Extracorporeal membrane oxygenation-hemostatic complications

The role of nafamostat mesilate as a regional anticoagulant during extracorporeal membrane oxygenation

BACKGROUND

Anticoagulation during extracorporeal membrane oxygenation (ECMO) usually is required to prevent thrombosis. The aim of this study was to investigate the usefulness of nafamostat mesilate (NM) as a regional anticoagulant during veno-arterial ECMO (VA-ECMO) treatment.

METHODS

We retrospectively reviewed the medical records of 16 patients receiving VA-ECMO and NM from January 2017 to June 2020 at Haeundae Paik Hospital. We compared clinical and laboratory data, including activated partial thromboplastin time (aPTT), which was measured simultaneously in patients and the ECMO site, to estimate the efficacy of regional anticoagulation.

RESULTS

The median patient age was 68.5 years, and 56.3% of patients were men. Cardiovascular disease was the most common primary disease (75.0%) requiring ECMO treatment, followed by respiratory disease (12.5%). The median duration of ECMO treatment was 7.5 days. Among 16 patients, seven were switched to NM after first using heparin as an anticoagulation agent, and nine received only NM. When comparing aPTT values in the NM group between patients and the ECMO site, that in patients was significantly lower than that at the ECMO site (73.57 vs. 79.25 seconds; P=0.010); in contrast, no difference was observed in the heparin group.

CONCLUSIONS

NM showed efficacy as a regional anticoagulation method by sustaining a lower aPTT value compared to that measured at the ECMO site. NM should be considered as a safer regional anticoagulation method in VA-ECMO for patients at high risk of bleeding.

A Comparison of Anticoagulation Strategies in Veno-venous Extracorporeal Membrane Oxygenation

Bleeding remains a major source of morbidity associated with veno-venous extracorporeal membrane oxygenation (VV-ECMO). Moreover, there remains significant controversy, and a paucity of data regarding the ideal anticoagulation strategy for VV-ECMO patients. All patients undergoing isolated, peripheral VV-ECMO between January 2009 and December 2014 at our institution were retrospectively reviewed. Patients (n = 123) were stratified into one of three sequential eras of anticoagulation strategies: activated clotting time (ACT: 160-180 seconds, n = 53), high-partial thromboplastin time (H-PTT: 60-80 seconds, n = 25), and low-PTT (L-PTT: 45-55 seconds, n = 25) with high-flow (>4 L/min). Pre-ECMO APACHE II scores, SOFA scores, and Murray scores were not significantly different between the groups. Patients in the L-PTT group required less red blood cell units on ECMO than the ACT or H-PTT group (2.1 vs. 1.3 vs. 0.9; p < 0.001) and patients in the H-PTT and L-PTT group required less fresh frozen plasma than the ACT group (0.33 vs. 0 vs. 0; p = 0.006). Overall, major bleeding events were significantly lower in the L-PTT group than in the ACT and H-PTT groups. There was no difference in thrombotic events. In this single-institution experience, a L-PTT, high-flow strategy on VV-ECMO was associated with fewer bleeding and no difference in thrombotic events than an ACT or H-PTT strategy.

Overlooked but Serious Gallbladder Disease during Extracorporeal Membrane Oxygenation: A Retrospective Analysis

Background: To date, there have been no reports assessing the incidence, risk factors, and clinical outcomes of GB disease in patients receiving ECMO for cardiorespiratory failure. Methods: The medical records of adults (aged > 18 years) who underwent ECMO between May 2010 and October 2019 were retrospectively reviewed. We investigated the prevalence and related factors of GB disease during ECMO therapy, compared clinical outcomes between patients with and without GB disease, and performed propensity-matched analysis. Results: In total, 446 patients were included, and symptomatic GB disease was found in 62 patients (13.9%, 76.2/1000 ECMO days). Complicated GB disease occurred in 42 patients (9.4%, 89.4/1000 ECMO days) and presented as acute cholecystitis, acute cholangitis, and biliary pancreatitis in 33 (7.4%), 7 (1.6%), and 5 (1.1%) patients, respectively. In multivariate Cox regression analysis, longer ECMO support (>2 weeks) (hazard ratio (HR), 2.95; 95% confidence interval (CI), 1.69−5.15) and elevated plasma hemoglobin (Hb, >50 mg/dL) (HR. 2.12; 95% CI, 1.18−3.78) were significantly associated with the development of GB disease. In the propensity-matched cohort, the intensive care unit (ICU) and hospital survival rates were significantly lower for patients with GB disease than for those without GB disease (ICU survival rate, 64.5% vs. 84.7%; hospital survival rate, 59.7% vs. 81.5%). Conclusion: The incidence of GB disease was higher in patients who received ECMO than in the general ICU patients. Furthermore, elevated plasma Hb and prolonged ECMO therapy were significant factors for the development of GB disease during ECMO therapy.

Assessing Clinical Feasibility and Safety of Percutaneous Dilatational Tracheostomy During Extracorporeal Membrane Oxygenation Support in the Intensive Care Unit

Purpose: A tracheostomy is often used to wean patients off the ventilator, as it helps maintain extracorporeal membrane oxygenation (ECMO) without sedation. A percutaneous dilatational tracheostomy (PDT) performed in critically ill patients is widely accepted, however, its feasibility and safety in ECMO is unclear.Methods: This retrospective observational study included 78 patients who underwent a PDT and ECMO at the surgical intensive care unit (SICU) in a tertiary hospital between January 1, 2016 and December 31, 2019. We analyzed their medical records, including PDT-related complications and clinical variables.Results: The median values of hemoglobin, platelet count, international normalized ratio, partial thromboplastin time, and activated partial thromboplastin time before the tracheostomy were 9.2 (8.5-10.2) g/dL, 81 (56-103) × 103/dL, 1.22 (1.13-1.30), 15.2 (14.3-16.1) seconds, and 55.1 (47.4-61.1) seconds, respectively. No clotting was observed within the extracorporeal circuit, however, minimal bleeding was observed at the tracheostomy site in 10 (12.8%) patients. Of 4 patients with major bleeding, local hemorrhage was controlled in 3 patients, and intratracheal bleeding continued in 1 patient. The mortality rate was 60.9% and 57.1% in the complication and no-complication group, respectively. The durations of SICU stay, hospital stay, and mechanical ventilation were not statistically different between the groups.Conclusion: A PDT performed in critically ill patients was associated with a low rate of bleeding. Complications did not appear to significantly affect the patient outcome. PDT can be performed in patients who usually require a tracheostomy to maintain ECMO.

Outcomes of Patients Undergoing Interfacility Extracorporeal Membrane Oxygenation Transfer Based on Cannulation Location and Mode of Transport

As the use of extracorporeal membrane oxygenation (ECMO) expands, so has the need for interfacility transfer to ECMO centers. However, the impact of these transfers has not been fully studied. This study evaluates complications and inhospital mortality in adult patients treated with venovenous (V-V) ECMO based on institutional location of cannulation and mode of transport.

Acute Kidney Injury in Patients with Severe ARDS Requiring Extracorporeal Membrane Oxygenation: Incidence, Prognostic Impact and Risk Factors

(1) Background: Acute kidney injury (AKI) is a common but under-investigated complication in patients receiving extracorporeal membrane oxygenation (ECMO). We aimed to define the incidence and clinical course, as well as the predictors of AKI in adults receiving ECMO support. (2) Materials and Methods: This is a retrospective analysis of all patients undergoing veno-venous ECMO treatment in a tertiary care center between December 2008 and December 2017. The primary endpoint was the new occurrence of an AKI of stage 2 or 3 according to the Kidney Disease: Improving Global Outcomes (KDIGO) classification after ECMO implantation. (3) Results: During the observation period, 103 patients underwent veno-venous ECMO implantation. In total, 59 patients (57.3%) met the primary endpoint with an AKI of stage 2 or 3 and 55 patients (53.4%) required renal replacement therapy. Patients with an AKI of 2 or 3 suffered from more bleeding and infectious complications. Whereas weaning failure from ECMO (30/59 (50.8%) vs. 15/44 (34.1%), p = 0.08) and 30-day mortality (35/59 (59.3%) vs. 17/44 (38.6%), p = 0.06) only tended to be higher in the group with an AKI of stage 2 or 3, long-term survival of up to five years was significantly lower in the group with an AKI of stage 2 or 3 (p = 0.015). High lactate, serum creatinine, and ECMO pump-speed levels, and low platelets, a low base excess, and a low hematocrit level before ECMO were independent predictors of moderate to severe AKI. Primary hypercapnic acidosis was more common in AKI non-survivors (12 (32.4%) vs. 0 (0.0%), p < 0.01). Accordingly, pCO2-levels prior to ECMO implantation tended to be higher in AKI non-survivors (76.12 ± 27.90 mmHg vs. 64.44 ± 44.31 mmHg, p = 0.08). In addition, the duration of mechanical ventilation prior to ECMO-implantation tended to be longer (91.14 ± 108.16 h vs. 75.90 ± 86.81 h, p = 0.078), while serum creatinine (180.92 ± 115.72 mmol/L vs. 124.95 ± 77.77 mmol/L, p = 0.03) and bicarbonate levels were significantly higher in non-survivors (28.22 ± 8.44 mmol/L vs. 23.36 ± 4.19 mmol/L, p = 0.04). (4) Conclusion: Two-thirds of adult patients receiving ECMO suffered from moderate to severe AKI, with a significantly increased morbidity and long-term mortality.

