Search

Introduction: Extracorporeal membrane oxygenation (ECMO) is increasingly used for circulatory or pulmonary support not only in‐hospital but also out‐of‐hospital. Small dimensions and a lightweight design are important, especially for out‐of‐hospital use but also for intra‐hospital transportation of patients who require ECMO support. We share our first experience with the new Colibrì ECMO system. Patients and Methods: From December 2022 to January 2023, we used the new Colibrì extracorporeal circulation (ECC) system in six patients with cardiac or pulmonary failure. Results: The Colibrì system was used in‐hospital in six patients with post‐cardiac surgery low output syndrome, respiratory failure due to influenza or acute respiratory distress syndrome, cardiogenic shock, pulmonary embolism, and failed weaning from cardiopulmonary bypass. The system was implanted in venovenous (VV) and venoarterial (VA) fashion in 3 patients, respectively. In one patient, the configuration was switched from VA to VV after cardiac recovery. One patient received left‐ventricular unloading using the IMPELLA®5.5. ECMO run time was 1 to 13 days. We did not notice any ECC system‐associated complications. No ECMO system changes were required. Conclusion: Our case series concludes that the new Colibrì system is safe and effective for in‐hospital ECMO indications. The small dimensions and lightweight design are very beneficial for the transportation of patients. It might be especially helpful for out‐of‐hospital situations. [ABSTRACT FROM AUTHOR]

Background: Large Impella systems (5.0 or 5.5; i.e., Impella 5+) (Abiomed Inc., Danvers, MA, USA) help achieve better clinical outcomes through relevant left ventricular unloading in acute cardiogenic shock (CS). Here, we report our experience with Impella 5+, while focusing on the clinical outcomes depending on individual case scenarios in patients with acute CS. Methods: This single‐center retrospective observational study included 100 Impella 5+ implantations conducted on patients with acute CS from November 2018 to October 2021. After excluding 10 reimplantation cases, 90 cases were enrolled for further analysis. Results: In‐hospital and 30‐day mortality rates were 56.7% (n = 51) and 48.9% (n = 44), respectively. In‐hospital mortality was lower in patients with acute myocardial infarction (AMI) than in non‐AMI patients (p = 0.07). Young age and low lactate levels were the independent predictors of successful transition and survival after permanent mechanical circulatory support/heart transplantation (pMCS/HTX) (age, p = 0.03; lactate level, p = 0.04; survived after pMCS/HTX, n = 11; died on Impella, n = 41). During simultaneous utilization of venoarterial extracorporeal membrane oxygenation therapy and Impella 5+, termed ECMELLA therapy, high dose of noradrenaline was a predictive factor for in‐hospital mortality by multivariate analysis (n = 0.02). Conclusions: Our results suggest that enhanced Impella support might have better clinical outcomes among acute CS patients supported with large Impella, those with AMI than those with no AMI. Young age and low lactate levels were predictors of successful bridging to pMCS/HTX and favorable clinical outcomes thereafter. The clinical outcomes of ECMELLA therapy might depend on noradrenaline dose at the time of Impella 5+ implantation. [ABSTRACT FROM AUTHOR]

Background: Pulmonary complications often occur in patients receiving veno‐arterial extracorporeal membrane oxygenation (VA ECMO). However, the prognostic impact of lung damage has not been fully elucidated. Methods: This single‐center retrospective observational study targeted patients with cardiogenic shock who received VA ECMO between 2012 and 2021. This study included 65 patients who underwent chest computed tomography (CT) on VA ECMO, followed by escalation to central mechanical circulatory support (MCS) with left ventricular venting. The average density of lung CT images was measured using region‐of‐interest methods, and the primary endpoint was 180‐day all‐cause death after escalation to the central MCS. Results: Twenty‐two patients (34%) developed 180‐day all‐cause death. According to the Cox regression analysis, age (hazard ratio [HR], 1.08; 95% confidence interval [CI], 1.03–1.14; p = 0.001), ischemic etiology (HR, 5.53; 95% CI, 2.09–14.62; p < 0.001), duration of VA ECMO support (HR, 1.19; 95% CI, 1.00–1.40; p = 0.045), and lung CT density (≥ −481 Hounsfield unit [HU]) (HR, 6.33; 95% CI, 2.26–17.72; p < 0.001) were independently associated with all‐cause death. Receiver operating characteristic curve analysis determined that lung CT density ≥ −481 HU is an optimal cutoff value for predicting all‐cause death (area under the curve [AUC], 0.72). The 180‐day overall survival rate for patients with high lung CT density (≥ −481 HU) was significantly lower than that for those with low lung CT density (< −481 HU) (44.4% vs. 81.6%, respectively, p = 0.002). Conclusions: Higher lung CT density could be a useful predictor of death in patients with VA ECMO requiring central MCS escalation. [ABSTRACT FROM AUTHOR]

Background: High‐quality evidence for post‐cardiotomy extracorporeal life support (PC‐ECLS) management is lacking. This study investigated real‐world PC‐ECLS clinical practices. Methods: This cross‐sectional, multi‐institutional, international pilot survey explored center organization, anticoagulation management, left ventricular unloading, distal limb perfusion, PC‐ECLS monitoring, and transfusion practices. Twenty‐nine questions were distributed among 34 hospitals participating in the Post‐cardiotomy Extra‐Corporeal Life Support Study. Results: Of the 32 centers [16 low‐volume (50%); 16 high‐volume (50%)] that responded, 16 (50%) had dedicated ECLS specialists. Twenty‐six centers (81.3%) reported using additional mechanical circulatory supports. Anticoagulation practices were highly heterogeneous: 24 hospitals (75%) reported using patients bleeding status as a guide, without a specific threshold in 54.2% of cases. Transfusion targets ranged from 7 to 10 g/dL. Most centers used cardiac venting on a case‐by‐case basis (78.1%) and regular distal limb perfusion (84.4%). Nineteen (54.9%) centers reported dedicated monitoring protocols, including daily echocardiography (87.5%), Swan‐Ganz catheterization (40.6%), cerebral near‐infrared spectroscopy (53.1%), and multimodal assessment of limb ischemia. Inspection of the circuit (71.9%), oxygenator pressure drop (68.8%), plasma free hemoglobin (75%), d‐dimer (59.4%), lactate dehydrogenase (56.3%), and fibrinogen (46.9%) are used to diagnose hemolysis and thrombosis. Conclusions: This study shows remarkable heterogeneity in clinical practices for PC‐ECLS management. More standardized protocols and better implementation of the available evidence are recommended. [ABSTRACT FROM AUTHOR]

Globalization in Asia and consequent strengthening of healthcare economic factors in tandem with an increasing heart failure (HF) population have enhanced potential for development and progress in the fields of HF medicine and mechanical circulatory support (MCS). In Japan, there are unique opportunities to investigate the outcome of acute and chronic MCS and a national registry for percutaneous and implantable left ventricular assist device (LVAD) including Impella pumps has been established. A Peripheral extracorporeal membrane oxygenation (ECMO) for acute MCS has been used in more than 7000 patients annually and Impella usage in more than 4000 patients over the past 4 years was noted. Recently, a novel centrifugal pump with hydrodynamically levitated impeller was developed and approved for mid‐term extracorporeal circulatory support. In terms of chronic MCS more than 1200 continuous flow LVADs have been implanted during the past decade, and 2‐year survival rate after primary LVAD implantation is 91%. Because of donor organ shortage, more than 70% of heart transplant recipients required LVAD support for more than 3 years and prevention and treatment of complications during long‐term LVAD support have become important. Five important topics including hemocompatibility‐related complications, LVAD infections, aortic valve insufficiency, right ventricular failure and cardiac recovery during LVAD support are discussed in this review for improving clinical outcomes. Findings from Japan will continue to provide useful information regarding MCS for the Asia‐Pacific region and beyond. [ABSTRACT FROM AUTHOR]

Acute right ventricular (RV) failure following massive pulmonary embolism (PE) can have significant hemodynamic consequences and is the mode of death. Temporary mechanical circulatory support can provide tissue perfusion required while thrombectomy or lysis‐aimed therapies act to relieve the thrombotic obstruction. Veno‐arterial extracorporeal membrane oxygenation (V‐A ECMO) has conventionally been the first line MCS. A more selective approach to RV support has been advocated in the form of an extracorporeal right ventricular assist device (RVAD) as it mitigates some of the shortcomings of V‐A ECMO. We present the first case series of four patients who received fully percutaneous RVAD, with an integrated oxygenator forming an Oxy‐RVAD, for selective right heart support following massive PE, including the application of single‐access dual‐lumen right atrium to pulmonary artery cannula. All patients achieved RV recovery and were successfully weaned from oxy‐RVAD support within 5–10 days demonstrating the feasibility of selective percutaneous right heart support in managing these challenging patients. [ABSTRACT FROM AUTHOR]

