Prolonged duration ECMO for ARDS: futility, native lung recovery, or transplantation?

Lung transplant outcomes after acute respiratory distress syndrome requiring extracorporeal life support: Lessons from the COVID-19 pandemic

OBJECTIVE

Lung transplant for acute respiratory distress syndrome in patients supported with extracorporeal membrane oxygenation was rare before 2020, but was rapidly adopted to rescue patients with COVID-19 with lung failure. This study aims to compare the outcomes of patients who underwent lung transplant for COVID-associated acute respiratory distress syndrome and non-COVID acute respiratory distress syndrome, and to assess the impact of type and duration of extracorporeal membrane oxygenation support on survival.

METHODS

Using the United Network for Organ Sharing database, we identified 311 patients with acute respiratory distress syndrome who underwent lung transplant from 2007 to 2022 and performed a retrospective analysis of the patients who required extracorporeal membrane oxygenation preoperatively, stratified by COVID-associated acute respiratory distress syndrome and non-COVID acute respiratory distress syndrome listing diagnoses. The primary outcome was 1-year survival. Secondary outcomes included the effect of type and duration of extracorporeal membrane oxygenation on survival.

RESULTS

During the study period, 236 patients with acute respiratory distress syndrome and preoperative extracorporeal membrane oxygenation underwent lung transplant; 181 patients had a listing diagnosis of COVID-associated acute respiratory distress syndrome (77%), and 55 patients had a listing diagnosis of non-COVID acute respiratory distress syndrome (23%). Patients with COVID-associated acute respiratory distress syndrome were older, were more likely to be female, had higher body mass index, and spent longer on the waitlist (all P < .02) than patients with non-COVID acute respiratory distress syndrome. The 2 groups had similar 1-year survival (85.8% vs 81.1%, P = .2) with no differences in postoperative complications. Patients with COVID-associated acute respiratory distress syndrome required longer times on extracorporeal membrane oxygenation pretransplant (P = .02), but duration of extracorporeal membrane oxygenation support was not a predictor of 1-year survival (P = .2).

CONCLUSIONS

Despite prolonged periods of pretransplant extracorporeal membrane oxygenation support, selected patients with acute respiratory distress syndrome can undergo lung transplant safely with acceptable short-term outcomes. Appropriate selection criteria and long-term implications require further analysis.

Lung transplantation for COVID-2019 respiratory failure in the United States: Outcomes 1-year posttransplant and the impact of preoperative extracorporeal membrane oxygenation support

OBJECTIVE

Patients with end-stage respiratory failure after severe coronavirus disease 2019 (COVID-19) infection may benefit from lung transplant; however, data on transplant outcomes and the impact of prolonged circulatory support before transplant in these patients are limited.

METHODS

We assessed survival, postoperative complications, and the impact of pretransplant extracorporeal membrane oxygenation (ECMO) in patients undergoing lung transplant in the United States from August 2020 through March 2022 using records validated by United Network for Organ Sharing experts and extracted from the United Network for Organ Sharing database.

RESULTS

In 305 patients with COVID-19-related respiratory failure and validated data, survival for up to 1-year posttransplant did not differ between 188 patients with COVID-19-related acute respiratory distress syndrome and 117 patients with post-COVID-19 pulmonary fibrosis (P = .8). Pretransplant ECMO support (median 66 days) was required in 191 patients (63%), and venovenous ECMO was used in 91.2% of patients. One-, 6-, and 12-month survival was not significantly different between patients requiring ECMO and patients without ECMO (95.8% vs 99.1%, 93.1% vs 96.4%, 84.8% vs 90.9%, P = .2) In addition, 1-year survival was similar in recipients requiring ECMO for COVID-19 lung failure and recipients requiring ECMO for non-COVID-19 restrictive lung failure (84.8% vs 78.0%, P = .1).

CONCLUSIONS

These findings suggest that lung transplant in patients with COVID-19 respiratory failure yields acceptable 1-year outcomes. Despite an often more complex postoperative course, prolonged ECMO pretransplant in well-selected patients was associated with adequate clinical and functional status.