Dynamic oxygenator blood volume during prolonged extracorporeal life support

Current methods for identification of oxygenator clotting during prolonged extracorporeal life support include visual inspection, evaluation of oxygenator resistance and oxygen exchange performance, and assessment of clotting-related laboratory parameters. However, these observations do not provide a quantitative assessment of oxygenator clot formation. By measuring changes in the dynamic oxygenator blood volume this study aimed to evaluate the relation to oxygenator resistance and oxygen transfer performance. Sixty-seven oxygenators were studied during adult extracorporeal life support. Oxygenator blood volume, oxygenator resistance, and oxygen transfer efficiency were monitored. Oxygenator blood volume decreased with increasing runtime (r = -0.462; p <0.001). There was a statistically significant, fair negative correlation between oxygenator blood volume and oxygenator resistance (r = -0.476; p<0.001) in all oxygenators, which became stronger analyzing only exchanged oxygenators (r = -0.680; p<0.001) and oxygenators with an oxygenator blood volume <187 mL (r = 0.831; p<0.001). No relevant correlation between oxygenator blood volume and O₂ transfer was found. Oxygenator blood volume declined over time and was clearly associated with an increasing oxygenator resistance during prolonged extracorporeal life support, though O₂ transfer was less affected.

Predictors of circuit health in neonatal patients receiving extracorporeal membrane oxygenation (ECMO)

To identify predictors of neonatal ECMO circuit health, a retrospective analysis of circuit functional pressure and flow parameters as well as infant clotting values were collected 48 h prior to and 24 h post circuit change. Circuit impairment was defined as need for partial or total circuit change. Statistical analysis used multivariate statistics and non-parametric Mann–Whitney U-test with possible non-normality of measurements. A total of 9764 ECMO circuit and clotting values in 21 circuits were analyzed. Circuit delta-P mean, and maximum values increased from 8.62 to 48.59 mmHg (p < 0.011) and 16.00 to 53.00 mmHg (p < 0.0128) respectively prior to need for circuit change. Maximum and mean Pump Flow Revolutions per minute (RPM) increased by 75% (p < 0.0043) and 81% (p < 0.0057), respectively. Mean plasma free hemoglobin (pfHb) increased from 26.45 to 76.00 mg/dl, (p < 0.0209). Sweep, venous pressure, and clotting parameters were unaffected. ECMO circuit delta-P, RPM, and pfHb were early predictors of circuit impairment.

Bivalirudin versus heparin in adult and pediatric patients with extracorporeal membrane oxygenation therapy: a systematic review and meta-analysis

BACKGROUND

Our study sought to investigate the efficacy and safety of bivalirudin versus those of unfractionated heparin (UFH) in patients undergoing extracorporeal membrane oxygenation (ECMO).

METHODS

PubMed, EMBASE and Cochrane Library were searched for studies enrolling ECMO patients on bivalirudin and UFH (from inception till July 2021). Meta-analysis was conducted. The I² statistic and p value were used in measuring heterogeneity, and random effects or fixed-effect model was adopted. The Newcastle-Ottawa Scale was used for the risk of bias assessment. Sensitivity and subgroup analyses were undertaken. We performed Egger's test to evaluate publication bias.

RESULTS

Fourteen eligible retrospective observational studies with 1501 subjects were identified. Compared with UFH, bivalirudin significantly reduced the risk of in-circuit thrombosis (OR = 0.44, 95% CI [0.31-0.61], p = 0.000), thrombosis (OR = 0.61, 95% CI [0.45-0.83], p = 0.002) and hospital mortality (OR = 0.78, 95% CI [0.61-0.99], p = 0.04) and had a positive impact on survival ECMO (OR = 1.50, 95% CI [1.04-2.16], p = 0.032). Decrease in risk of bleeding (OR = 0.36, 95% CI [0.14-0.91], p = 0.031) associated with bivalirudin was observed. Sources of heterogeneity were identified, and sensitivity analysis revealed similar results.

CONCLUSION

Our meta-analysis suggested that bivalirudin was associated with the decreased risk of in-circuit thrombosis, thrombosis, hospital mortality and bleeding in patients on ECMO and improved survival ECMO, indicating the superiority of bivalirudin to UFH in terms of efficacy and safety.

Major Bleeding in Adults Undergoing Peripheral Extracorporeal Membrane Oxygenation (ECMO): Prognosis and Predictors

Background. Major bleeding has been a common and serious complication with poor outcomes in ECMO patients. With a novel, less-invasive cannulation approach and closer coagulation monitoring regime, the incidence of major bleeding is currently not determined yet. Our study aims to examine the incidence of major bleeding, its determinants, and association with mortality in peripheral-ECMO patients. Method. We conducted a single-center retrospective study on adult patients undergoing peripheral-ECMO between January 2019 and January 2020 at a tertiary referral hospital. Determinants of major bleeding were defined by logistic regression analysis. Risk factors of in-hospital mortality were determined by Cox proportional hazard regression analysis. Results. Major bleeding was reported in 33/105 patients (31.4%) and was associated with higher in-hospital mortality [adjusted hazard ratio (aHR) 3.56, 95% confidence interval (CI) 1.63–7.80, $p<0.001$ ). There were no significant difference in age, sex, ECMO indications, ECMO modality, pre-ECMO APACHE-II and SOFA scores between two groups with and without major bleeding. Only APTT >72 seconds [adjusted odds ratio (aOR) 7.10, 95% CI 2.60–19.50, $p<0.001$ ], fibrinogen <2 g/L [aOR = 7.10, 95% CI 2.60–19.50, $p<0.001$ ], and ACT >220 seconds [aOR = 3.9, 95% CI 1.20–11.80, $p=0.017$ ] on days with major bleeding were independent predictors. Conclusions. In summary, major bleeding still had a fairly high incidence and poor outcome in peripheral-ECMO patients. APTT > 72 seconds, fibrinogen < 2 g/L were the strongest predicting factors for major bleeding events.

Intracranial Hemorrhages on Extracorporeal Membrane Oxygenation: Differences Between COVID-19 and Other Viral Acute Respiratory Distress Syndrome

OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) is a potentially lifesaving procedure in acute respiratory distress syndrome (ARDS) due to COVID-19. Previous studies have shown a high prevalence of clinically silent cerebral microbleeds in patients with COVID-19. Based on this fact, together with the hemotrauma and the requirement of therapeutic anticoagulation on ECMO support, we hypothesized an increased risk of intracranial hemorrhages (ICHs). We analyzed ICH occurrence rate, circumstances and clinical outcome in patients that received ECMO support due to COVID-19-induced ARDS in comparison to viral non-COVID-19-induced ARDS intracerebral hemorrhage.

DESIGN

Multicenter, retrospective analysis between January 2010 and May 2021.

SETTING

Three tertiary care ECMO centers in Germany and Switzerland.

PATIENTS

Two-hundred ten ARDS patients on ECMO support (COVID-19, n = 142 vs viral non-COVID, n = 68).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Evaluation of ICH occurrence rate, parameters of coagulation and anticoagulation strategies, inflammation, and ICU survival. COVID-19 and non-COVID-19 ARDS patients showed comparable disease severity regarding Sequential Organ Failure Assessment score, while the oxygenation index before ECMO cannulation was higher in the COVID group (82 vs 65 mm Hg). Overall, ICH of any severity occurred in 29 of 142 COVID-19 patients (20%) versus four of 68 patients in the control ECMO group (6%). Fifteen of those 29 ICH events in the COVID-19 group were classified as major (52%) including nine fatal cases (9/29, 31%). In the control group, there was only one major ICH event (1/4, 25%). The adjusted subhazard ratio for the occurrence of an ICH in the COVID-19 group was 5.82 (97.5% CI, 1.9-17.8; p = 0.002). The overall ICU mortality in the presence of ICH of any severity was 88%.

CONCLUSIONS

This retrospective multicenter analysis showed a six-fold increased adjusted risk for ICH and a 3.5-fold increased incidence of ICH in COVID-19 patients on ECMO. Prospective studies are needed to confirm this observation and to determine whether the bleeding risk can be reduced by adjusting anticoagulation strategies.

Cardiac tamponade in a patient supported by veno-arterial extracorporeal membrane oxygenation

Cardiac tamponade occurring in a patient supported on central veno-arterial extracorporeal membrane oxygenation is depicted in a transesophageal echocardiography image and associated rendering. Prompt recognition of tamponade, which can be assisted with echocardiography, and emergent evacuation is critical to restoring cardiovascular stability.