Background: Antithrombogenicity of extracorporeal membrane oxygenation (ECMO) devices, particularly oxygenators, is a current problem, with numerous studies and developments underway. However, there has been limited progress in developing methods to accurately compare the antithrombogenicity of oxygenators. Animal experiments are commonly conducted to evaluate the antithrombogenicity of devices; however, it is challenging to maintain a steady experimental environment. We propose an innovative experimental animal model to evaluate different devices in a constant experimental environment in real‐time. Methods: This model uses two venous–arterial ECMO circuits attached to one animal (one by jugular vein and carotid artery, one by femoral vein and artery) and real‐time assessment of thrombus formation in the oxygenator by indocyanine green (ICG) fluorescence imaging. Comparison studies were conducted using three pigs: one to compare different oxygenators (MERA vs. CAPIOX) (Case 1), and two to compare antithrombotic properties of the oxygenator (QUADROX) when used under different hydrodynamic conditions (continuous flow vs. pulsatile flow) (Cases 2 and 3). Results: Thrombi, visualized using ICG imaging, appeared as black dots on a white background in each oxygenator. In Case 1, differences in the site of thrombus formation and rate of thrombus growth were observed in real‐time in two oxygenators. In Case 2 and 3, the thrombus region was smaller in pulsatile than in continuous conditions. Conclusions: We devised an innovative experimental animal model for comparison of antithrombogenicity in ECMO circuits. This model enabled simultaneous evaluation of two different ECMO circuits under the same biological conditions and reduced the number of sacrificed experimental animals. [ABSTRACT FROM AUTHOR]

Background: Organs from donation after circulatory death (DCD) are increasingly used for liver transplantation, due to the persisting organ shortage and waiting list mortality. However, the use of DCD grafts is still limited by the inferior graft survival rate and the increased risk of primary non‐function and biliary complications when compared to brain death donors' grafts. Methods: Abdominal normothermic regional perfusion with extracorporeal membrane oxygenation (ECMO) is an in situ preservation strategy. which may mitigate ischemia–reperfusion injuries. and has been proposed to restore blood perfusion after the determination of death thus optimizing liver function before implantation. Results: In this systematic review, we highlighted the clinical evidence supporting the use of normothermic regional perfusion in DCD liver underlying the pathophysiological mechanisms, and technical, logistic, and regulatory aspects. Conclusions: Despite the lack of properly designed, prospective, randomized trials, the current available data suggest beneficial effects of normothermic regional perfusion on clinical outcomes after liver transplantation. [ABSTRACT FROM AUTHOR]

Background: Multiple organ failure is a common complication in patients undergoing ECLS significantly affecting patient outcomes. Gaining knowledge about the mechanisms of onset, clinical course, risk factors, and potential therapeutic targets is highly desirable. Methods: Data of 354 patients undergoing ECLS with one‐, two, three‐, and four organ failures were retrospectively analyzed. Incidence of multiple organ dysfunction (MODS), its impact on survival, risk factors for its occurrence, and the impact of proinflammatory mediators on the occurrence of MODS in patients undergoing ECLS were investigated. Results: The median follow‐up was 66 (IQR 6; 820) days. 245 (69.2%) patients could be weaned from ECLS, 30‐day survival and 1‐year survival were 194 (54.1%) and 157 (44.4%), respectively. The duration of mechanical support was 4 (IQR 2; 7) days in the median. Increasing severity of MODS resulted in significant prolongation of mechanical circulatory support and worsening of the outcome. Liver dysfunction had the strongest impact on patient mortality (OR = 2.5) and survival time (19 vs 367 days). The serum concentration of analyzed interleukins rose significantly with each, additional organ affected by dysfunction (p < 0.001). All analyzed proinflammatory cytokines showed significant predictivity relative to the occurrence of MODS with interleukin 8 serum level prior to ECLS showing the strongest predictive potential for the occurrence of MODS (AUC 0.78). Conclusion: MODS represents a frequent complication in patients undergoing ECLS with a significant impact on survival. Proinflammatory cytokines show prognostic capacity regarding the occurrence and severity of multi‐organ dysfunction. [ABSTRACT FROM AUTHOR]

Objective: To analyze the risk factors for gastrointestinal (GI) bleeding in congenital heart disease (CHD) patients supported with venoarterial extracorporeal membrane oxygenation (V‐A ECMO) after open‐heart surgery. Methods: A retrospective analysis was performed on children with (GI group: 26 cases) and without (control group: 122 cases) GI bleeding during ECMO at Shanghai Children's Medical Center from 2017 to 2020. Clinical data were analyzed and compared between groups to search for risk factors for GI bleeding. Results: A total of 148 cases were included in the study. The overall incidence of GI bleeding was 17.6% (26/148). The in‐hospital mortality rate in the GI group was 61.5% (16/26) versus 45.9% (56/122) in the control group. Twenty‐six patients suffered cardiac arrest before ECMO support. The GI bleeding incidence among extracorporeal cardiopulmonary resuscitation (ECPR) patients was 50.0% (13/26) versus 28.7 (35/122) among non‐ECPR patients, p = 0.035. The activated clotting time (ACT) was 201.40 s (180.47 to 247.27) in the GI group versus 177.63 s (167.79 to 203.13) (p = 0.050) in the control group. The lowest antithrombin level (Min AT) was 27.00 ± 13.07% versus 37.62 ± 15.18 (p = 0.001). The pH and lactate levels before ECMO (Pre PH and Pre Lac) were lower in the GI group than in the control group. (7.31 ± 0.23 vs. 7.35 ± 0.17, p = 0.035 and 12.2 ± 6.11 vs. 7.78 ± 6.67, p = 0.003). Liver function during ECMO support was statistically worse in the GI group than in the control group. Multivariate analysis showed that Pre Lac (OR = 1.106 [1.018–1.202], p = 0.0016) was an independent risk factor for GI bleeding. ROC analysis of Pre Lac and GI bleeding showed an area under the curve (AUC) of 0.700 (95% CI: 0.600–0.800, p = 0.002) and a cutoff value of 9.30 mmol/L (sensitivity, 73.1%; specificity, 62.7%). Conclusions: As the first study in this field, the probability of GI bleeding and related mortality was found to be high in children supported with V‐A ECMO after open‐heart surgery. A higher lactate level before ECMO was an independent risk factor for GI bleeding. [ABSTRACT FROM AUTHOR]

Objective: Myocardial damage occurs in up to 25% of coronavirus disease 2019 (COVID‐19) cases. While veno‐venous extracorporeal life support (V‐V ECLS) is used as respiratory support, mechanical circulatory support (MCS) may be required for severe cardiac dysfunction. This systematic review summarizes the available literature regarding MCS use rates, disease drivers for MCS initiation, and MCS outcomes in COVID‐19 patients. Methods: PubMed/EMBASE were searched until October 14, 2021. Articles including adults receiving ECLS for COVID‐19 were included. The primary outcome was the rate of MCS use. Secondary outcomes included mortality at follow‐up, ECLS conversion rate, intubation‐to‐cannulation time, time on ECLS, cardiac diseases, use of inotropes, and vasopressors. Results: Twenty‐eight observational studies (comprising both ECLS‐only populations and ECLS patients as part of larger populations) included 4218 COVID‐19 patients (females: 28.8%; median age: 54.3 years, 95%CI: 50.7–57.8) of whom 2774 (65.8%) required ECLS with the majority (92.7%) on V‐V ECLS, 4.7% on veno‐arterial ECLS and/or Impella, and 2.6% on other ECLS. Acute heart failure, cardiogenic shock, and cardiac arrest were reported in 7.8%, 9.7%, and 6.6% of patients, respectively. Vasopressors were used in 37.2%. Overall, 3.1% of patients required an ECLS change from V‐V ECLS to MCS for heart failure, myocarditis, or myocardial infarction. The median ECLS duration was 15.9 days (95%CI: 13.9–16.3), with an overall survival of 54.6% and 28.1% in V‐V ECLS and MCS patients. One study reported 61.1% survival with oxy‐right ventricular assist device. Conclusion: MCS use for cardiocirculatory compromise has been reported in 7.3% of COVID‐19 patients requiring ECLS, which is a lower percentage compared to the incidence of any severe cardiocirculatory complication. Based on the poor survival rates, further investigations are warranted to establish the most appropriated indications and timing for MCS in COVID‐19. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Age over 70 years seems to confer poor prognosis for patients under mechanical circulatory support (MCS). Advanced age is usually a relative contraindication. Our objective was to assess the impact of age on survival of patients with short‐term MCS. Methods: Retrospective analysis of ≥70‐year‐old patients supported with veno‐arterial extracorporeal membrane oxygenation (VA‐ECMO) or Impella CP® due to cardiogenic shock and other situations of hemodynamic instability in a referral hospital (elderly group), compared with younger patients (<70 years). We analyze factors associated with survival in elderly group. Results: Out of 164 short‐term MCS implants from 2013 to October 2020, 45 (27.4%) correspond to ≥70‐year‐old patients (73.3% VA‐ECMO; 26.7% Impella CP®), 80% as bridge to recovery and 15.6% for high‐risk percutaneous coronary intervention (PCI). We found no significant differences in complications developed between both groups. Survivals at discharge (40% vs. 43.7%, p = 0.403) and at follow‐up (median 13.6 [30] months) were similar in elderly and young patients (35.6% vs. 37.8%, log‐rank p = 0.061). Predictive factors of mortality in elderly patients were peripheral artery disease (p = 0.037), higher lactate (p = 0.003) and creatinine (p = 0.035) at implant, longer cardiac arrest (p = 0.003), and worse post‐implantation left ventricular ejection fraction (p = 0.003). Patients with indication of MCS for high‐risk PCI had higher survival compared to other indications (p = 0.013). Conclusion: Short‐term MCS with VA‐ECMO or Impella CP® in elderly patients may be a reasonable option in hemodynamic compromise situations as bridge to recovery or elective high‐risk PCI, without a significant increase in complications or mortality. Age should not be an absolute contraindication, but careful selection of candidate patients is necessary. [ABSTRACT FROM AUTHOR]

