Systematic review and meta-analysis of complications and mortality of veno-venous extracorporeal membrane oxygenation for refractory acute respiratory distress syndrome

Characterizing the Relationship Between Arterial Carbon Dioxide Trajectory and Serial Brain Biomarkers with Central Nervous System Injury During Veno-Venous Extracorporeal Membrane Oxygenation: A Prospective Cohort Study

BACKGROUND

Central nervous system (CNS) injury following initiation of veno-venous extracorporeal membrane oxygenation (VV-ECMO) is common. An acute decrease in partial pressure of arterial carbon dioxide (PaCO2) following VV-ECMO initiation has been suggested as an etiological factor, but the challenges of diagnosing CNS injuries has made discerning a relationship between PaCO2 and CNS injury difficult.

METHODS

We conducted a prospective cohort study of adult patients undergoing VV-ECMO for acute respiratory failure. Arterial blood gas measurements were obtained prior to initiation of VV-ECMO, and at every 2-4 h for the first 24 h. Neuroimaging was conducted within the first 7-14 days in patients who were suspected of having neurological injury or unable to be examined because of sedation. We collected blood biospecimens to measure brain biomarkers [neurofilament light (NF-L); glial fibrillary acidic protein (GFAP); and phosphorylated-tau 181] in the first 7 days following initiation of VV-ECMO. We assessed the relationship between both PaCO2 over the first 24 h and brain biomarkers with CNS injury using mixed methods linear regression. Finally, we explored the effects of absolute change of PaCO2 on serum levels of neurological biomarkers by separate mixed methods linear regression for each biomarker using three PaCO2 exposures hypothesized to result in CNS injury.

RESULTS

In our cohort, 12 of 59 (20%) patients had overt CNS injury identified on head computed tomography. The PaCO2 decrease with VV-ECMO initiation was steeper in patients who developed a CNS injury (- 0.32%, 95% confidence interval - 0.25 to - 0.39) compared with those without (- 0.18%, 95% confidence interval - 0.14 to - 0.21, P interaction < 0.001). The mean concentration of NF-L increased over time and was higher in those with a CNS injury (464 [739]) compared with those without (127 [257]; P = 0.001). GFAP was higher in those with a CNS injury (4278 [11,653] pg/ml) compared with those without (116 [108] pg/ml; P < 0.001). The mean NF-L, GFAP, and tau over time in patients stratified by the three thresholds of absolute change of PaCO2 showed no differences and had no significant interaction for time.

CONCLUSIONS

Although rapid decreases in PaCO2 following initiation of VV-ECMO were slightly greater in patients who had CNS injuries versus those without, data overlap and absence of relationships between PaCO2 and brain biomarkers suggests other pathophysiologic variables are likely at play.

Anti-Xa-guided Anticoagulation With Unfractionated Heparin and Thrombosis During Extracorporeal Membrane Oxygenation Support: A Systematic Review and Meta-analysis

OBJECTIVE

The initiation of extracorporeal membrane oxygenation (ECMO) triggers complex coagulation processes necessitating systemic anticoagulation. Therefore, anticoagulation monitoring is crucial to avoid adverse events such as thrombosis and hemorrhage. The main aim of this work was to analyze the association between anti-Xa levels and thrombosis occurrence during ECMO support.

DESIGN

Systematic literature review and meta-analysis (Scopus and PubMed, up to July 29, 2023).

SETTING

All retrospective and prospective studies.

PARTICIPANTS

Patients receiving ECMO support.

INTERVENTION

Anticoagulation monitoring during ECMO support.

MEASUREMENTS AND MAIN RESULTS

A total of 16 articles with 1,968 patients were included in the review and 7 studies in the meta-analysis (n = 374). Patients with thrombosis had significantly lower mean anti-Xa values (standardized mean difference -0.36, 95% confidence interval [CI] -0.62 to -0.11, p < 0.01). Furthermore, a positive correlation was observed between unfractionated heparin infusion and anti-Xa levels (pooled estimate of correlation coefficients 0.31, 95% CI 0.19 to 0.43, p < 0.001). The most common adverse events were major bleeding (42%) and any kind of hemorrhage (36%), followed by thromboembolic events (30%) and circuit or oxygenator membrane thrombosis (19%). More than half of the patients did not survive to discharge (52%).

CONCLUSIONS

This work revealed significantly lower levels of anti-Xa in patients experiencing thromboembolic events and a positive correlation between anti-Xa and unfractionated heparin infusion. Considering the contemplative limitations of conventional monitoring tools, further research on the role of anti-Xa is warranted. New trials should be encouraged to confirm these findings and determine the most suitable monitoring strategy for patients receiving ECMO support.

Usefulness of net retrieval devices for central airway obstruction caused by blood clots during extracorporeal membrane oxygenation: Case series

RATIONALE

Extracorporeal membrane oxygenation (ECMO) is the last trump card for severe respiratory failure. The main complications of ECMO are bleeding and thrombosis, both of which can be life-threatening. Large blood clots can cause central airway obstruction (CAO) during ECMO, and CAO should be removed as soon as possible because of asphyxiation. However, there is no comprehensive reports on its frequency and management. The purpose of this study is to share therapeutic experiences for rare and serious conditions and provide valuable insights.

PATIENT CONCERNS

We report 3 patients placed on ECMO for severe respiratory failure.

DIAGNOSIS

CAO due to large blood clots occurred during ECMO in all 3 patients.

INTERVENTIONS

Large blood clots were removed using flexible bronchoscopy, grasping forceps, and net retrieval devices in all 3 patients.

OUTCOMES

In all 3 patients, large blood clots were removed multiple times during ECMO. The patients' respiratory conditions improved and they were eventually weaned off the ECMO.

LESSONS

CAO due to large blood clots during ECMO is rare. The frequency of CAO requiring bronchoscopic removal was estimated to be approximately 1,5%. When this occurs, clots should be removed as soon as possible. Net retrieval devices are useful tools for the collection of large blood clots.

Progress towards permanent respiratory support

PURPOSE OF REVIEW

Although lung transplantation stands as the gold standard curative therapy option for end-stage lung disease, the scarcity of available organs poses a significant challenge in meeting the escalating demand. This review provides an overview of recent advancements in ambulatory respiratory assist systems, selective anticoagulation therapies that target the intrinsic pathway, and innovative surface coatings to enable permanent respiratory support as a viable alternative to lung transplantation.

RECENT FINDINGS

Several emerging ambulatory respiratory assist systems have shown promise in both preclinical and clinical trials. These systems aim to create more biocompatible, compact, and portable forms of extracorporeal membrane oxygenation that can provide long-term respiratory support. Additionally, innovative selective anticoagulation strategies, currently in various stages of preclinical or clinical development, present a promising alternative to currently utilized nonselective anticoagulants. Moreover, novel surface coatings hold the potential to locally prevent artificial surface-induced thrombosis and minimize bleeding risks.

SUMMARY

This review of recent advancements toward permanent respiratory support summarizes the development of ambulatory respiratory assist systems, selective anticoagulation therapies, and novel surface coatings. The integration of these evolving device technologies with targeted anticoagulation strategies may allow a safe and effective mode of permanent respiratory support for patients with chronic lung disease.

Extracorporeal Membrane Oxygenation in Amniotic Fluid Embolism: A Systematic Review of Case Reports

Amniotic fluid embolism (AFE) is an obstetric complication that can result in acute circulatory failure during and after labor. The effectiveness of extracorporeal membrane oxygenation (ECMO) in AFE patients has not been established, especially in the context of coagulopathy. This review aims to evaluate the efficacy of ECMO support in AFE patients. We conducted a systematic review of case reports following the Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Quality assessment was performed using a standardized tool. Out of 141 studies screened, 33 studies included 79 AFE patients. The median age was 34 years, and the median gestational age was 37.5 weeks. The majority of AFE cases occurred during cesarean section delivery (55.2%), followed by labor before fetal delivery (26.7%). Extracorporeal membrane oxygenation configurations included venoarterial ECMO (81.3%) and extracorporeal cardiopulmonary resuscitation (CPR, 10.7%). The maternal survival rate was 72%, with 21.2% experiencing minor neurological sequelae and 5.8% having major neurological sequelae. Rescue ECMO to support circulation has demonstrated both safety and efficacy in managing AFE. We suggest early activation of local or mobile ECMO as soon as an AFE diagnosis is established. Further studies are needed to assess the benefits and implications of early ECMO support in AFE patients.

Prevalence and risk factors for in-hospital mortality of adult patients on veno-arterial extracorporeal membrane oxygenation for cardiogenic shock and cardiac arrest: A systematic review and meta-analysis

OBJECTIVES

To synthesize quantitative research findings on the prevalence and risk factors for in-hospital mortality of patients on veno-arterial extracorporeal membrane oxygenation (VA-ECMO).

