were significantly longer in those with bleeding events (42.9 and 54.3 days) than in those without bleeding events (16.2 and 25.0 days) (p < 0.05). In addition, those with bleeding had higher fatality (45.8%) than those without (15.8%) (p < 0.05). Active extravasation was confirmed for 5 events in 4 of 24 patients. TAE was attempted and performed successfully in all but one of these four cases, in whom bleeding ceased spontaneously.

Conclusions

Elderly COVID-19 patients on ECMO had a greater risk of bleeding complications and fatal outcomes. TAE was effective in providing prompt hemostasis for patients who have the treatment indication.

Ischemic stroke and intracranial hemorrhage in extracorporeal membrane oxygenation for COVID-19: A systematic review and meta-analysis

PURPOSE

Extracorporeal membrane oxygenation (ECMO) is employed to support critically ill COVD-19 patients. The occurrence of ischemic stroke and intracranial hemorrhage (ICH), as well as the implementation of anticoagulation strategies under the dual influence of ECMO and COVID-19 remain unclear. We conducted a systematic review and meta-analysis to describe the ischemic stroke, ICH and overall in-hospital mortality in COVID-19 patients receiving ECMO and summarize the anticoagulation regimens.

METHODS

EMBASE, PubMed, Cochrane, and Scopus were searched for studies examining ischemic stroke, ICH, and mortality in COVID-19 patients supported with ECMO. The outcomes were incidences of ischemic stroke, ICH, overall in-hospital mortality and anticoagulation regimens. We calculated the pooled proportions and 95% confidence intervals (CIs) to summarize the results.

RESULTS

We analyzed 12 peer-reviewed studies involving 6039 COVID-19 patients. The incidence of ischemic stroke had a pooled estimate of 2.2% (95% CI: 1.2%-3.2%). The pooled prevalence of ICH was 8.0% (95% CI: 6.3%-9.6%). The pooled estimate of overall in-hospital mortality was 40.3% (95% CI: 33.1%-47.5%). The occurrence of ICH was significantly higher in COVID-19 patients supported with ECMO than in other respiratory ECMO [relative risk=1.75 (95% CI: 1.00-3.07)]. Unfractionated heparin was the most commonly used anticoagulant, and anticoagulation monitoring practice varied among centers.

CONCLUSIONS

Ischemic stroke and ICH were common under the double "hit" of COVID-19 and ECMO. The prevalence of ICH was significantly higher in COVID-19 patients supported with ECMO than non-COVID-19 patients requiring ECMO. Individualized anticoagulation regimens may be a good choice to balance thrombosis and bleeding. More detailed research and further exploration are needed to clarify the underlying mechanism and clinical management decisions.

Evaluating service needs for veno-venous extracorporeal membrane oxygenation in patients with severe acute respiratory distress syndrome in Saskatchewan

To determine the number of patients with acute respiratory distress syndrome (ARDS) who would be eligible to receive veno-venous extracorporeal membrane oxygenation (VV-ECMO). We conducted a retrospective observational study of ARDS patients admitted to Regina General Hospital Intensive Care Unit (ICU). VV-ECMO eligibility was assessed using selection criteria from the Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Syndrome trial (EOLIA), the Extracorporeal Life Support Organization (ELSO), New South Wales (NSW), Critical Care Services Ontario (CCSO) and a Regina-restrictive criteria. Of 415 patients admitted between October 16, 2018, and January 21, 2021, 103 (25%) had mild, 175 (42%) had moderate, and 64 (15%) had severe ARDS. Of the cohort, 144 (35%) had bacterial pneumonia, 86 (21%) had viral pneumonia (including COVID-19), and 72 (17%) had aspiration pneumonia. Using the EOLIA, ELSO, NSW, CCSO and Regina-restrictive criteria, 7/415 (1.7%), 6/415 (1.5%), 19/415 (4.6%), 26/415 (6.3%) and 12/415 (2.9%) were eligible for VV-ECMO, respectively. Of all ECMO-eligible patients, only one (2.4%) actually received VV-ECMO, 20/42 (48%) received prone positioning and 21/42 (50%) received neuromuscular blockade. There is potential for service expansion of VV-ECMO in Regina; however, there is still a need to improve the delivery of evidence-based ARDS therapies.

Post VV-ECMO Weaning Hyperinflammation-Can Prophylactic Hemoadsorption Treatment Prevent Complications?

Acute respiratory distress syndrome (ARDS) is a severe clinical condition characterized by acute respiratory failure and a high mortality risk despite conventional mechanical ventilatory support. Veno-venous extracorporeal membrane oxygenation (vvECMO) has emerged as an effective life-support technology for patients with ARDS. However, complications may arise following the decannulation of vvECMO, with a relatively frequent development of systemic hyperinflammation (SHI). Among the various treatment strategies for SHI, the use of hemoadsorption with CytoSorb® has shown promising results in removing excessive levels of cytokines and attenuating the hyperinflammatory response. In this case series, we present three critically ill patients with ARDS secondary to pneumonia who underwent vvECMO and subsequently received prophylactic hemoadsorption with CytoSorb® following decannulation as a part of our clinical practice. This case series aims to describe the potential positive effects of hemoadsorption in preventing the development of SHI after vvECMO decannulation in ARDS patients.