Supraglottic airway device and venoarterial extracorporeal membrane oxygenation support for curative surgery in a patient with huge thyroid mass: A case report

In the case of complete surgical resection of locally aggressive thyroid mass with severely compromised airways, airway management is difficult and can be considerably risky. We report a case of airway management using i-gel™ and cardiopulmonary bypass (CPB) with venoarterial extracorporeal membrane oxygenation (ECMO), which is a safe and feasible method of airway management for providing general anesthesia in a patient with a large thyroid mass.

Hemostasis in neonatal ECMO

Extracorporeal membrane oxygenation (ECMO) is a life-saving support for cardio-respiratory function. Over the last 50 years, the extracorporeal field has faced huge technological progress. However, despite the improvements in technique and materials, coagulation problems are still the main contributor to morbidity and mortality of ECMO patients. Indeed, the incidence and survival rates of the main hemorrhagic and thrombotic complications in neonatal respiratory ECMO are relevant. The main culprit is related to the intrinsic nature of ECMO: the contact phase activation. The exposure of the human blood to the non-endothelial surface triggers a systemic inflammatory response syndrome, which chronically activates the thrombin generation and ultimately leads to coagulative derangements. Pre-existing illness-related hemostatic dysfunction and the peculiarity of the neonatal clotting balance further complicate the picture. Systemic anticoagulation is the management's mainstay, aiming to prevent thrombosis within the circuit and bleeding complications in the patient. Although other agents (i.e., direct thrombin inhibitors) have been recently introduced, unfractionated heparin (UFH) is the standard of care worldwide. Currently, there are multiple tests exploring ECMO-induced coagulopathy. A combination of the parameters mentioned above and the evaluation of the patient's underlying clinical context should be used to provide a goal-directed antithrombotic strategy. However, the ideal algorithm for monitoring anticoagulation is currently unknown, resulting in a large inter-institutional diagnostic variability. In this review, we face the features of the available monitoring tests and approaches, mainly focusing on the role of point-of-care (POC) viscoelastic assays in neonatal ECMO. Current gaps in knowledge and areas that warrant further study will also be addressed.

Is bivalirudin an alternative anticoagulant for extracorporeal membrane oxygenation (ECMO) patients? A systematic review and meta-analysis

BACKGROUND

Anticoagulation is important for extracorporeal membrane oxygenation (ECMO). Heparin is widely used; however, in some cases, it is not suitable for patients. Bivalirudin has been recently proposed for ECMO patients, and there is no evidence regarding its effectiveness and safety.

OBJECTIVE

We aimed to systematically review the effectiveness and safety of bivalirudin in ECMO patients.

STUDY DESIGN AND METHODS

PubMed, Web of Science, Cochrane Library, and EMBASE were searched to find relevant research on the use of bivalirudin versus heparin for anticoagulation in ECMO patients. Outcomes included in-hospital mortality, ECMO duration, major bleeding events, thrombosis events and circuit intervention events. Types of studies included randomized control trials (RCTs), cohort studies, and case-control studies. Case reports, studies lacking comparison with heparin, and where patients transitioned between heparin and bivalirudin, were excluded. Publication bias was evaluated when the number of included studies was more than ten. Sensitivity analysis was performed to examine the stability of the results.

RESULTS

Ten articles were selected, and nine articles were included in the meta-analysis. The results of the meta-analysis showed hospital mortality [OR = 0.65, 95%CI (0.44, 0.95), P = 0.03] and thrombosis events decreased (OR = 0.55, 95%CI [0.37, 0.83], P = 0.004) in bivalirudin group compared with heparin in adult patients. Major bleeding events (OR = 0.66, 95%CI [0.17, 2.55], P = 0.55), ECMO duration (MD = 18.92, 95%CI [-29.33, 67.17], P = 0.44) and circuit intervention events (OR = 1.67, 95%CI [0.54, 5.18], P = 0.37) in the bivalirudin group was not statistically significant compared with the heparin group.

CONCLUSION

Bivalirudin may provide survival benefits and reduce thrombosis in adult patients on ECMO compared with heparin. There is no difference in treating major bleeding events between bivalirudin and heparin group. However, because all included studies were retrospective observational studies, the evidence level of this systematic review is low and heterogeneity could not be avoided. More high-quality clinical studies are urgently needed to confirm these benefits.

HEROES V-V-HEmorRhagic cOmplications in Veno-Venous Extracorporeal life Support-Development and internal validation of multivariable prediction model in adult patients

BACKGROUND

During extracorporeal life support (ECLS), bleeding is one of the most frequent complications, associated with high morbidity and increased mortality, despite continuous improvements in devices and patient care. Risk factors for bleeding complications in veno-venous (V-V) ECLS applied for respiratory support have been poorly investigated. We aim to develop and internally validate a prediction model to calculate the risk for bleeding complications in adult patients receiving V-V ECLS support.

METHODS

Data from adult patients reported to the extracorporeal life support organization (ELSO) registry between the years 2010 and 2020 were analyzed. The primary outcome was bleeding complications recorded during V-V ECLS. Multivariable logistic regression with backward stepwise elimination was used to develop the predictive model. The performance of the model was tested by discriminative ability and calibration with receiver operating characteristic curves and visual inspection of the calibration plot.

RESULTS

In total, 18 658 adult patients were included, of which 3 933 (21.1%) developed bleeding complications. The prediction model showed a prediction of bleeding complications with an AUC of 0.63. Pre-ECLS arrest, surgical cannulation, lactate, pO₂ , HCO₃ , ventilation rate, mean airway pressure, pre-ECLS cardiopulmonary bypass or renal replacement therapy, pre-ECLS surgical interventions, and different types of diagnosis were included in the prediction model.

CONCLUSIONS

The model is based on the largest cohort of V-V ECLS patients and reveals the most favorable predictive value addressing bleeding events given the predictors that are feasible and when compared to the current literature. This model will help identify patients at risk of bleeding complications, and decision making in terms of anticoagulation and hemostatic management.

Research Trends and Hotspots of Extracorporeal Membrane Oxygenation: A 10-Year Bibliometric Study and Visualization Analysis

Objective: To determine the research hotspots and trends in the field of extracorporeal membrane oxygenation (ECMO), and to provide a reference for further and wider research in the future. Methods: The literatures on ECMO from January 2011 to July 2021 in the Web of Science Core Collection (WOSCC) database were searched, and Citespace5.8.R1 software was used to conduct bibliographic and visual analysis on the literature by country, institution, author and keywords. Results: A total of 5,986 articles were enrolled. According to an observation, the number of articles published in the past decade has increased, especially from 2019 to 2020. The USA had the largest number of publications, while less ECMO related studies were conducted among non-developed countries. The University of Michigan (Univ Michigan) was the institution that had the largest number of publications and the highest centrality, and Daniel B was the author who had the largest number of publications. However, more inter-institutional cooperation among author teams was needed. The focus of existing ECMO research has primarily been on the treatment of patients suffering from severe cardiopulmonary failure, and the prevention and management of complications during the application ECMO. Conclusion: Inter-regional and inter-institutional cooperation and exchanges should be carried out among ECMO research teams and institutions. The suggested research direction is to further broaden the application scope of ECMO, while determining the ways to reduce the incidence of complications and the cost, cultivate specialized team talents, and promote the application thereof.

Risk factors for intracranial hemorrhage and mortality in adult patients with severe respiratory failure managed using veno-venous extracorporeal membrane oxygenation

Background:

Intracerebral hemorrhage (ICH) is one of the most severe complications during veno-venous extracorporeal membrane oxygenation (VV-ECMO). This study aimed to determine the risk factors for ICH and mortality in such patients.

Methods:

We analyzed the clinical data of 77 patients who received VV-ECMO due to severe respiratory failure from July 2013 to May 2019 at China-Japan Friendship Hospital. Demographical data, laboratory indices, imaging characteristics, and other clinical information were collected. Multivariable logistic regression analyses were performed to identify risk factors for ICH and mortality.

Results:

Of 77 patients, 11 (14.3%) suffered from ICH, and 36 (46.8%) survived. The survival rate was significantly lower (18.2% [2/11] vs. 51.5% [34/66], P = 0.040) in patients with ICH than in those without ICH. Multivariable analysis revealed that factors independently associated with ICH were diabetes mellitus (adjusted odds ratio [aOR]: 12.848, 95% confidence interval [CI]: 1.129–146.188, P = 0.040) and minimum fibrinogen during ECMO (aOR: 2.557, 95% CI: 1.244–5.252, P = 0.011). Multivariable analysis showed that factors independently associated with mortality were acute hepatic failure during ECMO (aOR: 9.205, 95% CI: 1.375–61.604, P = 0.022), CO₂ retention before ECMO (aOR: 7.602, 95% CI: 1.514–38.188, P = 0.014), and minimum platelet concentration during ECMO (aOR: 0.130, 95% CI: 0.029–0.577, P = 0.007).