Introduction: Mechanical circulatory support (MCS) devices are increasingly used as a treatment option in resuscitation or in patients with cardiogenic shock (CS). Prophylactic implantation in high‐risk percutaneous coronary interventions (HRPCI) is another upcoming indication. The i‐cor ECG‐synchronized cardiac assist device combines the hemodynamic support of a veno‐arterial extracorporeal membrane oxygenation (VA‐ECMO) with the ability to generate a pulsatile flow and thus decreasing adverse effects of VA‐ECMO on myocardial function. Aim of this study was to obtain data concerning feasibility, safety and outcomes in both indications. Methods: A total of 47 patients (34 HRPCI, 13 CS) were included in nine German centers and participated in this study. Demographic and clinical parameters, procedural as well as follow‐up data were prospectively recorded and analyzed. Results: Device implantation and initiation of ECG‐synchronized cardiac assist was technical successful in all cases and no failures of the consoles or disposable parts were observed. Furthermore, intended percutaneous coronary interventions and successful weaning from cardiac assist was achieved in 97.1% of HRPCI patients. We observed a 30d‐survival of 94.1% in the HRPCI group and 69.2% in the CS group. Main complications in both groups were bleeding events (14.7% HRPCI, 23.1% CS) and critical limb ischemia (2.9% HRPCI, 38.5% CS). Conclusion: The i‐cor ECG‐synchronized cardiac assist device appears safe and feasible showing clinical outcomes comparable to existing data in the setting of high‐risk percutaneous coronary interventions and acute cardiogenic shock. Further prospective trials are warranted to identify optimal patient and interventional characteristics that will benefit most of this novel kind of mechanical circulatory support. [ABSTRACT FROM AUTHOR]

Background: Sheep are a primary model of mechanical circulatory support (MCS) with heparin anticoagulation therapy frequently being monitored by activated clotting time (ACT) due to ease and cost. In patients undergoing long‐term heparin therapy, other anticoagulation monitoring strategies, such as activated partial thromboplastin time (aPTT), have proven to be more reliable indicators for the adequacy of anticoagulation, frequently determined by heparin concentration. As there is a paucity of similar studies in sheep, we sought to investigate the correlation between heparin concentration and ACT and aPTT using whole sheep blood in an ex vivo model. Methods: Fresh whole blood was serially drawn from an adult female Dorset‐hybrid sheep and aliquots were placed into tubes containing heparin saline solutions with concentrations ranging from 0 to 7.81 U heparin per mL of whole blood. ACT and aPTT values were measured on each of the samples. The experiment was performed four times with the same animal. A simple linear regression was performed to determine correlation, and subgroup analysis was performed on low versus high heparin concentrations typically seen in human patients on long‐term MCS, such as extracorporeal membrane oxygenation (ECMO), versus cardiopulmonary bypass, respectively. Results: aPTT measurements versus the heparin concentration had an R2 = 0.7295. ACT measurements versus the heparin concentration had a R2 = 0.4628. aPTT measurements versus the ACT measurements had a R2 = 0.2974. The strength of the correlation between aPTT and heparin concentration increased at low heparin concentrations (R2 = 0.8392). Conclusion: aPTT had a more reliable correlation to heparin concentration and thus anticoagulation level than ACT. This was particularly true at lower heparin concentrations, similar to ranges seen for patients on ECMO. The correlation between aPTT and ACT values was poor. Further in vivo studies should be performed to confirm our results. [ABSTRACT FROM AUTHOR]

Background: Major airway surgery can pose a complex problem to perioperative central airway management. Adjuncts to advanced ventilation strategies have included cardiopulmonary bypass, veno‐arterial, or veno‐venous extracorporeal life support. We performed a systematic review to assess the existing evidence utilizing these strategies. Methods: An electronic search was conducted to identify studies written in English reporting the use of extracorporeal life support (ECLS) during central airway surgery. Thirty‐six articles consisting of 78 patients were selected and patient‐level data were analyzed. Results: Median patient age was 47 [IQR: 34‐53] and 59.0% (46/78) were male. Indications for surgery included central airway or mediastinal cancer in 57.7% (45/78), lesion or injury in 15.4% (12/78), and stenosis in 12.8% (10/78). Support was initiated pre‐operatively in 9.9% (7/71) and at the time of induction in 55.3% (42/76). It was most commonly used at the time of tracheal resection/repair [93.2% (68/73)], intubation of the tracheal stump [94.4% (68/72)], and re‐anastomosis [94.2% (65/69)]; 13.7% (10/73) patients were supported post‐operatively. The most commonly performed surgery was tracheal repair or resection in 70.3% (52/74). Median hospital stay was 12 [8, 25] days and in‐hospital mortality was 7.9% (6/76). There was no significant difference in survival between the three groups (p =.54). Conclusions: Extracorporeal membrane oxygenation offers versatility in timing, surgical approach, and ECLS runtime that makes it a viable addition to the surgical armamentarium for treating complex central airway pathologies. [ABSTRACT FROM AUTHOR]

Timing and causes of hospital mortality in adult patients undergoing veno‐arterial extracorporeal membrane oxygenation (V‐A ECMO) have been poorly described. Aim of the current review was to investigate the timing and causes of death of adult patients supported with V‐A ECMO and subsequently define the "V‐A ECMO gap," which represents the patients who are successfully weaned of ECMO but eventually die during hospital stay. A systematic search was performed using electronic MEDLINE and EMBASE databases through PubMed. Studies reporting on adult V‐A ECMO patients from January 1993 to December 2020 were screened. The studies included in this review were studies that reported more than 10 adult, human patients, and no mechanical circulatory support other than V‐A ECMO. Information extracted from each study included mainly mortality and causes of death on ECMO and after weaning. Complications and discharge rates were also extracted. Sixty studies with 9181 patients were included for analysis in this systematic review. Overall mortality was 38.0% (95% confidence intervals [CIs] 34.2%‐41.9%) during V‐A ECMO support (reported by 60 studies) and 15.3% (95% CI 11.1%‐19.5%, reported by 57 studies) after weaning. Finally, 44.0% of patients (95% CI 39.8‐52.2) were discharged from hospital (reported by 60 studies). Most common causes of death on ECMO were multiple organ failure, followed by cardiac failure and neurological causes. More than one‐third of V‐A ECMO patients die during ECMO support. Additionally, many of successfully weaned patients still decease during hospital stay, defining the "V‐A ECMO gap." Underreporting and lack of uniformity in reporting of important parameters remains problematic in ECMO research. Future studies should uniformly define timing and causes of death in V‐A ECMO patients to better understand the effectiveness and complications of this support. [ABSTRACT FROM AUTHOR]