Determinants of survival in patients on extracorporeal membrane oxygenation therapy due to severe covid-19

BACKGROUND

Severe acute respiratory distress syndrome (ARDS) due to Coronavirus Disease-19 (COVID-19) is associated with high mortality. Although survival on mechanical circulatory support has improved, determinants for better prognosis are still unclear. Here, we report on the outcome of our patient population with the need for mechanical circulatory support due to severe COVID-19 (sCOVID-19) induced ARDS.

METHODS

All patients treated with extracorporeal membrane oxygenation (ECMO) for severe ARDS due to sCOVID-19 were analysed. Patients > 18 years of age at the time of initiation of ECMO were included. Pre-existing comorbidities, complications during ECMO implantation, and ECMO runtime were reviewed. The latency to intubation, proning, tracheotomy, and ECMO implantation was analysed. Furthermore, the survival and non-survival population were compared to determine factors in favour of a better outcome.

RESULTS

In total, 85 patients were treated with veno-venous membrane oxygenation (vv-ECMO) for severe ARDS in our medical centre. The patient population was predominantly male (83.5%) with a mean patient age of 54.9 years. A history of cardiovascular disease (p = .01), smoking (p < .05), need for vasopressor- (p < .05), and renal replacement therapy (p < .001) was associated with a worse prognosis. Overall survival was 50%. The survival population was significantly younger (p = .004), had a significantly higher body weight (p = .02) and body mass index (BMI) (p = .01). Furthermore, survival was significantly better when vv-ECMO was initiated within 48 h after admission (p < .001).

CONCLUSIONS

Pre-existing cardiovascular disease, higher age, history of nicotine abuse, and development of renal failure are associated with poor outcome. Early start of vv-ECMO therapy may lead to better survival in sCOVID-19 patients, although complications during ECMO therapy are associated with a worse prognosis.

Extracorporeal membrane oxygenation in COVID-19- Associated acute respiratory distress syndrome - Outcome and experience in a tertiary care intensive care unit - A retrospective study

Background

Extracorporeal membrane oxygenation (ECMO) has been used in patients with severe acute respiratory distress syndrome (ARDS) due to coronavirus disease 2019 (COVID-19) who fail conventional treatment.

Methods

A retrospective observational study was designed in patients who underwent ECMO for severe COVID-19 ARDS in a tertiary care centre from September 2020 to July 2021. The primary outcome was to assess factors influencing clinical outcomes and survival to hospital discharge. Secondary outcomes were to assess the clinical profile and pre-ECMO features, ECMO characteristics and complications. Collected data were entered in Excel software and analysed using R software version 4.0.2 (R foundation for statistical computing, Vienna, Austria).

Results

A total of 19 patients underwent ECMO. Ten patients survived and discharge. Survivors had a longer median (interquartile range [IQR]) duration (days) on ECMO, that is, 25 (7-50), compared to non-survivors, that is, 12 (1-34) (P = 0.133). We also noted that patients who survived had a longer median (IQR) duration (days) of intensive care unit (ICU) stay, that is, 41.5 (30-70), compared to non-survivors, that is, 9 (2-40) (P = 0.001).

Conclusion

In our study, 52.3% of patients survived and discharge, and with ECMO outcomes for COVID-19 ARDS were at par with ECMO outcomes for non-COVID-19 ARDS despite requiring ECMO for longer duration and increased ICU length of stay.

Update on Anticoagulation Strategies in Patients with ECMO-A Narrative Review

The use of extracorporeal membrane oxygenation (ECMO) has recently increased exponentially. ECMO has become the preferred mode of organ support in refractory respiratory or circulatory failure. The fragile balance of haemostasis physiology is massively altered by the patient's critical condition and specifically the aetiology of the underlying disease. Furthermore, an application of ECMO conveys another disturbance of haemostasis due to blood-circuit interaction and the presence of an oxygenator. The purpose of this review is to summarise current knowledge on the anticoagulation management in patients undergoing ECMO therapy. The unfractionated heparin modality with monitoring of activated partial thromboplastin tests is considered to be a gold standard for anticoagulation in this specific subgroup of intensive care patients. However, alternative modalities with other agents are comprehensively discussed. Furthermore, other ways of monitoring can represent the actual state of coagulation in a more complex fashion, such as thromboelastometric/graphic methods, and might become more frequent. In conclusion, the coagulation system of patients with ECMO is altered by multiple variables, and there is a significant lack of evidence in this area. Therefore, a highly individualised approach is the best solution today.

Anticoagulation strategies in COVID-19 infected patients receiving ECMO support

BACKGROUND

Hospitalized COVID-19 patients with hypoxemic respiratory failure may deteriorate despite invasive mechanical ventilation and thus require extracorporeal membrane oxygenation (ECMO) support. Unfractionated heparin (UFH) is the antithrombotic of choice, however, bivalirudin may offer more predictable pharmacokinetics resulting in consistent anticoagulant effects with lower bleeding and thrombotic occurrences. The aim of this study was to evaluate efficacy and safety outcomes in patients undergoing venovenous (VV) ECMO receiving bivalirudin or UFH-based anticoagulation.

