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

COVID-19 Drug Treatments Are Prone to Sequestration in Extracorporeal Membrane Oxygenation Circuits: An Ex Vivo Extracorporeal Membrane Oxygenation Study

Drug treatments for coronavirus disease 2019 (COVID-19) dramatically improve patient outcomes, and although extracorporeal membrane oxygenation (ECMO) has significant use in these patients, it is unknown whether ECMO affects drug dosing. We used an ex vivo adult ECMO model to measure ECMO circuit effects on concentrations of specific COVID-19 drug treatments. Three identical ECMO circuits used in adult patients were set up. Circuits were primed with fresh human blood (temperature and pH maintained within normal limits). Three polystyrene jars with 75 ml fresh human blood were used as controls. Remdesivir, GS-441524, nafamostat, and tocilizumab were injected in the circuit and control jars at therapeutic concentrations. Samples were taken from circuit and control jars at predefined time points over 6 h and drug concentrations were measured using validated assays. Relative to baseline, mean (± standard deviation [SD]) study drug recoveries in both controls and circuits at 6 h were significantly lower for remdesivir (32.2% [±2.7] and 12.4% [±2.1], p < 0.001), nafamostat (21.4% [±5.0] and 0.0% [±0.0], p = 0.018). Reduced concentrations of COVID-19 drug treatments in ECMO circuits is a clinical concern. Remdesivir and nafamostat may need dose adjustments. Clinical pharmacokinetic studies are suggested to guide optimized COVID-19 drug treatment dosing during ECMO.

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

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

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.

Persistent Critical Illness and Long-Term Outcomes in Patients With COVID-19: A Multicenter Retrospective Cohort Study

OBJECTIVES

A nontrivial number of patients in ICUs experience persistent critical illness (PerCI), a phenomenon in which features of the ICU course more consistently predict mortality than the initial indication for admission. We aimed to describe PerCI among patients with critical illness caused by COVID-19, and these patients' short- and long-term outcomes.

DESIGN

Multicenter retrospective cohort study.

SETTING

Australian and New Zealand Intensive Care Society Adult Patient Database of 114 Australian ICUs between January 1, 2020, and March 31, 2022.

PATIENTS

Patients 16 years old or older with COVID-19, and a documented ICU length of stay.

EXPOSURE

The presence of PerCI, defined as an ICU length of stay greater than or equal to 10 days.

MEASUREMENTS

We compared the survival time up to 2 years from ICU admission using time-varying robust-variance estimated Cox proportional hazards models. We further investigated the impact of PerCI in subgroups of patients, stratifying based on whether they survived their initial hospitalization.

MAIN RESULTS

We included 4961 patients in the final analysis, and 882 patients (17.8%) had PerCI. ICU mortality was 23.4% in patients with PerCI and 6.5% in those without PerCI. Patients with PerCI had lower 2-year (70.9% [95% CI, 67.9-73.9%] vs. 86.1% [95% CI, 85.0-87.1%]; p < 0.001) survival rates compared with patients without PerCI. Patients with PerCI had higher mortality (adjusted hazards ratio: 1.734; 95% CI, 1.388-2.168); this was consistent across several sensitivity analyses. When analyzed as a nonlinear predictor, the hazards of mortality were inconsistent up until 10 days, before plateauing.

CONCLUSIONS

In this multicenter retrospective observational study patients with PerCI tended to have poorer short-term and long-term outcomes. However, the hazards of mortality plateaued beyond the first 10 days of ICU stay. Further studies should investigate predictors of developing PerCI, to better prognosticate long-term outcomes.

Age and associated outcomes among patients receiving venovenous extracorporeal membrane oxygenation for acute respiratory failure: analysis of the Extracorporeal Life Support Organization registry

PURPOSE

Venovenous extracorporeal membrane oxygenation (VV-ECMO) can be used to support patients with refractory acute respiratory failure, though guidance on patient selection is lacking. While age is commonly utilized as a factor in establishing the potential VV-ECMO candidacy of these patients, little is known regarding its association with outcome. We studied the association between increasing patient age and outcomes among patients with acute respiratory failure receiving VV-ECMO.

METHODS

In this registry-based cohort study, we used individual patient data from 144 centres. We included adult patients (≥ 18 years of age) receiving VV-ECMO from 2017 to 2022. The primary outcome was hospital mortality. Secondary outcomes included a composite of complications following initiation of VV-ECMO. We conducted Bayesian analyses to estimate the association between chronological age and outcomes.