Extracorporeal Membrane Oxygenation for COVID-19: Collaborative Experience From the Texas Medical Center in Houston With 2 Years Follow-Up

Patients with severe refractory hypoxemic respiratory failure may benefit from extracorporeal membrane oxygenation (ECMO) for salvage therapy. The Coronavirus disease 2019 (COVID-19) pandemic offered three high-volume independent ECMO programs at a large medical center the chance to collaborate to optimize ECMO care at the beginning of the pandemic in Spring 2020. Between March 15, 2020, and May 30, 2020, 3,615 inpatients with COVID-19 were treated at the Texas Medical Center. During this time, 35 COVID-19 patients were cannulated for ECMO, all but one in a veno-venous configuration. At hospital discharge, 23 (66%) of the 35 patients were alive. Twelve patients died of vasodilatory shock (n = 9), intracranial hemorrhage (n = 2), and cannulation-related bleeding and multiorgan dysfunction (n = 1). The average duration of ECMO was 13.6 days in survivors and 25.0 days in nonsurvivors ( p < 0.04). At 1 year follow-up, all 23 discharged patients were still alive, making the 1 year survival rate 66% (23/35). At 2 years follow-up, the overall rate of survival was 63% (22/35). Of those patients who survived 2 years, all were at home and alive and well at follow-up.

Indications for Lung Transplantation and Patient Selection

Globally, thousands of patients undergo lung transplantation owing to end-stage lung disease each year. As lung transplantation evolves, recommendations and indications are constantly being updated. In 2021, the International Society for Heart and Lung Transplantation published a new consensus document for selecting candidates for lung transplantation. However, it is still difficult to determine appropriate candidates for lung transplantation among patients with complex medical conditions and various diseases. Therefore, it is necessary to analyze each patient’s overall situation and medical condition from various perspectives, and ongoing efforts to optimize the analysis will be necessary. The purpose of this study is to review the extant literature and discuss recent updates.

Fracture of dual lumen cannula leading to cerebrovascular accident in a patient supported with ECMO

Extended duration extracorporeal membrane oxygenation (ECMO), using dual-lumen cannulas, is being used with increased frequency to support patients, including those with COVID-19; both as a bridge to transplant and lung recovery. During such an extended duration of support, there are several factors that might lead to the attrition of the physical structure of the ECMO cannulas, predisposing them to the risk of fracture. Although rare, fracture of the ECMO cannula can be a potentially lethal event. Here, we present a case where fracture of a dual lumen cannula during veno-venous (VV) ECMO support resulted in a cerebrovascular accident. We discuss the potential contributing factors and suggest steps to mitigate the risks for such a complication.

COVID-19 case of ventilator-induced lung injury on extracorporeal membrane oxygenation: Physicians' clinical struggle and ethical conflict in a novel pandemic

Resource scarcity was concerned in the initial surge of the COVID-19 pandemic. To open slots for Extracorporeal Membrane Oxygenation (ECMO), we tried ECMO weaning allowing invasive ventilation in a 66-year-old male with severe COVID-19, backfiring as ventilator-induced lung injury. We will discuss ethical conflict in pandemics in this report.

Lung transplantation for acute respiratory distress syndrome - a retrospective European Cohort Study

BACKGROUND

The published experience of lung transplantation (LTX) in acute respiratory distress syndrome (ARDS) is limited. The aim of this study was to investigate the contemporary results of LTX attempts in ARDS in major European centers.

METHODS

We conducted a retrospective multicenter cohort study of all patients listed for LTX between 2011 and 2019. We surveyed 68 centers in 22 European countries. All patients admitted to the waitlist for lung transplantation with a diagnosis of "ARDS//pneumonia" were included. Patients without extracorporeal membrane oxygenation (ECMO) or mechanical ventilation were excluded. Patients were followed until October 1st 2020 or death. Multivariable analysis for 1-year survival after listing and lung transplantation were performed.

RESULTS

Forty-eight centers (74%) with a total transplant activity of 12 438 lung transplants during the 9-year period gave feedback. Forty patients with a median age of 35 years were identified. Patients were listed for LTX in 18 different centers in 10 countries. Thirty-one-patients underwent LTX (0·25% of all indications) and 9 patients died on the waitlist. Ninety percent of transplanted patients were on ECMO in combination with mechanical ventilation before LTX. On multivariable analysis, transplantation during 2015 until 2019 was independently associated with better 1-year survival after LTX (odds ratio 10.493, 95% CI 1.977, 55.705, p=0.006). Sixteen survivors out of 23 patients with known status (70%) returned to work after LTX.

CONCLUSION

LTX in highly selected ARDS patients is feasible and outcome has improved in the modern era. The selection process remains ethically and technically challenging.

Outcomes from the Use of Perioperative Extracorporeal Membrane Oxygenation in Patients Undergoing Thoracic Surgery: An 8-Year Single-Center Experience

Background

Extracorporeal membrane oxygenation (ECMO) plays an important role in thoracic surgery. This retrospective study from a single center aimed to evaluate patient outcomes from the use of perioperative ECMO in 22 patients undergoing thoracic surgery during an 8-year period.

