Ultra-Protective Ventilation Reduces Biotrauma in Patients on Venovenous Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome*:

Mortality Trends of Oncology and Hematopoietic Stem Cell Transplant Patients Supported on Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis

BACKGROUND

There is an increasing frequency of oncology and hematopoietic stem cell transplant (HSCT) patients seen in the intensive care unit and requiring extracorporeal membrane oxygenation (ECMO), however, prognosis of this population over time is unclear.

METHODS

MEDLINE, EMBASE, Cochrane and Web of Science were searched from earliest publication until April 10, 2020 for studies to determine the mortality trend over time in oncology and HSCT patients requiring ECMO. Primary outcome was hospital mortality. Random-effects meta-analysis model was used to obtain pooled estimates of mortality and 95% confidence intervals. A priori subgroup metanalysis compared adult versus pediatric, oncology versus HSCT, hematological malignancy versus solid tumor, allogeneic versus autologous HSCT, and veno-arterial versus veno-venous ECMO populations. Multivariable meta-regression was also performed for hospital mortality to account for year of study and HSCT population.

RESULTS

17 eligible observational studies (n = 1109 patients) were included. Overall pooled hospital mortality was 72% (95% CI: 65, 78). In the subgroup analysis, only HSCT was associated with a higher hospital mortality compared to oncology subgroup [84% (95% CI: 70, 93) vs. 66% (95% CI: 56, 74); P = 0.021]. Meta-regression showed that HSCT was associated with increased mortality [adjusted odds ratio (aOR) 3.84 (95% CI 1.77, 8.31)], however, mortality improved with time [aOR 0.92 (95% CI: 0.85, 0.99) with each advancing year].

CONCLUSION

This study reports a high overall hospital mortality in oncology and HSCT patients on ECMO which improved over time. The presence of HSCT portends almost a 4-fold increased risk of mortality and this finding may need to be taken into consideration during patient selection for ECMO.

A radiological predictor for pneumomediastinum/pneumothorax in COVID-19 ARDS patients

Purpose

To determine whether Macklin effect (a linear collection of air contiguous to the bronchovascular sheath) on baseline CT imaging is an accurate predictor for subsequent pneumomediastinum (PMD)/pneumothorax (PNX) development in invasively ventilated patients with COVID-19-related acute respiratory distress syndrome (ARDS).

Materials and methods

This is an observational, case-control study. From a prospectively acquired database, all consecutive invasively ventilated COVID-19 ARDS patients who underwent at least one baseline chest CT scan during the study time period (February 25th, 2020–December 31st, 2020) were identified; those who had tracheal lesion or already had PMD/PNX at the time of the first available chest imaging were excluded.

Results

37/173 (21.4%) patients enrolled had PMD/PNX; specifically, 20 (11.5%) had PMD, 10 (5.8%) PNX, 7 (4%) both. 33/37 patients with subsequent PMD/PNX had Macklin effect on baseline CT (89.2%, true positives) 8.5 days [range, 1–18] before the first actual radiological evidence of PMD/PNX. Conversely, 6/136 patients without PMD/PNX (4.4%, false positives) demonstrated Macklin effect (p < 0.001). Macklin effect yielded a sensitivity of 89.2% (95% confidence interval [CI]: 74.6–96.9), a specificity of 95.6% (95% CI: 90.6–98.4), a positive predictive value (PV) of 84.5% (95% CI: 71.3–92.3), a negative PV of 97.1% (95% CI: 74.6–96.9) and an accuracy of 94.2% (95% CI: 89.6–97.2) in predicting PMD/PNX (AUC:0.924).

Conclusions

Macklin effect accurately predicts, 8.5 days in advance, PMD/PNX development in COVID-19 ARDS patients.

Tracheostomy management in patients with severe acute respiratory distress syndrome receiving extracorporeal membrane oxygenation: an International Multicenter Retrospective Study

Background

Current practices regarding tracheostomy in patients treated with extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome are unknown. Our objectives were to assess the prevalence and the association between the timing of tracheostomy (during or after ECMO weaning) and related complications, sedative, and analgesic use.

Methods

International, multicenter, retrospective study in four large volume ECMO centers during a 9-year period.