RESULTS

We included 27,811 patients receiving VV-ECMO. Of these, 11,533 (41.5%) died in hospital. For the analysis conducted using weakly informed priors, and as compared to the reference category of age 18-29, the age brackets of 30-39 (odds ratio [OR] 1.17, 95% credible interval [CrI] 1.06-1.31), 40-49 (OR 1.65, 95% CrI 1.49-1.82), 50-59 (OR 2.39, 95% CrI 2.16-2.61), 60-69 (OR 3.29, 95% CrI 2.97-3.67), 70-79 (OR 4.57, 95% CrI 3.90-5.37), and ≥ 80 (OR 8.08, 95% CrI 4.85-13.74) were independently associated with increasing hospital mortality. Similar results were found between increasing age and post-ECMO complications.

CONCLUSIONS

Among patients receiving VV-ECMO for acute respiratory failure, increasing age is significantly associated with poorer outcomes, and this association emerges as early as 30 years of age.

Single-center experience of temporary-permanent pacemaker use in COVID-19 patients supported with veno-venous ECMO: A case series

INTRODUCTION

In the first year of the COVID-19 pandemic, nine out of 129 patients (7%) developed life-threatening bradycardia episodes ultimately requiring a TPPM, whilst being supported with VV-ECMO for severe COVID-19 ARDS in our tertiary cardio-pulmonary failure center.

ANALYSIS

All subjects had asystole due to sinus node dysfunction and experienced at least one episode involving cardiopulmonary resuscitation. Most bradycardic events were seen in the context of vagal hypersensitivity. Mean time from general ICU admission to TPPM insertion was 20.6 ± 8.9 days. One patient developed a large chest wall hematoma weeks after TPPM implantation, no other TPPM-related issues were observed. No patient required a long-term pacing system. Six-months survival rate was high (89%).

CONCLUSION

These findings suggested that transient life-threatening sinus node disease is not uncommon in ECMO-dependent COVID-19 ARDS patients. TPPM with an active fixation lead is sometimes needed to facilitate ongoing ICU care, however, long-term permanent pacing was not required.

ERS International Congress 2023: highlights from the Respiratory Intensive Care Assembly

Early career members of Assembly 2 (Respiratory Intensive Care) attended the 2023 European Respiratory Society International Congress in Milan, Italy. The conference covered acute and chronic respiratory failure. Sessions of interest to our assembly members and to those interested in respiratory critical care are summarised in this article and include the latest updates in respiratory intensive care, in particular acute respiratory distress syndrome and mechanical ventilation.

Outcomes of ECMO support with polypropylene membrane during pandemic times: a retrospective cohort study

BACKGROUND

The SARS-CoV-2 pandemic resulted in shortages of supplies, which limited the use of extracorporeal membrane oxygenation (ECMO) support. As a contingency strategy, polypropylene (PP) oxygenation membranes were used. This study describes the clinical outcomes in patients on ECMO with PP compared to poly-methylpentene (PMP) oxygenation membranes.

METHODS

Retrospective cohort of patients in ECMO support admitted between 2020 and 2021.

RESULTS

A total of 152 patients with ECMO support were included, 71.05% were men with an average age of 42 (SD 9.91) years. Veno-venous configuration was performed in 75.6% of cases. The PP oxygenation membranes required more changes 22 (63.1%), than the PMP Sorin® 24 (32,8%) and Euroset® 15 (31,9%) (p.0.022). The main indication for membrane change was low oxygen transfer for PP at 56.2%, Sorin® at 50%, and Euroset® at 14.8%. Renal replacement therapy was the most frequent complication with PP membrane in 22 patients (68.7%) Sorin® 25 patients (34.2%), and Euroset® 15 patients (31.9%) (p 0.001) without statistically significant differences in mortality.

CONCLUSION

PP oxygenation membranes was a useful and feasible strategy. It allowed a greater disponibility of ECMO support for critically ill in a situation of great adversity during the SARS-CoV-2 pandemic.