METHODS

This retrospective, single-center, observational cohort study included patients with confirmed COVID-19 infection requiring VV ECMO support receiving anticoagulation with UFH or bivalirudin. Primary endpoints were time to reach therapeutic aPTT, percent time spent in aPTT range, and the occurrence of thrombotic events over the entire course of ECMO support. Secondary endpoints included the incidence of major/minor bleeding, the ability to wean off ECMO support, in-hospital mortality, and length of stay.

RESULTS

Twenty-two patients were included in the study (n = 10 UFH, n = 12 bivalirudin). Time to therapeutic aPTT was achieved faster with UFH (10 h vs. 20 h). The percentage time spent within the goal aPTT range was similar between UFH and bivalirudin (50% vs. 52%). Thrombotic events were significantly higher in the UFH group (40% DVT, 40% PE, 80% oxygenator thrombus in ECMO machine, 10% ischemic stroke) versus bivalirudin (8% DVT, 17% PE, 33% oxygenator thrombus, no ischemic strokes) (CI 95%, p = 0.04). The overall bleeding incidence was higher in the UFH arm (90% vs. 75%). The mortality rate was 90% in the UFH group and 58% in the bivalirudin group. The length of stay was similar between the two study arms.

CONCLUSION

In hospitalized patients with COVID-19-associated acute respiratory distress syndrome (ARDS) on VV ECMO support, the use of bivalirudin showed to be a viable anticoagulation alternative in terms of efficacy compared to UFH and resulted in a favorable safety profile with lower rates of bleeding and thrombotic events.

COVID-19 outcomes of venovenous extracorporeal membrane oxygenation for acute respiratory failure vs historical cohort of non-COVID-19 viral infections

INTRODUCTION

Veno-venous extracorporeal membrane oxygenation (VV ECMO) has become a support modality for patients with acute respiratory failure refractory to standard therapies. VV ECMO has been increasingly used during the current COVID-19 pandemic for patients with refractory respiratory failure. The object of this study was to evaluate the outcomes of VV ECMO in patients with COVID-19 compared to patients with non-COVID-19 viral infections.

METHODS

We retrospectively reviewed all patients supported with VV ECMO between 8/2014 and 8/2020 whose etiology of illness was a viral pulmonary infection. The primary outcome of this study was to evaluate in-hospital mortality. The secondary outcomes included length of ECMO course, ventilator duration, hospital length of stay, incidence of adverse events through ECMO course.

RESULTS

Eighty-nine patients were included (35 COVID-19 vs 54 non-COVID-19). Forty (74%) of the non-COVID-19 patients had influenza virus. Prior to cannulation, COVID-19 patients had longer ventilator duration (3 vs 1 day, p = .003), higher PaCO2 (64 vs 53 mmHg, p = .012), and white blood cell count (14 vs 9 ×103/μL, p = .004). Overall in-hospital mortality was 33.7% (n = 30). COVID-19 patients had a higher mortality (49% vs. 24%, p = .017) when compared to non-COVID-19 patients. COVID-19 survivors had longer median time on ECMO than non-COVID-19 survivors (24.4 vs 16.5 days p = .03) but had a similar hospital length of stay (HLOS) (41 vs 48 Extracorporeal Membrane Oxygenationdays p = .33).

CONCLUSION

COVID-19 patients supported with VV ECMO have a higher mortality than non-COVID-19 patients. While COVID-19 survivors had significantly longer VV ECMO runs than non-COVID-19 survivors, HLOS was similar. This data add to a growing body of literature supporting the use of ECMO for potentially reversible causes of respiratory failure.

Body mass index does not impact survival in COVID-19 patients requiring veno-venous extracorporeal membrane oxygenation

INTRODUCTION

With the increased demand for veno-venous extracorporeal membrane oxygenation (VV ECMO) during the COVID-19 pandemic, guidelines for patient candidacy have often limited this modality for patients with a body mass index (BMI) less than 40 kg/m2. We hypothesize that COVID-19 VV ECMO patients with at least class III obesity (BMI ≥ 40) have decreased in-hospital mortality when compared to non-COVID-19 and non-class III obese COVID-19 VV ECMO populations.

METHODS

This is a single-center retrospective study of COVID-19 VV ECMO patients from January 1, 2014, to November 30, 2021. Our institution used BMI ≥ 40 as part of a multi-disciplinary VV ECMO candidate screening process in COVID-19 patients. BMI criteria were not considered for exclusion criteria in non-COVID-19 patients. Univariate and multivariable analyses were performed to assess in-hospital mortality differences.