Results

Of the 1,168 patients treated with ECMO for severe ARDS (age 48 ± 16 years, 76% male, SAPS II score 51 ± 18) during the enrollment period, 353 (30%) and 177 (15%) underwent tracheostomy placement during or after ECMO, respectively. Severe complications were uncommon in both groups. Local bleeding within 24 h of tracheostomy was four times more frequent during ECMO (25 vs 7% after ECMO, p < 0.01). Cumulative sedative consumption decreased more rapidly after the procedure with sedative doses almost negligible 48–72 h later, when tracheostomy was performed after ECMO decannulation (p < 0.01). A significantly increased level of consciousness was observed within 72 h after tracheostomy in the “after ECMO” group, whereas it was unchanged in the “during-ECMO” group.

Conclusion

In contrast to patients undergoing tracheostomy after ECMO decannulation, tracheostomy during ECMO was neither associated with a decrease in sedation and analgesia levels nor with an increase in the level of consciousness. This finding together with a higher risk of local bleeding in the days following the procedure reinforces the need for a case-by-case discussion on the balance between risks and benefits of tracheotomy when performed during ECMO.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03649-8.

Awake Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome: Which Clinical Issues Should Be Taken Into Consideration

With the goal of protecting injured lungs and extrapulmonary organs, venovenous extracorporeal membrane oxygenation (VV-ECMO) has been increasingly adopted as a rescue therapy for patients with severe acute respiratory distress syndrome (ARDS) when conventional mechanical ventilation failed to provide effective oxygenation and decarbonation. In recent years, it has become a promising approach to respiratory support for awake, non-intubated, spontaneously breathing patients with respiratory failure, referred to as awake ECMO, to avoid possible detrimental effects associated with intubation, mechanical ventilation, and the adjunctive therapies. However, several complex clinical issues should be taken into consideration when initiating and implementing awake ECMO, such as selecting potential patients who appeared to benefit most; techniques to facilitating cannulation and maintain stable ECMO blood flow; approaches to manage pain, agitation, and delirium; and approaches to monitor and modulate respiratory drive. It is worth mentioning that there had also been some inherent disadvantages and limitations of awake ECMO compared to the conventional combination of ECMO and invasive mechanical ventilation. Here, we review the use of ECMO in awake, spontaneously breathing patients with severe ARDS, highlighting the issues involving bedside clinical practice, detailing some of the technical aspects, and summarizing the initial clinical experience gained over the past years.

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

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

Management of Adult Patients Supported with Venovenous Extracorporeal Membrane Oxygenation (VV ECMO): Guideline from the Extracorporeal Life Support Organization (ELSO)

Disclaimer: The use of venovenous extracorporeal membrane oxygenation (VV ECMO) in adults has rapidly increased worldwide. This ELSO guideline is intended to be a practical guide to patient selection, initiation, cannulation, management, and weaning of VV ECMO for adult respiratory failure. This is a consensus document which has been updated from the previous version to provide guidance to the clinician.

Carbon Dioxide Elimination During Veno-Venous Extracorporeal Membrane Oxygenation Weaning: A Pilot Study

Veno-venous extracorporeal membrane oxygenation (V-V ECMO) represents a component of the treatment strategy for severe respiratory failure. Clinical evidence on the management of the lung during V-V ECMO are limited just as the consensus regarding timing of weaning. The monitoring of the carbon dioxide (CO2) removal (V'CO2TOT) is subdivided into two components: the membrane lung (ML) and the native lung (NL) are both taken into consideration to evaluate the improvement of the function of the lung and to predict the time to wean off ECMO. We enrolled patients with acute respiratory distress syndrome (ARDS). The V'CO2NL ratio (V'CO2NL/V'CO2TOT) value was calculated based on the distribution of CO2 between the NL and the ML. Of 18 patients, 15 were successfully weaned off of V-V ECMO. In this subgroup, we observed a significant increase in the V'CO2NL ratio comparing the median values of the first and last quartiles (0.32 vs. 0.53, p = 0.0045), without observing any modifications in the ventilation parameters. An increase in the V'CO2NL ratio, independently from any change in ventilation could, despite the limitations of the study, indicate an improvement in pulmonary function and may be used as a weaning index for ECMO.