An Integrative Review: Evaluating the Risks, Benefits, and Efficacy of Extracorporeal Membrane Oxygenation (ECMO) in Treating ARDS Secondary to COVID-19

The onset of the COVID-19 pandemic has led to an increased use of extracorporeal membrane oxygenation (ECMO) for severe acute respiratory distress syndrome (ARDS); however, there are ongoing concerns about its associated risks and benefits, making a comprehensive understanding vital for clinical decision-making. This review aims to evaluate the efficacy, risks, and practical implications of ECMO as a therapeutic intervention in severe ARDS secondary to COVID-19. The results indicate that ECMO is a key therapeutic intervention for managing severe COVID-19, but due to its associated risks and resource constraints, its application needs careful consideration. Nurse practitioners need to acquire specialized skills to manage ECMO and stay updated with ongoing research and revised protocols. Given the potential for future virus mutations or pandemics, and finite resources, a multidisciplinary approach to ECMO therapy is necessary. Careful patient selection, strategic resource allocation, and continuous education are pivotal elements for improved patient outcomes.

A Comprehensive Review of Extra Corporeal Membrane Oxygenation: The Lifeline in Critical Moments

Extracorporeal membrane oxygenation (ECMO) has evolved into a pivotal intervention in critical care, offering a lifeline for patients facing severe respiratory or cardiac failure. This review provides a comprehensive exploration of ECMO, spanning its definition and historical background to its contemporary advancements and ongoing impact in critical care. The versatility of ECMO in addressing diverse critical conditions, careful patient selection criteria, and the nuanced management of complications are discussed. Advances in technology, including miniaturization, novel circuit designs, and the integration of remote monitoring, showcase the evolving landscape of ECMO. The review underscores the ongoing impact of ECMO in improving survival rates, enhancing mobility, and enabling remote expertise. As a symbol of hope and innovation, ECMO's lifesaving potential is evident in its ability to navigate the complexities of critical care and redefine the boundaries of life support interventions.

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.

Outcomes of patients with COVID-19 supported by venovenous extracorporeal membrane oxygenation for greater than 90 days

Objective

To determine the characteristics and outcomes of patients requiring prolonged (>90 days) venovenous extracorporeal membrane oxygenation (VV ECMO) support for refractory Coronavirus disease 2019 (COVID-19)-associated respiratory failure.

Methods

A retrospective, observational analysis of consecutive patients requiring VV ECMO for COVID-19-associated respiratory failure was performed at a single institution between March 2020 and January 2022. Data were collected from the medical records. Patients were predominantly cannulated and supported long-term with a single, dual-lumen cannula in the internal jugular vein with the tip positioned in the pulmonary artery. All patients were managed with an awake VV ECMO approach, emphasizing avoidance of sedatives, extubation, ambulation, physical therapy, and nutrition. Patients requiring >90 days of ECMO were identified, analyzed, and compared to those needing a shorter duration of support.

Results

A total of 44 patients were supported on VV ECMO during the study period, of whom 36 (82%) survived to discharge. Thirty-one patients were supported for <90 days, of whom 28 (90%) were discharged alive. Thirteen patients required >90 days of ECMO. All patients were extubated. Eight patients (62%) survived to discharge, with 1 patient requiring lung transplantation prior to decannulation. All survivors were free from mechanical ventilation and alive at a 6-month follow-up. Of the 4 patients who died on prolonged ECMO, 2 developed hemothorax necessitating surgery and 2 succumbed to fatal intracranial hemorrhage.

Conclusions

Patients treated with VV ECMO for COVID-19-associated respiratory failure may require prolonged support to recover. Extubation, ambulation, aggressive rehabilitation, and nutritional support while on ECMO can yield favorable outcomes.

COVID-19 versus Other Disease Etiologies as the Cause of ARDS in Patients Necessitating Venovenous Extracorporeal Membrane Oxygenation-A Comparison of Patients' Data during the Three Years of the COVID-19 Pandemic