Conclusions:

Diabetes mellitus and minimum fibrinogen concentration during ECMO are risk factors for ICH in patients with severe respiratory failure managed using VV-ECMO. This indicated that anticoagulants use and nervous system monitoring should be performed more carefully in patients with diabetes when treated with VV-ECMO due to severe respiratory failure.

A comprehensive review of vascular complications in COVID-19

This study aims to review the available literature pertinent to vascular complications in COVID-19. A systematic search was performed using PubMed and Google Scholar to identify all relevant studies based on our study objective. Multiple studies have reported widespread systemic inflammation and procoagulant/hypercoagulable state in COVID-19, including thrombotic microangiopathy, endothelial dysfunction, bleeding disorder, and thrombosis. However, large specialised studies on vascular complications are lacking despite current evidence indicating dysfunctional coagulation pathways. Furthermore, there are no clear and definitive recommendations regarding thromboprophylaxis or full therapeutic anticoagulation in COVID-19. Several studies have reported hypercoagulability and vascular complications as important predictors of patient outcome in COVID-19. Therefore, it is important to understand the pathogenesis, epidemiology, management, and outcomes of patients who develop venous or arterial thrombosis and those with a pre-existing thrombotic disease who contract COVID-19 for risk stratification, thromboprophylaxis, optimal antithrombotic therapy during active infection and long-term anticoagulation following discharge or recovery.

Retrospective Study of Critically Ill COVID-19 Patients With and Without Extracorporeal Membrane Oxygenation Support in Wuhan, China

Background: Extracorporeal membrane oxygenation (ECMO) might benefit critically ill COVID-19 patients. But the considerations besides indications guiding ECMO initiation under extreme pressure during the COVID-19 epidemic was not clear. We aimed to analyze the clinical characteristics and in-hospital mortality of severe critically ill COVID-19 patients supported with ECMO and without ECMO, exploring potential parameters for guiding the initiation during the COVID-19 epidemic.

Methods: Observational cohort study of all the critically ill patients indicated for ECMO support from January 1 to May 1, 2020, in all 62 authorized hospitals in Wuhan, China.

Results: Among the 168 patients enrolled, 74 patients actually received ECMO support and 94 not were analyzed. The in-hospital mortality of the ECMO supported patients was significantly lower than non-ECMO ones (71.6 vs. 85.1%, P = 0.033), but the role of ECMO was affected by patients' age (Logistic regression OR 0.62, P = 0.24). As for the ECMO patients, the median age was 58 (47–66) years old and 62.2% (46/74) were male. The 28-day, 60-day, and 90-day mortality of these ECMO supported patients were 32.4, 68.9, and 74.3% respectively. Patients survived to discharge were younger (49 vs. 62 years, P = 0.042), demonstrated higher lymphocyte count (886 vs. 638 cells/uL, P = 0.022), and better CO₂ removal (PaCO2 immediately after ECMO initiation 39.7 vs. 46.9 mmHg, P = 0.041). Age was an independent risk factor for in-hospital mortality of the ECMO supported patients, and a cutoff age of 51 years enabled prediction of in-hospital mortality with a sensitivity of 84.3% and specificity of 55%. The surviving ECMO supported patients had longer ICU and hospital stays (26 vs. 18 days, P = 0.018; 49 vs. 29 days, P = 0.001 respectively), and ECMO procedure was widely carried out after the supplement of medical resources after February 15 (67.6%, 50/74).

Conclusions: ECMO might be a benefit for severe critically ill COVID-19 patients at the early stage of epidemic, although the in-hospital mortality was still high. To initiate ECMO therapy under tremendous pressure, patients' age, lymphocyte count, and adequacy of medical resources should be fully considered.

Safety and Efficacy of a Novel Centrifugal Pump and Driving Devices of the OASSIST ECMO System: A Preclinical Evaluation in the Ovine Model

Background: Extracorporeal membrane oxygenation (ECMO) provides cardiopulmonary support for critically ill patients. Portable ECMO devices can be applied in both in-hospital and out-of-hospital emergency conditions. We evaluated the safety and biocompatibility of a novel centrifugal pump and ECMO device of the OASSIST ECMO System (Jiangsu STMed Technologies Co., Suzhou, China) in a 168-h ovine ECMO model.

Methods: The portable OASSIST ECMO system consists of the control console, the pump drive, and the disposable centrifugal pump. Ten healthy sheep were used to evaluate the OASSIST ECMO system. Five were supported on veno-venous ECMO and five on veno-arterial ECMO, each for 168 h. The systemic anticoagulation was achieved by continuous heparin infusion to maintain the activated clotting time (ACT) between 220 and 250 s. The rotary speed was set at 3,200–3,500 rpm. The ECMO configurations and ACT were recorded every 6 hours (h). The free hemoglobin (fHb), complete blood count, and coagulation action test were monitored, at the 6th h and every 24 h after the initiation of the ECMO. The dissection of the pump head and oxygenator were conducted to explore thrombosis.

Results: Ten sheep successfully completed the study duration without device-related accidents. The pumps ran stably, and the ECMO flow ranged from 1.6 ± 0.1 to 2.0 ± 0.11 L/min in the V-V group, and from 1.8 ± 0.1 to 2.4 ± 0.14 L/min in the V-A group. The anticoagulation was well-performed. The ACT was maintained at 239.78 ± 36.31 s, no major bleeding or thrombosis was observed during the ECMO run or in the autopsy. 3/5 in the V-A group and 4/5 in the V-V group developed small thrombus in the bearing pedestal. No obvious thrombus formed in the oxygenator was observed. The hemolytic blood damage was not significant. The average fHb was 0.17 ± 0.12 g/L. Considering hemodilution, the hemoglobin, white blood cell, and platelets didn't reduce during the ECMO runs.

Conclusions: The OASSIST ECMO system shows satisfactory safety and biocompatibility for the 168-h preclinical evaluation in the ovine model. The OASSIST ECMO system is promising to be applied in clinical conditions in the future.

Reliability of prognostic biomarkers after prehospital extracorporeal cardiopulmonary resuscitation with target temperature management

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) performed at the emergency scene in out-of-hospital cardiac arrest (OHCA) can minimize low-flow time. Target temperature management (TTM) after cardiac arrest can improve neurological outcome. A combination of ECPR and TTM, both implemented as soon as possible on scene, appears to have promising results in OHCA. To date, it is still unknown whether the implementation of TTM and ECPR on scene affects the time course and value of neurological biomarkers.

METHODS

69 ECPR patients were examined in this study. Blood samples were collected between 1 and 72 h after ECPR and analyzed for S100, neuron-specific enolase (NSE), lactate, D-dimers and interleukin 6 (IL6). Cerebral performance category (CPC) scores were used to assess neurological outcome after ECPR upon hospital discharge. Resuscitation data were extracted from the Regensburg extracorporeal membrane oxygenation database and all data were analyzed by a statistician. The data were analyzed using non-parametric methods. Diagnostic accuracy of biomarkers was determined by area under the curve (AUC) analysis. Results were compared to the relevant literature.

RESULTS

Non-hypoxic origin of cardiac arrest, manual chest compression until ECPR, a short low-flow time until ECPR initiation, low body mass index (BMI) and only a minimal need of extra-corporeal membrane oxygenation support were associated with a good neurological outcome after ECPR. Survivors with good neurological outcome had significantly lower lactate, IL6, D-dimer, and NSE values and demonstrated a rapid decrease in the initial S100 value compared to non-survivors.

CONCLUSIONS

A short low-flow time until ECPR initiation is important for a good neurological outcome. Hypoxia-induced cardiac arrest has a high mortality rate even when ECPR and TTM are performed at the emergency scene. ECPR patients with a higher BMI had a worse neurological outcome than patients with a normal BMI. The prognostic biomarkers S100, NSE, lactate, D-dimers and IL6 were reliable indicators of neurological outcome when ECPR and TTM were performed at the emergency scene.

Case Series: The Coexistence of Thrombocytopenia and Thromboembolism in COVID-19 Patients on ECMO: A Case Series and Literature Review

Thrombocytopenia and thromboembolism are common complications in coronavirus disease 2019 (COVID-19) patients. The fact that COVID-19 patients develop both thrombocytopenia and thromboembolism has been observed, and multiple studies have investigated the underlying pathophysiology. Extracorporeal membrane oxygenation (ECMO) is reserved for COVID-19 patients who develop respiratory failure and not respond to conventional mechanical ventilation. ECMO induces thromboembolism and raises the incidence of developing thromboembolic events in COVID-19 patients. Here, we report the hospital courses and outcomes of three COVID-19 patients who were treated with ECMO, then developed both thrombocytopenia and thromboembolism. The coexistence of thrombocytopenia and thromboembolism challenges the clinical treatment strategy, including the decision of initiating anticoagulation. Based on current data, anticoagulation is recommended to all hospitalized COVID-19 patients unless there is active bleeding, previous bleeding history within 3 days, or platelet count is lower than 30,000 cells/μl. Further investigation into the mechanisms and implications of thrombocytopenia and thromboembolism in patients with COVID-19 pneumonia will lead to significantly improved outcomes and prognosis for the patients.