Effect of Driving Pressure Change During Extracorporeal Membrane Oxygenation in Adults With Acute Respiratory Distress Syndrome: A Randomized Crossover Physiologic Study

OBJECTIVES

Venovenous extracorporeal membrane oxygenation is an effective intervention to improve gas exchange in patients with severe acute respiratory distress syndrome. However, the mortality of patients with severe acute respiratory distress syndrome supported with venovenous extracorporeal membrane oxygenation remains high, and this may be due in part to a lack of standardized mechanical ventilation strategies aimed at further minimizing ventilator-induced lung injury. We tested whether a continuous positive airway pressure ventilation strategy mitigates ventilator-induced lung injury in patients with severe acute respiratory distress syndrome on venovenous extracorporeal membrane oxygenation, compared with current ventilation practice that employs tidal ventilation with limited driving pressure. We used plasma biomarkers as a surrogate outcome for ventilator-induced lung injury.

DESIGN

Randomized crossover physiologic study.

SETTING

Single-center ICU.

PATIENTS

Ten patients with severe acute respiratory distress syndrome supported on venovenous extracorporeal membrane oxygenation.

INTERVENTIONS

The study included four phases. After receiving pressure-controlled ventilation with driving pressure of 10 cm H2O for 1 hour (phase 1), patients were randomly assigned to receive first either pressure-controlled ventilation 20 cm H2O for 2 hours (phase 2) or continuous positive airway pressure for 2 hours (phase 3), and then crossover to the other phase for 2 hours; during phase 4 ventilation settings returned to baseline (pressure-controlled ventilation 10 cm H2O) for 4 hours.

MEASUREMENTS AND MAIN RESULTS

There was a linear relationship between the change in driving pressure and the plasma concentration of interleukin-6, soluble receptor for advanced glycation end products, interleukin-1ra, tumor necrosis factor alpha, surfactant protein D, and interleukin-10.

CONCLUSIONS

Ventilator-induced lung injury may occur in acute respiratory distress syndrome patients on venovenous extracorporeal membrane oxygenation despite the delivery of volume- and pressure-limited mechanical ventilation. Reducing driving pressure to zero may provide more protective mechanical ventilation in acute respiratory distress syndrome patients supported with venovenous extracorporeal membrane oxygenation. However, the risks versus benefits of such an approach need to be confirmed in studies that are designed to test patient centered outcomes.

Mechanical Ventilation Strategy Guided by Transpulmonary Pressure in Severe Acute Respiratory Distress Syndrome Treated With Venovenous Extracorporeal Membrane Oxygenation

OBJECTIVES

Previous studies have suggested that adjusting ventilator settings based on transpulmonary pressure measurements may minimize ventilator-induced lung injury, but this has never been investigated in patients with severe acute respiratory distress syndrome supported with venovenous extracorporeal membrane oxygenation. We aimed to evaluate whether a transpulmonary pressure-guided ventilation strategy would increase the proportion of patients successfully weaned from venovenous extracorporeal membrane oxygenation support in patients with severe acute respiratory distress syndrome.

DESIGN

Single-center, prospective, randomized controlled trial.

SETTING

Sixteen-bed, respiratory ICU at a tertiary academic medical center.

PATIENTS

Severe acute respiratory distress syndrome patients receiving venovenous extracorporeal membrane oxygenation.

INTERVENTIONS

One-hundred four patients were randomized to transpulmonary pressure-guided ventilation group (n = 52) or lung rest strategy group (n = 52) groups. Two patients had cardiac arrest during establishment of venovenous extracorporeal membrane oxygenation in the lung rest group did not receive the assigned intervention. Thus, 102 patients were included in the analysis.

MEASUREMENTS AND MAIN RESULTS

The proportion of patients successfully weaned from venovenous extracorporeal membrane oxygenation in the transpulmonary pressure-guided group was significantly higher than that in the lung rest group (71.2% vs 48.0%; p = 0.017). Compared with the lung rest group, driving pressure, tidal volumes, and mechanical power were significantly lower, and positive end-expiratory pressure was significantly higher, in the transpulmonary pressure-guided group during venovenous extracorporeal membrane oxygenation support. In the transpulmonary pressure-guided group, levels of interleukin-1β, interleukin-6, and interleukin-8 were significantly lower, and interleukin-10 was significantly higher, than those of the lung rest group over time. Lung density was significantly lower in the transpulmonary pressure-guided group after venovenous extracorporeal membrane oxygenation support than in the lung rest group.

CONCLUSIONS

A transpulmonary pressure-guided ventilation strategy could increase the proportion of patients with severe acute respiratory distress syndrome successfully weaned from venovenous extracorporeal membrane oxygenation.