Recently, veno‐venous extracorporeal membrane oxygenation (V‐V ECMO) has been commonly used in the world to support patients with severe respiratory failure. However, V‐V ECMO is a new technology compared to veno‐arterial extracorporeal membrane oxygenation and cardiopulmonary bypass, and there are few reports of basic research. Although continuing research is desired, clinical research that standardizes conditions such as patients' background characteristics is difficult. The purpose of this study was to establish a simple and stably maintainable miniature V‐V ECMO model to study the mechanisms of the biological reactions in circulation during V‐V ECMO. The V‐V ECMO system consisted of an original miniature membrane oxygenator, polyvinyl chloride tubing line, and roller pump. The priming volume of this system was only 8 mL. Polyethylene tubing was used to cannulate the right femoral vein as the venous return cannula for the V‐V ECMO system. A 16‐G cannula was passed through the right internal jugular vein and advanced into the right atrium as the conduit for venous uptake. The animals were divided into 2 groups: SHAM group and V‐V ECMO group. V‐V ECMO was initiated and maintained at 50‐60 mL/kg/min, and oxygen was added into the oxygenator during V‐V ECMO at a concentration of 100% (pump flow:oxygen = 1:10). Blood pressure was measured continuously, and blood cells were measured by blood collection. During V‐V ECMO, the blood pressure and hemodilution rate were maintained around 80 mm Hg and 20%, respectively. Hb was kept at >10 g/dL, and V‐V ECMO could be maintained without blood transfusion. It was possible to confirm oxygenation of and carbon dioxide removal from the blood. Likewise, the pH was adequately maintained. There were no problems with this miniature V‐V ECMO system, and extracorporeal circulation progressed safely. In this study, a novel miniature V‐V ECMO model was established in the rat. A miniature V‐V ECMO model appears to be very useful for studying the mechanisms of the biological reactions during V‐V ECMO and to perform basic studies of circulation assist devices. [ABSTRACT FROM AUTHOR]

Mortality and morbidity of children received veno‐arterial extracorporeal membrane oxygenation (VA‐ECMO) support after cardiac surgery remain high despite remarkable advances in medical management and devices. The purpose of this study was to describe outcomes and risk factors of applying VA‐ECMO in the surgical pediatric population. We retrospectively analyzed 85 consecutive pediatric patients (aged <18 years) who received postcardiotomy VA‐ECMO from January 2010 to December 2018. Median (IQR) age at ECMO implantation in this cohort was 12.7 (6.4, 43.2) months, median weight was 8.5 (6.0, 12.8) kg, mean ECMO duration was 143.2 ± 81.6 hours and mean hospital length of stay was 48.4 ± 32.4 days. Seventy‐five patients (88.2%) were indicated for postcardiotomy cardiogenic shock. The successful ECMO weaning rate was 70.6% and in‐hospital mortality was 52.9%. The most common diagnosis was transposition of great arteries (n = 18, 21.2%), while acute kidney injury occurred most often (n = 64, 75.3%). Multivariate logistic regression analysis showed that thrombocytopenia, hemolysis, and nosocomial infection were positively correlated with in‐hospital mortality. Multivariate Cox proportional hazard regression analysis presented that thrombocytopenia significantly increased the 180‐day mortality in patients with successful weaning. Therefore, multiple factors had adverse effects on prognosis. Patient selection and procedures from ECMO implantation to weaning need to be closely monitored and performed in a timely manner to improve outcome. [ABSTRACT FROM AUTHOR]

Similarly, ECMO for COVID-19 related ARDS was discussed from the French perspective by Dr. Matthieu Schmidt from Piié Salpetrière Hospital and Dr. Keiki Shimizu the Japanese experience, Dr. Xiaotong Hou the Chinese experience, Dr. Urvi Shukla the Indian experience and Dr. Eva Marwali the Indonesian experience. Dr. Chiao-Feng Cheng from National Taiwan University received the second-place award for his abstract on ECMO in immunocompromised patients with ARDS. The Asia-Pacific Extracorporeal Life Support Organization (APELSO) is the Asia-Pacific Chapter of the Extracorporeal Life Support Organization (ELSO), which had its first meeting in Melbourne, July 2012, hosted by Dr. Vin Pellegrino from the Alfred Hospital, Melbourne, and Dr. Steve Conrad, then the Chair of the Global ELSO Steering Committee. [Extracted from the article]

This study aims to investigate the outcomes of venoarterial extracorporeal life support (VA‐ECLS) in a large single‐center patient cohort regarding survival and adverse events. Between June 2009 and March 2019, 462 consecutive patients received VA‐ECLS. The mean age was 66.2 ± 11.9 years. Two patient groups were identified: Group 1—patients with ECLS due to postcardiotomy shock (PCS) after cardiac surgery (PCS, n = 357); Group 2—patients with ECLS due to cardiogenic shock (CS) without previous surgery (nonPCS, n = 105). The primary end point was overall in‐hospital survival, while secondary end points were adverse events during the study period. Overall, the in‐hospital survival rate was 26%. There was no statistically significant difference between the groups: 26.3% for PCS and 24.8% for nonPCS, respectively (P >.05). Weaning from VA‐ECLS was possible in 44.3% for PCS and in 29.5% for nonPCS (P =.004). The strong predictors of overall mortality were postoperative hepatic dysfunction (OR = 14.362, 95%CI = 1.948‐105.858), cardiopulmonary resuscitation > 30 minutes (OR = 6.301, 95%CI = 1.488‐26.673), bleeding with a need for revision (OR = 2.123, 95%CI = 1.343‐3.355), and previous sternotomy (OR = 2.077, 95%CI = 1.021‐4.223). Despite its low survival rates, VA‐ECLS therapy is the last resort and the only lifesaving option for patients in refractory CS. In contrast, there is still a lack of evidence for VA‐ECLS in PCS patients. Future studies are warranted to evaluate the outcomes of VA‐ECLS therapy after cardiac surgery. [ABSTRACT FROM AUTHOR]

The ProtekDuo is a single site, dual lumen cannula that may be used in a multitude of configurations.1 It was initially designed as right ventricular assist device (RVAD) cannula that comes in conjunction with the TandemHeart pump (LivaNova PLC, London, UK). As such it is a game changer in the setting of ECMO in COVID-19 patients suffering from ARDS and may be recommended for initial use in these patients. This method still provides reduced RV blood flow by about 40% and was sufficient offloading the RV in this patient.7 At the present time, ECMO management with the ProtekDuo cannula appears to reduce mortality, AKI and length of the ECMO run. [Extracted from the article]

Extracorporeal membrane oxygenation (ECMO) provides cardiorespiratory support during cardiopulmonary resuscitation unresponsive to conventional methods. Here, we analyzed the extracorporeal cardiopulmonary resuscitation (ECPR) results of children in a cardiac arrest setting after cardiac surgery. Of 3119 cases of pediatric open‐heart surgery, 31 required postoperative ECMO. Among the 31 patients, 11 experienced cardiac arrest and ECPR in the early postoperative period. These 11 patients' median age is 1.5 [range, 0.1‐19] months and median weight is 3.9 [range, 2.9‐10.3] kg. The medical records of ECPR cases were analyzed. The median ECMO‐assisted time was 68 (range, 13‐456) hours and 4 cases (36.4%) survived. The ECMO‐assisted times were ≤2 days in 4 patients (all eventually died), ≥6 days in 3 patients (all also died), and all 4 cases supported for 2‐6 days were discharged successfully (P = 0.006). In the survivors and nonsurvivors, peak lactate levels were 10.8 ± 7.04 and 22.8 ± 6.98 mmol/L (P = 0.023) and peak creatinine levels were 47.50 ± 25.9 and 153.7 ± 73.9 mg/dL (P = 0.035), respectively. In these 11 ECPR cases, the most common complications were bleeding requiring re‐exploration (n = 6, 54.5%) and renal failure (n = 6, 54.5%). The incidence of renal failure was significantly correlated with hypoperfusion time (P = 0.015). ECPR is valuable in children with postoperative cardiac arrest. The higher peak lactate level, higher peak creatinine level, and prolonged ECMO duration were associated with higher mortality. Early diagnosis and intervention of residual anatomical problems could improve survival. Bleeding and renal failure were the most common complications and the incidence of renal failure may be correlated with longer hypoperfusion duration. [ABSTRACT FROM AUTHOR]