Veno-arteriovenous extracorporeal membrane oxygenation-A single center experience

BACKGROUND

Patients with combined circulatory shock and respiratory failure may benefit from veno-arteriovenous (V-AV) extracorporeal membrane oxygenation support (ECMO). We report our center's experience with V-AV ECMO and propose an algorithm to help identify patients that may benefit from early V-AV ECMO support.

METHODS

Clinical data were extracted from electronic medical records between November 1, 2016 and November 1, 2019.

RESULTS

Out of a total of 369 patients placed on extracorporeal life support (ECLS), we identified a total of 26 patients who underwent hybrid ECMO placement. Three patients were excluded from our analysis due to veno-venoarterial extracorporeal membrane oxygenation (V-VA ECMO) configuration, therefore 23 patients were included in our analysis. The median age was 53 (range 25-73) years. Hybrid ECMO support was instituted most commonly for differential hypoxemia in patients on venoarterial (V-A) ECMO support, and cardiogenic shock in patients who were initially started on venovenous (V-V) ECMO. The initial ECMO cannulation was V-A in 12 patients, V-V in 8 patients, and directly V-AV in 3 patients. Nine out of 23 patients were successfully decannulated (39.1%) and survived until hospital discharge. The main ECMO-related complications included bleeding (n = 10), circuit exchange either due to hemolysis or oxygenator failure (n = 4), ECMO cannula site infection (n = 2), deep venous thrombosis (n = 2), and death during ECMO cannula exchange (n = 1).

CONCLUSIONS

V-AV ECMO represents a rescue strategy in critically ill patients with combined respiratory failure and cardio-circulatory shock.

Enhancement of the anticoagulant capacity of polyvinyl chloride tubing for cardiopulmonary bypass circuit using aluminum oxide nanoscale coating applied through atomic layer deposition

For cardiopulmonary bypass, the polyvinyl chloride (PVC) circuit which can initiate the activation of platelets and the coagulation cascade after blood cell contacting is the possible detrimental effect. Surface coating of the PVC tubing system can be an effective approach to enhance circuit's hemocompatibility. In this study, aluminum oxide (Al₂ O₃ ) thin films were deposited through thermal atomic layer deposition (T-ALD) or plasma-enhanced ALD (PE-ALD) on PVC samples, and the anticoagulation of the Al₂ O₃ -coated PVC samples was demonstrated. The results revealed that Al₂ O₃ deposition through ALD increased surface roughness, whereas T-ALD had a relative hydrophilicity compared with blank PVC and PE-ALD. Whole blood immersion tests showed that blood clots formed on blank PVC and that a large amount of red blood cells was found on PE-ALD substrates, whereas less blood cells were noted in T-ALD samples. Both T-ALD and PE-ALD Al₂ O₃ films did not cause activation of blood cells, as evidenced in CD3⁺ /CD4⁺ /CD8⁺ , CD61⁺ /CD62P⁺ , and CD45⁺ /CD42b⁺ populations. Analysis of serum coagulation factors showed that a lower amount of prothrombin was absorbed on T-ALD Al₂ O₃ samples than that on blank PVC. For albumin and fibrinogen immersion tests, immunostaining and scanning electron microscopy further revealed that a thin albumin layer was absorbed on T-ALD Al₂ O₃ substrates but not on PVC samples. This study revealed that deposition of Al₂ O₃ films by T-ALD can improve anticoagulation of the PVC tubing system.

Prior Antiplatelet Therapy and Stroke Risk in Critically Ill Patients Undergoing Extracorporeal Membrane Oxygenation

We aimed to investigate whether prior exposure to antiplatelet therapy (anti-PLT) was associated with stroke incidence after the initiation of extracorporeal membrane oxygenation (ECMO) therapy. We conducted a population-based cohort study based on health records obtained from the National Health Insurance Service database in South Korea. Adult patients (aged ≥ 18 years) who underwent ECMO therapy in the intensive care unit during 2009-2018 were enrolled. In total, 17,237 patients who underwent ECMO therapy were included; stroke occurred in 779 (4.5%) of 17,237 patients within 7 days of initiating the ECMO therapy. The number of patients in the anti-PLT and control groups was 3909 (22.7%) and 13,328 (77.3%), respectively. In the multivariable logistic regression analysis, the anti-PLT group showed 33% lower incidence of stroke than the control group (odds ratio (OR): 0.67, 95% confidence interval (CI): 0.55-0.82; p < 0.001). The cardiovascular group showed 35% lower incidence of stroke than the control group (OR: 0.65, 95% CI: 0.52-0.78; p < 0.001), whereas the respiratory group (p = 0.821) and the other group (p = 0.705) did not show any significant association. Prior anti-PLT therapy was associated with a lower incidence of stroke within 7 days of initiating ECMO therapy, which was more evident in the cardiovascular group.

New Trends, Advantages and Disadvantages in Anticoagulation and Coating Methods Used in Extracorporeal Life Support Devices

The use of extracorporeal life support (ECLS) devices has significantly increased in the last decades. Despite medical and technological advancements, a main challenge in the ECLS field remains the complex interaction between the human body, blood, and artificial materials. Indeed, blood exposure to artificial surfaces generates an unbalanced activation of the coagulation cascade, leading to hemorrhagic and thrombotic events. Over time, several anticoagulation and coatings methods have been introduced to address this problem. This narrative review summarizes trends, advantages, and disadvantages of anticoagulation and coating methods used in the ECLS field. Evidence was collected through a PubMed search and reference scanning. A group of experts was convened to openly discuss the retrieved references. Clinical practice in ECLS is still based on the large use of unfractionated heparin and, as an alternative in case of contraindications, nafamostat mesilate, bivalirudin, and argatroban. Other anticoagulation methods are under investigation, but none is about to enter the clinical routine. From an engineering point of view, material modifications have focused on commercially available biomimetic and biopassive surfaces and on the development of endothelialized surfaces. Biocompatible and bio-hybrid materials not requiring combined systemic anticoagulation should be the future goal, but intense efforts are still required to fulfill this purpose.

Platelet, Red Cell, and Endothelial Activation and Injury During Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) can be lifesaving but suffers from high rates of bleeding and repeated transfusions. Current monitoring of blood cell damage during ECMO is limited to platelet counts, hematocrit, and plasma hemoglobin levels. Extracelluar vesicles (EV) are small cell fragments released when cells are activated/injured. The objective was to evaluate flow cytometric measurements of EV during ECMO as an indication of platelet, red cell, and endothelial activation/injury. Samples were collected from 55 patients (1 day to 19 years) during 58 ECMO runs. ECMO activated or injured blood cells, but the extent was highly variable and patient dependent. On average platelet activation was increased sevenfold during ECMO with up to 60-fold increased activation during the first 24 hours in some patients. EV associated with platelet and red-cell injury were increased eightfold on average but up to 200-fold in patients with disseminated intravascular coagulation, severe hemolysis, or massive transfusion. Approximately 9% of ECMO patients showed a red-cell and endothelial activation pattern that was associated with poor prognosis. Extracellular vesicles with autofluorescence similar to bilirubin appeared to come from monocytes processing hemoglobin. ECMO is associated with a highly variable, sustained increase in platelet, red-cell, and endothelial activation and injury that is a combination of circuit and transfusion related events, the patients underlying condition and possibly genetic influences on blood cell activation and injury. Extracellular vesicle measurements may improve our understanding of cellular activation and injury during ECMO as we work to improve the biocompatibility of these systems.

Oseltamivir Improved Thrombocytopenia During Veno-Arterial Extracorporeal Membrane Oxygenation in Adults With Refractory Cardiac Failure: A Single-Center Retrospective Real-World Study

Background: Severe thrombocytopenia is a common complication of extracorporeal membrane oxygenation (ECMO). Oseltamivir can be used to treat infection-associated thrombocytopenia.

Objective: To evaluate the effect of oseltamivir on attenuating severe thrombocytopenia during ECMO.

Methods: This was a single-center real-world study in critically ill patients supported with venous-arterial extracorporeal membrane oxygenation (VA-ECMO). Patients suspected or confirmed with influenza received oseltamivir according to the Chinese guidelines. Thrombocytopenia and survival were compared between the oseltamivir-treated and untreated group. The factors associated with survival were analyzed by multivariable Cox analysis.