Material/Methods

Data were collected retrospectively from 22 patients who received ECMO (veno-arterial and veno-venous ECMO) as perioperative treatment during general thoracic surgery from January 2012 to October 2020. Patients required ECMO due to perioperative cardiopulmonary resuscitation (CPR) (2 cases), perioperative pulmonary embolism (PE) (2 cases), lung transplant (4 cases), undergoing complicated thoracic surgery (5 cases), postoperative acute respiratory distress syndrome (ARDS) (6 cases), and thoracic trauma (3 cases).

Results

Veno-arterial ECMO was used for circulatory support in 13 cases and veno-venous ECMO was used for respiratory support in 9 cases. The average ECMO support time was 71.6±42.4 h. Twenty patients (90.9%) were successfully decannulated and 17 (77.2%) survived to discharge. Complications included severe hemorrhage (3/22 patients, 13.6%), sepsis (3/22, 13.6%), and destruction of blood cells (1/22, 4.5%). There were no significant differences in survival rates between patients receiving pre- or postoperative ECMO (P=0.135) or between veno-venous ECMO (V-V ECMO) and veno-arterial ECMO (V-A ECMO) (P=0.550).

Conclusions

The findings from this small retrospective study from a single center showed that perioperative ECMO improved cardiac and respiratory function in patients undergoing thoracic surgery. Optimal results require surgeons to have an understanding of the indications and ability to control the complications of ECMO.

Consensus document for the selection of lung transplant candidates: An update from the International Society for Heart and Lung Transplantation

Tens of thousands of patients with advanced lung diseases may be eligible to be considered as potential candidates for lung transplant around the world each year. The timing of referral, evaluation, determination of candidacy, and listing of candidates continues to pose challenges and even ethical dilemmas. To address these challenges, the International Society for Heart and Lung Transplantation appointed an international group of members to review the literature, to consider recent advances in the management of advanced lung diseases, and to update prior consensus documents on the selection of lung transplant candidates. The purpose of this updated consensus document is to assist providers throughout the world who are caring for patients with pulmonary disease to identify potential candidates for lung transplant, to optimize the timing of the referral of these patients to lung transplant centers, and to provide transplant centers with a framework for evaluating and selecting candidates. In addition to addressing general considerations and providing disease specific recommendations for referral and listing, this updated consensus document includes an ethical framework, a recognition of the variability in acceptance of risk between transplant centers, and establishes a system to account for how a combination of risk factors may be taken into consideration in candidate selection for lung transplantation.

Hospital survival outcomes in acute respiratory distress syndrome patients receiving veno-venous extracorporeal membrane oxygenation for longer than 28 days: A retrospective study

The successful use of prolonged (ie, >28 days) veno-venous extracorporeal membrane oxygenation (V-V ECMO) is being increasingly reported. However, limited data are available on its outcomes. This study investigated the outcomes of acute respiratory distress syndrome (ARDS) patients on prolonged ECMO support. We retrospectively evaluated 57 patients requiring V-V ECMO for ARDS between 2015 and 2020. The patients were divided into two groups according to ECMO duration: (a) ≤28 days group (n = 43, 75%) or (b) >28 days (n = 14, 25%) group. Clinical characteristics, complications, and outcomes between these two groups were statistically compared. There were no significant differences in demographics, comorbidity, ARDS etiology, and severity scores between the two groups. However, the mechanical ventilation period before ECMO initiation was significantly longer in the >28 days group than in the ≤28 days group (10.5 days vs. 1 day; P < .05). The incidence of positive bacterial blood culture results during ECMO was significantly higher in the >28 days group than in the ≤28 days group (43% vs. 9%; P < .05). Additionally, the hospital survival rate was significantly lower in the >28 days group than in the ≤28 days ECMO group (21% vs. 60%; P < .05). Prolonged ECMO was associated with worse hospital survival outcomes. Early initiation of ECMO along with meticulous care and appropriate treatment against infection during ECMO could improve the hospital survival of ARDS patients on prolonged ECMO support.

Circulating miRNAs as Promising Biomarkers to Evaluate ECMO Treatment Responses in ARDS Patients

The use of extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome (ARDS) has increased in the last decade. However, mortality remains high, and the complexity of ECMO requires individualized treatment. There are some biomarkers to monitor progression and predict clinical outcomes of ARDS. This project aims to advance the management of ARDS patients treated with ECMO by exploring miRNA expression in whole blood. The analysis was conducted on two groups with different length of ECMO: Group A (longer runs) and group B (shorter runs). We analyzed miRNAs before ECMO cannulation, and at 7 and 14 days of ECMO support. Our results showed that in the group B patients, 11 deregulated miRNAs were identified, and showed an opposite trend of expression compared to the group A patients. In silico analysis revealed that these 11 miRNAs were related to processes involved in the pathogenesis and evolution of ARDS. This scenario could represent homeostatic mechanisms by which, in ECMO responsive patients, pathways activated during ARDS progression are switched-off. Circulating miRNAs could represent promising biomarkers to monitor the evolution of ARDS under ECMO support. Further studies may shed light on this topic to improve a personalized approach in such a complex setting of patients.