The effectiveness of intra‐aortic balloon pump (IABP) combined with venoarterial extracorporeal membrane oxygenation (VA‐ECMO) in patients with cardiogenic shock or cardiac arrest remains controversial. The aim of this systematic review and meta‐analysis was to investigate the short‐term clinical outcomes of IABP combined with VA‐ECMO versus VA‐ECMO alone. We searched PubMed, Embase, and the Cochrane Library for English language articles published from inception to August 18, 2018. Observational studies comparing IABP combined with VA‐ECMO with VA‐ECMO were considered eligible for the current study. Twelve observational studies with 3704 patients were included. In the IABP combined with VA‐ECMO group mortality was 59.7%, compared with 65.8% in the VA‐ECMO alone group. The risk ratio (RR) for this comparison was 0.90 (95% confidence interval [CI], 0.80–1.02; P = 0.107; 59.7% vs. 65.8%). In the one‐way sensitivity analysis for estimating the effect of each study on mortality, omission of each study did not make a significant difference. Furthermore, the proportion of patients weaned from VA‐ECMO was significantly higher in IABP combined VA‐ECMO group than in the VA‐ECMO alone group (RR, 1.28; 95% CI, 1.21–1.35; P < 0.001; 77.9% vs. 61.2%). IABP combined with VA‐ECMO could improve success rate of weaning from VA‐ECMO, but did not reduce in‐hospital mortality in patients with cardiogenic shock or cardiac arrest. [ABSTRACT FROM AUTHOR]

Translational research is a useful tool to provide scientific evidence for cannula selection during extracorporeal life support (ECLS). The objective of this study was to evaluate four Avalon Elite bi‐caval dual lumen cannulas and nine femoral arterial cannulas in terms of flow range, circuit pressure, pressure drop, and hemodynamic energy transmission in a simulated adult ECLS model. A veno‐venous ECLS circuit was used to evaluate four Avalon Elite bi‐caval dual lumen cannulas (20, 23, 27, and 31 Fr), and a veno‐arterial ECLS circuit was used to evaluate nine femoral arterial cannulas (15, 17, 19, 21, and 23 Fr). The two circuits included a Rotaflow centrifugal pump, a Quadrox‐D adult oxygenator, and 3/8 in ID tubing for arterial and venous lines. The circuits were primed with lactated Ringer's solution and packed human red blood cells (hematocrit 40%). Trials were conducted at rotational speeds from 1000 to 5000 RPM (250 rpm increments) for each Avalon cannula, and at different flow rates (0.5–7 L/min) for each femoral arterial cannula. Real‐time pressure and flow data were recorded for analysis. Small caliber cannulas created higher circuit pressures, higher pressure drops and higher M‐numbers compared with large ones. The inflow side of Avalon dual lumen cannula had a significantly higher pressure drop than the outflow side (inflow vs. outflow: 20 Fr‐100.2 vs. 49.2 mm Hg at 1.1 L/min, 23 Fr‐93.7 vs. 41.4 mm Hg at 1.6 L/min, 27 Fr‐102.3 vs. 42.8 mm Hg at 2.6 L/min, 31 Fr‐98.1 vs. 44.7 mm Hg at 3.8 L/min). There was more hemodynamic energy lost in the veno‐arterial ECLS circuit using small cannulas compared to larger ones (17 Fr vs. 19 Fr vs. 21 Fr at 4 L/min—Medtronic: 71.0 vs. 64.8 vs. 60.9%; Maquet: 71.4 vs. 65.6 vs. 62.0%). Medtronic femoral arterial cannulas had lower pressure drops (Medtronic vs. Maquet at 4 L/min: 17 Fr‐121.7 vs. 125.0 mm Hg, 19 Fr‐71.2 vs. 73.7 mm Hg, 21 Fr‐42.9 vs. 47.4 mm Hg) and hemodynamic energy losses (Medtronic vs. Maquet at 4 L/min: 17 Fr‐43.6 vs. 44.4%, 19 Fr‐31.0 vs. 31.4%, 21 Fr‐20.8 vs. 22.4%) at high flow rates when compared with the Maquet cannulae. The results for this study provided valuable hemodynamic characteristics of all evaluated adult cannulas with human blood in order to guide ECLS cannula selection in clinical practice. Use of larger cannulas are suggested for VV‐ and VA‐ECLS. [ABSTRACT FROM AUTHOR]

Abstract: Bridge to heart transplantation (HTx) with ECMO is associated with poor outcome, but patient status, according to different levels of multiorgan compromise, is generally not considered. The aim of this study was to analyze the prognostic value of acute physiology, age, and chronic health evaluation IV (APACHE IV) score in this setting. Thirty‐two patients underwent HTx bridged with ECMO at our institution between 2005 and 2017; they were divided into two groups, according to a cutoff value of APACHE IV score obtained by Receiver operating characteristic curve analysis for 30‐day mortality. Kaplan–Meyer survival curves were plotted, and compared through the log‐Rank test. Cox regression model was used to estimate which factors were associated with overall survival. The 30‐day mortality prediction of the APACHE IV score showed an AUC of 0.98 [95% C.I. 0.84–0.99], with a cutoff value corresponding to a score value of 47 (specificity of 84.6% and sensitivity of 100%) in order to discriminate between a group with low probability (Group A, patients with an APACHE IV score <47), and a group with high probability (Group B, patients with an APACHE IV score ≥47) of 30‐day mortality. Median follow up was 26.9 months (range: 0.03–143.8). On overall, patients bridged with ECMO showed a high early mortality (18.7% <30 days, n = 6). All deaths occurred in Group B, where 30‐day mortality was 60%. Survival probability among Group B patients was 26.6% at both 1 and 5 years. Conversely, in Group A no early mortality was reported, and the estimated survival was 89.7% at 1 year and 81.5% at 5 years, respectively. Mortality correlated at univariate analysis with recipient age, APACHE IV score and female sex, while the multivariate Cox regression analysis showed that only an APACHE IV score (HR 1.23 [1.08–1.39, 95% C.I.]) and female sex (HR 6.68 [1.42–31.43, 95% C.I.]) had an adverse impact on survival. This study shows that the APACHE IV score could be considered a powerful predictor of survival in patients bridged by ECMO to HTx, and can account for a better selection of patients on ECMO support at time of listing. [ABSTRACT FROM AUTHOR]

Abstract: Several articles have discussed the weaning process for venoarterial extracorporeal membrane oxygenation; however, there is no published report to outline a standardized approach for weaning a patient from venovenous extracorporeal membrane oxygenation (ECMO). This complex process requires an organized approach and a thorough understanding of ventilator management and ECMO physiology. The purpose of this article is to describe the venovenous ECMO weaning protocol used at our institution as well as provide a review of the literature. [ABSTRACT FROM AUTHOR]

Abstract: As it is common for patients treated with extracorporeal life support (ECLS) to subsequently require continuous renal replacement therapy (CRRT), and neonatal patients encounter limitations due to lack of access points, inclusion of CRRT in the ECLS circuit could provide advanced treatment for this population. The objective of this study was to evaluate an alternative neonatal ECLS circuit containing either a Maquet RotaFlow centrifugal pump or Maquet HL20 roller pump with one of seven configurations of CRRT using the Prismaflex 2000 System. All ECLS circuit setups included a Quadrox‐iD Pediatric diffusion membrane oxygenator, a Better Bladder, an 8‐Fr arterial cannula, a 10‐Fr venous cannula, and 6 feet of ¼‐inch diameter arterial and venous tubing. The circuit was primed with lactated Ringer's solution and packed human red blood cells resulting in a total priming volume of 700 mL for both the circuit and the 3‐kg pseudopatient. Hemodynamic data were recorded for ECLS flow rates of 200, 400, and 600 mL/min and a CRRT flow rate of 50 mL/min. When a centrifugal pump is used, the hemodynamic performance of any combined ECLS and CRRT circuit was not significantly different than that of the circuit without CRRT, thus any configuration could potentially be used. However, introduction of CRRT to a circuit containing a roller pump does affect performance properties for some CRRT positions. The circuits with CRRT positions B and G demonstrated decreased total hemodynamic energy (THE) levels at the post‐arterial cannula site, while positions D and E demonstrated increased post‐arterial cannula THE levels compared to the circuit without CRRT. CRRT positions A, C, and F did not have significant changes with respect to pre‐arterial cannula flow and THE levels, compared to the circuit without CRRT. Considering hemodynamic performance, for neonatal combined extracorporeal membrane oxygenation (ECMO) and CRRT circuits with both blood pumps, we recommend the use of CRRT position A due to its hemodynamic similarities to the ECMO circuit without CRRT. [ABSTRACT FROM AUTHOR]