Results: A total of 82 patients were included. All patients developed thrombocytopenia after initiating VA-ECMO. Twenty-three patients received oseltamivir (O⁺ group), and 59 did not use oseltamivir (O⁻ group). During the first 8 days after VA-ECMO initiation, the platelet count in the O⁺ group was higher than that in the O⁻ group (all P < 0.05). The patients in the O⁺ group had a higher median nadir platelet count (77,000/μl, 6,000–169,000/μl) compared with the O⁻ group (49,000/μl, 2,000–168,000/μl; P = 0.04). A nadir platelet count of <50,000/μl was seen in 26% of the patients in the O⁺ group, compared with 53% in the O⁻ group (P = 0.031). No significant difference in survival from cardiac failure was seen between the O⁺ and O⁻ group (48 vs. 56%, P = 0.508). The Sequential Organ Failure Assessment (SOFA) score on initiation of VA-ECMO were independently associated with survival (OR = 1.12, 95% confidence interval (95% CI): 1.02–1.22, P = 0.015).

Conclusions: Oseltamivir could ameliorate VA-ECMO-related thrombocytopenia. These findings suggested the prophylactic potential of oseltamivir on severe thrombocytopenia associated with the initiation of VA-ECMO.

Awake extracorporeal membrane oxygenation support for a critically ill COVID-19 patient: A case report

BACKGROUND

A critically ill coronavirus disease 2019 (COVID-19) patient complicated by acute respiratory distress syndrome is reported. The patient survived following treatment with awake veno-venous extracorporeal membrane oxygenation (ECMO).

CASE SUMMARY

A 53-year-old male patient attended our hospital following a cough for 11 d and fever for 9 d. According to his computed tomography (CT) scan and real-time reverse transcription-polymerase chain reaction assay of a throat swab, nucleic acid was positive, confirming that he had COVID-19. He was subsequently transferred to the intensive care unit due to respiratory failure. The patient received antiviral drugs, a small dose of glucocorticoid, and respiratory support, including mechanical ventilation, but the treatment effect was poor. On the 28th day after admission, veno-venous ECMO and prone position ventilation (PPV) were performed, combined with awake ECMO and other comprehensive rehabilitation measures. On the 17th day of ECMO, the patient started to improve and his chest CT and lung compliance improved. ECMO was discontinued after 27 days, and mechanical ventilation was also discontinued after 9 days. The patient was then transferred to the rehabilitation department.

CONCLUSION

COVID-19 can damage lung tissues and cause evident inflammatory exudation, thus affecting oxygenation function. Awake ECMO, PPV, and comprehensive rehabilitation are effective in patients with critical COVID-19 and respiratory failure.

Extracorporeal membrane oxygenation (ECMO) for critically ill patients with coronavirus disease 2019 (COVID-19): A retrospective cohort study

Purpose

The role of extracorporeal membrane oxygenatio (ECMO) for rescue therapy of respiratory failure in critically ill coronavirus disease 2019 (COVID‐19) patients remains controversial. We aimed to evaluate the clinical outcomes of ECMO in the treatment of COVID‐19 compared with conventional ventilation support.

Methods

In this retrospective cohort study, data were collected on extremely critical patients with COVID‐19 from January 2020 to March 2020 in intensive care unit of a hospital in charge by national rescue team in Wuhan, China, the epicenter of pandemic. Patients were classified into the ECMO group and the conventional ventilation non‐ECMO group. Clinical characteristics, technical characteristics, laboratory results, mortality, and complications of the two groups were analyzed.

Results

88 patients with extremely critical COVID‐19 were screened; 34 received ECMO support and 31 received conventional ventilation support. Both groups had comparable characteristics at baseline in terms of age, gender, and comorbidities. Before ECMO or conventional therapy, patients in the two groups had sever acute respiratory distress syndrome with a mean partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO₂/FiO₂) ratio of 69.6 and 75.4, respectively. At the time of reporting, patients in the ECMO had significantly lower in‐hospital mortality compared with the control group (58.8 vs. 93.5%, p = .001).

Conclusion

ECMO is shown to decrease the mortality of extremely critical ill COVID‐19 patients compared with the conventional treatment. Although complications occurred frequently, ECMO could still be a rescue therapy for the treatment of COVID‐19 during the pandemic.

Extracorporeal Support Prognostication-Time to Move the Goal Posts?

Advances in extracorporeal membrane oxygenation (ECMO) technology are associated with expanded indications, increased utilization and improved outcome. There is growing interest in developing ECMO prognostication scores to aid in bedside decision making. To date, the majority of available scores have been limited to mostly registry-based data and with mortality as the main outcome of interest. There continues to be a gap in clinically applicable decision support tools to aid in the timing of ECMO cannulation to improve patients' long-term outcomes. We present a brief review of the commonly available adult and pediatric ECMO prognostication tools, their limitations, and future directions.

Influence of transfusions, hemodialysis and extracorporeal life support on hyperferritinemia in critically ill patients

BACKGROUND

Ferritin is the major iron storage protein and an acute phase reactant. Hyperferritinemia is frequently seen in the critically ill where it has been hypothesized that not only underlying conditions but also factors such as transfusions, hemodialysis and extracorporeal life support (ECLS) lead to hyperferritinemia. This study aims to investigate the influence of transfusions, hemodialysis, and ECLS on hyperferritinemia in a multidisciplinary ICU cohort.

METHODS

This is a post-hoc analysis of a retrospective observational study including patients aged ≥ 18 years who were admitted to at least one adult ICU between January 2006 and August 2018 with hyperferritinemia ≥ 500 μg/L and of ≥ 14 days between two ICU ferritin measurements. Patients with hemophagocytic lymphohistiocytosis (HLH) were excluded. To identify the influence of transfusions, hemodialysis, and ECLS on ferritin change, multivariable linear regression analysis with ferritin change between two measurements as dependent variable was performed.

RESULTS

A total of 268 patients was analyzed. Median duration between measurements was 36 days (22-57). Over all patients, ferritin significantly increased between the first and last measurement (p = 0.006). Multivariable linear regression analysis showed no effect of transfusions, hemodialysis, or ECLS on ferritin change. Changes in aspartate aminotransferase (ASAT) and sequential organ failure assessment (SOFA) score were identified as influencing factors on ferritin change [unstandardized regression coefficient (B) = 2.6; (95% confidence interval (CI) 1.9, 3.3); p < 0.001 and B = 376.5; (95% CI 113.8, 639.1); p = 0.005, respectively]. Using the same model for subgroups of SOFA score, we found SOFA platelet count to be associated with ferritin change [B = 1729.3; (95% CI 466.8, 2991.9); p = 0.007]. No association of ferritin change and in-hospital mortality was seen in multivariable analysis.

CONCLUSIONS

The present study demonstrates that transfusions, hemodialysis, and ECLS had no influence on ferritin increases in critically ill patients. Hyperferritinemia appears to be less the result of iatrogenic influences in the ICU thereby underscoring its unskewed diagnostic value.

TRIAL REGISTRATION

The study was registered with www.ClinicalTrials.gov (NCT02854943) on August 1, 2016.

Venovenous Extracorporeal Membrane Oxygenation to Facilitate Removal of Endobronchial Tumors

Short-term extracorporeal membrane oxygenation is a useful adjunct to thoracic procedures. We report the cases of 2 middle-aged men who were supported with venovenous extracorporeal membrane oxygenation to facilitate tumor debulking and recanalization of the carina and mainstem bronchi. Neither patient had major complications or adverse events. These cases suggest that short-term extracorporeal membrane oxygenation is safe in patients undergoing complex resection or debulking of endobronchial lesions.

Combined Renal-Pulmonary Extracorporeal Support with Low Blood Flow Techniques: A Retrospective Observational Study (CICERO Study)

BACKGROUND

Critically ill patients with acute respiratory failure frequently present concomitant lung and kidney injury, within a multiorgan failure condition due to local and systemic mediators. To face this issue, extracorporeal carbon dioxide removal (ECCO2R) systems have been integrated into continuous renal replacement therapy (CRRT) platforms to provide a combined organ support, with efficient clearance of CO2 with very low extracorporeal blood flows (<400 mL/min).

OBJECTIVES

To evaluate efficacy and safety of combined ECCO2R-CRRT support with PrismaLung®-Prismaflex® in patients affected by hypercapnic respiratory acidosis associated with AKI in a second level intensive care unit.

METHODS

We carried out a retrospective observational study enrolling patients submitted to PrismaLung®-Prismaflex® due to mild to moderate acute respiratory distress syndrome (ARDS) or acute exacerbation of chronic obstructive pulmonary disease (aeCOPD). The primary endpoints were the shift to protective ventilation and extubation of mechanically ventilated patients and the shift to invasive mechanical ventilation of patients receiving noninvasive ventilation (NIV). Clinical-laboratoristic data and operational characteristics of ECCO2R-CRRT were recorded.

RESULTS

Overall, 12/17 patients on mechanical ventilation shifted to protective ventilation, CO2 clearance was satisfactorily maintained during the whole observational period, and pH was rapidly corrected. Treatment prevented NIV failure in 4 out of 5 patients. No treatment-related complications were recorded.