Chronic respiratory disease and survival outcomes after extracorporeal membrane oxygenation

Background

Quality of life following extracorporeal membrane oxygenation (ECMO) therapy is an important health issue. We aimed to describe the characteristics of patients who developed chronic respiratory disease (CRD) following ECMO therapy, and investigate the association between newly diagnosed post-ECMO CRDs and 5-year all-cause mortality among ECMO survivors.

Methods

We analyzed data from the National Health Insurance Service in South Korea. All adult patients who underwent ECMO therapy in the intensive care unit between 2006 and 2014 were included. ECMO survivors were defined as those who survived for 365 days after ECMO therapy. Chronic obstructive pulmonary disease (COPD), asthma, interstitial lung disease, lung cancer, lung disease due to external agents, obstructive sleep apnea, and lung tuberculosis were considered as CRDs.

Results

A total of 3055 ECMO survivors were included, and 345 (11.3%) were newly diagnosed with CRDs 365 days after ECMO therapy. The prevalence of asthma was the highest at 6.1% (185). In the multivariate logistic regression, ECMO survivors who underwent ECMO therapy for acute respiratory distress syndrome (ARDS) or respiratory failure had a 2.00-fold increase in post-ECMO CRD (95% confidence interval [CI]: 1.39 to 2.89; P < 0.001). In the multivariate Cox regression, newly diagnosed post-ECMO CRD was associated with a 1.47-fold (95% CI: 1.17 to 1.86; P = 0.001) higher 5-year all-cause mortality.

Conclusions

At 12 months after ECMO therapy, 11.3% of ECMO survivors were newly diagnosed with CRDs. Patients who underwent ECMO therapy for ARDS or respiratory failure were associated with a higher incidence of newly diagnosed post-ECMO CRD compared to those who underwent ECMO for other causes. Additionally, post-ECMO CRDs were associated with a higher 5-year all-cause mortality. Our results suggest that ECMO survivors with newly diagnosed post-ECMO CRD might be a high-risk group requiring dedicated interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01796-8.

Extracorporeal membrane oxygenation in critically ill neonatal and pediatric patients with acute respiratory failure: a guide for the clinician

Intro: Extracorporeal membrane oxygenation for neonatal and pediatric respiratory failure continues to demonstrate improving outcomes, largely due to advances in technology along with refined management strategies despite mounting patient acuity and complexity. Successful use of ECMO requires thoughtful initiation and candidacy strategies, along with reducing the risk of ventilator induced lung injury and the progression to multiorgan failure.Areas Covered: This review describes current ECMO management strategies for neonatal and pediatric patients with acute refractory respiratory failure and summarizes relevant published literature. ECMO initiation and candidacy, along with ventilator and sedation management, are highlighted. Additionally, rapidly expanding areas of interest such as anticoagulation strategies, transfusion thresholds, rehabilitation on ECMO, and drug pharmacokinetics are described.Expert Opinion: Over the last few decades, published studies supporting ECMO use for acute refractory respiratory failure, along with institutional experience, have resulted in increased utilization although more randomized-controlled trials are needed. Future research should focus on filling the knowledge gaps that remain regarding anticoagulation, transfusion thresholds, ventilator strategies, sedation, and approaches to rehabilitation to subsequently implement into clinical practice. Additionally, efforts should focus on well-designed trials, including population pharmacokinetic studies, to develop dosing recommendations.

Beyond Frontiers: Feasibility and Outcomes of Prolonged Veno-Venous Extracorporeal Membrane Oxygenation in Severe Acute Respiratory Distress Syndrome

Extracorporeal membrane oxygenation (ECMO) use in acute respiratory failure is increasing. We aim to compare characteristics and outcomes of patients with prolonged (≥21 days) veno-venous (VV) ECMO runs (pECMO), to patients with short (<21 days) VV ECMO runs (sECMO). The observational retrospective single-center study compared patients who received VV ECMO from January 2018 to June 2019 at Prince Mohamed Bin Abdulaziz Center in Riyadh, Saudi Arabia. Forty-three patients were supported with VV ECMO during the study period, of whom 37 are included as six patients were still receiving ECMO at time of data collection: 24 sECMO and 13 pECMO patients. Baseline characteristics and comorbidities were similar except pECMO patients were older and had a lower P/F ratio (61 [58-68] vs. 71[58-85.5], p = 0.05). Survival to hospital discharge (69% vs. 83%, p = 0.32; pECMO vs. sECMO) and 90 day survival (62% vs. 75%, p = 0.413; pECMO vs. sECMO) were similar among groups. At 1 year follow-up, all patients were still alive and independently functioning except for one patient in the pECMO group who required a walking aid related to trauma. In this single-center study, patients requiring pECMO had similar short- and long-term survival to those requiring sECMO duration.