Abstract: Extracorporeal membrane oxygenation (ECMO) is a life support system that circulates the blood through an oxygenating system to temporarily (days to months) support heart or lung function during cardiopulmonary failure until organ recovery or replacement. Currently, the need for high levels of systemic anticoagulation and the risk for bleeding are main drawbacks of ECMO that can be addressed with a redesigned ECMO system. Our lab has developed an approach using microelectromechanical systems (MEMS) fabrication techniques to create novel gas exchange membranes consisting of a rigid silicon micropore membrane (SμM) support structure bonded to a thin film of gas‐permeable polydimethylsiloxane (PDMS). This study details the fabrication process to create silicon membranes with highly uniform micropores that have a high level of pattern fidelity. The oxygen transport across these membranes was tested in a simple water‐based bench‐top set‐up as well in a porcine in vivo model. It was determined that the mass transfer coefficient for the system using SµM‐PDMS membranes was 3.03 ± 0.42 mL O2 min−1 m−2 cm Hg−1 with pure water and 1.71 ± 1.03 mL O2 min−1 m−2 cm Hg−1 with blood. An analytic model to predict gas transport was developed using data from the bench‐top experiments and validated with in vivo testing. This was a proof of concept study showing adequate oxygen transport across a parallel plate SµM‐PDMS membrane when used as a membrane oxygenator. This work establishes the tools and the equipoise to develop future generations of silicon micropore membrane oxygenators. [ABSTRACT FROM AUTHOR]

Complications due to pump thrombus remain the weak point of mechanical circulatory support (MCS), such as the use of a left ventricular assist device (LVAD) or extracorporeal membrane oxygenation, leading to poor outcomes. Hyperspectral imaging (HSI) is an effective imaging method using a hyperspectral (HS) camera, which comprises a spectrophotometer and a charge-coupled device camera to discriminate thrombus from whole blood. Animal experiments were conducted to analyze dynamic imaging of thrombus inside a prototype of a hydrodynamically levitated centrifugal blood pump using an HSI system. Six pigs were divided into a venous circulation group ( n = 3) and an arterial circulation group ( n = 3). Inflow and outflow cannulae were inserted into the jugular veins in the venous circulation group. The latter simulated an LVAD application. To create thrombogenic conditions, pump flow was maintained at 1 L/min without anticoagulation. An image of the bottom surface of the pump was captured by the HS camera every 4 nm over the wavelength range of 608-752 nm. Real-time dynamic images of the inside of the pump were displayed on the monitor. Appearance of an area displaying thrombus was detected within 24 h after the start of the circulation in every experiment. This imaging system also succeeded in determining the origins of pump thrombus: from inside the pump in two cases, and from outside in four cases. Two main possible sources of pump thrombus originating outside the pump were identified on autopsy: wedge thrombus around the inflow cannula; and string-like thrombus at the junction between the pump inlet and circuit tube. The results of this study from close observation of the changing appearance of pump thrombus may contribute to improvements in the safety of extracorporeal MCS. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare patients with severe biventricular heart failure who underwent Berlin Heart Excor implantation with (cardiogenic shock [CS] status) or without the need for preoperative extracorporeal life support (ECLS) as a bridge to long-term device. A total of 40 consecutive patients with severe biventricular heart failure underwent Berlin Heart Excor implantation with (CS status, n = 20, 50%) or without (control, n = 20, 50%) the need for preoperative ECLS as a bridge to long-term device from March 2007 to May 2015 at our institution. Demographics and preoperative baseline characteristics as well as early and long-term outcomes including mortality and complication rates were retrospectively compared between the two groups. There were no statistically significant differences in terms of demographics and most preoperative clinical characteristics. The mean age in the ECLS (CS group) and control group was 43.5 ± 19.4 and 41.3 ± 16.4 ( P = 0.705), whereas 20 and 25% of patients were females ( P = 1.000). However, patients from the ECLS group had preoperatively higher lactate ( P = 0.037), aspartate aminotransferase ( P < 0.001), and alanine aminotransferase ( P < 0.001) levels, all of them significantly decreased after surgery ( P = 0.004, P = 0.017, and P = 0.001, respectively) and did not show any statistical differences to the corresponding values from the control group ( P = 0.597, P = 0.491, and P = 0.339, respectively). Postoperatively, patients from the control and ECLS groups had statistically similar incidences of liver failure (30 vs. 35%, P = 0.736), renal failure (45 vs. 70%, P = 0.110), need for reopening (35 vs. 60%, P = 0.113), major cerebrovascular events (35 vs. 30%, P = 0.736), sepsis (10 vs. 25%, P = 0.407), wound infection (20 vs. 30%, P = 0.716), abdominal ischemia requiring surgery (28.6 vs. 36.8%, P = 0.719), and acute respiratory distress syndrome (25 vs. 35.3%, P = 1.000). The proportion of patients who were bridged to transplantation was statistically similar between the ECLS and the control groups (40 vs. 52.6%, P = 0.429). Furthermore, there were no statistically significant differences in terms of early (Breslow [generalized Wilcoxon] P = 0.907) and long-term (log-rank [Mantel-Cox] P = 0.787) overall cumulative survival accounting for 30-day survival of 75 versus 75%, 6-month survival of 60 versus 55%, 1-year survival of 54 versus 40%, and 7-year survial of 47 versus 40% in the control and ECLS groups, respectively. ECLS in critical CS as a bridge to implantation of the Berlin Heart Excor ventricular assist device is safe and is associated with improvement in end-organ function leading to similar excellent early and long-term survival and incidences of major complications as in patients without the need for preoperative ECLS support. [ABSTRACT FROM AUTHOR]

As of today, there exist no reliable, objective methods for early detection of thrombi in the extracorporeal membrane oxygenators (ECMO) system. Within the ECMO system, thrombi are not always fixed to a certain component or location in the circuit. Thus, clot fragments of different shapes and consistencies may circulate and give rise to vibrations and sound generation. By bedside sound measurements and additional laboratory experiments (although not detailed herein), we found that the presence of particles (clots or aggregates and fragments of clots) can be detected by analyzing the strength of infra-sound (< 20 Hz) modes of the spectrum near the inlet and outlet of the centrifugal pump in the ECMO circuit. For the few patients that were considered in this study, no clear false positive or negative examples were found when comparing the spectral approach with clinical observations. A laboratory setup provided insight to the flow in and out of the pump, confirming that in the presence of particles a low-amplitude low-frequency signal is strongly amplified, enabling the identification of a clot. [ABSTRACT FROM AUTHOR]

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is indicated in reversible life-threatening circulatory failure with or without respiratory failure. Arterial desaturation in the upper body is frequently seen in patients with peripheral arterial cannulation and severe respiratory failure. The importance of venous cannula positioning was explored in a computer simulation model and a clinical case was described. A closed-loop real-time simulation model has been developed including vascular segments, the heart with valves and pericardium. ECMO was simulated with a fixed flow pump and a selection of clinically relevant venous cannulation sites. A clinical case with no tidal volumes due to pneumonia and an arterial saturation of below 60% in the right hand despite VA-ECMO flow of 4 L/min was described. The case was compared with simulation data. Changing the venous cannulation site from the inferior to the superior caval vein increased arterial saturation in the right arm from below 60% to above 80% in the patient and from 64 to 81% in the simulation model without changing ECMO flow. The patient survived, was extubated and showed no signs of hypoxic damage. We conclude that venous drainage from the superior caval vein improves upper body arterial saturation during veno-arterial ECMO as compared with drainage solely from the inferior caval vein in patients with respiratory failure. The results from the simulation model are in agreement with the clinical scenario. [ABSTRACT FROM AUTHOR]

The article discusses advancements in the extracorporeal life support (ECLS) systems with pulsatile flow. Topics include decline in mortality by respiratory failure due to circuit improvement in ECLS' oxygenators and pumps; several changes in the ECLS systems such as low priming volume, low set-up time, and improved safety; and advantages of electrocardiogram (ECG) synchronized pulsatile flow like end-organ protection, increase coronary artery flow, and left ventricular function preservation.