Driving pressure monitoring during acute respiratory failure in 2020

PURPOSE OF REVIEW

Assess the most recent studies using driving pressure (DP) as a monitoring technique under mechanical ventilation and describe the technical challenges associated with its measurement.

RECENT FINDINGS

DP is consistently associated with survival in acute respiratory failure and acute respiratory distress syndrome (ARDS) and can detect patients at higher risk of ventilator-induced lung injury. Its measurement can be challenged by leaks and ventilator dyssynchrony, but is also feasible under pressure support ventilation. Interestingly, an aggregated summary of published results suggests that its level is on average slightly lower in patients with coronavirus disease-19 induced ARDS than in classical ARDS.

SUMMARY

The DP is easy to obtain and should be incorporated as a minimal monitoring technique under mechanical ventilation.

Mechanical Power during Veno-Venous Extracorporeal Membrane Oxygenation Initiation: A Pilot-Study

Mechanical power (MP) represents a useful parameter to describe and quantify the forces applied to the lungs during mechanical ventilation (MV). In this multi-center, prospective, observational study, we analyzed MP variations following MV adjustments after veno-venous extra-corporeal membrane oxygenation (VV ECMO) initiation. We also investigated whether the MV parameters (including MP) in the early phases of VV ECMO run may be related to the intensive care unit (ICU) mortality. Thirty-five patients with severe acute respiratory distress syndrome were prospectively enrolled and analyzed. After VV ECMO initiation, we observed a significant decrease in median MP (32.4 vs. 8.2 J/min, p < 0.001), plateau pressure (27 vs. 21 cmH₂O, p = 0.012), driving pressure (11 vs. 8 cmH₂O, p = 0.014), respiratory rate (RR, 22 vs. 14 breaths/min, p < 0.001), and tidal volume adjusted to patient ideal body weight (V_T/IBW, 5.5 vs. 4.0 mL/kg, p = 0.001) values. During the early phase of ECMO run, RR (17 vs. 13 breaths/min, p = 0.003) was significantly higher, while positive end-expiratory pressure (10 vs. 14 cmH₂O, p = 0.048) and V_T/IBW (3.0 vs. 4.0 mL/kg, p = 0.028) were lower in ICU non-survivors, when compared to the survivors. The observed decrease in MP after ECMO initiation did not influence ICU outcome. Waiting for large studies assessing the role of these parameters in VV ECMO patients, RR and MP monitoring should not be underrated during ECMO.

A successful case of extracorporeal membrane oxygenation treatment for intractable pneumothorax in a patient with COVID-19

Background

Some patients with coronavirus disease 2019 (COVID‐19) develop pneumothorax. Tube thoracotomy and bulla resection could generate aerosols and cause virus transmission; the optimal treatment strategy remains unclear.

Case Presentation

A 57‐year‐old male was transferred as a severe COVID‐19 pneumonia case. On the 16th day after admission, the patient’s respiratory condition deteriorated, and the chest X‐ray revealed the presence of severe right‐sided pneumothorax. A chest drain was immediately inserted; however, a significant air leak continued, and severe ventilator settings were required. Thus, veno‐venous extracorporeal membrane oxygenation (VV‐ECMO) treatment was initiated to allow the lungs to rest. After 10 days of lung‐protective ventilation, the patient was weaned from ECMO and the chest drain was removed on the following day with no major comorbidities.

Conclusion

The combination of ECMO with lung rest strategy could be a treatment option for intractable pneumothorax with COVID‐19 to avoid unnecessary surgical procedures and aerosol generation.

Extracorporeal support to achieve lung-protective and diaphragm-protective ventilation

PURPOSE OF REVIEW

Extracorporeal support allows ultraprotective controlled and assisted ventilation, which can prevent lung and diaphragm injury. We focused on most recent findings in the application of extracorporeal support to achieve lung protection and diaphragm- protection, as well as on relevant monitoring.

RECENT FINDINGS

A recent randomized trial comparing the efficacy of extracorporeal support as a rescue therapy to conventional protective mechanical ventilation was stopped for futility but post hoc analyses suggested that extracorporeal support is beneficial for patients with very severe acute respiratory distress syndrome. However, the optimal ventilation settings during extracorporeal support are still debated. It is conceivable that they should enable the highest amount of CO2 removal with lowest mechanical power.Extracorporeal CO2 removal can minimize acidosis and enable the use of ultra-protective lung ventilation strategies when hypoxemia is not a major issue. Moreover, it can protect lung and diaphragm function during assisted ventilation through control of the respiratory effort.Lung mechanics, gas exchange, diaphragm electrical activity, ultrasound, electrical impedance tomography could be integrated into clinical management to define lung and diaphragm protection and guide personalized ventilation settings.