Long-term Respiratory Extracorporeal Membrane Oxygenation and Prognosis: A Retrospective Analysis

The duration of extracorporeal membrane oxygenation (ECMO) treatments increases, however, data presented from prolonged support is limited. We retrospectively analyzed all patients during a 4-year period undergoing respiratory ECMO for duration of therapy, demographics, therapy-associated parameters, and outcome according to ECMO duration (<28 days and ≥28 days = long-term ECMO). Out of 55 patients undergoing ECMO for ARDS or during bridging to lung transplantation, 18 were on ECMO for ≥28 days (33%). In the long-term group, median ECMO run time was 40 days (interquartile range 34-54 days). Hospital survival was not significantly different between the groups (54% in short-term and 50% in long-term ECMO patients). There was a significantly higher proportion of patients suffering from malignancy in the group of long-term nonsurvivors. Recovery occurred after more than 40 days on ECMO in 3 patients. The longest ECMO run time in a hospital survivor was 65 days. Duration of ECMO support alone was no prognostic factor and should not represent a basis for decision-making. In patients suffering from malignancy, long-term ECMO support seems to be a factor of adverse prognosis, if not futile.

Postoperative extracorporeal membrane oxygenation can successfully support patients following upper airway reconstruction

BACKGROUND

Patients requiring intensive upper airway reconstruction are anatomically restricted in terms of the respiratory support they can receive. While intraoperative extracorporeal membrane oxygenation (ECMO) has been effectively utilized, little has been shown regarding the utility of ECMO for long-term support in these patients.

METHODS

We demonstrate how a patient with tongue and hypopharyngeal squamous cell carcinoma that necessitated upper airway reconstruction was supported with veno-venous (VV) ECMO due to postoperative respiratory failure and an inability to maintain a stable airway.

RESULTS

By initiating VV ECMO, we were able to decrease positive pressure ventilation and FiO₂ , thereby minimizing ventilator-associated trauma and irritation to facilitate wound healing. Over time, ventilatory support was increased in parallel with decreasing ECMO support, allowing discharge to rehabilitation after 74 days of ECMO.

CONCLUSION

ECMO can effectively support patients with ongoing respiratory requirements following upper airway reconstruction when standard ventilatory techniques are inadequate or not feasible.

Timing it right: the challenge of recipient selection for lung transplantation

Selection criteria for the referral and potential listing of patients for lung transplantation (LTx) have changed considerably over the last three decades but one key maxim prevails, the ultimate focus is to increase longevity and quality of life by careful utilization of a rare and precious resource, the donor organs. In this article, we review how the changes have developed and the outcomes of those changes, highlighting the impact of the lung allocation score (LAS) system. Major diseases, including interstitial lung disease (ILD), chronic obstructive pulmonary disease and pulmonary hypertension are considered in detail as well as the concept of retransplantation where appropriate. Results from bridging to LTx using extracorporeal membrane oxygenation (ECMO) are discussed and other potential contraindications evaluated such as advanced age, frailty and resistant infections. Given the multiplicity of risk factors it is a credit to those working in the field that such excellent and improving results are obtained with an ongoing dedication to achieving best practice.

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.

Spontaneous breathing in patients with severe acute respiratory distress syndrome receiving prolonged extracorporeal membrane oxygenation

Background

The use of extracorporeal membrane oxygenation (ECMO) in awake, spontaneously breathing and non-intubated patients (awake ECMO) may be a novel therapeutic strategy for severe acute respiratory distress syndrome (ARDS) patients. The purpose of this study is to assess the feasibility and safety of awake ECMO in severe ARDS patients receiving prolonged ECMO (> 14 days).

Methods

We describe our experience with 12 consecutive severe ARDS patients (age, 39.1 ± 16.4 years) supported with awake ECMO to wait for native lung recovery during prolonged ECMO treatment from July 2013 to January 2018. Outcomes are reported including the hospital mortality, ECMO-related complications and physiological data on weaning from invasive ventilation.

Results

The patients received median 26.0 (15.5, 64.8) days of total ECMO duration in the cohort. The longest ECMO support duration was 121 days. Awake ECMO and extubation was implemented after median 10.2(5.0, 42.9) days of ECMO. Awake ECMO was not associated with increased morbidity. The total invasive ventilation duration, lengths of stay in the ICU and hospital in the cohort were 14.0(12.0, 37.3) days, 33.0(22.3, 56.5) days and 46.5(27.3, 84.8) days, respectively. The hospital mortality rate was 33.3% (4/12) in the cohort. Survivors had more stable respiratory rate and heart rate after extubation when compared to the non-survivors.