CONCLUSION

ECCO2R-CRRT was effective and safe in patients with aeCOPD and ARDS associated with AKI.

Overview of Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) Support for the Management of Cardiogenic Shock

Cardiogenic shock accounts for ~100,000 annual hospital admissions in the United States. Despite improvements in medical management strategies, in-hospital mortality remains unacceptably high. Multiple mechanical circulatory support devices have been developed with the aim to provide hemodynamic support and to improve outcomes in this population. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is the most advanced temporary life support system that is unique in that it provides immediate and complete hemodynamic support as well as concomitant gas exchange. In this review, we discuss the fundamental concepts and hemodynamic aspects of VA-ECMO support in patients with cardiogenic shock of various etiologies. In addition, we review the common indications, contraindications and complications associated with VA-ECMO use.

Tethered Liquid Perfluorocarbon Coating for 72 Hour Heparin-Free Extracorporeal Life Support

Coagulopathic complications during extracorporeal life support (ECLS) result from two parallel processes: 1) foreign surface contact and shear stress during blood circulation and 2) administration of anticoagulant drugs to prevent circuit thrombosis. To address these problems, biocompatible surfaces are developed to prevent foreign surface-induced coagulopathy, reducing or eliminating the need for anticoagulants. Tethered liquid perfluorocarbon (TLP) is a nonadhesive coating that prevents adsorption of plasma proteins and thrombus deposition. We examined application of TLP to complete ECLS circuits (membranes, tubing, pumps, and catheters) during 72 hours of ECLS in healthy swine (n = 5/group). We compared TLP-coated circuits used without systemic anticoagulation to standard of care: heparin-coated circuits with continuous heparin infusion. Coagulopathic complications, device performance, and systemic effects were assessed. We hypothesized that TLP reduces circuit thrombosis and iatrogenic bleeding, without impeding gas exchange performance or causing untoward effects. No difference in bleeding or thrombotic complication rate was observed; however, circuit occlusion occurred in both groups (TLP = 2/5; CTRL = 1/5). TLP required elevated sweep gas rate to maintain normocapnia during ECLS versus CTRL (10-20 vs. 5 L/min; p = 0.047), suggesting impaired gas exchange. Thrombus deposition and protein adhesion on explanted membranes were comparable, and TLP did not preserve platelet or blood cell counts relative to controls. We conclude that neither TLP nor standard of care is an efficacious solution to prevent coagulation disturbances during ECLS. Further testing of promising biomaterials for ECLS utilizing the model outlined here is warranted.

Analysis of the 2020 EACTS/ELSO/STS/AATS Expert Guidelines on the Management of Adult Postcardiotomy Extracorporeal Life Support

Extracorporeal life support (ECLS), also known as extracorporeal membrane oxygenation (ECMO), increasingly is used in postcardiotomy (PC) shock to facilitate a bridge to sustained recovery, long-term mechanical support, or heart transplantation. Given increasing prevalence and complexity of PC-ECLS, a joint expert consensus guideline was created in 2020 for management of adult PC-ECLS by the European Association for Cardio-Thoracic Surgery (EACTS), the Extracorporeal Life Support Organization (ELSO), the Society of Thoracic Surgeons (STS), and the American Association of Thoracic Surgery (AATS). The aim of this analysis was to comprehensively review the expert consensus guidelines, with particular emphasis on PC-ECLS candidacy, timing, cannula configuration, left ventricular distention, anticoagulation, ECLS weaning, and intensive care unit complications. This analysis finds the expert consensus guideline to be timely, pertinent, and clinically valuable, although there remains the need for larger clinical trials to codify best practices.

Venoarterial extracorporeal membrane oxygenation as an early treatment for amniotic fluid embolism with cardiac arrest: A case report

Amniotic fluid embolism (AFE) is a rare but fatal obstetric complication, characterized by sudden cardiovascular collapse, respiratory failure, and disseminated intravascular coagulation. Maternal mortality associated with AFE is high, making early recognition and prompt treatment important. In AFE with cardiac arrest, survival following acute cardiopulmonary dysfunction is crucial. In recent years, venoarterial extracorporeal membrane oxygenation (VA-ECMO) has attracted attention as an aggressive treatment for AFE with cardiac arrest. A 40-year-old woman experienced sudden cardiac arrest due to AFE during cesarean section. Cardiopulmonary resuscitation and VA-ECMO (also called percutaneous cardiopulmonary support) were initiated early. Finally, she recovered without any complications. VA-ECMO can provide temporary respiratory and hemodynamic support until cardiopulmonary function improves after a few days in intensive care. VA-ECMO should be considered as an early treatment for AFE with cardiac arrest.

Efficacy of thromboelastography in the management of anticoagulation for veno-venous extracorporeal membrane oxygenation in a coronavirus disease 2019 patient: A case report

RATIONALE

In coronavirus disease 2019 (COVID-19) patients with acute respiratory distress syndrome refractory to optimal conventional management, we should consider the indication for veno-venous extracorporeal membrane oxygenation (V-V ECMO). Growing evidence indicates that COVID-19 frequently causes coagulopathy, presenting as hypercoagulation and incidental thrombosis. For these reasons, a multifactorial approach with several anticoagulant markers should be considered in the management of anticoagulation using heparin in COVID-19 patients on V-V ECMO.

PATIENT CONCERNS

A 48-year-old man was infected with COVID-19 with a worsening condition manifesting as acute respiratory distress syndrome.

DIAGNOSES

He was refractory to conventional therapy, thus we decided to introduce V-V ECMO. We used heparin as an anticoagulant therapy for V-V ECMO and adjusted the doses of heparin by careful monitoring of the activated clotting time (ACT) and activated partial thromboplastin time (APTT) to avoid both hemorrhagic and thrombotic complications. We controlled the doses of heparin in the therapeutic ranges of ACT and APTT, but clinical hemorrhaging and profound elevation of coagulant marker became apparent.

INTERVENTIONS

Using thromboelastography (TEG; Haemonetics) in addition to ACT and APTT, we were able to clearly detect not only sufficient coagulability of COVID19 on V-V ECMO (citrated rapid thromboelastography-R 0.5 min, angle 75.5°, MA 64.0 mm, citrated functional fibrinogen-MA 20.7 mm) but also an excessive effect of heparin (citrated kaolin -R 42.7 min, citrated kaolin with heparinase 11.7 min).

OUTCOMES

Given the TEG findings indicating an excessive heparin effect, the early withdrawal of ECMO was considered. After an evaluation of the patient's respiratory capacity, withdrawal from V-V ECMO was achieved and then anticoagulation was stopped. The hemorrhagic complications and elevated thrombotic marker levels dramatically decreased.

LESSONS

TEG monitoring might be a useful option for managing anticoagulation in COVID-19 patients on V-V ECMO frequently showing a hypercoagulative state and requiring massive doses of heparin, to reduce both hemorrhagic and thrombotic complications.

Neonatal respiratory and cardiac ECMO in Europe

Neonatal extracorporeal membrane oxygenation (ECMO) is a life-saving procedure for critically ill neonates suffering from a potentially reversible disease, causing severe cardiac and/or respiratory failure and refractory to maximal conventional management. Since the 1970s, technology, management, and clinical applications of neonatal ECMO have changed. Pulmonary diseases still represent the principal neonatal diagnosis, with an overall 74% survival rate, and up to one-third of cases are due to congenital diaphragmatic hernia. The overall survival rate in cardiac ECMO is lower, with congenital heart defect representing the main indication. This review provides an overview of the available evidence in the field of neonatal ECMO. We will address the changing epidemiology, basic principles, technologic advances in circuitry, and monitoring, and deliver a current multidisciplinary management framework, focusing on ECMO applications, complications, and long-term morbidities. Lastly, areas for further research will be highlighted.Conclusions: ECMO is a life support with a potential impact on long-term patients' outcomes. In the next years, advances in knowledge, technology, and expertise may push neonatal ECMO boundaries towards more premature and increasingly complex infants, with the final aim to reduce the burden of ECMO-related complications and improve overall patients' outcomes. What is Known: • ECMO is a life-saving option in newborns with refractory respiratory and/or cardiac failure. • The multidisciplinary ECMO management is challenging and may expose neonates to complications with an impact on long-term outcomes. What is New: • Advances in technology and biomaterials will improve neonatal ECMO management and, eventually, the long-term outcome of these complex patients. • Experimental models of artificial placenta and womb technology are under investigation and may provide clinical translation and future research opportunities.

Brain Injury Is More Common in Venoarterial Extracorporeal Membrane Oxygenation Than Venovenous Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis

OBJECTIVES

Despite the common occurrence of brain injury in patients undergoing extracorporeal membrane oxygenation, it is unclear which cannulation method carries a higher risk of brain injury. We compared the prevalence of brain injury between patients undergoing venoarterial and venovenous extracorporeal membrane oxygenation.

DATA SOURCES

PubMed and six other databases from inception to April 2020.