RESULTS

A total of 380 patients were included in our analysis: The COVID-19 group had a lower survival rate that was not statistically significant (65.7% vs.74.9%, p = .07). The median BMI between BMI ≥ 40 COVID-19 and non-COVID-19 patients was not different (44.5 vs 45.5, p = .2). There was no difference in survival between the groups (73.3% vs. 78.5%, p = .58), nor was there a difference in survival between the COVID-19 BMI ≥ 40 and BMI < 40 patients (73.3, 62.7, p= .29). Multivariable logistic regression with the outcome of in-hospital mortality was performed and BMI was not found to be significant (OR 0.99, 95% CI 0.89, 1.01; p = .92).

CONCLUSION

BMI ≥ 40 was not an independent risk factor for decreased in-hospital survival in this cohort of VV ECMO patients at a high-volume center. BMI should not be the sole factor when deciding VV ECMO candidacy in patients with COVID-19.

Global scientific outputs of extracorporeal membrane oxygenation in COVID-19: A bibliometric overview

AIM

Although the number of global studies on ECMO, which is an important support system in the treatment of COVID-19 related respiratory failure, has increased in recent months, there is still no bibliometric study on the use of ECMO in COVID-19 in the literature. The aim of this study is to analyze the scientific articles on the use of ECMO in COVID-19 by statistical and bibliometric methods.

METHOD

Articles published between 2019-2022 about the use of ECMO in COVID-19 were obtained from the Web of Science (WoS) database and analyzed using statistical and bibliometric methods. Spearman correlation coefficient was used for correlation studies. Network visualization maps were used to identify effe analysis and trending topics.

RESULTS

A total of 1197 publications were found. 758 (63.3%) of these publications were articles. The top 3 contributing countries to the literature were USA (257, 33.9%), Germany (102, 13.4%) and Japan (87, 11.5%). The top 3 most active institutions were League of European Research Universities (90), Harvard University (50), and Udice French Research Universities (39). The top 3 journals with the highest count of publications were ASAIO Journal (n = 36), Frontiers in Medicine (22), and Perfusion-UK (n = 20). According to the average count of citations per article, the most influential journals were JAMA (1319), Intensive Care Medicine (327), and Lancet (95.7), respectively. We have shared a summary of 758 articles in this comprehensive bibliometric study on the use of ECMO in COVID-19.

CONCLUSION

It can be said that the use of ECMO in COVID-19 has been the trending topic recently and most of the studies are from countries in the ELSO Awards of Excellence list which indicates that the follow-up of ECMO in certain centers and teams can also be influencing the publications. This article can be a useful resource for clinicians, scientists, and students concerning global output for ECMO use in COVID-19.

Acute Formation of Thrombus on a Left Atrial Appendage Occlusion Device Immediately After Detachment

Clots can form on the left atrial surface of left atrial appendage closure devices, with subsequent thromboembolization. However, we are unaware of any reports of clots forming on the devices immediately after deployment. We report a case where an acute thrombus strand formed at the tip of an occlusion device immediately after deployment. (Level of Difficulty: Intermediate.).

T cell immune response predicts survival in severely ill COVID-19 patients requiring venovenous extracorporeal membrane oxygenation support

Introduction

There is a critical gap in understanding which SARS-CoV-2 patients would benefit most from venovenous extracorporeal membrane oxygenation (VV-ECMO) support. The potential role of a dysregulated immune response is still unclear in this patient population.

Objectives

To assess the potential predictive value of SARS-CoV-2 specific cellular and humoral immune responses for survival in critically ill COVID-19 patients requiring VV-ECMO.

Methods

We conducted a prospective single-center observational study of unvaccinated patients requiring VV-ECMO support treated at the intensive care unit of Semmelweis University Heart and Vascular Center between March and December 2021. Peripheral blood samples were collected to measure the humoral and cellular immune statuses of the patients at the VV-ECMO cannulation. Patients were followed until hospital discharge.

Results

Overall, 35 COVID-19 patients (63% men, median age 37 years) on VV-ECMO support were included in our study. The time from COVID-19 verification to ECMO support was a median (IQR) of 10 (7-14) days. Of the patients, 9 (26%) were discharged alive and 26 (74%) died during their hospital stay. Immune tests confirmed ongoing SARS-CoV-2 infection in all the patients, showing an increased humoral immune response. SARS-CoV-2-specific cellular immune response was significantly higher among survivors compared to the deceased patients. A higher probability of survival was observed in patients with markers indicating a higher T cell response detected by both QuantiFeron (QF) and flow cytometry (Flow) assays. (Flow S1 CD8+ ≥ 0.15%, Flow S1 CD4+ ≥ 0.02%, QF CD4 ≥ 0.07, QF whole genome ≥ 0.59). In univariate Cox proportional hazard regression analysis BMI, right ventricular (RV) failure, QF whole genome T cell level, and Flow S1 CD8+ T cell level were associated with mortality, and we found that an increased T cell response showed a significant negative association with mortality, independent of BMI and RV failure.

Conclusion

Evaluation of SARS-CoV-2 specific T cell response before the cannulation can aid the risk stratification and evaluation of seriously ill COVID-19 patients undergoing VV-ECMO support by predicting survival, potentially changing our clinical practice in the future.