Conclusions

With carefully selected patients, awake ECMO is a feasible and safe strategy for severe pulmonary ARDS patients receiving prolonged ECMO support to wait for native lung recovery.

Veno-venous extracorporeal life support for blastomycosis-associated acute respiratory distress syndrome

BACKGROUND

Blastomyces is a dimorphic fungus endemic to regions of North America, which can lead to pneumonia and fatal severe acute respiratory diseases syndrome in up to 89% of patients. Extracorporeal life support can provide adequate oxygenation while allowing the lungs to rest and heal, which might be an ideal therapy in this patient group, although long-term clinical and radiological outcomes are not known.

CLINICAL FEATURES

We report on five consecutive patients admitted to Toronto General Hospital intensive care unit between January 2012 and September 2016, with progressive respiratory failure requiring veno-venous extracorporeal life support within 24-96 hours following mechanical ventilation. Ultra-lung protective mechanical ventilation was achieved within 24 hours. Recovery was the initial goal in all patients. Extracorporeal life support was provided for a prolonged period (up to 49 days), and four patients were successfully discharged from the intensive care unit. Long-term radiological assessment in three patients showed major improvement within 2 years of follow-up with some persistent disease-related changes (bronchiectasis, fibrosis, and cystic changes). In two patients, long-term functional and neuropsychological outcomes showed similar limitations to what is seen in acute respiratory distress syndrome patients who are not supported with extracorporeal life support and in acute respiratory distress syndrome patients without blastomycosis, but worse pulmonary function outcomes in the form of obstructive and restrictive changes that correlated with the radiological imaging.

CONCLUSION

Veno-venous extracorporeal life support can effectively provide prolonged support for patients with blastomycosis-associated acute respiratory distress syndrome that is safe and associated with favorable long-term outcomes.

Clinical outcomes of patients receiving prolonged extracorporeal membrane oxygenation for respiratory support

BACKGROUND

There are limited data regarding prolonged extracorporeal membrane oxygenation (ECMO) support, despite increase in ECMO use and duration in patients with respiratory failure. The objective of this study was to investigate the outcomes of severe acute respiratory failure patients supported with prolonged ECMO for more than 28 days.

METHODS

Between January 2012 and December 2015, all consecutive adult patients with severe acute respiratory failure who underwent ECMO for respiratory support at 16 tertiary or university-affiliated hospitals in South Korea were enrolled retrospectively. The patients were divided into two groups: short-term group defined as ECMO for ⩽28 days and long-term group defined as ECMO for more than 28 days. In-hospital and 6-month mortalities were compared between the two groups.

RESULTS

A total of 487 patients received ECMO support for acute respiratory failure during the study period, and the median support duration was 8 days (4-20 days). Of these patients, 411 (84.4%) received ECMO support for ⩽28 days (short-term group), and 76 (15.6%) received support for more than 28 days (long-term group). The proportion of acute exacerbation of interstitial lung disease as a cause of respiratory failure was higher in the long-term group than in the short-term group (22.4% versus 7.5%, p < 0.001), and the duration of mechanical ventilation before ECMO was longer (4 days versus 1 day, p < 0.001). The hospital mortality rate (60.8% versus 69.7%, p = 0.141) and the 6-month mortality rate (66.2% versus 74.0%, p = 0.196) were not different between the two groups. ECMO support longer than 28 days was not associated with hospital mortality in univariable and multivariable analyses.

CONCLUSIONS

Short- and long-term survival rates among patients receiving ECMO support for more than 28 days for severe acute respiratory failure were not worse than those among patients receiving ECMO for 28 days or less.

Weaning from prolonged veno-venous extracorporeal membrane oxygenation (ECMO) after transfer to a specialized center: a retrospective study

Veno-venous extracorporeal membrane oxygenation (vvECMO) is increasingly used as rescue therapy in severe respiratory failure. In patients with pre-existent lung diseases or persistent lung injury weaning from vvECMO can be challenging. This study sought to investigate outcomes of patients transferred to a specialized ECMO center after prolonged ECMO therapy. We performed a retrospective analysis of all patients admitted to our medical intensive care unit (ICU) between 01/2013 and 12/2016 who were transferred from an external ICU after > 8 days on vvECMO. 12 patients on ECMO for > 8 days were identified. Prior to transfer, patients underwent ECMO therapy for 18 ± 9.5 days. Total time on ECMO was 60 ± 46.6 days. 11/12 patients could be successfully weaned from ECMO, 7/12 in the first 28 days after transfer (8 ± 8.8 ECMO-free days at day 28). In 7 patients, ECMO could be terminated after at least partial lung recovery, in 4 patients after salvage lung transplant. No patient died or needed re-initiation of ECMO therapy at day 28. In summary, weaning from vvECMO was feasible even after prolonged ECMO courses and salvage lung transplant could be avoided in most cases. Patients may benefit from transfer to a specialized ECMO center.