Veno-venous extracorporeal lung assist ( ECLA) can provide sufficient gas exchange even in most severe cases of acute respiratory distress syndrome. Commercially available systems are manually controlled, although an automatically controlled ECLA could allow individualized and continuous adaption to clinical requirements. Therefore, we developed a demonstrator with an integrated control algorithm to keep continuously measured peripheral oxygen saturation and partial pressure of carbon dioxide constant by automatically adjusting extracorporeal blood and gas flow. The ' SmartECLA' system was tested in six animal experiments with increasing pulmonary hypoventilation and hypoxic inspiratory gas mixture to simulate progressive acute respiratory failure. During a cumulative evaluation time of 32 h for all experiments, automatic ECLA control resulted in a peripheral oxygen saturation ≥90% for 98% of the time with the lowest value of 82% for 15 s. Partial pressure of venous carbon dioxide was between 40 and 49 mm Hg for 97% of the time with no value <35 mm Hg or >49 mm Hg. With decreasing inspiratory oxygen concentration, extracorporeal oxygen uptake increased from 68 ± 25 to 154 ± 34 mL/min ( P < 0.05), and reducing respiratory rate resulted in increasing extracorporeal carbon dioxide elimination from 71 ± 37 to 92 ± 37 mL/min ( P < 0.05). The ' SmartECLA' demonstrator allowed reliable automatic control of the extracorporeal circuit. Proof of concept could be demonstrated for this novel automatically controlled veno-venous ECLA circuit. [ABSTRACT FROM AUTHOR]

It is essential to establish an appropriate initial treatment strategy for pediatric fulminant myocarditis. We reviewed eight cases of pediatric fulminant myocarditis that required extracorporeal membrane oxygenation (ECMO) from 2012 to 2015. The median age was 8 years (range 3 months-13 years), and the median body surface area was 0.89 m2 (range 0.35-1.34 m2). Peripheral veno-arterial ECMO was initially applied, and we evaluated whether heart decompression was sufficient. If the pump flow was insufficient, central cannulation was performed via median sternotomy (central ECMO). The need for subsequent ventricular assist device (VAD) support was determined 72 h after ECMO initiation. Six patients were bridged to recovery using peripheral ECMO support only (for 3-11 days), whereas two required VAD support. One patient was switched to central ECMO before VAD implantation. Three patients died of multiorgan failure, even though cardiac function recovered in two of those patients. The duration from hospital arrival to ECMO initiation was shorter in the survival (3.3 ± 1.3 h; range 1.6-4.7 h) than in the nonsurvival group (32 ± 28 h; range 0.7-55 h). Peripheral ECMO can be useful as a bridge to decision for pediatric fulminant myocarditis, which is frequently followed by a successful bridge to recovery. It is important to determine whether ECMO support should be initiated before organ dysfunction advances to preserve organ function, which provides a better bridge to subsequent VAD therapy and heart transplant or recovery. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented about systematic venoarterial extracorporeal membrane oxygenation after surgical correction of post-infarcton ventricular septal defect.

The effect of normothermic extracorporeal membrane oxygenation (NECMO) on small bowel preservation in a clinically relevant large animal model of expected donation after cardiac death (eDCD) was evaluated. Thirty domestic crossbred donor pigs were divided into five groups. The first group served as the live donation (LD) group, the second group served as the donation after cardiac death (DCD) group, and the remaining were further assigned into three subgroups: E1 group (1 h NECMO support), E3 group (3 h NECMO support), and E5 group (5 h NECMO support). Pathology, electron microscopy, energy metabolism, cell apoptosis, and tight junction (TJ) protein expression level of intestinal mucosa and the level of plasma d-lactic acid were evaluated in normal, cardiac death and at the end of extracorporeal support, respectively. The mean arterial pressure and PaO2 were maintained over 60 and 267 mm Hg during NECMO support, respectively. One hour of extracorporeal support could improve the energy status in intestines of the DCD group. Although the histologic damage and apoptosis of the E1 group had no significant difference with those of the LD and DCD groups ( P > 0.05), the levels of intestinal mucosa TJ protein decreased ( P < 0.05), and plasma d-lactic acid increased progressively ( P < 0.05). With the extension of extracorporeal support, the degree of intestinal mucosa damage and intestinal permeability gradually increased, as well as the content of adenosine triphosphate in intestinal mucosa. The normothermic extracorporeal support for 1 h in DCD is beneficial for improving the energy status and viability of the bowel. However, the integrity of intestinal mucosa was destroyed gradually as extracorporeal support time went by. And the activation of intestinal epithelial apoptosis and hyperoxia might be the factors that lead to intestinal mucosa injury. [ABSTRACT FROM AUTHOR]

Acute kidney injury (AKI) is common in patients treated with veno-arterial (VA-) or veno-venous (VV-) extracorporeal membrane oxygenation (ECMO). In this setting, the use of continuous renal replacement therapy (CRRT) can help to optimize fluid status but may also negatively impact on patients' outcome. In contrast, the relationship between AKI, CRRT, and survival in critically ill adult patients receiving ECMO is not well defined. The institutional ECMO database ( n = 162) from November 2008 to December 2013, excluding patients with ICU survival <24 hours was reviewed. Demographics, co-morbidities, and concomitant therapies for all patients were collected. AKI was defined according to the Acute Kidney Injury Network (AKIN) criteria. ICU mortality was noted. Data were retrieved for 135 patients (79 with VA-ECMO and 56 with VV-ECMO). Of these, 95 developed AKI, 63 (47%) of whom required CRRT; thus three groups of patients were identified: (a) no AKI; (b) AKI without CRRT (AKINOCRRT); and (c) CRRT with AKI (AKICRRT). AKINOCCRT patients were more likely to have preexisting heart disease, to be more severely ill, and to be treated with VA-ECMO than those without AKI. AKICRRT patients were also more likely to be treated with VA-ECMO, had more organ dysfunction at the time of ECMO insertion, and needed more transfusions and inotropic agents than patients without AKI. ICU mortality was 53% (72/135) and was similar in the three groups, even when different AKI stages or VA/VV-ECMO were analyzed separately. In this study, the use of CRRT was not associated with an increased mortality in an adult population of patients treated with ECMO, even after adjustment for confounders. [ABSTRACT FROM AUTHOR]

Early graft failure (EGF) is a major risk factor for death after heart transplantation (Htx). We investigated the predictive risk factors for moderate-to-severe EGF requiring an intra-aortic balloon pump (IABP) or extracorporeal membrane oxygenation (ECMO) circulatory support as treatment after Htx. Between January 2000 and December 2014, 412 consecutive adult patients underwent isolated Htx at our institution. Moderate and severe EGF were defined as the need for IABP and ECMO support, respectively, within 24 h after Htx. All available recipient and donor variables were analyzed to assess the risk of EGF occurrence. Overall, moderate-to-severe EGF occurred in 46 (11.1%) patients. Twenty-nine (63.04%) patients required peripheral or central ECMO support in the treatment of severe EGF and 17 (36.9%) patients required IABP support for the treatment of moderate EGF. The predictive risk factors for moderate-to-severe EGF in recipients, as assessed by logistic regression analysis, were a preoperative transpulmonary gradient > 12 mm Hg (odds ratio [OR] 5.2; P = 0.023), a preoperative inotropic score > 10 (OR 8.5; P = 0.0001), and preoperative ECMO support (OR 4.2; P = 0.012). For donors, the predictive risk factor was a donor score ≥ 17 (OR 8.3; P = 0.006). The absence of EGF was correlated with improved long-term survival: 94% at 1 year and 81% at 5 years without EGF versus 76% and 36% at 1 year ( P < 0.001), and 70% and 28% at 5 years ( P < 0.001) with EGF requiring IABP and ECMO support, respectively. In-hospital weaned and survived patients after IABP or ECMO treatment for moderate-to-severe EGF had a similar 5-year conditional survival rate as transplant patients who had not suffered EGF: 88% without EGF versus 84% with EGF treated with mechanical circulatory support devices ( P = 0.08). The occurrence of EGF is a multifactorial deleterious event that depends on donor and recipient profiles. IABP and ECMO support are reliable treatment strategies, depending on the grade of EGF. Furthermore, surviving patients treated with IABP or ECMO have the same long-term conditional survival rate as patients who have not suffered EGF. [ABSTRACT FROM AUTHOR]

The objective of this study was to compare the effects of pulsatile and nonpulsatile extracorporeal membrane oxygenation (ECMO) on hemodynamic energy and systemic microcirculation in an acute cardiac failure model in piglets. Fourteen piglets with a mean body weight of 6.08 ± 0.86 kg were divided into pulsatile ( N = 7) and nonpulsatile ( N = 7) ECMO groups. The experimental ECMO circuit consisted of a centrifugal pump, a membrane oxygenator, and a pneumatic pulsatile flow generator system developed in-house. Nonpulsatile ECMO was initiated at a flow rate of 140 mL/kg/min for the first 30 min with normal heart beating, with rectal temperature maintained at 36°C. Ventricular fibrillation was then induced with a 3.5-V alternating current to generate a cardiac dysfunction model. Using this model, we collected the data on pulsatile and nonpulsatile groups. The piglets were weaned off ECMO at the end of the experiment (180 min after ECMO was initiated). The animals did not receive blood transfusions, inotropic drugs, or vasoactive drugs. Blood samples were collected to measure hemoglobin, methemoglobin, blood gases, electrolytes, and lactic acid levels. Hemodynamic energy was calculated using the Shepard's energy equivalent pressure. Near-infrared spectroscopy was used to monitor brain and kidney perfusion. The pulsatile ECMO group had a higher atrial pressure (systolic and mean), and significantly higher regional saturation at the brain level, than the nonpulsatile group (for both, P < 0.05). Additionally, the pulsatile ECMO group had higher methemoglobin levels within the normal range than the nonpulsatile group. Our study demonstrated that pulsatile ECMO produces significantly higher hemodynamic energy and improves systemic microcirculation, compared with nonpulsatile ECMO in acute cardiac failure. [ABSTRACT FROM AUTHOR]