METHODS

A comprehensive search was conducted for the period from May 2008 to December 2023 by searching the five electronic databases of PubMed, CINAHL, Web of Science, EMBASE, and Cochrane library. The quality of included studies was assessed using the Newcastle-Ottawa scale. The meta-analysis estimated the pooled odds ratio or standard mean difference and 95% confidence intervals.

RESULTS

A total of twenty-five studies with 10,409 patients were included in the analysis. The overall in-hospital mortality of patients on VA-ECMO was 56.7 %. In the subgroup analysis, in-hospital mortality of VA-ECMO for cardiogenic shock and cardiac arrest was 49.2 % and 75.2 %, respectively. The number of significant factors associated with an increased risk of in-hospital mortality in the pre-ECMO period (age, body weight, creatinine, chronic kidney disease, pH, and lactic acid) was greater than that in the intra- and post-ECMO periods. Renal replacement, bleeding, and lower limb ischemia were the most significant risk factors for in-hospital mortality in patients receiving VA-ECMO.

CONCLUSION

Early detection of the identified risk factors can contribute to reducing in-hospital mortality in patients on VA-ECMO. Intensive care unit nurses should provide timely and appropriate care before, during, and after VA-ECMO.

IMPLICATIONS FOR CLINICAL PRACTICE

Intensive care unit nurses should be knowledgeable about factors associated with the in-hospital mortality of patients on VA-ECMO to improve outcomes. The present findings may contribute to developing guidelines for reducing in-hospital mortality among patients considering ECMO.

Candent issues in pneumonia. Reflections from the Fifth Annual Meeting of Spanish Experts 2023

Pneumonia is a multifaceted illness with a wide range of clinical manifestations, degree of severity and multiple potential causing microorganisms. Despite the intensive research of recent decades, community-acquired pneumonia remains the third-highest cause of mortality in developed countries and the first due to infections; and hospital-acquired pneumonia is the main cause of death from nosocomial infection in critically ill patients. Guidelines for management of this disease are available world wide, but there are questions which generate controversy, and the latest advances make it difficult to stay them up to date. A multidisciplinary approach can overcome these limitations and can also aid to improve clinical results. Spanish medical societies involved in diagnosis and treatment of pneumonia have made a collaborative effort to actualize and integrate last expertise about this infection. The aim of this paper is to reflect this knowledge, communicated in Fifth Pneumonia Day in Spain. It reviews the most important questions about this disorder, such as microbiological diagnosis, advances in antibiotic and sequential therapy, management of beta-lactam allergic patient, preventive measures, management of unusual or multi-resistant microorganisms and adjuvant or advanced therapies in Intensive Care Unit.

Tube Thoracostomy Complications in Patients With ARDS Requiring ECMO: Worse in COVID-19 Patients?

INTRODUCTION

The incidence and management outcomes of COVID-19 patients with acute respiratory distress syndrome (ARDS) on veno-venous extracorporeal membrane oxygenation (V-V ECMO) requiring chest tubes are not well-described. This study sought to explore differences in tube thoracostomy rates and subsequent complications between patients with and without COVID-19 ARDS on V-V ECMO.

MATERIALS AND METHODS

This study is a single institution, retrospective cohort study of patients with COVID-19 ARDS requiring V-V ECMO. The control cohort consisted of patients who required V-V ECMO for ARDS-related diagnoses from January 2018 to January 2021. The primary outcome was any complication following initial tube thoracostomy placement. Study approval was obtained from the Brooke Army Medical Center Institutional Review Board (C.2017.152d).

RESULTS

Twenty-five COVID-19 patients and 38 controls were included. Demographic parameters did not differ between the groups. The incidence of pneumothorax was not significantly different between the two groups (44% COVID-19 vs. 22% control, OR 2.8, 95% CI 0.95-7.9, P = 0.09). Patients with COVID-19 were as likely to receive tube thoracostomy as controls (36% vs. 24%, OR 1.8, 95% CI 0.55-5.7). Complications, however, were more likely to occur in the COVID-19 group (89% vs. 33%, OR 16, 95% CI, 1.6-201, P = 0.0498).

CONCLUSIONS

Tube thoracostomy placement in COVID-19 patients with ARDS requiring V-V ECMO is common, as are complications following initial placement. Clinicians should anticipate the need for re-intervention in this patient population. Small-bore (14Fr and smaller) pigtail catheters appeared to be safe and efficacious in this setting, but further study on tube thoracostomy management in ECMO patients is needed.

Extracorporeal Membrane Oxygenation in Acute Respiratory Failure due to Hemorrhagic Alveolitis in a Patient with Acute Myeloblastic Leukemia

Introduction. Extracorporeal membrane oxygenation (ECMO) support for severe acute respiratory distress syndrome (ARDS) is nowadays widely used with notable results on the overall survival as reported in the ELSO registry near to 55% at 90 days. This is the reason why ECMO teams force the use of this extreme technique to several populations, even though there is still a lack of data about its use on hematological patients. Case Report. A 39-year-old woman without a history of previous diseases, but a new diagnosis of acute myeloblastic leukemia (AML) was admitted to intensive care unit (ICU) for worsening hypoxia and respiratory acidosis, presenting an ARDS with PaO2/FiO2 < 100 in spontaneous breathing treated with noninvasive ventilation via full-face mask. Meanwhile, chemotherapy was started leading to a severe bone marrow aplasia that was managed with multiple blood and platelet transfusions. These conditions did not allow physicians to start any invasive approaches. After 14 days, ARDS worsened whereas bone marrow recovered, making possible the beginning of an invasive mechanical ventilation, with low positive end-expiratory pressure and a low tidal volume. Moreover, an immediate extracorporeal CO2 removal (ECCO2R) therapy was added. Despite these efforts, no improvement was achieved, and that is why venovenous ECMO throughout femoral-jugular cannulation was applied. A full protective lung ventilation by ultralow tidal volumes was guaranteed. After 2 weeks of ECMO, a gradual weaning from ECMO support was started and completed after two days. No ECMO-related complications were registered. In the end, the patient started her weaning from the mechanical ventilation and reached 12 hours of spontaneous ventilation in oxygen therapy. Discussion. ECMO is used as a rescue therapy in patients affected by severe respiratory failure with life-threatening hypoxia and respiratory acidosis nonresponsive to other maneuvers. However, immunosuppression and coagulopathies of hematological malignancies are considered relative contraindications for ECMO, while long-lasting respiratory failure represents another relative contraindication to extracorporeal support. ECMO could be a valid option to improve the survival of hematological patients with severe ARDS and thrombocytopenia, and management could change case by case, even if high incidence of recurrency.

Outcomes of Severe ARDS COVID-19 Patients Denied for Venovenous ECMO Support: A Prospective Observational Comparative Study

Background: Few data are available concerning the outcome of patients denied venovenous extracorporeal membrane oxygenation (VV-ECMO) relative to severe acute respiratory distress syndrome (ARDS) due to COVID-19. Methods: We compared the 90-day survival rate of consecutive adult patients for whom our center was contacted to discuss VV-ECMO indication. Three groups of patients were created: patients for whom VV-ECMO was immediately indicated (ECMO-indicated group), patients for whom VV-ECMO was not indicated at the time of the call (ECMO-not-indicated group), and patients for whom ECMO was definitely contraindicated (ECMO-contraindicated group). Results: In total, 104 patients were referred for VV-ECMO support due to severe COVID-19 ARDS. Among them, 32 patients had immediate VV-ECMO implantation, 28 patients had no VV-ECMO indication, but 1 was assisted thereafter, and 44 patients were denied VV-ECMO for contraindication. Among the 44 patients denied, 30 were denied for advanced age, 24 for excessive prior duration of mechanical ventilation, and 16 for SOFA score >8. The 90-day survival rate was similar for the ECMO-indicated group and the ECMO-not-indicated group at 62.1 and 61.9%, respectively, whereas it was significantly lower (20.5%) for the ECMO-contraindicated group. Conclusions: Despite a low survival rate, 50% of patients were at home 3 months after being denied for VV-ECMO for severe ARDS due to COVID-19.

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

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

Use of venovenous (VV) extracorporeal membrane oxygenation (ECMO) in near-fatal asthma: a case series

Introduction

Status asthmaticus (SA) and near-fatal asthma (NFA) are life-threatening conditions that continue to present a management challenge for physicians. Extracorporeal Membrane Oxygenation (ECMO) has been employed as a last resort in treating these patients.