Idiopathic pulmonary fibrosis patient supported with extracorporeal membrane oxygenation for 403 days while waiting for a lung transplant: A case report

According to the Extracorporeal Life Support Organization, the average duration of veno-venous extracorporeal membrane oxygenation (V-V ECMO) in adults with acute respiratory failure is 10.5-13.5 days. Some patients on V-V ECMO may not recover in such a short period of time, and recently, there have been more reports of prolonged V-V ECMO. However, we do not know how long it is feasible to wait for native lung recovery or lung transplant (LTx) with the use of ECMO. We describe a patient with acute exacerbation of idiopathic pulmonary fibrosis supported by ECMO for 403 days while waiting for a LTx. In this case, we kept the patient awake, and he was communicating frequently with his family. We changed the membrane oxygenator 23 times and the cannula 10 times without complication. However, we terminated the treatment on day 403 of ECMO because there was no access site for cannula insertion due to blockage by a venous thrombotic occlusion, making it impossible to continue this bridge to lung transplantation. It has become possible to maintain patients on ECMO for extended periods of time, but it is difficult to manage ECMO for more than one year without the development of a more durable lung support system.

One-Year Experience With a Mobile Extracorporeal Life Support Service

BACKGROUND

Severe acute respiratory distress syndrome is associated with a high mortality rate. The International Extracorporeal Membrane Oxygenation Network recommends regionalization of extracorporeal life support (ECLS) to high-volume centers and development of mobile ECLS teams to rescue patients with severe acute respiratory disease.

METHODS

A tertiary medical center developed a mobile team and the infrastructure to support a ECLS transport service available 24 hours a day, 7 days a week. We conducted a retrospective study of all consecutive patients presenting for ECLS for severe acute respiratory distress syndrome from outside hospitals through our mobile ECLS program associated with hemodynamic instability from January 1, 2015, until December 31, 2015.

RESULTS

During the study period, 106 consultations for ECLS were received, and 36 patients were placed on ECLS. Of these 36 ECLS patients, 11 were deemed stable enough for transport before ECLS, and 21 required mobile ECLS by the mobile ECLS, with a survival of 67% (14 of 21). The other 4 ECLS patients were inhouse patients and therefore received ECLS in a nonmobile fashion. In addition, 28 patients were transferred to our hospital who did not receive ECLS. Patient survival increased significantly with increased experience with the program, as the highest mortality rates were early in the program (p = 0.006), and in conjunction with stricter adherence to our exclusion criteria.

CONCLUSIONS

The formation of a mobile ECLS program is a complex undertaking that took 2 years of planning to develop. Development of criteria for ECLS implementation can guide appropriate resources utilization and may prevent their use in patients with little to no chance of survival.

Extracorporeal Membrane Oxygenation (ECMO) for Lung Injury in Severe Acute Respiratory Distress Syndrome (ARDS): Review of the Literature

Despite advances in mechanical ventilation, severe acute respiratory distress syndrome (ARDS) is associated with high morbidity and mortality rates ranging from 26% to 58%. Extracorporeal membrane oxygenation (ECMO) is a modified cardiopulmonary bypass circuit that serves as an artificial membrane lung and blood pump to provide gas exchange and systemic perfusion for patients when their own heart and lungs are unable to function adequately. ECMO is a complex network that provides oxygenation and ventilation and allows the lungs to rest and recover from respiratory failure while minimizing iatrogenic ventilator-induced lung injury. In critical care settings, ECMO is proven to improve survival rates and outcomes in patients with severe ARDS. This review defines severe ARDS; describes the ECMO circuit; and discusses recent research, optimal use of the ECMO circuit, limitations of therapy including potential complications, economic impact, and logistical factors; and discusses future research considerations.