Body mass index is not associated with time on veno-venous extracorporeal membrane oxygenation or in-hospital mortality

Morbid obesity, as characterized by BMI, is often utilized as an exclusion criterion for VV-ECMO because of presumed poor prognosis and technically complex cannulation. However, the "obesity paradox" suggests obesity may be protective during critical illness, and BMI does not capture variations in body type, adiposity, or fluid balance. This study examines relationships between BMI and patient outcomes. Adult VV-ECMO patients with BMI ≥ 35 kg/m2 admitted January 2012 to June 2021 were identified from an institutional registry. BMI and outcomes were analyzed with Mann-Whitney U tests and Pearson correlations with Bayesian post-hoc analyses. 116 of 960 ECMO patients met inclusion criteria. Median (Q1, Q3) BMI was 42.3 (37.3, 50.8) and min, max of 35.0, 87.8 with 9.0 (5.0, 15.5) ECMO days. BMI was not significantly correlated with ECMO days (r = -0.102; p = .279). Bayesian analyses showed moderate evidence against BMI correlating with ECMO days. In-hospital mortality (27%) was significantly associated with ECMO days (p = .014) but not BMI (p = .485). In this cohort of high-BMI patients, BMI was not associated with survival or time on ECMO. BMI itself should not be used as an exclusion criterion for VV-ECMO.

Association between obesity and mortality in critically ill COVID-19 patients requiring invasive mechanical ventilation: a multicenter retrospective observational study

This study aimed to determine whether obesity and disease outcomes are associated in patients with critically-ill coronavirus disease 2019 (COVID-19) requiring invasive mechanical ventilation (IMV). This retrospective observational study using Japanese multicenter registry data included COVID-19 patients who required IMV and were discharged between January and September 2020. The patients were divided into the obese (body mass index [BMI] ≥ 25 kg/m²) and nonobese (BMI < 25 kg/m²) groups. Logistic regression models were used to analyze the association between obesity and disease outcomes. The primary outcome was in-hospital mortality; the secondary outcome was venovenous extracorporeal membrane oxygenation (VV-ECMO) implementation. Altogether, 477 patients were enrolled (obese, n = 235, median BMI, 28.2 kg/m²; nonobese, n = 242, median BMI, 22.4 kg/m²). Obesity was significantly associated with lower in-hospital mortality in the unadjusted logistic regression model (odds ratio 0.63; 95% confidence interval, 0.42-0.97; p = 0.033), but not with mortality in the adjusted logistic regression model using age, sex, and Charlson Comorbidity Index as covariates (p = 0.564). Obesity was not associated with VV-ECMO implementation in both unadjusted and adjusted models (unadjusted, p = 0.074; adjusted, p = 0.695). Obesity was not associated with outcomes in COVID-19 patients requiring IMV. Obesity may not be a risk factor for poor outcomes in these patients.

Reduced anticoagulation strategy is associated with a lower incidence of intracerebral hemorrhage in COVID-19 patients on extracorporeal membrane oxygenation

BACKGROUND

Optimal anticoagulation strategies for COVID-19 patients with the acute respiratory distress syndrome (ARDS) on venovenous extracorporeal membrane oxygenation (VV ECMO) remain uncertain. A higher incidence of intracerebral hemorrhage (ICH) during VV ECMO support compared to non-COVID-19 viral ARDS patients has been reported, with increased bleeding rates in COVID-19 attributed to both intensified anticoagulation and a disease-specific endotheliopathy. We hypothesized that lower intensity of anticoagulation during VV ECMO would be associated with a lower risk of ICH. In a retrospective, multicenter study from three academic tertiary intensive care units, we included patients with confirmed COVID-19 ARDS requiring VV ECMO support from March 2020 to January 2022. Patients were grouped by anticoagulation exposure into higher intensity, targeting anti-factor Xa activity (anti-Xa) of 0.3-0.4 U/mL, versus lower intensity, targeting anti-Xa 0.15-0.3 U/mL, cohorts. Mean daily doses of unfractionated heparin (UFH) per kg bodyweight and effectively measured daily anti-factor Xa activities were compared between the groups over the first 7 days on ECMO support. The primary outcome was the rate of ICH during VV ECMO support.

RESULTS

141 critically ill COVID-19 patients were included in the study. Patients with lower anticoagulation targets had consistently lower anti-Xa activity values over the first 7 ECMO days (p < 0.001). ICH incidence was lower in patients in the lower anti-Xa group: 4 (8%) vs 32 (34%) events. Accounting for death as a competing event, the adjusted subhazard ratio for the occurrence of ICH was 0.295 (97.5% CI 0.1-0.9, p = 0.044) for the lower anti-Xa compared to the higher anti-Xa group. 90-day ICU survival was higher in patients in the lower anti-Xa group, and ICH was the strongest risk factor associated with mortality (odds ratio [OR] 6.8 [CI 2.1-22.1], p = 0.001).

CONCLUSIONS

For COVID-19 patients on VV ECMO support anticoagulated with heparin, a lower anticoagulation target was associated with a significant reduction in ICH incidence and increased survival.