STUDY SELECTION

Observational studies and randomized clinical trials in adult patients undergoing venoarterial extracorporeal membrane oxygenation or venovenous extracorporeal membrane oxygenation reporting brain injury.

DATA EXTRACTION

Two independent reviewers extracted the data from the studies. Random-effects meta-analyses were used to pool data.

DATA SYNTHESIS

Seventy-three studies (n = 16,063) met inclusion criteria encompassing 8,211 patients (51.2%) undergoing venoarterial extracorporeal membrane oxygenation and 7,842 (48.8%) undergoing venovenous extracorporeal membrane oxygenation. Venoarterial extracorporeal membrane oxygenation patients had more overall brain injury compared with venovenous extracorporeal membrane oxygenation (19% vs 10%; p = 0.002). Venoarterial extracorporeal membrane oxygenation patients had more ischemic stroke (10% vs 1%; p < 0.001), hypoxic-ischemic brain injury (13% vs 1%; p < 0.001), and brain death (11% vs 1%; p = 0.001). In contrast, rates of intracerebral hemorrhage (6% vs 8%; p = 0.35) did not differ. Survival was lower in venoarterial extracorporeal membrane oxygenation (48%) than venovenous extracorporeal membrane oxygenation (64%) (p < 0.001). After excluding studies that included extracorporeal cardiopulmonary resuscitation, no significant difference was seen in the rate of overall acute brain injury between venoarterial extracorporeal membrane oxygenation and venovenous extracorporeal membrane oxygenation (13% vs 10%; p = 0.4). However, ischemic stroke (10% vs 1%; p < 0.001), hypoxic-ischemic brain injury (7% vs 1%; p = 0.02), and brain death (9% vs 1%; p = 0.005) remained more frequent in nonextracorporeal cardiopulmonary resuscitation venoarterial extracorporeal membrane oxygenation compared with venovenous extracorporeal membrane oxygenation.

CONCLUSIONS

Brain injury was more common in venoarterial extracorporeal membrane oxygenation compared with venovenous extracorporeal membrane oxygenation. While ischemic brain injury was more common in venoarterial extracorporeal membrane oxygenation patients, the rates of intracranial hemorrhage were similar between venoarterial extracorporeal membrane oxygenation and venovenous extracorporeal membrane oxygenation. Further research on mechanism, timing, and effective monitoring of acute brain injury and its management is necessary.

Novel application of indocyanine green fluorescence imaging for real-time detection of thrombus in a membrane oxygenator

Extracorporeal membrane oxygenation (ECMO) plays an important role in the coronavirus disease 2019 (COVID-19) pandemic. Management of thrombi in ECMO is generally an important issue; especially in ECMO for COVID-19 patients who are prone to thrombus formation, the thrombus formation in oxygenators is an unresolved issue, and it is very difficult to deal with. To prevent thromboembolic complications, it is necessary to develop a method for early thrombus detection. We developed a novel method for detailed real-time observation of thrombi formed in oxygenators using indocyanine green (ICG) fluorescence imaging. The purpose of this study was to verify the efficacy of this novel method through animal experiments. The experiments were performed three times using three pigs equipped with veno-arterial ECMO comprising a centrifugal pump (CAPIOX SL) and an oxygenator (QUADROX). To create thrombogenic conditions, the pump flow rate was set at 1 L/min without anticoagulation. The diluted ICG (0.025 mg/mL) was intravenously administered at a dose of 10 mL once an hour. A single dose of ICG was 0.25mg. The oxygenator was observed with both an optical detector (PDE-neo) and the naked eye every hour after measurement initiation for a total of 8 hours. With this dose of ICG, we could observe it by fluorescence imaging for about 15 minutes. Under ICG imaging, the inside of the oxygenator was observed as a white area. A black dot suspected to be the thrombus appeared 6-8 hours after measurement initiation. The thrombus and the black dot on ICG imaging were finely matched in terms of morphology. Thus, we succeeded in real-time thrombus detection in an oxygenator using ICG imaging. The combined use of ICG imaging and conventional routine screening tests could compensate for each other's weaknesses and significantly improve the safety of ECMO.

Toxic effects of cell-free hemoglobin on the microvascular endothelium: implications for pulmonary and nonpulmonary organ dysfunction

Levels of circulating cell-free hemoglobin are elevated during hemolytic and inflammatory diseases and contribute to organ dysfunction and severity of illness. Though several studies have investigated the contribution of hemoglobin to tissue injury, the precise signaling mechanisms of hemoglobin-mediated endothelial dysfunction in the lung and other organs are not yet completely understood. The purpose of this review is to highlight the knowledge gained thus far and the need for further investigation regarding hemoglobin-mediated endothelial inflammation and injury to develop novel therapeutic strategies targeting the damaging effects of cell-free hemoglobin.

Contrast-Enhanced Echocardiography Application in Patients Supported by Extracorporeal Membrane Oxygenation (ECMO): A Narrative Review

Extracorporeal membrane oxygenation (ECMO) is a lifesaving intervention increasingly used to support patients with severe respiratory and cardiac dysfunction. Echocardiography is an important tool, aiding implantation and monitoring during ECMO therapy, but often its use is limited by poor acoustic windows. This limitation may be overcome by the use of echocardiography contrast agents to improve diagnostic yield and reduce the need for other imaging modalities that may require patient transfer, involve ionizing radiation and, occasionally, nephrotoxic radio-opaque contrast medium. In this article the authors review the literature addressing the use of contrast-enhanced echocardiography (CEE) in ECMO-supported patients. The authors discuss the role of CEE in guiding implantation of ECMO, cardiac assessment and diagnosis of complications during ECMO therapy, as well as the safety of ultrasound-enhancing agents in this cohort of patients.

Perioperative, protective use of extracorporeal membrane oxygenation in complex thoracic surgery

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is increasingly used in patients undergoing complex thoracic surgical procedures. However, studies reporting the clinical outcomes of these patients are limited to case reports, without real consensus. Our aim was to evaluate the perioperative use of ECMO as respiratory and/or circulatory support in thoracic surgery: indications, benefits, and perioperative management.

METHODS

Between May 2013 and December 2018, we reviewed the clinical data of 15 patients (11 males and 4 females; mean age: 47 years old; range, 25-73 years) undergoing ECMO-assisted thoracic surgery in our hospital.

RESULTS

Of the 15 patients, 10 cases received peripheral veno-arterial (VA) ECMO and five cases received veno-venous (VV) ECMO. Indications for ECMO were pulmonary transplantation with hard-to-maintain oxygenation (n = 5), traumatic main bronchial rupture (n = 2), traumatic lung injury (n = 1), airway tumor leading to severe airway stenosis (n = 2), huge thoracic mass infiltrated vena cava (n = 5). The ECMO duration was 1-51 hours. All patients were successfully extubated and weaned from ECMO postoperatively. The main complications were hemorrhage (26.7%), infection (33.3%), acute hepatic dysfunction (33.3%), and venous thrombosis (26.7%). There was only one hospital death and postoperative one-year survival rate was 86%.

CONCLUSION

Our experience indicates that ECMO is a feasible method for complex trachea-bronchial surgery, huge thoracic mass excision and lung transplantation, and the ECMO-related risks may be justified. With further accumulation of experience with ECMO, a more sophisticated protocol for management of critical airway or heart failure problems in thoracic surgeries can be derived.

Establishment and evaluation of a rat model of extracorporeal membrane oxygenation (ECMO) thrombosis using a 3D-printed mock-oxygenator

Background

Extracorporeal membrane oxygenation (ECMO) research using large animals requires a significant amount of resources, slowing down the development of new means of ECMO anticoagulation. Therefore, this study developed and evaluated a new rat ECMO model using a 3D-printed mock-oxygenator.

Methods

The circuit consisted of tubing, a 3D-printed mock-oxygenator, and a roller pump. The mock-oxygenator was designed to simulate the geometry and blood flow patterns of the fiber bundle in full-scale oxygenators but with a low (2.5 mL) priming volume. Rats were placed on arteriovenous ECMO at a 1.9 mL/min flow rate at two different heparin doses (n = 3 each): low (15 IU/kg/h for eight hours) versus high (50 IU/kg/h for one hour followed by 25 IU/kg/h for seven hours). The experiment continued for eight hours or until the mock-oxygenator failed. The mock-oxygenator was considered to have failed when its blood flow resistance reached three times its baseline resistance.

Results

During ECMO, rats maintained near-normal mean arterial pressure and arterial blood gases with minimal hemodilution. The mock-oxygenator thrombus weight was significantly different (p < 0.05) between the low (0.02 ± 0.006 g) and high (0.003 ± 0.001 g) heparin delivery groups, and blood flow resistance was also larger in the low anticoagulation group.

Conclusions

This model is a simple, inexpensive system for investigating new anticoagulation agents for ECMO and provides low and high levels of anticoagulation that can serve as control groups for future studies.