Extracorporeal Membrane Oxygenation (ECMO)/Extracorporeal Carbon Dioxide Removal (ECCO2R)

Extracorporeal membrane oxygenation (ECMO) is a means of supporting severe pulmonary and cardiac dysfunction. It stabilizes critical derangements of oxygenation and ventilation, allowing time to diagnose, treat, and recover from the underlying cause of organ failure. The extracorporeal circuit has three main components: large-bore cannulae and circuit tubing to provide access to the native circulation, an artificial membrane lung to provide gas exchange, and an active pump to facilitate perfusion. Multiple clinical studies have evaluated this technology, the strongest evidence to date supporting its use being the Conventional Ventilation or ECMO for Severe Adult Respiratory Failure (CESAR) trial, which showed survival advantage when patients were treated with a protocol that included ECMO. Extracorporeal carbon dioxide removal (ECCO₂R) is similar in concept to ECMO, but has a lower flow rate and does not significantly oxygenate the patient. It is a primary treatment for hypercarbic respiratory failure or is an adjunct to reduce potentially injurious levels of mechanical ventilator support in hypoxemic respiratory failure. Complications are common occurrences on both types of therapy. Strong institutional commitment and a team approach are critical to successful implementation. Additional randomized trials are needed to clarify the appropriate indications and best practices for these lifesaving therapies.

Long-Term Venovenous Extracorporeal Membrane Oxygenation Support for Acute Respiratory Distress Syndrome

BACKGROUND

Given substantial advances in venovenous extracorporeal membrane oxygenation (ECMO) technology, long-term support is increasingly feasible. Although the benefits of short-term ECMO as a bridge to recovery in acute respiratory distress syndrome (ARDS) are well described, the utility and outcomes of long-term support remain unclear.

METHODS

Patients requiring ECMO for ARDS between January 2009 and November 2012 were retrospectively reviewed and analyzed separately for those requiring ECMO support for less than 3 weeks or for 3 weeks or longer. Demographic factors, ECMO variables, and outcomes were assessed.

RESULTS

Fifty-five patients with ARDS received ECMO during the study period, with 11 patients requiring long-term ECMO support and a median duration of 36 (interquartile range: 24 to 68) days. Recovery was the initial goal in all patients. Pre-ECMO mechanical ventilatory support, indices of disease severity, and the ECMO cannulation strategy were similar between the two groups. Eight (73%) patients receiving long-term support were bridged to recovery, and 1 patient was bridged to transplantation after a refractory course. Eight (73%) patients receiving long-term support and 25 (57%) patients receiving short-term support survived to 30 days and hospital discharge.

CONCLUSIONS

Previously, long-term ECMO support was thought to be associated with unfavorable outcomes. This study, however, may provide support for the efficacy of ECMO support even for 3 weeks or more as a bridge to recovery or transplantation.

Extracorporeal life support: experience with 2,000 patients

This is a review of the University of Michigan experience with extracorporeal life support (ECLS) also known as extracorporeal membrane oxygenation (ECMO). Two thousand patients were managed with ECMO from 1973 to 2010. The first 1,000 patients were reported previously. Of the 2,000 patients, 74% were weaned from ECLS, and 64% survived to hospital discharge. In patients with respiratory failure, survival to hospital discharge was 84% in 799 neonates, 76% in 239 children, and 50% in 353 adults. Survival in patients with cardiac failure was 45% in 361 children and 38% in 119 adults. ECLS during extracorporeal cardiopulmonary resuscitation was performed in 129 patients, with 41% surviving to discharge. Survival decreased from 74 to 55% between the first and second 1,000 patients. The most common complication was bleeding at sites other than the head, with an incidence of 39%, and the least frequent complication was pump malfunction, with a 2% incidence. Intracranial bleeding or infarction occurred in 8% of patients, with a 43% survival rate. This is the largest series of ECLS at one institution reported in the world to date. Our experience has shown that ECLS saves lives of moribund patients with acute pulmonary and cardiac failure in all age groups.

Efficacy of veno-venous extracorporeal membrane oxygenation in severe acute respiratory failure

PURPOSE

The objective of this study was to evaluate our institutional experience with veno-venous (VV) extracorporeal membrane oxygenation (ECMO) in patients with severe acute respiratory failure (ARF).

MATERIALS AND METHODS

From January 2007 to August 2013, 31 patients with severe ARF that was due to various causes and refractory to mechanical ventilation with conventional therapy were supported with VV ECMO. A partial pressure of arterial oxygen (PaO₂)/inspired fraction of oxygen (FiO₂) <100 mm Hg at an FiO₂ of 1.0 or a pH <7.25 due to CO₂ retention were set as criteria for VV ECMO.

RESULTS

Overall, 68% of patients survived among those who had received VV ECMO with a mean PaO₂/FiO₂ of 56.8 mm Hg. Furthermore, in trauma patients, early use of ECMO had the best outcome with a 94% survival rate.

CONCLUSION

VV ECMO is an excellent, life-saving treatment option in patients suffering from acute and life-threatening respiratory failure due to various causes, especially trauma, and early use of VV ECMO therapy improved outcomes in these patients.