Case presentation

We described six patients who were admitted to the ICU for NFA and received ECMO treatment at a high-complexity institution in Cali, Colombia, between 2015 and 2019. All patients are registered in the ELSO registry. Baseline patient characteristics, arterial blood gases (ABG), ventilatory parameters, and complications were collected as specified in the ELSO registry form. Efficacy was analyzed in terms of the improvement in respiratory acidosis, the number of ventilator-free days (VFD), and a reduction in mechanical power (MP). MP, which refers to the energy associated with the mechanical forces involved in breathing and the functioning of the respiratory system, was calculated using a mathematical formula. Safety was evaluated based on the incidence of complications. After 12 hours of ECMO, we achieved a correction of respiratory acidosis, a significant decrease in all ventilatory parameters, and a reduction in MP ranging from 52.8% to 89%. There was one mortality. Among the five surviving patients, all except one, who required a tracheostomy, had a high VFD score, with a mode of 26 days, demonstrating a reduction in ventilation time.

Conclusion

Further randomized controlled trials are needed to fully understand the efficacy and safety profiles of ECMO in SA/NFA. MP is being widely used to achieve safer ventilation, and although more data is required, it appears to be a promising option for evaluating the risk of developing VILI and the success of the therapy.

Treatment of Refractory Cardiac Arrest by Controlled Reperfusion of the Whole Body: A Multicenter, Prospective Observational Study

Background: Survival following cardiac arrest (CA) remains poor after conventional cardiopulmonary resuscitation (CCPR) (6-26%), and the outcomes after extracorporeal cardiopulmonary resuscitation (ECPR) are often inconsistent. Poor survival is a consequence of CA, low-flow states during CCPR, multi-organ injury, insufficient monitoring, and delayed treatment of the causative condition. We developed a new strategy to address these issues. Methods: This all-comers, multicenter, prospective observational study (69 patients with in- and out-of-hospital CA (IHCA and OHCA) after prolonged refractory CCPR) focused on extracorporeal cardiopulmonary support, comprehensive monitoring, multi-organ repair, and the potential for out-of-hospital cannulation and treatment. Result: The overall survival rate at hospital discharge was 42.0%, and a favorable neurological outcome (CPC 1+2) at 90 days was achieved for 79.3% of survivors (CPC 1+2 survival 33%). IHCA survival was very favorable (51.7%), as was CPC 1+2 survival at 90 days (41%). Survival of OHCA patients was 35% and CPC 1+2 survival at 90 days was 28%. The subgroup of OHCA patients with pre-hospital cannulation showed a superior survival rate of 57.1%. Conclusions: This new strategy focusing on repairing damage to multiple organs appears to improve outcomes after CA, and these findings should provide a sound basis for further research in this area.

Factors associated with 30-day in-hospital mortality in critically ill adult patients receiving extracorporeal membrane oxygenation: A retrospective cohort study

OBJECTIVE

To identify factors associated with the 30-day in-hospital mortality rate among adult patients requiring extracorporeal membrane oxygenation (ECMO) in intensive care units.

RESEARCH METHODOLOGY

Retrospective cohort study including 148 patients who underwent ECMO for at least 48 h between March 2010 and August 2021. The patients were divided into survivors and non-survivors based on their 30-day in-hospital survival. We obtained the sociodemographic information and pre- and post-ECMO data from electronic medical records. Kaplan-Meier survival curves and Multivariate Cox proportional hazards regression were used to analyse the data.

SETTING

A tertiary-care university hospital in South Korea.

MAIN OUTCOME MEASURES

The 30-day in-hospital mortality rate was the principal outcome measure.

RESULTS

The 30-day in-hospital mortality rate was 49.3% (n = 73). Kaplan-Meier analysis demonstrated that the duration of ECMO support in the 50th percentile of surviving patients was 13 days. Multivariable Cox regression analysis showed that new-onset renal failure, lower mean arterial pressure, and ECMO weaning failure were associated with an increased 30-day in-hospital mortality risk among patients who received ECMO. Subgroup analysis also revealed a significant association between weaning failure and 30-day in-hospital mortality after adjusting for covariates in patients undergoing veno-arterial ECMO.

CONCLUSION

Close monitoring of post-ECMO renal function and mean arterial pressure is required to minimize the risk of 30-day in-hospital mortality, especially in adults within the first two weeks of ECMO initiation. Moreover, the success of ECMO weaning should be optimized by collaboration within the ECMO team.

IMPLICATIONS FOR CLINICAL PRACTICE

Critical care nurses should pay close attention to patients' response to weaning trials as well as alternations in renal function and mean arterial pressure during ECMO support. Furthermore, developing nursing care guidelines for adult patients receiving ECMO and standardized training programs for nurses in intensive care, are required in Korea.

Extracorporeal Cardiopulmonary Resuscitation

BACKGROUND

Around the world, survival rates after cardiac arrest range between <14% for in-hospital (IHCA) and <10% for outof- hospital cardiac arrest (OHCA). This situation could potentially be improved by using extracorporeal membrane oxygenation (ECMO) during cardiopulmonary resuscitation (CPR), i.e. by extracorporeal cardiopulmonary resuscitation (ECPR).

METHODS

A selective literature search of Pubmed and Embase using the searching string ((ECMO) OR (ECLS)) AND (ECPR)) was carried out in February 2023 to prepare an up-to-date review of published trials comparing the outcomes of ECPR with those of conventional CPR.

RESULTS

Out of 573 initial results, 12 studies were included in this review, among them three randomized controlled trials comparing ECPR with CPR, involving a total of 420 patients. The survival rates for ECPR ranged from 20% to 43% for OHCA and 20% to 30.4% for IHCA. Most of the publications were associated with a high degree of bias and a low level of evidence.

CONCLUSION

ECPR can potentially improve survival rates after cardiac arrest compared to conventional CPR when used in experienced, high-volume centers in highly selected patients (young age, initial shockable rhythm, witnessed cardiac arrest, therapy-refractory high-quality CPR). No general recommendation for the use of ECPR can be issued at present.

[When mechanical ventilation fails-Venovenous extracorporeal membrane oxygenation]

Venovenous extracorporeal membrane oxygenation (VV-ECMO) is predominantly being used as a rescue strategy in patients with acute lung failure, suffering from severe oxygenation and/or decarboxylation impairment. Cannulas introduced into the central veins lead blood through a membrane oxygenator in which it is oxygenated via sweep gas (pO2 up to 600 mm Hg) flow, eliminating CO2. According to the largest randomized studies carried out so far, the two most important indications for VV-ECMO are hypoxic respiratory failure (paO2 < 80 mm Hg for more than 6 h) and refractory hypercapnia (pH < 7.25 und pCO2 > 60 mm Hg with a breathing frequency of >30/min) despite optimal protective mechanical ventilation settings (ARDS, Δp < 14 mbar, plateau pressure < 30 mbar, tidal volume VT < 6 ml/kg idealized body weight). Relative contraindications are life-limiting comorbidities and terminal pulmonary diseases that cannot be treated by lung transplantation. Advanced patient age is not regarded as an absolute contraindication, though it highly impacts ARDS survival rates, especially for pneumonia associated with coronavirus disease 2019 (COVID-19). The most frequent complications of VV-ECMO include bleeding, thrombus formation and rare cases of cannula-associated infections. Its use in nonintubated patients (awake ECMO) is possible in specific cases and has proven valuable as a bridge to lung transplant approach. Some ECMO centers offer cannulation of a patient at primary care hospitals, facilitating subsequent transport to the center (ECMO transport). The COVID-19 pandemic not only caused the number of VV-ECMO runs to skyrocket but has also drawn public attention to this extracorporeal procedure. Strict quality control to improve vvECMO outcomes according to the German hospital reform is urgently needed, especially so since the technique has a high demand in resources and bears significant risks when performed by untrained personnel.

Extracorporeal membrane oxygenation for critically ill adults

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) may provide benefit in certain populations of adults, including those with severe cardiac failure, severe respiratory failure, and cardiac arrest. However, it is also associated with serious short- and long-term complications, and there remains a lack of high-quality evidence to guide practice. Recently several large randomized controlled trials (RCTs) have been published, therefore, we undertook an update of our previous systematic review published in 2014.

OBJECTIVES

To evaluate whether venovenous (VV), venoarterial (VA), or ECMO cardiopulmonary resuscitation (ECPR) improve mortality compared to conventional cardiopulmonary support in critically ill adults.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was March 2022. The search was limited to English language only.

SELECTION CRITERIA

We included RCTs, quasi-RCTs, and cluster-RCTs that compared VV ECMO, VA ECMO or ECPR to conventional support in critically ill adults.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcome was 1. all-cause mortality at day 90 to one year. Our secondary outcomes were 2. length of hospital stay, 3. survival to discharge, 4. disability, 5. adverse outcomes/safety events, 6. health-related quality of life, 7. longer-term health status, and 8. cost-effectiveness. We used GRADE to assess certainty of evidence.