SUMMARY

Technological improvement and the latest evidence indicate that extracorporeal support may be an effective tool for lung and diaphragm protection.

The Prolonged Use of VV ECMO Support in COVID-19: A Case Report

COVID-19 has resulted in unprecedented global health and economic challenges. The reported mortality in patients with COVID-19 requiring mechanical ventilation is high. VV ECMO may serve as a lifesaving rescue therapy for a minority of patients with COVID-19; however, its impact on overall survival of these patients is unknown. To date, few reports describe successful discharge from ECMO in COVID-19 after a prolonged ECMO run. The only Australian case of a COVID-19 patient, supported by prolonged VV ECMO in conjunction with prone ventilation, complicated by significant airway bleeding, and successfully decannulated after forty-two days, is described. VV ECMO is a resource-intense form of respiratory support. Providing complex therapies such as VV ECMO during a pandemic has its unique challenges. This case report provides a unique insight into the potential clinical sequelae of COVID-19, supported in an intensive care environment which was not resource-limited at the time, and adds to the evolving experience of prolonged VV ECMO support for ARDS with a goal to lung recovery.

Extracorporeal Membrane Oxygenation in Severe Acute Respiratory Distress Syndrome: Possible Late Indication for Coronavirus Disease 2019?

Background:

There is now substantial evidence to support venovenous extracorporeal membrane oxygenation efficacy and safety for patients with severe acute respiratory distress syndrome. However, recent guidelines recommend against the initiation of extracorporeal membrane oxygenation in patients with mechanical ventilation for coronavirus disease 2019 severe acute respiratory distress syndrome for greater than 7–10 days.

Case Summary:

We report the case of a patient with coronavirus disease 2019 severe acute respiratory distress syndrome with successful late venovenous extracorporeal membrane oxygenation initiation after 20 days of mechanical ventilation. Respiratory compliance, arterial blood gases, and radiological lesions improved progressively under venovenous extracorporeal membrane oxygenation and ultraprotective ventilation. The patient was discharged from ICU.

Conclusions:

As coronavirus disease 2019 is a new and incompletely understood entity, we believe that late extracorporeal membrane oxygenation may be considered in selected patients as a bridge to recovery. Further prospective studies are, however, needed.

Case Report of Patients with Acute Respiratory Distress Syndrome Caused by COVID-19: Successfully Treated by Venovenous Extracorporeal Membrane Oxygenation and an Ultra-Protective Ventilation

Coronavirus disease (COVID-19) started in Wuhan (China) at the end of 2019, and then increased rapidly. In patients with severe acute respiratory distress syndrome (ARDS) caused by COVID-19, venovenous extracorporeal membrane oxygenation (VV-ECMO) is considered a rescue therapy that provides adequate gas exchange. The way in which mechanical ventilation is applied during VV-ECMO is not clear, however it is associated with prognosis. Currently, the mortality rate of COVID-19 patients that receive VV-ECMO stands at approximately 50%. Here, we report three patients that successfully recovered from COVID-19-induced ARDS after VV-ECMO and implementation of an ultra-protective ventilation. This ventilation strategy involved maintaining a peak inspiratory pressure of ≤20 cmH₂O and a positive end-expiratory pressure (PEEP) of ≤ 10 cmH₂O, which are lower values than have been previously reported. Thus, we suggest that this ultra-protective ventilation be considered during VV-ECMO as it minimizes the ventilator-induced lung injury.

COVID19 Acute respiratory distress syndrome and extra-corporeal membrane oxygenation; A mere option or ultimate necessity

Extracorporeal membrane oxygenation (ECMO) is considered a salvage therapy in patients with acute respiratory distress syndrome (ARDS) and refractory hypoxemia (hypoxemia persisting despite lung-protective ventilation). One aspect of ECMO is whether there would be an application of the technology related to the Coronavirus pandemic. The number of people diagnosed with Coronavirus disease (COVID19) has crossed the five million mark on 9 August 2020, with a case fatality rate of 5.2%. Due to this exponential increase in the number of coronavirus disease (COVID19) cases particularly the ones associated with ARDS, experts are evaluating the need for ECMO in intensive care units. Herein, we chronicle a review encompassing the available evidence on ECMO and its potential role in COVID19 ARDS, as we aim for optimal patient care with appropriate resource utilization and conservation.