Extracorporeal Membrane Oxygenation to Support COVID-19 Patients: A Propensity-Matched Cohort Study

Background

In patients with severe respiratory failure from COVID-19, extracorporeal membrane oxygenation (ECMO) treatment can facilitate lung-protective ventilation and may improve outcome and survival if conventional therapy fails to assure adequate oxygenation and ventilation. We aimed to perform a confirmatory propensity-matched cohort study comparing the impact of ECMO and maximum invasive mechanical ventilation alone (MVA) on mortality and complications in severe COVID-19 pneumonia.

Materials and Methods

All 295 consecutive adult patients with confirmed COVID-19 pneumonia admitted to the intensive care unit (ICU) from March 13^th, 2020, to July 31^st, 2021 were included. At admission, all patients were classified into 3 categories: (1) full code including the initiation of ECMO therapy (AAA code), (2) full code excluding ECMO (AA code), and (3) do-not-intubate (A code). For the 271 non-ECMO patients, match eligibility was determined for all patients with the AAA code treated with MVA. Propensity score matching was performed using a logistic regression model including the following variables: gender, P/F ratio, SOFA score at admission, and date of ICU admission. The primary endpoint was ICU mortality.

Results

A total of 24 ECMO patients were propensity matched to an equal number of MVA patients. ICU mortality was significantly higher in the ECMO arm (45.8%) compared with the MVA cohort (16.67%) (OR 4.23 (1.11, 16.17); p=0.02). Three-month mortality was 50% with ECMO compared to 16.67% after MVA (OR 5.91 (1.55, 22.58); p < 0.01). Applied peak inspiratory pressures (33.42 ± 8.52 vs. 24.74 ± 4.86 mmHg; p < 0.01) and maximal PEEP levels (14.47 ± 3.22 vs. 13.52 ± 3.86 mmHg; p=0.01) were higher with MVA. ICU length of stay (LOS) and hospital LOS were comparable in both groups.

Conclusion

ECMO therapy may be associated with an up to a three-fold increase in ICU mortality and 3-month mortality compared to MVA despite the facilitation of lung-protective ventilation settings in mechanically ventilated COVID-19 patients. We cannot confirm the positive results of the first propensity-matched cohort study on this topic. This trial is registered with NCT05158816.

Outcomes of patients with coronavirus disease versus other lung infections requiring venovenous extracorporeal membrane oxygenation

Background

Patients with Coronavirus Disease (COVID-19) often develop severe acute respiratory distress syndrome (ARDS) requiring prolonged mechanical ventilation (MV), and venovenous extracorporeal membrane oxygenation (V-V ECMO).Mortality in COVID-19 patients on V-V ECMO was exceptionally high; therefore, whether survival can be ameliorated should be investigated.

Methods

We collected data from 85 patients with severe ARDS who required ECMO support at the University Hospital Magdeburg from 2014 to 2021. The patients were divided into the COVID-19 group (52 patients) and the non-COVID-19 group (33 patients). Demographic and pre-, intra-, and post-ECMO data were retrospectively recorded. The parameters of mechanical ventilation, laboratory data before using ECMO, and during ECMO were compared.

Results

There was a significant difference between the two groups regarding survival: 38.5% of COVID-19 patients and 63.6% of non-COVID-19 patients survived 60 days (p = 0.024). COVID-19 patients required V-V ECMO after 6.5 days of MV, while non-COVID-19 patients required V-V ECMO after 2.0 days of MV (p = 0.048). The COVID-19 group had a greater proportion of patients with ischemic heart disease (21.2% vs 3%, p = 0.019). The rates of most complications were comparable in both groups, whereas the COVID-19 group showed a significantly higher rate of cerebral bleeding (23.1 vs 6.1%, p = 0.039) and lung bacterial superinfection (53.8% vs 9.1%, p = <0.001).

Conclusion

The higher 60-days mortality among patients with COVID-19 with severe ARDS was attributable to superinfection, a higher risk of intracerebral bleeding, and the pre-existing ischemic heart disease.

Extracorporeal Membrane Oxygenation for Severe COVID-19 in Indian Scenario: A Single Center Retrospective Study

Background

Initial reports from Wuhan (China) suggested poor outcomes for severe COVID-19 patients treated with Extracorporeal Membrane Oxygenation (ECMO). Extracorporeal Life Support Organization (ELSO) interim 2019 guidelines also recommended using ECMO only when all conventional therapies are exhausted. However, later studies showed that delayed ECMO initiation may lead to longer ECMO runs, offsetting any benefit from resource conservation by delaying the initiation. Hence, this study was intended to analyze the sociodemographic characteristics, type of ECMO, and complications of its outcome in the Indian scenario.

Materials and methods

Demographic and patient clinical outcome data of all the patients of severe ARDS due to COVID-19 being treated with ECMO from 1st June 2020 to 31st May 2021 at Medica Super-specialty Hospital (Kolkata, India), were retrospectively compiled and analyzed.