MAIN RESULTS

Five RCTs met our inclusion criteria, with four new studies being added to the original review (total 757 participants). Two studies were of VV ECMO (429 participants), one VA ECMO (41 participants), and two ECPR (285 participants). Four RCTs had a low risk of bias and one was unclear, and the overall certainty of the results (GRADE score) was moderate, reduced primarily due to indirectness of the study populations and interventions. ECMO was associated with a reduction in 90-day to one-year mortality compared to conventional treatment (risk ratio [RR] 0.80, 95% confidence interval [CI] 0.70 to 0.92; P = 0.002, I2 = 11%). This finding remained stable after performing a sensitivity analysis by removing the single trial with an uncertain risk of bias. Subgroup analyses did not reveal a significant subgroup effect across VV, VA, or ECPR modes (P = 0.73). Four studies reported an increased risk of major hemorrhage with ECMO (RR 3.32, 95% CI 1.90 to 5.82; P < 0.001), while two studies reported no difference in favorable neurologic outcome (RR 2.83, 95% CI 0.36 to 22.42; P = 0.32). Other secondary outcomes were not consistently reported across the studies.

AUTHORS' CONCLUSIONS

In this updated systematic review, which included four additional RCTs, we found that ECMO was associated with a reduction in day-90 to one-year all-cause mortality, as well as three times increased risk of bleeding. However, the certainty of this result was only low to moderate, limited by a low number of small trials, clinical heterogeneity, and indirectness across studies.

Standardized approach for extubation during extracorporeal membrane oxygenation in severe acute respiratory distress syndrome: a prospective observational study

BACKGROUND

Extubation during extracorporeal oxygenation (ECMO) in severe acute respiratory distress syndrome (ARDS) has not been well studied. Despite the potential benefits of this strategy, weaning from ECMO before liberation from invasive mechanical ventilation remains the most frequent approach. Our aim was to evaluate the safety and feasibility of a standardized approach for extubation during ECMO in patients with severe ARDS.

RESULTS

We conducted a prospective observational study to assess the safety and feasibility of a standardized approach for extubation during ECMO in severe ARDS among 254 adult patients across 4 intensive care units (ICU) from 2 tertiary ECMO centers over 6 years. This consisted of a daily assessment of clinical and gas exchange criteria based on an Extracorporeal Life Support Organization guideline, with extubation during ECMO after validation by a dedicated intensive care medicine specialist. Fifty-four (21%) patients were extubated during ECMO, 167 (66%) did not reach the clinical criteria, and in 33 (13%) patients, gas exchange precluded extubation during ECMO. At ECMO initiation, there were fewer extrapulmonary organ dysfunctions (lower SOFA score [OR, 0.88; 95% CI, 0.79-0.98; P = .02] with similar PaO2/FiO2) when compared with patients not extubated during ECMO. Extubation during ECMO associated with shorter duration of invasive mechanical ventilation (7 (4-18) vs. 32 (18-54) days; P < .01) and of ECMO (12 (7-25) vs. 19 (10-41) days; P = .01). This was accompanied by a lower incidence of hemorrhagic shock (2 vs. 11%; P = .05), but more cannula-associated deep vein thrombosis (49 vs. 31%; P = .02) and failed extubation (20 vs. 6%; P < .01). There were no increased major adverse events. Extubation during ECMO is associated with a lower risk of all-cause death, independently of measured confounding (adjusted logistic regression OR 0.23; 95% confidence interval 0.08-0.69, P = .008).

CONCLUSIONS

A standardized approach was safe and feasible allowing extubation during ECMO in 21% of patients with severe ARDS, selecting patients who will have a shorter duration of invasive mechanical ventilation, ECMO course, and ICU stay, as well as fewer infectious complications, and high hospital survival.

The prothrombin time/international normalized ratio predicts prognosis in cardiogenic shock

OBJECTIVE

The study investigates the prognostic impact of the prothrombin time/international normalized ratio (PT/INR) in patients with cardiogenic shock.

BACKGROUND

Despite ongoing improvements regarding the treatment of cardiogenic shock patients, intensive care unit (ICU)-related mortality in cardiogenic shock patients remains unacceptably high. Limited data regarding the prognostic value of the PT/INR during the course of cardiogenic shock treatment is available.

METHODS

All consecutive patients with cardiogenic shock from 2019 to 2021 were included at one institution. Laboratory values were collected from the day of disease onset (day 1) and days 2, 3, 4 and 8. The prognostic impact of the PT/INR was tested for 30-day all-cause mortality, as well as the prognostic role of PT/INR changes during course of ICU hospitalization. Statistical analyses included univariable t -test, Spearman's correlation, Kaplan-Meier analyses, C-Statistics and Cox proportional regression analyses.

RESULTS

Two hundred twenty-four cardiogenic shock patients were included with a rate of all-cause mortality at 30 days of 52%. The median PT/INR on day 1 was 1.17. The PT/INR on day 1 was able to discriminate 30-day all-cause mortality in cardiogenic shock patients [area under the curve 0.618; 95% confidence interval (CI), 0.544-0.692; P  = 0.002). Patients with PT/INR > 1.17 were associated with an increased risk of 30-day mortality [62% vs. 44%; hazard ratio (HR) = 1.692; 95% CI, 1.174-2.438; P  = 0.005], which was still evident after multivariable adjustment (HR = 1.551; 95% CI, 1.043-2.305; P  = 0.030). Furthermore, especially patients with an increment of the PT/INR by ≥10% from day 1 to day 2 were associated with an increased risk of 30-day all-cause mortality (64% vs. 42%; log-rank P  = 0.014; HR = 1.833; 95% CI, 1.106-3.038; P  = 0.019).

CONCLUSION

Baseline PT/INR and an increase of the PT/INR during the course of ICU treatment were associated with the risk of 30-day all-cause mortality in cardiogenic shock patients.

Plasma Transfusion and Procoagulant Product Administration in Extracorporeal Membrane Oxygenation: A Secondary Analysis of an International Observational Study on Current Practices

OBJECTIVES

To achieve optimal hemostatic balance in patients on extracorporeal membrane oxygenation (ECMO), a liberal transfusion practice is currently applied despite clear evidence. We aimed to give an overview of the current use of plasma, fibrinogen concentrate, tranexamic acid (TXA), and prothrombin complex concentrate (PCC) in patients on ECMO.

DESIGN

A prespecified subanalysis of a multicenter retrospective study. Venovenous (VV)-ECMO and venoarterial (VA)-ECMO are analyzed as separate populations, comparing patients with and without bleeding and with and without thrombotic complications.

SETTING

Sixteen international ICUs.

PATIENTS

Adult patients on VA-ECMO or VV-ECMO.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 420 VA-ECMO patients, 59% (n = 247) received plasma, 20% (n = 82) received fibrinogen concentrate, 17% (n = 70) received TXA, and 7% of patients (n = 28) received PCC. Fifty percent of patients (n = 208) suffered bleeding complications and 27% (n = 112) suffered thrombotic complications. More patients with bleeding complications than patients without bleeding complications received plasma (77% vs. 41%, p < 0.001), fibrinogen concentrate (28% vs 11%, p < 0.001), and TXA (23% vs 10%, p < 0.001). More patients with than without thrombotic complications received TXA (24% vs 14%, p = 0.02, odds ratio 1.75) in VA-ECMO, where no difference was seen in VV-ECMO. Of 205 VV-ECMO patients, 40% (n = 81) received plasma, 6% (n = 12) fibrinogen concentrate, 7% (n = 14) TXA, and 5% (n = 10) PCC. Thirty-nine percent (n = 80) of VV-ECMO patients suffered bleeding complications and 23% (n = 48) of patients suffered thrombotic complications. More patients with than without bleeding complications received plasma (58% vs 28%, p < 0.001), fibrinogen concentrate (13% vs 2%, p < 0.01), and TXA (11% vs 2%, p < 0.01).

CONCLUSIONS

The majority of patients on ECMO receive transfusions of plasma, procoagulant products, or antifibrinolytics. In a significant part of the plasma transfused patients, this was in the absence of bleeding or prolonged international normalized ratio. This poses the question if these plasma transfusions were administered for another indication or could have been avoided.

Predictors of health-related quality of life in patients undergoing extracorporeal membrane oxygenation for acute severe respiratory failure

Background

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a form of life support used in severe respiratory failure. While the short-term complications of VV-ECMO are well described, impacts on health-related quality of life (HRQOL) are less well characterised. This study aims to assess the HRQOL of patients who underwent VV-ECMO for acute severe respiratory failure and explore predictors of poor HRQOL.

Methods

We performed a retrospective, observational study of a large cohort of adults who underwent VV-ECMO for acute severe respiratory failure in a single tertiary centre (June 2013-March 2019). Patients surviving critical care discharge were invited to a six-month clinic, where they completed an EQ-5D-5L questionnaire assessing HRQOL. Multivariate analysis was performed to assess prognostic factors for HRQOL.

