Extracorporeal Membrane Oxygenation System Research Articles

Perioperative Management of Adult Surgical Patients on Extracorporeal Membrane Oxygenation Support

XTRACORPOREAL MECHANICAL support devices are used as an adjunct in the management of critically ill patients who are refractory to more conventional modes of therapy. Extracorporeal membrane oxygenation (ECMO) is one such device that has been used mainly in the management of patients in cardiogenic shock or respiratory failure who failed therapy on maximal ventilator settings and maximal pharmacologic support. ECMO has the advantage of being rapidly deployable, both at the bedside and in the operating room, and can be initiated without the need for general anesthesia. ECMO has been used as a bridging device to recovery or to more definitive therapy. In patients who are awaiting lung transplantation, ECMO has been used as a bridge to transplant when decompensation occurs and also as an adjunct in physical rehabilitation before transplant. The science and instrumentation of ECMO are direct outgrowths of the development of cardiopulmonary bypass (CPB) technology that reached its full potential in support of cardiac surgery in the latter half of the 20th century. This is a fascinating history in itself and has been reviewed thoughtfully at key points by physician-scientists directly involved in the process. 1-3 Over the last decade, the design and reliability of components of the ECMO circuit have improved markedly from earlier iterations, and clinical teams have gained experience with a multidisciplinary approach to the management of patients on ECMO. These advancements have led to more prolonged and widespread use of ECMO as an alternative for support in patients with otherwise nonsurvivable respiratory or cardiopulmonary failure. Outcomes also have improved from what is reported in the older medical literature. With the increase in the use of ECMO, anesthesiologists have become more involved in the perioperative management of these critically ill patients, and an understanding of the physiologic changes that occur in patients on ECMO is essential for perioperative management. In addition, a number of issues remain controversial, mainly regarding risk/benefit differentials in pediatric versus older age groups, end-stage versus acute disease, and the timing and duration of therapy. This review addresses the practical clinical problems during the perioperative management of adult patients on ECMO. TYPES OF ECMO Three major configurations of ECMO are available. Venovenous (VV) ECMO is used in the management of patients with refractory pulmonary failure and stable cardiovascular status. Venoarterial (VA) ECMO is used in patients with refractory cardiogenic shock or cardiorespiratory failure. The third configuration, arteriovenous (AV) ECMO, also known as the “artificial lung,” can be used in patients with acute lung injury presenting with stable cardiovascular status. In this review, the term “inflow cannula” refers to the cannula that carries blood from the patient into the ECMO system, and “outflow cannula” refers to the cannula that carries oxygenated blood from the ECMO system back to the patient. In VV ECMO, the inflow and outflow ECMO cannulae run in and out of the venous system in the patient. In VA ECMO, the inflow cannula is from the patient’s venous system, but the outflow cannula runs into the arterial system. Conversely, in AV ECMO, the inflow cannula is from the patient’s arterial system with the outflow cannula from the oxygenator running into the patient’s venous system. AV ECMO differs from VA and VV ECMO in that the AV ECMO circuit does not incorporate a pump to maintain blood flow in the circuit. Blood flow in this type of circuit is a function of systemic blood pressure, cardiovascular stability, the resistance of the membrane oxygenator, the size and length of the conducting circuit, and blood viscosity. Adequate blood pressure and cardiovascular stability are required to maintain blood flow in this form of circuit. Commonly used inflow cannulation sites during VV and VA ECMO are the femoral vein, the inferior vena cava, the superior vena cava, and the right atrium. Outflow during VV ECMO may be into any of these sites. In patients on VA ECMO, inflow usually is into the femoral artery, axillary artery, ascending aorta, or the pulmonary artery. Inflow during AV ECMO may

Abstract 229: Access to a Portable Miniaturized Extracorporeal Membrane Oxygenation System Increases Utilization for Cardiac Arrest Patients

Background: Extracorporeal membrane oxygenation (ECMO) has improved outcomes in patients with cardiogenic shock (CS). Recent data and guidelines have recommended the use of venous-arterial (VA) ECMO in patients who have been successfully resuscitated from cardiac arrest (ROSC) to ameliorate the effects of post-resuscitation myocardial dysfunction. Use of ECMO often involves taking a patient to the operating room delaying the onset of care. We hypothesized that utilization of the Maquet Cardiohelp, a portable miniaturized ECMO system, in the cardiac catheterization laboratory (CCL), would increase use of ECMO for cardiac arrest patients. Methods: Cardiohelp (CH) ECMO was acquired in March 2012 by our tertiary care university hospital. We performed a retrospective analysis comparing the patients who received CH ECMO from March 2012 until June 2012 to those that received Centrimag (CM), a traditional ECMO circuit, in the in the 6 months prior to March 2012. Results: All patients were treated with femoral VA ECMO with antegrade perfusion distal via a percutaneous catheter in the superficial femoral artery. Overall, more patients were treated with CH compared to CM. Compared to patients who received CM, CH patients were more likely to have been referred for ECMO after ROSC from cardiac arrest and were more likely to have been transferred directly from the Emergency Department (ED). CM patients were slightly younger and were referred for ECMO treatment primarily due to cardiogenic shock (SBP3 pressors). 30 day survival was similar in both groups and there were no cases of stroke or limb ischemia. Conclusions: Use of the portable CH ECMO system with CCL initiation is associated with increased utilization of ECMO and particularly for the treatment of ED ROSC patients. This may be due to the portability of the device and existing relationships between the CCL and the ED. Rapid utilization of ECMO for these patients may lead to improved clinical outcomes.