Considering the characteristics of coronavirus disease 2019 (COVID-19) acute respiratory distress syndrome (ARDS), we compared the clinical course and outcomes of patients with ARDS who received venovenous extracorporeal membrane oxygenation (VV ECMO) based on the etiology of ARDS. This retrospective single-center study included adult patients with severe ARDS necessitating VV ECMO during the COVID-19 pandemic. Among 45 patients who received VV ECMO, 21 presented with COVID-19. COVID-19 patients exhibited lower sequential organ failure assessment scores (9 [8-12.75] versus 8 [4-11.5], p = 0.033) but longer duration of VV ECMO support (10.5 days [3.25-29.25] versus 28 days [10.5-70.5] p = 0.018), which was accompanied by an weaning off rate from VV ECMO in 12/24 (50%) versus 12/21 (57.1%) and 28-day mortality in 9/24 [37.5%] versus 2/21 [9.5%] in non-COVID-19 and COVID-19 patients (p = 0.767, p = 0.040), respectively. Finally, in the adjusted Cox regression model for hospital mortality, the hazard ratio of COVID-19 was not significant (hazard ratio 0.350, 95% confidence interval 0.110-1.115, p = 0.076). Although the VV ECMO period was longer, COVID-19 did not significantly impact ECMO weaning off and mortality rates. Nonetheless, judicious patient selections based on risk factors should be followed.

Validation of extracorporeal membrane oxygenation mortality prediction and severity of illness scores in an international COVID-19 cohort

BACKGROUND

Veno-venous extracorporeal membrane oxygenation (V-V ECMO) is a lifesaving support modality for severe respiratory failure, but its resource-intensive nature led to significant controversy surrounding its use during the COVID-19 pandemic. We report the performance of several ECMO mortality prediction and severity of illness scores at discriminating survival in a large COVID-19 V-V ECMO cohort.

METHODS

We validated ECMOnet, PRESET (PREdiction of Survival on ECMO Therapy-Score), Roch, SOFA (Sequential Organ Failure Assessment), APACHE II (acute physiology and chronic health evaluation), 4C (Coronavirus Clinical Characterisation Consortium), and CURB-65 (Confusion, Urea nitrogen, Respiratory Rate, Blood Pressure, age >65 years) scores on the ISARIC (International Severe Acute Respiratory and emerging Infection Consortium) database. We report discrimination via Area Under the Receiver Operative Curve (AUROC) and Area under the Precision Recall Curve (AURPC) and calibration via Brier score.

RESULTS

We included 1147 patients and scores were calculated on patients with sufficient variables. ECMO mortality scores had AUROC (0.58-0.62), AUPRC (0.62-0.74), and Brier score (0.286-0.303). Roch score had the highest accuracy (AUROC 0.62), precision (AUPRC 0.74) yet worst calibration (Brier score of 0.3) despite being calculated on the fewest patients (144). Severity of illness scores had AUROC (0.52-0.57), AURPC (0.59-0.64), and Brier Score (0.265-0.471). APACHE II had the highest accuracy (AUROC 0.58), precision (AUPRC 0.64), and best calibration (Brier score 0.26).

CONCLUSION

Within a large international multicenter COVID-19 cohort, the evaluated ECMO mortality prediction and severity of illness scores demonstrated inconsistent discrimination and calibration highlighting the need for better clinically applicable decision support tools.

Thoracic Epidural Anesthesia in Cardiac Surgery: A Systematic Review, Meta-Analysis, and Trial Sequential Analysis of Randomized Controlled Trials

BACKGROUND

Research on fast-track recovery protocols postulates that thoracic epidural anesthesia (TEA) in cardiac surgery contributes to improved postoperative outcomes. However, concerns about TEA's safety hinder its widespread usage. We conducted a systematic review and meta-analysis to assess the benefits and risks of TEA in cardiac surgery.

METHODS

We searched 4 databases for randomized controlled trials (RCTs) assessing the use of TEA against only general anesthesia (GA) in adults undergoing cardiac surgery, up till June 4, 2022. We conducted random-effects meta-analyses, evaluated risk of bias using the Cochrane Risk-of-Bias 2 tool, and rated certainty of evidence via the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. Primary outcomes were intensive care unit (ICU), hospital length of stay, extubation time (ET), and mortality. Other outcomes included postoperative complications. Trial sequential analysis (TSA) was conducted on all outcomes to elicit statistical and clinical benefit.

RESULTS

Our meta-analysis included 51 RCTs (2112 TEA patients and 2220 GA patients). TEA significantly reduced ICU length of stay (-6.9 hours; 95% confidence interval [CI], -12.5 to -1.2; P = .018), hospital length of stay (-0.8 days; 95% CI, -1.1 to -0.4; P < .0001), and ET (-2.9 hours; 95% CI, -3.7 to -2.0; P < .0001). However, we found no significant change in mortality. TSA found that the cumulative Z-curve passed the TSA-adjusted boundary for ICU length of stay, hospital length of stay, and ET, suggesting a clinical benefit. TEA also significantly reduced pain scores, pooled pulmonary complications, transfusion requirements, delirium, and arrhythmia, without additional complications such as epidural hematomas, of which the risk was estimated to be <0.14%.