Results

Total number of patients treated was 79 with 10% female representation. The mean age was 43 ± 3.2 years and the mean body mass index 37 ± 4.3. Fifty percent of the patient survived. The mean duration of the ECMO run was 17 ± 5.2 days. Sepsis (65%) was the commonest complication observed followed by acute kidney injury (39%).

Conclusion

This study provides significant insight into the outcomes of patients of COVID-19 treated by ECMO in the Indian scenario. Mortality rates of COVID-19 patients on ECMO were comparable to the non-COVID-19 patients, although the ECMO run time was relatively longer. Our study concluded that ECMO should be considered as a treatment option in appropriate COVID-19 cases. However, if the capacity diminishes in a pandemic situation, ECMO consideration should be based on more stringent criteria.

How to cite this article

Sulakshana S, Chatterjee D, Chakraborty A. Extracorporeal Membrane Oxygenation for Severe COVID-19 in Indian Scenario: A Single Center Retrospective Study. Indian J Crit Care Med 2023;27(6):381-385.

Extracorporeal Membrane Oxygenation Characteristics and Outcomes in Children and Adolescents With COVID-19 or Multisystem Inflammatory Syndrome Admitted to U.S. ICUs

OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) has been used successfully to support adults with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related cardiac or respiratory failure refractory to conventional therapies. Comprehensive reports of children and adolescents with SARS-CoV-2-related ECMO support for conditions, including multisystem inflammatory syndrome in children (MIS-C) and acute COVID-19, are needed.

DESIGN

Case series of patients from the Overcoming COVID-19 public health surveillance registry.

SETTING

Sixty-three hospitals in 32 U.S. states reporting to the registry between March 15, 2020, and December 31, 2021.

PATIENTS

Patients less than 21 years admitted to the ICU meeting Centers for Disease Control criteria for MIS-C or acute COVID-19.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The final cohort included 2,733 patients with MIS-C ( n = 1,530; 37 [2.4%] requiring ECMO) or acute COVID-19 ( n = 1,203; 71 [5.9%] requiring ECMO). ECMO patients in both groups were older than those without ECMO support (MIS-C median 15.4 vs 9.9 yr; acute COVID-19 median 15.3 vs 13.6 yr). The body mass index percentile was similar in the MIS-C ECMO versus no ECMO groups (89.9 vs 85.8; p = 0.22) but higher in the COVID-19 ECMO versus no ECMO groups (98.3 vs 96.5; p = 0.03). Patients on ECMO with MIS-C versus COVID-19 were supported more often with venoarterial ECMO (92% vs 41%) for primary cardiac indications (87% vs 23%), had ECMO initiated earlier (median 1 vs 5 d from hospitalization), shorter ECMO courses (median 3.9 vs 14 d), shorter hospital length of stay (median 20 vs 52 d), lower in-hospital mortality (27% vs 37%), and less major morbidity at discharge in survivors (new tracheostomy, oxygen or mechanical ventilation need or neurologic deficit; 0% vs 11%, 0% vs 20%, and 8% vs 15%, respectively). Most patients with MIS-C requiring ECMO support (87%) were admitted during the pre-Delta (variant B.1.617.2) period, while most patients with acute COVID-19 requiring ECMO support (70%) were admitted during the Delta variant period.

CONCLUSIONS

ECMO support for SARS-CoV-2-related critical illness was uncommon, but type, initiation, and duration of ECMO use in MIS-C and acute COVID-19 were markedly different. Like pre-pandemic pediatric ECMO cohorts, most patients survived to hospital discharge.

Right Ventricular Perforation Leading to Sudden Death Due to Extracorporeal Membrane Oxygenation (ECMO) Canula Dislodgement

ECMO has been playing an increasingly important role in the management of coronavirus disease (COVID-19)-related acute respiratory distress syndrome (ARDS). However, despite its potential benefits, high mortality rates are still being reported worldwide. Herein, we report the case of a 32-year-old male who presented with worsening shortness of breath secondary to COVID-19. Unfortunately, he experienced a sentinel event when the cannula became dislodged due to coughing, which led to a right ventricular perforation and sudden pulseless electrical activity (PEA) cardiac arrest.

Inadequate Energy Delivery Is Frequent among COVID-19 Patients Requiring ECMO Support and Associated with Increased ICU Mortality

BACKGROUND

Patients receiving extracorporeal membrane oxygenation (ECMO) support are at high risk for malnutrition. There are currently no general nutrition guidelines for coronavirus disease 2019 (COVID-19) patients during ECMO therapy.

METHODS

We conducted a retrospective analysis of COVID-19 patients requiring venovenous ECMO support at a large tertiary hospital center. Nutrition goals were calculated using 25 kcal/kg body weight (BW)/day. Associations between nutrition support and outcome were evaluated using Kaplan-Meier and multivariable Cox regression analyses.

RESULTS

Overall, 102 patients accounted for a total of 2344 nutrition support days during ECMO therapy. On 40.6% of these days, nutrition goals were met. Undernutrition was found in 40.8%. Mean daily calorie delivery was 73.7% of calculated requirements, mean daily protein delivery was 0.7 g/kg BW/d. Mean energy intake of ≥70% of calculated targets was associated with significantly lower ICU mortality independently of age, disease severity at ECMO start and body mass index (adjusted hazard ratio: 0.372, p = 0.007).