Results

Among the 245 consecutive patients included in this study (median age 45 years), 187 (76.3%) survived until ECMO decannulation and 172 (70.2%) until hospital discharge. Of those, 98 (57.3%) attended a follow-up clinic at a mean (±SD) of 204 (±45) days post-discharge. Patients reported problems with pain/discomfort (56%), usual daily activities (53%), anxiety/depression (49%), mobility (46%), and personal care (21%). Multivariate analysis identified limb ischaemia (-0.266, 95% C.I. [-0.116; -0.415], p = 0.0005), renal replacement therapy (-0.149, [-0.046; -0.252], p = 0.0044), and having received more than four platelet units (-0.157, [-0.031; -0.283], p = 0.0146) as predictors of poor HRQOL.

Conclusion

We report that survivors of VV-ECMO have reduced HRQOL in multiple domains at 6 months, with pain reported most frequently. Patients who had limb ischaemia, renal replacement therapy or were transfused more than four units of platelets are particularly at risk of poor HRQOL and may benefit from added support measures.

Pediatric surgical interventions on ECMO

Extra Corporeal Membrane Oxygenation (ECMO) has historically been reserved for refractory pulmonary and cardiac support in children and adult. Operative intervention on ECMO was traditionally contraindicated due to hemorrhagic complications exacerbated by critical illness and anticoagulation needs. With advancements in ECMO circuitry and anticoagulation strategies operative procedures during ECMO have become feasible with minimal hemorrhagic risks. Here we review anticoagulation and operative intervention considerations in the pediatric population during ECMO cannulation. Pediatric surgical interventions currently described in the literature while on ECMO support include thoracotomy/thoracoscopy, tracheostomy, laparotomy, and injury related procedures i.e. wound debridement. A patient should not be precluded from a surgical intervention while on ECMO, if the surgery is indicated.

Acquired Factor XIII Deficiency Is Common during ECMO Therapy and Associated with Major Bleeding Events and Transfusion Requirements

BACKGROUND

Bleeding events are frequent complications during extracorporeal membrane oxygenation therapy (ECMO).

OBJECTIVE

To determine the rate of acquired factor XIII deficiency and its association with major bleeding events and transfusion requirements in adults undergoing ECMO therapy.

MATERIALS AND METHODS

A retrospective single centre cohort study. Adult patients receiving veno-venous or veno-arterial ECMO therapy during a 2-year period were analysed and screened for factor XIII activity measurements. Factor XIII deficiency was defined based on the lowest factor XIII activity measured during ECMO therapy.

RESULTS

Among 84 subjects included into the analysis, factor XIII deficiency occurred in 69% during ECMO therapy. There were more major bleeding events (OR, 3.37; 95% CI, 1.16-10.56; p = 0.02) and higher transfusion requirements (red blood cells, 20 vs. 12, p < 0.001; platelets, 4 vs. 2, p = 0.006) in patients with factor XIII deficiency compared to patients with normal factor XIII activity. In a multivariate regression model, factor XIII deficiency was independently associated with bleeding severity (p = 0.03).

CONCLUSIONS

In this retrospective single centre study, acquired factor XIII deficiency was observed in 69% of adult ECMO patients with a high bleeding risk. Factor XIII deficiency was associated with higher rates of major bleeding events and transfusion requirements.

Factor XII Silencing Using siRNA Prevents Thrombus Formation in a Rat Model of Extracorporeal Life Support

Heparin anticoagulation increases the bleeding risk during extracorporeal life support (ECLS). This study determined whether factor XII (FXII) silencing using short interfering RNA (siRNA) can provide ECLS circuit anticoagulation without bleeding. Adult male, Sprague-Dawley rats were randomized to four groups (n = 3 each) based on anticoagulant: (1) no anticoagulant, (2) heparin, (3) FXII siRNA, or (4) nontargeting siRNA. Heparin was administered intravenously before and during ECLS. FXII or nontargeting siRNA were administered intravenously 3 days before the initiation of ECLS via lipidoid nanoparticles. The rats were placed on pumped, arteriovenous ECLS for 8 hours or until the blood flow resistance reached three times its baseline resistance. Without anticoagulant, mock-oxygenator resistance tripled within 7 ± 2 minutes. The resistance in the FXII siRNA group did not increase for 8 hours. There were no significant differences in resistance or mock-oxygenator thrombus volume between the FXII siRNA and the heparin groups. However, the bleeding time in the FXII siRNA group (3.4 ± 0.6 minutes) was significantly shorter than that in the heparin group (5.5 ± 0.5 minutes, p < 0.05). FXII silencing using siRNA provided simpler anticoagulation of ECLS circuits with reduced bleeding time as compared to heparin. http://links.lww.com/ASAIO/A937.

Hemorrhage, Disseminated Intravascular Coagulopathy, and Thrombosis Complications Among Critically Ill Patients with COVID-19: An International COVID-19 Critical Care Consortium Study

OBJECTIVES

To determine the prevalence and outcomes associated with hemorrhage, disseminated intravascular coagulopathy, and thrombosis (HECTOR) complications in ICU patients with COVID-19.

DESIGN

Prospective, observational study.

SETTING

Two hundred twenty-nine ICUs across 32 countries.

PATIENTS

Adult patients (≥ 16 yr) admitted to participating ICUs for severe COVID-19 from January 1, 2020, to December 31, 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

HECTOR complications occurred in 1,732 of 11,969 study eligible patients (14%). Acute thrombosis occurred in 1,249 patients (10%), including 712 (57%) with pulmonary embolism, 413 (33%) with myocardial ischemia, 93 (7.4%) with deep vein thrombosis, and 49 (3.9%) with ischemic strokes. Hemorrhagic complications were reported in 579 patients (4.8%), including 276 (48%) with gastrointestinal hemorrhage, 83 (14%) with hemorrhagic stroke, 77 (13%) with pulmonary hemorrhage, and 68 (12%) with hemorrhage associated with extracorporeal membrane oxygenation (ECMO) cannula site. Disseminated intravascular coagulation occurred in 11 patients (0.09%). Univariate analysis showed that diabetes, cardiac and kidney diseases, and ECMO use were risk factors for HECTOR. Among survivors, ICU stay was longer (median days 19 vs 12; p < 0.001) for patients with versus without HECTOR, but the hazard of ICU mortality was similar (hazard ratio [HR] 1.01; 95% CI 0.92-1.12; p = 0.784) overall, although this hazard was identified when non-ECMO patients were considered (HR 1.13; 95% CI 1.02-1.25; p = 0.015). Hemorrhagic complications were associated with an increased hazard of ICU mortality compared to patients without HECTOR complications (HR 1.26; 95% CI 1.09-1.45; p = 0.002), whereas thrombosis complications were associated with reduced hazard (HR 0.88; 95% CI 0.79-0.99, p = 0.03).

CONCLUSIONS

HECTOR events are frequent complications of severe COVID-19 in ICU patients. Patients receiving ECMO are at particular risk of hemorrhagic complications. Hemorrhagic, but not thrombotic complications, are associated with increased ICU mortality.

Adverse Outcomes Associated With Atrial Arrhythmias After Veno-Venous Extracorporeal Membrane Oxygenation

Veno-venous extracorporeal membrane oxygenation (VV ECMO) is used as a treatment modality in those who fail to respond to conventional care. Hypoxia and medications used in the intensive care unit may increase risk for atrial arrhythmias (AA). This study aims to evaluate the impact of AA on post-VV ECMO outcome. A retrospective review of patients who were placed on VV ECMO between October 2016 and October 2021. One hundred forty-five patients were divided into two groups, AA and no AA. Baseline characteristic and potential risk factors were assessed. Uni- and multivariate analysis using logistic regression models were constructed to evaluate the predictors of mortality between groups. Survival between groups was estimated by the Kaplan-Meier method using the log-rank test. Advanced age with history of coronary artery disease and hypertension were associated with increased risk to develop AA post-VV ECMO placement ( p value < 0.05). Length on ECMO, time intubated, hospital length of stay, and sepsis were significantly increased in patients in the AA group ( p value < 0.05). There was no difference in the overall mortality between the two groups. AAs were associated with worse hospital course and complications but no difference in overall mortality rate. Age and cardiovascular disease seem to be predisposing risk factors for this. Further studies are needed to investigate potential strategies to prevent AAs development in this population.

Efficacy and safety of extracorporeal membrane oxygenation for burn patients: a comprehensive systematic review and meta-analysis

BACKGROUND

Respiratory and circulatory dysfunction are common complications and the leading causes of death among burn patients, especially in severe burns and inhalation injury. Recently, extracorporeal membrane oxygenation (ECMO) has been increasingly applied in burn patients. However, current clinical evidence is weak and conflicting. This study aimed to comprehensively evaluate the efficacy and safety of ECMO in burn patients.