CONCLUSIONS

TEA reduces ICU and hospital length of stay, and postoperative complications in patients undergoing cardiac surgery with minimal reported complications such as epidural hematomas. These findings favor the use of TEA in cardiac surgery and warrant consideration for use in cardiac surgeries worldwide.

Lactate Dehydrogenase and Hemorrhagic Stroke During Extracorporeal Membrane Oxygenation for COVID-19

PURPOSE

Hemorrhagic stroke (HS) is a devastating complication during extracorporeal membrane oxygenation (ECMO) but markers of risk stratification during COVID-19 are unknown. Lactate dehydrogenase (LDH) is a readily available biomarker of cell injury and permeability. We sought to determine whether an elevated LDH before ECMO placement is related to the occurrence of HS during ECMO for COVID-19.

METHODS

Adult patients with COVID-19 requiring ECMO between March 2020 and February 2022 were included. LDH values prior to ECMO placement were captured. Patients were categorized into high (> 750 U/L) or low (≤ 750 U/L) LDH groups. Multivariable regression modeling was used to determine the association between LDH and HS during ECMO.

RESULTS

There were 520 patients that underwent ECMO placement in 17 centers and 384 had an available LDH. Of whom, 122 (32%) had a high LDH. The overall incidence of HS was 10.9%, and patients with high LDH had a higher incidence of HS than those with low LDH level (17% vs 8%, p = 0.007). At 100 days, the probability of a HS was 40% in the high LDH group and 23% in those with a low LDH, p = 0.002. After adjustment for clinical covariates, high LDH remained associated with subsequent HS (aHR: 2.64, 95% CI 1.39-4.92). Findings were similar when restricting to patients supported by venovenous ECMO only.

CONCLUSION

Elevated LDH prior to ECMO cannulation is associated with a higher incidence of HS during device support. LDH can risk stratify cases for impending cerebral bleeding during ECMO.

A Comparison of Long-Term Outcomes in Patients Managed With Venovenous Extracorporeal Membrane Oxygenation in the First and Second Waves of the COVID-19 Pandemic in the United Kingdom

OBJECTIVES

Early studies of venovenous extracorporeal membrane oxygenation (ECMO) in COVID-19 have revealed similar outcomes to historical cohorts. Changes in the disease and treatments have led to differences in the patients supported on venovenous ECMO in the first and second waves. We aimed to compare these two groups in both the acute and follow-up phase.

DESIGN

Retrospective single-center cohort study comparing mortality at censoring date (November 30, 2021) and decannulation, patient characteristics, complications and lung function and quality of life (QOL-by European Quality of Life 5 Dimensions 3 Level Version) at first follow-up in patients supported on venovenous ECMO between wave 1 and wave 2 of the COVID-19 pandemic.

SETTING

Critical care department of a severe acute respiratory failure service.

PATIENTS

Patients supported on ECMO for COVID-19 between wave 1 (March 17, 2020, to August 31, 2020) and wave 2 (January 9, 2020, to May 25, 2021).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One hundred twenty-three patients were included in our analysis. Survival at censoring date (χ 2 , 6.35; p = 0.012) and decannulation (90.4% vs 70.0%; p < 0.001) was significantly lower in the second wave, while duration of ECMO run was longer (12.0 d [18.0-30.0 d] vs 29.5 d [15.5-58.3 d]; p = 0.005). Wave 2 patients had longer application of noninvasive ventilation (NIV) prior to ECMO and a higher frequency of barotrauma. Patient age and NIV use were independently associated with increased mortality (odds ratio 1.07 [1.01-1.14]; p = 0.025 and 3.37 [1.12-12.60]; p = 0.043, respectively). QOL and lung function apart from transfer coefficient of carbon monoxide corrected for hemoglobin was similar at follow-up across the waves.

CONCLUSIONS

Most patients with COVID-19 supported on ECMO in both waves survived in the short and longer term. At follow-up patients had similar lung function and QOL across the two waves. This suggests that ECMO has an ongoing role in the management of a carefully selected group of patients with COVID-19.