CONCLUSIONS

Patients with a mean energy delivery of ≥70% of calculated targets during ECMO therapy had a better ICU survival compared to patients with unmet energy goals. These results indicate that adequate nutritional support needs to be a major priority in the treatment of COVID-19 patients requiring ECMO support.

Right ventricle dysfunction does not predict mortality in patients with SARS-CoV-2-related acute respiratory distress syndrome on extracorporeal membrane oxygenation support

BACKGROUND

The prognostic role of right ventricle dilatation and dysfunction (RVDD) has not been elucidated in patients with coronavirus disease (COVID)-related respiratory failure refractory to standard treatment needing extracorporeal membrane oxygenation (ECMO) support.

AIM

To assess whether pre veno-venous (VV) ECMO RVDD were related to in-intensive care unit (ICU) mortality.

METHODS

We enrolled 61 patients with COVID-related acute respiratory distress syndrome refractory to conventional treatment submitted to VV ECMO and consecutively admitted to our ICU (an ECMO referral center) from 31^th March 2020 to 31^th August 2021. An echocardiographic exam was performed immediately before VV ECMO implantation.

RESULTS

Males were prevalent (73.8%) and patients with a body mass index > 30 kg/m² were the majority (46/61, 75%). The overall in-ICU mortality rate was 54.1% (33/61). RVDD was detectable in more than half of the population (34/61, 55.7%) and associated with higher simplified organ functional assessment (SOFA) values (P = 0.029) and a longer mechanical ventilation duration prior to ECMO support (P = 0.046). Renal replacement therapy was more frequently needed in RVDD patients (P = 0.002). A higher in-ICU mortality (P = 0.024) was observed in RVDD patients. No echo variables were independent predictors of in-ICU death.

CONCLUSION

In patients with COVID-related respiratory failure on ECMO support, RVDD (dilatation and dysfunction) is a common finding and identifies a subset of patients characterized by a more severe disease (as indicated by higher SOFA values and need of renal replacement therapy) and by a higher in-ICU mortality. RVDD (also when considered separately) did not result independently associated with in-ICU mortality in these patients.

Multi-horizon predictive models for guiding extracorporeal resource allocation in critically ill COVID-19 patients

OBJECTIVE

Extracorporeal membrane oxygenation (ECMO) resource allocation tools are currently lacking. We developed machine learning (ML) models for predicting COVID-19 patients at risk of receiving ECMO to guide patient triage and resource allocation.

MATERIAL AND METHODS

We included COVID-19 patients admitted to intensive care units for >24 h from March 2020 to October 2021, divided into training and testing development and testing-only holdout cohorts. We developed ECMO deployment timely prediction model ForecastECMO using Gradient Boosting Tree (GBT), with pre-ECMO prediction horizons from 0 to 48 h, compared to PaO2/FiO2 ratio, Sequential Organ Failure Assessment score, PREdiction of Survival on ECMO Therapy score, logistic regression, and 30 pre-selected clinical variables GBT Clinical GBT models, with area under the receiver operator curve (AUROC) and precision recall curve (AUPRC) metrics.

RESULTS

ECMO prevalence was 2.89% and 1.73% in development and holdout cohorts. ForecastECMO had the best performance in both cohorts. At the 18-h prediction horizon, a potentially clinically actionable pre-ECMO window, ForecastECMO, had the highest AUROC (0.94 and 0.95) and AUPRC (0.54 and 0.37) in development and holdout cohorts in identifying ECMO patients without data 18 h prior to ECMO.

DISCUSSION AND CONCLUSIONS

We developed a multi-horizon model, ForecastECMO, with high performance in identifying patients receiving ECMO at various prediction horizons. This model has potential to be used as early alert tool to guide ECMO resource allocation for COVID-19 patients. Future prospective multicenter validation would provide evidence for generalizability and real-world application of such models to improve patient outcomes.

Hemodynamic oxygenator exchange-related effects during veno-venous extracorporeal membrane oxygenation for the treatment of acute SARS-CoV-2 respiratory distress syndrome

Few patients with coronavirus disease 2019-associated severe acute respiratory distress syndrome (ARDS) require veno-venous extracorporeal membrane oxygenation (VV-ECMO). Prolonged VV-ECMO support necessitates repeated oxygenator replacement, increasing the risk for complications. Transient hypoxemia, induced by VV-ECMO stop needed for this procedure, may induce transient myocardial ischemia and acutely declining cardiac output in critically ill patients without residual pulmonary function. This is amplified by additional activation of the sympathetic nervous system (tachycardia, pulmonary vasoconstriction, and increased systemic vascular resistance). Immediate reinjection of the priming solution of the new circuit and induced acute iatrogenic anemia are other potentially reinforcing factors. The case of a critically ill patient presented here provides an instructive illustration of the hemodynamic relationships occurring during VV-ECMO support membrane oxygenator exchange.