The objectives of this study were to investigate the relationship between revolution speed of a conventional centrifugal pump and negative pressure at the inlet of the pump by clamping the tubing upstream of the pump, and to verify whether negative pressure leads to gaseous microemboli ( GME) production in a simulated adult extracorporeal life support ( ECLS) system. The experimental circuit, including a Maquet Rotaflow centrifugal pump and a Medos Hilite 7000 LT polymethyl-pentene membrane oxygenator, was primed with packed red blood cells (hematocrit 35%). Negative pressure was created in the circuit by clamping the tubing upstream of the pump for 10 s, and then releasing the clamp. An emboli detection and classification quantifier was used to record GME volume and count at pre-oxygenator and post-oxygenator sites, and pressure and flow rate data were collected using a custom-based data acquisition system. All trials were conducted at 36°C at revolution speeds of 2000-4000 rpm (500 rpm increment). The flow rates were 1092.5-4708.4 mL/min at the revolution speeds of 2000-4000 rpm. Higher revolution speed generated higher negative pressure at the pre-pump site when clamping the tubing upstream of the pump (−108.3 ± 0.1 to −462.0 ± 0.5 mm Hg at 2000-4000 rpm). Moreover, higher negative pressure was associated with a larger number and volume of GME at pre-oxygenator site after de-clamp ( GME count 10 573 ± 271 at pre-oxygenator site at 4000 rpm). The results showed that there was a potential danger of delivering GME to the patient when clamping pre-pump tubing during ECLS using a centrifugal pump. Our results warrant further clinical studies to investigate this phenomenon. [ABSTRACT FROM AUTHOR]

In patients requiring left ventricular assist device ( LVAD) support, it can be difficult to ascertain suitability for long-term mechanical support with LVAD and eventual transplantation. LVAD implantation in a shocked patient is associated with increased morbidity and mortality. Interest is growing in the utilization of extracorporeal life support ( ECLS) as a bridge-to-bridge support for these critically unwell patients. Here, we reviewed our experience with ECLS double bridging. We hypothesized that ECLS double bridging would stabilize end-organ dysfunction and reduce ventricular assist device ( VAD) implant perioperative mortality. We conducted a retrospective review of prospectively collected data for 58 consecutive patients implanted with a continuous-flow LVAD between January 2010 and December 2013 at The Alfred Hospital, Melbourne, Victoria, Australia. Twenty-three patients required ECLS support pre- LVAD while 35 patients underwent LVAD implantation without an ECLS bridge. Preoperative morbidity in the ECLS bridge group was reflected by increased postoperative intensive care duration, blood loss, blood product use, and postoperative renal failure, but without negative impact upon survival when compared with the no ECLS group. ECLS stabilization improved end-organ function pre- VAD implant with significant improvements in hepatic and renal dysfunction. This series demonstrates that the use of ECLS bridge to VAD stabilizes end-organ dysfunction and reduces VAD implant perioperative mortality from that traditionally reported in these 'crash and burn' patients. [ABSTRACT FROM AUTHOR]

Extracorporeal membrane oxygenation ( ECMO) has traditionally been and, for the most part, still is being performed using roller pumps. Use of first-generation centrifugal pumps has yielded controversial outcomes, perhaps due to mechanical properties of the same and the ensuing risk of hemolysis and renal morbidity. Latest-generation centrifugal pumps, using magnetic levitation (ML), exhibit mechanical properties which may have overcome limitations of first-generation devices. This retrospective study aimed to assess the safety and efficacy of veno-arterial ( V- A) ECMO for cardiac indications in neonates, infants, and children, using standard ( SP) and latest-generation ML centrifugal pumps. Between 2002 and 2014, 33 consecutive neonates, infants, and young children were supported using V- A ECMO for cardiac indications. There were 21 males and 12 females, with median age of 29 days (4 days-5 years) and a median body weight of 3.2 kg (1.9-18 kg). Indication for V- A ECMO were acute circulatory collapse in ICU or ward after cardiac repair in 16 (49%) patients, failure to wean after repair of complex congenital heart disease in 9 (27%), fulminant myocarditis in 4 (12%), preoperative sepsis in 2 (6%), and refractory tachy-arrhythmias in 2 (6%). Central cannulation was used in 27 (81%) patients and peripheral in 6. Seven (21%) patients were supported with SP and 26 (79%) with ML centrifugal pumps. Median duration of support was 82 h (range 24-672 h), with 26 (79%) patients weaned from support. Three patients required a second ECMO run but died on support. Seventeen (51%) patients required peritoneal dialysis for acute renal failure. Overall survival to discharge was 39% (13/33 patients). All patients with fulminant myocarditis and with refractory arrhythmias were weaned, and five (83%) survived, whereas no patient supported for sepsis survived. Risk factors for hospital mortality included lower (<2.5 kg) body weight ( P = 0.02) and rescue ECMO after cardiac repair ( P = 0.03). During a median follow-up of 34 months (range 4-62 months), there were three (23%) late deaths and two late survivors with neurological sequelae. Weaning rate (5/7 vs. 21/26, P = NS) and prevalence of renal failure requiring dialysis (4/7 vs. 13/26, P = NS) were comparable between SP and ML ECMO groups. Patients supported with ML had a trend toward higher hospital survival (1/7 vs. 12/26, P = 0.07) and significantly higher late survival (0/7 vs. 10/26, P = 0.05). The present experience shows that V- A ECMO for cardiac indications using centrifugal pumps in infants and children yields outcomes absolutely comparable to international registry ( ELSO) data using mostly roller pumps. Although changes in practice may have contributed to these results, use of ML centrifugal pumps appears to further improve end-organ recovery and hospital and late survival. [ABSTRACT FROM AUTHOR]

The author reflects on the impact of the 2013-2014 influenza season on the patients that need extracorporeal membrane oxygenation (ECMO). He mentions that on the said period, more patients were put on veno-venous ECMO for respiratory failure while the early to middle-aged adults were considered to be hit the hardest. An overview on the assertion of the U.S. Centers for Disease Control and Prevention (CDC) that September through the end of April is the influenza season is offered.

Molecular Adsorbent Recirculating System ( MARS) is a liver support system widely employed in the treatment of liver failure. The method is normally well tolerated. To develop a liver support system combining high efficiency and tolerability, we modified the MARS albumin circuit with the insertion of double adsorption units in parallel. Four patients have been treated with this modified method (high-efficiency MARS, HE MARS): two had very high serum bilirubin and two had very high total bile acids. After a single MARS session bilirubin was reduced more with HE MARS than standard MARS (from 27.6 to 52.3% in patient A and from 27.9 to 49.1% in patient B), and bile acid reduction increased from 40 to 59.8% in patient C and from 39.9 to 60% in patient D. The results of this preliminary investigation in only a very small number of patients do support the possibility of developing a liver support system that combines good tolerability and high efficacy. [ABSTRACT FROM AUTHOR]

Roller pumps are commonly used in circulatory assist devices to deliver blood, but the inherent high mechanical stresses (especially wall shear stress) may cause considerable damage to cells. Conventional experimental approaches to evaluate and reduce device-induced cell damage require considerable effort and resources. In this work, we describe the use of a new computational fluid dynamics method to more effectively study roller pump systems. A generalized parametric model for the fluid field in a typical roller pump system is presented first, and analytical formulations of the moving boundary are then derived. Based on the model and formulations, the dynamic geometry and mesh of the fluid field can be updated automatically according to the time-dependent roller positions. The described method successfully simulated the pulsing flow generated by the pump, offering a convenient way to visualize the inherent flow pattern and to assess shear-induced cell damage. Moreover, the highly reconfigurable model and the semiautomated simulation process extend the usefulness of the presented method to a wider range of applications. Comparison studies were conducted, and valuable indications about the detailed effects of structural parameters and operational conditions on the produced wall shear stress were obtained. Given the good consistency between the simulated results and the existing experimental data, the presented method displays promising potential to more effectively guide the development of improved roller pump systems which produce less mechanical damage to cells. [ABSTRACT FROM AUTHOR]