Outcomes of patients with COVID-19 requiring extracorporeal membrane oxygenation and continuous renal replacement therapy in the United States

BACKGROUND

Coronavirus disease 2019 (COVID-19) infection is associated with significant morbidity and mortality. Some patients develop severe acute respiratory distress syndrome and kidney failure requiring the combination of extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT).

METHODS

Retrospective cohort study of 127 consecutive patients requiring combined ECMO and CRRT support in intensive care units at an ECMO center in Marietta, GA, United States.

RESULTS

Sixty and 67 patients with and without COVID-19, respectively, required ECMO-CRRT support. After adjusting for confounding variables, patients with COVID-19 had increased mortality at 30 days (hazard ratio [HR], 5.19; 95% confidence interval [CI], 2.51-10.7; P<0.001) and 90 days (HR, 6.23; 95% CI, 2.60-14.9; P<0.001).

CONCLUSIONS

In this retrospective study, patients with COVID-19 who required ECMO-CRRT had increased mortality when compared to patients without COVID-19.

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.

Optimal positive end-expiratory pressure reduces right ventricular dysfunction in COVID-19 patients on venovenous extracorporeal membrane oxygenation: A retrospective single-center study

While mechanical ventilation practices on venovenous extracorporeal membrane oxygenation (VV ECMO) are variable, most institutions utilize a lung rest strategy utilizing relatively low positive end-expiratory pressure (PEEP). The effect of PEEP titration using esophageal manometry during VV ECMO on pulmonary and cardiac function is unknown. This was a retrospective study of 69 patients initiated on VV ECMO between March 2020 through November 2021. Patients underwent standard PEEP (typically 10 cm H₂O) or optimal PEEP (PEEP titrated to an end-expiratory transpulmonary pressure 0-3 cm H₂O) throughout the ECMO run. The optimal PEEP strategy had higher levels of applied PEEP (17.9 vs. 10.8 cm H₂O on day 2 of ECMO), decreased incidence of hemodynamically significant RV dysfunction (4.55% vs. 44.0%, p = 0.0001), and higher survival to decannulation (72.7% vs. 44.0%, p = 0.022). Survival to discharge did not reach statistical significance (27% vs. 11%, p = 0.211). In univariate logistic regression analysis, optimal PEEP was associated with less hemodynamically significant RV dysfunction with an odds ratio (OR) of 0.06 (95% confidence interval [CI] = 0.01-0.27, p = 0.0008) and increased survival to decannulation with an OR of 3.39 (95% CI 1.23-9.79), p = 0.02), though other confounding factors may have contributed.

Expert consensus statement on venovenous extracorporeal membrane oxygenation ECMO for COVID-19 severe ARDS: an international Delphi study

BACKGROUND

The high-quality evidence on managing COVID-19 patients requiring extracorporeal membrane oxygenation (ECMO) support is insufficient. Furthermore, there is little consensus on allocating ECMO resources when scarce. The paucity of evidence and the need for guidance on controversial topics required an international expert consensus statement to understand the role of ECMO in COVID-19 better. Twenty-two international ECMO experts worldwide work together to interpret the most recent findings of the evolving published research, statement formulation, and voting to achieve consensus.

OBJECTIVES

To guide the next generation of ECMO practitioners during future pandemics on tackling controversial topics pertaining to using ECMO for patients with COVID-19-related severe ARDS.

METHODS

The scientific committee was assembled of five chairpersons with more than 5 years of ECMO experience and a critical care background. Their roles were modifying and restructuring the panel's questions and, assisting with statement formulation in addition to expert composition and literature review. Experts are identified based on their clinical experience with ECMO (minimum of 5 years) and previous academic activity on a global scale, with a focus on diversity in gender, geography, area of expertise, and level of seniority. We used the modified Delphi technique rounds and the nominal group technique (NGT) through three face-to-face meetings and the voting on the statement was conducted anonymously. The entire process was planned to be carried out in five phases: identifying the gap of knowledge, validation, statement formulation, voting, and drafting, respectively.