METHODS

A comprehensive search of PubMed, Web of Science and Embase from inception to 18 March 2022 was performed to identify clinical studies on ECMO in burn patients. The main outcome was in-hospital mortality. Secondary outcomes included successful weaning from ECMO and complications associated with ECMO. Meta-analysis, meta-regression and subgroup analyses were conducted to pool the clinical efficacy and identify influencing factors.

RESULTS

Fifteen retrospective studies with 318 patients were finally included, without any control groups. The commonest indication for ECMO was severe acute respiratory distress syndrome (42.1%). Veno-venous ECMO was the commonest mode (75.29%). Pooled in-hospital mortality was 49% [95% confidence interval (CI) 41-58%] in the total population, 55% in adults and 35% in pediatrics. Meta-regression and subgroup analysis found that mortality significantly increased with inhalation injury but decreased with ECMO duration. For studies with percentage inhalation injury ≥50%, pooled mortality (55%, 95% CI 40-70%) was higher than in studies with percentage inhalation injury <50% (32%, 95% CI 18-46%). For studies with ECMO duration ≥10 days, pooled mortality (31%, 95% CI 20-43%) was lower than in studies with ECMO duration <10 days (61%, 95% CI 46-76%). In minor and major burns, pooled mortality was lower than in severe burns. Pooled percentage of successful weaning from ECMO was 65% (95% CI 46-84%) and inversely correlated with burn area. The overall rate of ECMO-related complications was 67.46%, and infection (30.77%) and bleedings (23.08%) were the two most common complications. About 49.26% of patients required continuous renal replacement therapy.

CONCLUSIONS

ECMO seems to be an appropriate rescue therapy for burn patients despite the relatively high mortality and complication rate. Inhalation injury, burn area and ECMO duration are the main factors influencing clinical outcomes.

Veno-venous extracorporeal membrane oxygenation for the treatment of respiratory compromise

Extracorporeal membrane oxygenation for the purpose of intervening upon profound cardiovascular or pulmonary compromise has proven to be a worthy intervention. Technological advancements have allowed this mode of therapy to become more effective and widespread. Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a commonly used strategy to help manage patients with pulmonary dysfunction refractory to traditional management methods. This review intends to focus upon common indications and the clinical considerations for the institution of VV-ECMO as well as some of its known complications.

Current and future strategies to monitor and manage coagulation in ECMO patients

Extracorporeal membrane oxygenation (ECMO) can provide life-saving support for critically ill patients suffering severe respiratory and/or cardiac failure. However, thrombosis and bleeding remain common and complex problems to manage. Key causes of thrombosis in ECMO patients include blood contact to pro-thrombotic and non-physiological surfaces, as well as high shearing forces in the pump and membrane oxygenator. On the other hand, adverse effects of anticoagulant, thrombocytopenia, platelet dysfunction, acquired von Willebrand syndrome, and hyperfibrinolysis are all established as causes of bleeding. Finding safe and effective anticoagulants that balance thrombosis and bleeding risk remains challenging. This review highlights commonly used anticoagulants in ECMO, including their mechanism of action, monitoring methods, strengths and limitations. It further elaborates on existing anticoagulant monitoring strategies, indicating their target range, benefits and drawbacks. Finally, it introduces several highly novel approaches to real-time anticoagulation monitoring methods including sound, optical, fluorescent, and electrical measurement as well as their working principles and future directions for research.

A descriptive evaluation of causes of death in venovenous extracorporeal membrane oxygenation

Veno-venous extracorporeal membrane oxygenation (VV ECMO) has become an important support modality for patients with acute respiratory failure refractory to optimal medical therapy, such as low tidal volume mechanical ventilator support, early paralytic infusion, and early prone positioning. The objective of this cohort study was to investigate the causes and timing of in-hospital mortality in patients on VV ECMO. All patients, excluding trauma and bridge to lung transplant, admitted 8/2014-6/2019 to a specialty ICU for VV ECMO were reviewed. Two hundred twenty-five patients were included. In-hospital mortality was 24.4% (n = 55). Most non-survivors (46/55, 84%) died prior to lung recovery and decannulation from VV ECMO. Most common cause of death (COD) for patients who died on VV ECMO was removal of life sustaining therapy (LST) in setting of multisystem organ failure (MSOF) (n = 24). Nine patients died a median of 9 days [6, 11] after decannulation. Most common COD in these patients was palliative withdrawal of LST due to poor prognosis (n = 3). Non-survivors were older and had worse predictive mortality scores than survivors. We found that death in patients supported with VV ECMO in our study most often occurs prior to decannulation and lung recovery. This study demonstrated that the most common cause of death in patients supported with VV ECMO was removal of LST due MSOF. Acute hemorrhage (systemic or intracranial) was not found to be a common cause of death in our patient population.

Medical nutrition therapy in patients receiving extracorporeal membrane oxygenation: knowledge in progress

Nutritional support in adult patients receiving extracorporeal membrane oxygenation (ECMO) therapy is controversial. Although there are guidelines for the NS (Nutritional support) in pediatric patients with ECMO, in adults these guidelines are not available for the use, type, route and timing of nutritional therapy. In critically ill patients it is well known that early enteral nutrition is beneficial, however there is the possibility that in patients with ECMO early enteral nutrition leads to gastrointestinal complications. Likewise, there have not been established caloric targets, proteins and doses or types of micronutrients to use for this specific population being a challenge for the clinician. In addition, patients with ECMO are some of the most seriously ill in intensive care units, where malnutrition is associated with increased morbidity and mortality. Regarding the use of parenteral nutrition (NP) it has not been described if it implies a risk of circuit failure at the time of introducing lipids to the oxygenator. Therefore, a correct evaluation and specific nutritional intervention by experts in the field is imperative to improve the prognosis and quality of life in this population, which is a primary goal in the care of adult patients receiving extracorporeal membrane oxygen.

Outcomes With Direct and Indirect Thrombin Inhibition During Extracorporeal Membrane Oxygenation for COVID-19

Anticoagulation during extracorporeal membrane oxygenation (ECMO) for Coronovirus Disease 2019 (COVID-19) can be performed by direct or indirect thrombin inhibitors but differences in outcomes with these agents are uncertain. A retrospective, multicenter study was conducted. All consecutive adult patients with COVID-19 placed on ECMO between March 1, 2020 and April 30, 2021 in participating centers, were included. Patients were divided in groups receiving either a direct thrombin inhibitor (DTI) or an indirect thrombin inhibitor such as unfractionated heparin (UFH). Overall, 455 patients with COVID-19 from 17 centers were placed on ECMO during the study period. Forty-four patients did not receive anticoagulation. Of the remaining 411 patients, DTI was used in 160 (39%) whereas 251 (61%) received UFH. At 90-days, in-hospital mortality was 50% (DTI) and 61% (UFH), adjusted hazard ratio: 0.81, 95% confidence interval (CI): 0.49-1.32. Deep vein thrombosis [adjusted odds ratio (aOR): 2.60, 95% CI: 0.90-6.65], ischemic (aOR: 1.58, 95% CI: 0.18-14.0), and hemorrhagic (aOR:1.22, 95% CI: 0.39-3.87) stroke were similar with DTI in comparison to UFH. Bleeding requiring transfusion was lower in patients receiving DTI (aOR: 0.40, 95% CI: 0.18-0.87). Anticoagulants that directly inhibit thrombin are associated with similar in-hospital mortality, stroke, and venous thrombosis and do not confer a higher risk of clinical bleeding in comparison to conventional heparin during ECMO for COVID-19.

Cost-effectiveness of extracorporeal cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest: A modelling study

Background

Methods

Results

Conclusion

Complications Associated With Venovenous Extracorporeal Membrane Oxygenation-What Can Go Wrong?

OBJECTIVES

Despite increasing use and promising outcomes, venovenous extracorporeal membrane oxygenation (V-V ECMO) introduces the risk of a number of complications across the spectrum of ECMO care. This narrative review describes the variety of short- and long-term complications that can occur during treatment with ECMO and how patient selection and management decisions may influence the risk of these complications.

DATA SOURCES

English language articles were identified in PubMed using phrases related to V-V ECMO, acute respiratory distress syndrome, severe respiratory failure, and complications.

STUDY SELECTION

Original research, review articles, commentaries, and published guidelines from the Extracorporeal Life support Organization were considered.

DATA EXTRACTION

Data from relevant literature were identified, reviewed, and integrated into a concise narrative review.