Early Initiation of Awake Veno-Venous Extracorporeal Membrane Oxygenation Can Attenuate Muscle Atrophy and Weakness in Acute Respiratory Distress Syndrome

Patients with acute respiratory distress syndrome (ARDS) exhibit prominent muscle atrophy and weakness. Although these patients often require deep sedation to perform lung-protective ventilation, extracorporeal membrane oxygenation (ECMO) can keep patients awake and make mobilization possible. A 60-year-old man was treated with ECMO due to ARDS. A multidisciplinary team conducted mobilization with standing on day 3. During intensive care unit (ICU) stay, catabolism was ongoing (urinary titin: 24.1-38.4 pmol/mg Cr), but the rectus femoris muscle, measured by ultrasound, moderately decreased by 5.3%, 10.8%, and 13.0% on days 3, 5, and 7, respectively, with maintained Medical Research Council score of 58-60. Diaphragm thickness remained unchanged. On day 5, he was separated from ECMO. After ambulation training, he was discharged from ICU on day 7. He returned home without prominent physical dysfunction. Our experience indicates early initiation of awake ECMO can accompany mobilization and attenuate muscle atrophy and weakness in ARDS.

COVID-19 and ECMO: the interplay between coagulation and inflammation-a narrative review

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has presently become a rapidly spreading and devastating global pandemic. Veno-venous extracorporeal membrane oxygenation (V-V ECMO) may serve as life-saving rescue therapy for refractory respiratory failure in the setting of acute respiratory compromise such as that induced by SARS-CoV-2. While still little is known on the true efficacy of ECMO in this setting, the natural resemblance of seasonal influenza's characteristics with respect to acute onset, initial symptoms, and some complications prompt to ECMO implantation in most severe, pulmonary decompensated patients. The present review summarizes the evidence on ECMO management of severe ARDS in light of recent COVID-19 pandemic, at the same time focusing on differences and similarities between SARS-CoV-2 and ECMO in terms of hematological and inflammatory interplay when these two settings merge.

Extracorporeal membrane oxygenation support in adult patients with acute respiratory distress syndrome

Introduction: The global number of patients receiving extracorporeal membrane oxygenation (ECMO) support has been growing after several studies highlighted the favorable results attained in cases of severe respiratory failure. However, evidence-based guidelines for optimal use of ECMO are lacking.Areas covered: This review covers optimal candidates, timing of initiation, strategies for patient management including mechanical ventilation, and decision-making regarding discontinuation of ECMO based on its potential role in treatment of patients with acute respiratory distress syndrome.Expert opinion: Early initiation of ECMO should be considered if hypoxemia and uncompensated hypercapnia do not respond to optimal conventional treatment. Use of a comprehensive management approach for preventing additional lung injury and extrapulmonary organ failure is critical during ECMO support to ensure the best outcome. The possibility of weaning from ECMO should be fully assessed by a multidisciplinary team during ECMO support. Futility should not be determined solely by duration of ECMO, and use of prolonged ECMO for lung recovery may be worthwhile.

ECLS-associated infections in adults: what we know and what we don't yet know

Extracorporeal life support (ECLS) is increasingly used in the management of patients with severe cardiopulmonary disease. Infections are frequently the etiologies underlying the respiratory, and occasionally cardiac, failure that necessitates ECLS. Just as importantly, infections are among the most commonly reported adverse events during ECLS. Infections in this setting may be the sequelae of prolonged critical illness or of underlying immune dysregulation; they may be hospital-acquired infections, and they may or may not be attributable to the presence of ECLS itself, the latter being an aspect that can be difficult to determine. Current registry data and evidence from the literature offer some insights, but also leave open many questions regarding the nature and significance of infections reported both before and during ECLS, including the question of any causal link between ECLS and the development of infections. An ongoing lack of consistency in the identification, diagnosis, management, and prevention of infections during ECLS is limiting our ability to interpret literature data and thus highlighting the need for more rigorous investigation and standardization of definitions. This review aims to characterize the current understanding of infections associated with the use of ECLS, taking into account data from the updated Extracorporeal Life Support Organization Registry, which provides important context for understanding the epidemiology and outcomes of these patients.