RESULTS

In phase I, the scientific committee obtained 52 questions on controversial topics in ECMO for COVID-19, further reviewed for duplication and redundancy in phase II, resulting in nine domains with 32 questions with a validation rate exceeding 75% (Fig. 1). In phase III, 25 questions were used to formulate 14 statements, and six questions achieved no consensus on the statements. In phase IV, two voting rounds resulted in 14 statements that reached a consensus are included in four domains which are: patient selection, ECMO clinical management, operational and logistics management, and ethics.

CONCLUSION

Three years after the onset of COVID-19, our understanding of the role of ECMO has evolved. However, it is incomplete. Tota14 statements achieved consensus; included in four domains discussing patient selection, clinical ECMO management, operational and logistic ECMO management and ethics to guide next-generation ECMO providers during future pandemic situations.

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.

Extracorporeal Membrane Oxygenation in Children With COVID-19: A Systematic Review and Meta-Analysis

OBJECTIVES

The indication, complications, and outcomes of extracorporeal membrane oxygenation (ECMO) in children with COVID-19-related illnesses remain unelucidated. Our study aimed to investigate the characteristics and outcomes of ECMO in children with COVID-19-related illnesses.

DATA SOURCES

We searched PubMed and EMBASE databases in March 2022.

STUDY SELECTION

We retrieved all studies involving children (age ≤ 18 yr) with COVID-19-related illnesses who received ECMO.

DATA EXTRACTION

Two authors independently extracted data and assessed the risk of bias. Mortality, successful weaning rate, and complications while on ECMO were synthesized by a one-group meta-analysis using a random-effect model. Meta-regression was performed to explore the risk factors for mortality.

DATA SYNTHESIS

We included 18 observational studies, four case series, and 22 case reports involving 110 children with COVID-19-related illnesses receiving ECMO. The median age was 8 years (range, 10 d to 18 yr), and the median body mass index was 21.4 kg/m 2 (range, 12.3-56.0 kg/m 2 ). The most common comorbidities were obesity (11% [7/63]) and congenital heart disease (11% [7/63]), whereas 48% (30/63) were previously healthy. The most common indications for ECMO were multisystem inflammatory syndrome in children (52% [47/90]) and severe acute respiratory distress syndrome (40% [36/90]). Seventy-one percent (56/79) received venoarterial-ECMO. The median ECMO runtime was 6 days (range, 3-51 d) for venoarterial ECMO and 11 days (range, 3-71 d) for venovenous ECMO. The mortality was 26.6% (95% CI, 15.9-40.9), and the successful weaning rate was 77.0% (95% CI, 55.4-90.1). Complications were seen in 37.0% (95% CI, 23.1-53.5) while on ECMO, including stroke, acute kidney injury, pulmonary edema, and thromboembolism. Corticosteroids and IV immunoglobulin therapies were associated with lower mortality.

CONCLUSIONS

The mortality of children on ECMO for COVID-19 was relatively low. This invasive treatment can be considered as a treatment option for critically ill children with COVID-19.

Indirect Calorimetry in Spontaneously Breathing, Mechanically Ventilated and Extracorporeally Oxygenated Patients: An Engineering Review

Indirect calorimetry (IC) is considered the gold standard for measuring resting energy expenditure (REE). This review presents an overview of the different techniques to assess REE with special regard to the use of IC in critically ill patients on extracorporeal membrane oxygenation (ECMO), as well as to the sensors used in commercially available indirect calorimeters. The theoretical and technical aspects of IC in spontaneously breathing subjects and critically ill patients on mechanical ventilation and/or ECMO are covered and a critical review and comparison of the different techniques and sensors is provided. This review also aims to accurately present the physical quantities and mathematical concepts regarding IC to reduce errors and promote consistency in further research. By studying IC on ECMO from an engineering point of view rather than a medical point of view, new problem definitions come into play to further advance these techniques.

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.

The Use of ECMO for COVID-19: Lessons Learned

The coronavirus disease 2019 (COVID-19) pandemic has seen an increase in global cases of severe acute respiratory distress syndrome (ARDS), with a concomitant increased demand for extracorporeal membrane oxygenation (ECMO). Outcomes of patients with severe ARDS due to COVID-19 infection receiving ECMO support are evolving. The need for surge capacity, practical and ethical limitations on implementing ECMO, and the prolonged duration of ECMO support in patients with COVID-19-related ARDS has revealed limitations in organization and resource utilization. Coordination of efforts at multiple levels, from research to implementation, resulted in numerous innovations in the delivery of ECMO.

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

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