DATA SYNTHESIS

Selecting patients for V-V ECMO exposes the patient to a number of complications. Adequate knowledge of these risks is needed to weigh them against the anticipated benefit of treatment. Timing of ECMO initiation and transfer to centers capable of providing ECMO affect patient outcomes. Choosing a configuration that insufficiently addresses the patient's physiologic deficit leads to consequences of inadequate physiologic support. Suboptimal mechanical ventilator management during ECMO may lead to worsening lung injury, delayed lung recovery, or ventilator-associated pneumonia. Premature decannulation from ECMO as lungs recover can lead to clinical worsening, and delayed decannulation can prolong exposure to complications unnecessarily. Short-term complications include bleeding, thrombosis, and hemolysis, renal and neurologic injury, concomitant infections, and technical and mechanical problems. Long-term complications reflect the physical, functional, and neurologic sequelae of critical illness. ECMO can introduce ethical and emotional challenges, particularly when bridging strategies fail.

CONCLUSIONS

V-V ECMO is associated with a number of complications. ECMO selection, timing of initiation, and management decisions impact the presence and severity of these potential harms.

Comparison of Hemostatic Changes in Pump-driven Extracorporeal Carbon Dioxide Removal and Venovenous Extracorporeal Membrane Oxygenation

Extracorporeal carbon dioxide removal (ECCO 2 R) has gained widespread use as a supposedly less invasive alternative for hypercapnic respiratory failure besides venovenous extracorporeal membrane oxygenation (VV ECMO). Despite technological advances, coagulation-related adverse events remain a major challenge in both therapies. The overlapping operating areas of VV ECMO and pump-driven ECCO 2 R could allow for a device selection targeted at the lowest risk of such complications. This retrospective analysis of 47 consecutive patients compared hemostatic changes between pump-driven ECCO 2 R (n = 23) and VV ECMO (n = 24) by application of linear mixed effect models. A significant decrease in platelet count, increase in D-dimer levels, and decrease of fibrinogen levels were observed. However, except for fibrinogen, the type of extracorporeal support did not have a significant effect on the time course of these parameters. Our findings suggest that in terms of hemocompatibility, pump-driven ECCO 2 R is not significantly different from VV ECMO.

A phased intervention bundle to decrease the mortality of patients with extracorporeal membrane oxygenation in intensive care unit

Aim

To evaluate whether a phased multidimensional intervention bundle would decrease the mortality of patients with extracorporeal membrane oxygenation (ECMO) and the complication incidence.

Materials and methods

We conducted a prospective observational study in comparison with a retrospective control group in six intensive care units (ICUs) in China. Patients older than 18 years supported with ECMO between March 2018 to March 2022 were included in the study. A phased intervention bundle to improve the outcome of patients with ECMO was developed and implemented. Multivariable logistic regression modeling was used to compare the mortality of patients with ECMO and the complication incidence before, during, and up to 18 months after implementation of the intervention bundle.

Results

The cohort included 297 patients in 6 ICUs, mostly VA ECMO (68.7%) with a median (25th–75th percentile) duration in ECMO of 9.0 (4.0–15.0) days. The mean (SD) APECHII score was 24.1 (7.5). Overall, the mortality of ECMO decreased from 57.1% at baseline to 21.8% at 13–18 months after implementation of the study intervention (P < 0.001). In multivariable analysis, even after excluding the confounding factors, such as age, APECHII score, pre-ECMO lactate, and incidence of CRRT during ECMO, the intervention bundle still can decrease the mortality independently, which also remained true in the statistical analysis of V-V and V-A ECMO separately. Among all the ECMO-related complications, the incidence of bloodstream infection and bleeding decreased significantly at 13–18 months after implementation compared with the baseline. The CUSUM analysis revealed a typical learning curve with a point of inflection during the implementation of the bundle.

Conclusion

A phased multidimensional intervention bundle resulted in a large and sustained reduction in the mortality of ECMO that was maintained throughout the 18-month study period.

Clinical trial registration

[ClinicalTrials.gov], identifier [NCT05024786].

Effect of Initial Anticoagulation Targets on Bleeding and Thrombotic Complications for Patients With Acute Respiratory Distress Syndrome Receiving Extracorporeal Membrane Oxygenation

OBJECTIVE

To evaluate the effect of anticoagulation targets and intensity on bleeding events, thrombotic events, and transfusion requirements in patients with acute respiratory distress syndrome (ARDS) receiving venovenous extracorporeal membrane oxygenation (ECMO) and continuous-infusion heparin.

DESIGN

A retrospective cohort study.

SETTING

At a single-center, large academic medical center.

PARTICIPANTS

One hundred thirty-six critically ill patients.

INTERVENTIONS

The following three therapeutic targets were implemented over time and evaluated: (1) no protocol (September 2013-August 2016): no standardized anticoagulation protocol or transfusion thresholds; (2) <50 seconds (September 2016-January 2018): standardized activated partial thromboplastin time (aPTT) goal of <50 seconds, maximum heparin infusion rate of 1,200 units/h, transfusion threshold of hemoglobin (Hgb) <8 g/dL; and (3) 40-to-50 seconds (February 2018-December 2019): aPTT goal of 40-to-50 sec, no maximum heparin infusion rate, transfusion threshold of Hgb <7 g/dL.

MEASUREMENTS AND MAIN RESULTS

Continuous variables were compared using the Kruskal-Wallis test, and categorical variables were compared using Fisher exact tests. The primary endpoint, an incidence of at least 1 bleeding event, was highest in the no-protocol group though not statistically different among groups (39.3% v 26.7% v 34%, p = 0.5). Thrombotic complications were similar. The median units of packed red blood cells transfused were highest in the no-protocol group (3 v 2 v 0.5, p < 0.001).

CONCLUSION

Anticoagulation protocols standardizing aPTT goals to <50 or 40-to-50 seconds may be a reasonable strategy for patients receiving venovenous ECMO for ARDS. More restrictive hemoglobin transfusion thresholds, in combination with lower aPTT targets, may be associated with a reduction in transfusion requirements.

Early predictors of oxygenator exchange during veno-venous extracorporeal membrane oxygenation: A retrospective analysis

INTRODUCTION

Oxygenator exchange during extracorporeal membrane oxygenation (ECMO) is a life-threatening procedure. D-dimer has been used to predict oxygenator failure, but it is a parameter used a few days before oxygenator exchange. This study investigated parameters before and immediately after ECMO initiation that predict oxygenator exchange.

METHODS

This was a single-center, retrospective study of 28 patients who received veno-venous ECMO with heparin/silicone-coated polypropylene oxygenator (NSH-R HPO-23WH-C; Senko Medical Inc., Tokyo, Japan), due to acute respiratory failure, from April 2015 to March 2020. Clinical data before ECMO initiation and during the first 3 days on ECMO were compared between the patients with oxygenator exchange (exchange group) and those without oxygenator exchange (non-exchange group).

RESULTS

Nine (32%) patients required oxygenator exchange. The exchange group had significantly higher white blood cell count (WBC) (16,944 ± 2423/µL vs 10,342 ± 1442/µL, p < 0.05) and Acute Physiology and Chronic Health Evaluation (APACHE) II score (31 ± 5 vs 25 ± 8, p < 0.05) before ECMO initiation than the non-exchange group. The partial pressure of oxygen at the outlet of the oxygenator (PO_{2 outlet}) and activated partial thromboplastin time (aPTT) during the first 3 days on ECMO were significantly lower in the exchange group than in the non-exchange group.

CONCLUSIONS

High WBC and APACHE II score before ECMO initiation, low PO_{2 outlet}, and aPTT during the first 3 days on ECMO were associated with oxygenator exchange during veno-venous ECMO. These parameters could be used to avoid unexpected oxygenator exchange.

Complications related to extracorporeal membrane oxygenation support as a bridge to lung transplantation and their clinical significance

BACKGROUND

Incidence of complications related extracorporeal membrane oxygenation (ECMO) support as a bridge to lung transplantation (BTT) and its association with the patient outcome in lung transplantation (LT) has not been well documented in previous studies.

OBJECTIVES

We evaluated the incidence of complications related to the use of ECMO support as a BTT, and the association between the occurrence of the complications and patient outcomes in LTs.

METHODS

This retrospective cohort study investigated 100 consecutive patients who started ECMO support as a BTT between April 2013 and March 2020. Data for the analyses were retrieved from electronic medical records.

RESULTS

Fifty-six percent of the patients experienced at least one complication during the BTT with ECMO. Major bleeding was the most common complication. In multivariate logistic regression analysis, occurrence of oxygenator thromboses (OR 16.438, P = 0.008) and the use of renal replacement therapy (RRT) (OR 32.288, P < 0.001) were associated with a failed BTT. In the subgroup analysis of the LT recipients, intracranial hemorrhages, (OR 13.825, P = 0.021), RRT use, (OR 11.395, P = 0.038), and bloodstream infection occurrence (OR 6.210; P = 0.034) were identified as risk factors for in-hospital mortality.

CONCLUSIONS

The occurrence of complications during the use of ECMO support as a BTT was associated with unfavorable outcomes in LTs. Close monitoring and the proper management of these complications may be important to achieve better outcomes in patients using ECMO support as a BTT.

A Comparison of Activated Partial Thromboplastin Time and Activated Coagulation Time for Anticoagulation Monitoring during Extracorporeal Membrane Oxygenation Therapy

BACKGROUND

 Unfractionated heparin is used to prevent coagulation activation in patients undergoing extracorporeal membrane oxygenation (ECMO) support. We designed this study to determine the preferable indicator for anticoagulation monitoring.

METHODS

 We conducted a retrospective study and divided the patients into an activated coagulation time (ACT)-target group and an activated partial thromboplastin time (aPTT)-target group. The correlations between ACT, aPTT, and the heparin dose were explored.

RESULTS

 Thirty-six patients were included (19 aPTT-target and 17 ACT-target patients); a total of 555 matched pairs of ACT/aPTT results were obtained. The correlation between the ACT and aPTT measurements was Spearman's Rank Correlation Coefficient (rs) = 0.518 in all 555 pairs. The Bland-Altman plot showed data points outside the displayed range (51.2-127.7), suggesting that the agreement between ACT and aPTT was poor. The aPTT group had fewer heparin dose changes (2.12 ± 0.68 vs. 2.57 ± 0.64, p = 0.05) and a lower cumulative heparin dose (317.6 ± 108.5 vs. 396.3 ± 144.3, p = 0.00) per day than the ACT group. There was no difference in serious bleeding (9 vs. 5; p = 0.171) or embolism events (3 vs. 3; p = 1.0) or in the red blood cell and fresh frozen plasma transfusion volumes between the ACT- and aPTT-target groups. Similarly, there was no significant difference in the ECMO duration (9 [4-15] days vs. 4 [3-14] days; p = 0.124) or length of ICU hospitalization (17 [5-32] days vs. 13 [4-21] days; p = 0.451) between the groups.

CONCLUSION

 The correlation between ACT and aPTT and the heparin dose was poor. The aPTT group had fewer daily heparin dose changes and a lower cumulative heparin dose per day than the ACT group, with no more bleeding and thrombotic events. Therefore, we recommend aPTT rather than ACT to adjust heparin dose in the absence of better monitoring indicators.

Successful Application of Argatroban During VV-ECMO in a Pregnant Patient Complicated With ARDS due to Severe Tuberculosis: A Case Report and Literature Review

Severe tuberculosis during pregnancy may progress to acute respiratory distress syndrome (ARDS), and venovenous (VV) extracorporeal membrane oxygenation (ECMO) should be considered if conventional lung-protective mechanical ventilation fails. However, thrombocytopenia often occurs with ECMO, and there are limited reports of alternative anticoagulant therapies for pregnant patients with thrombocytopenia during ECMO. This report describes the first case of a pregnant patient who received argatroban during ECMO and recovered. Furthermore, we summarized the existing literature on VV-ECMO and argatroban in pregnant patients. A 31-year-old woman at 17 weeks of gestation was transferred to our hospital with ARDS secondary to severe tuberculosis. We initiated VV-ECMO after implementing a protective ventilation strategy and other conventional therapies. Initially, we selected unfractionated heparin anticoagulant therapy. However, on ECMO day 3, the patient’s platelet count and antithrombin III (AT-III) level declined to 27 × 103 cells/μL and 26.9%, respectively. Thus, we started the patient on a 0.06 μg/kg/min argatroban infusion. The argatroban infusion maintenance dose ranged between 0.9 and 1.2 μg/kg/min. The actual activated partial thromboplastin clotting time and activated clotting time ranged from 43 to 58 s and 220–260 s, respectively, without clinically significant bleeding and thrombosis. On day 27, the patient was weaned off VV-ECMO and eventually discharged. VV-ECMO may benefit pregnant women with refractory ARDS, and argatroban may be an alternative anticoagulant for pregnant patients with thrombocytopenia and AT-III deficiency during ECMO.

Extracorporeal Membrane Oxygenation (ECMO) Dependent Acute Respiratory Distress Syndrome (ARDS): A Systematic Review and Meta-Analysis

Background: Extracorporeal membrane oxygenation (ECMO) has emerged as a newer method for managing severe acute respiratory distress syndrome (ARDS) and ARDS refractory to conventional management. However, its current role in the management of ARDS is not clear. Therefore, we conducted this meta-analysis to compare the mortality rates of ECMO over conventional management in ARDS.

Methods: PubMed, PubMed Central, Embase, and Scopus were searched using appropriate keywords. We selected studies in adults with ARDS that compared the outcomes of patients treated with ECMO vs. conventional management. Cochrane Risk of Bias (RoB) 2.0 and the JBI (Joanna Briggs Institute) quality assessment tools were used for assessing the risk of bias in RCTs and observational studies, respectively. The I² statistic was used to evaluate heterogeneity, and quantitative synthesis was performed using fixed or random effects to pool studies based on heterogeneities. Meta-analysis was conducted using Revman 5.4.

Result: Twelve studies were included in this meta-analysis. As compared to the conventional management (mechanical ventilation: MV), patients treated with ECMO had lower odds of 30-days mortality (OR, 0.56; 95% CI, 0.37 to 0.84) and 90 days mortality (OR, 0.59; 95% CI, 0.41 to 0.85). However, there was no significant difference between in-hospital mortality (OR, 0.75; 95% CI, 0.40 to 1.41) and intensive care unit (ICU) mortality (OR, 1.00; 95% CI, 0.36 to 2.79). Similarly, length of hospital stays (LOS) (MD, 3.92; 95% CI, -6.26 to 14.11) did not show statistically significant differences across the two groups. However, the average ICU stay (ICU LOS) was 7.28 days longer in the ECMO group compared with the MV group (MD, 7.28; 95% CI, 2.55 to 12.02).

Conclusion: Twenty-eight days and 90-days mortality were decreased in patients managed with ECMO compared with the MV group. Also, ICU LOS was found to be longer in the ECMO group. Furthermore, no statistical difference was found between the two groups for in-hospital mortality and hospital LOS. 

Characteristics and outcomes of patients with COVID-19 supported by extracorporeal membrane oxygenation: A retrospective multicenter study

OBJECTIVE

To determine characteristics, outcomes, and clinical factors associated with death in patients with COVID-19 requiring extracorporeal membrane oxygenation (ECMO) support.

METHODS

A multicenter, retrospective cohort study was conducted. The cohort consisted of adult patients (18 years of age and older) requiring ECMO in the period from March 1, 2020, to September 30, 2020. The primary outcome was in-hospital mortality after ECMO initiation assessed with a time to event analysis at 90 days. Multivariable Cox proportional regression was used to determine factors associated with in-hospital mortality.

RESULTS

Overall, 292 patients from 17 centers comprised the study cohort. Patients were 49 (interquartile range, 39-57) years old and 81 (28%) were female. At the end of the follow-up period, 19 (6%) patients were still receiving ECMO, 25 (9%) were discontinued from ECMO but remained hospitalized, 135 (46%) were discharged or transferred alive, and 113 (39%) died during the hospitalization. The cumulative in-hospital mortality at 90 days was 42% (95% confidence interval [CI], 36%-47%). Factors associated with in-hospital mortality were age (adjusted hazard ratio [aHR], 1.31; 95% CI, 1.06-1.61 per 10 years), renal dysfunction measured according to serum creatinine level (aHR, 1.21; 95% CI, 1.01-1.45), and cardiopulmonary resuscitation before ECMO placement (aHR, 1.87; 95% CI, 1.01-3.46).

CONCLUSIONS

In patients with severe COVID-19 necessitating ECMO support, in-hospital mortality occurred in fewer than half of the cases. ECMO might serve as a viable modality for terminally ill patients with refractory COVID-19.

Extracorporeal Membrane Oxygenation in Patients With COVID-19

Coronavirus disease 2019 (COVID-19) is characterized by a clinical spectrum of diseases ranging from asymptomatic or mild cases to severe pneumonia with acute respiratory distress syndrome (ARDS) requiring mechanical ventilation. Extracorporeal membrane oxygenation (ECMO) has been used as rescue therapy in appropriate patients with COVID-19 complicated by ARDS refractory to mechanical ventilation. In this study, we review the indications, challenges, complications, and clinical outcomes of ECMO utilization in critically ill patients with COVID-19-related ARDS. Most of these patients required venovenous ECMO. Although the risk of mortality and complications is very high among patients with COVID-19 requiring ECMO, it is similar to that of non-COVID-19 patients with ARDS requiring ECMO. ECMO is a resource-intensive therapy, with an inherent risk of complications, which makes its availability limited and its use challenging in the midst of a pandemic. Well-maintained data registries, with timely reporting of outcomes and evidence-based clinical guidelines, are necessary for the careful allocation of resources and for the development of standardized utilization protocols.