Lungenersatzverfahren – Einsatz und Management extrakorporaler Lungenersatzverfahren

In patients with the most severe forms of acute respiratory distress syndrome (ARDS) refractory to conventional mechanical ventilation and adjunctive or rescue therapies like kinetic therapy, inhaled vasodilators or extracorporeal CO2-elimination (extracorporeal lung assist), the use of the extracorporeal membrane oxygenation (ECMO) can secure gas exchange. Due to technical improvements and miniaturization, the new ECMO system is safer and simpler. Nowadays the ECMO-systems are heparin-coated, so that there is no need of therapeutic systemic anticoagulation, and thus bleeding complications are less frequent. Recent data suggests, that outcome of patients with severe ARDS treated with ECMO may improve. This review describes the function and the management of ECMO-therapy in ARDS-patients.

4.2.2 Application of Systems Engineering to Improve Extracorporeal Membrane Oxygenation (ECMO) Therapy

AbstractThough able to boost survival rates from below 25% to nearly 75% in patients that qualify for treatment, the complexity of the currently implemented Extracorporeal Membrane Oxygenation (ECMO) system of systems keeps it from being used across an even wider range of patients. Representatives from the Children's Healthcare of Atlanta asked a team from the Georgia Tech Professional Masters in Applied Systems Engineering for assistance in reducing the complexity of the current implementation as well as help provide a way forward for future improvement to the therapy. This paper examines the application of systems engineering methodologies as performed by the team, including Model Based Systems Engineering (MBSE), gap analysis of the system architecture and data visualization prototyping. Additionally the paper describes how the selection of tools and models fostered dialog between two groups of distinctly different backgrounds and provides a proposed roadmap for robust system design, development and future work.

Hemolytic and thrombocytopathic characteristics of extracorporeal membrane oxygenation systems at simulated flow rate for neonates*

A state-of-the-art centrifugal pump combined with hollow-fiber oxygenator for extracorporeal membrane oxygenation has potential advantages such as smaller priming volumes and decreased potential to cause tubing rupture as compared with the traditional roller head/silicone membrane systems. Adoption of these state-of-the-art systems has been slow in neonates as a result of past evidence of severe hemolysis that may lead to renal failure and increased mortality. Extracorporeal systems have also been linked to platelet dysfunction, a contributing factor toward intracranial hemorrhage, a leading cause of infant morbidity. Little data exist comparing the centrifugal systems with the roller systems in terms of hemolysis and platelet aggregation at low flow rates commonly used in neonatal extracorporeal membrane oxygenation. Prospective, comparative laboratory study. University research laboratory. Centrifugal pump, roller pump, hollow-fiber oxygenator, and silicone membrane oxygenator. Comparative study using two pumps, the centrifugal Jostra Rotaflow (Maquet, Wayne, NJ) and the roller-head (Jostra, Maquet, Wayne, NJ), and two oxygenators, polymethlypentene Quadrox-D (Maquet) and silicone membrane (Medtronic, Minneapolis, MN). Five test runs of four circuit combinations were examined for hemolysis and platelet aggregation during 6 hrs of continuous use in a simulated in vitro extracorporeal membrane oxygenation circuit circulating whole swine blood at 300 mL/min. Hemolysis was assessed by spectrophometric measurement of plasma-free hemoglobin. Platelet aggregation was evaluated using monoclonal CD61 antibody fluorescent flow cytometry profiles. All of the extracorporeal membrane oxygenation systems created plasma-free hemoglobin at a similar rate compared with static blood control. There was no difference in the mean normalized index of hemolysis of the centrifugal/hollow-fiber oxygenator system as compared with the roller-head/silicone membrane systems (0.0032 g/100 L vs. 0.0058 g/100 L, p ≥ .7). None of the extracorporeal membrane oxygenation systems had a significant increase in platelet aggregation above baseline. In a low-flow neonatal environment, a state-of-the-art centrifugal pump combined with new fiber-type oxygenators appear to be safe in regard to hemolysis and platelet aggregation.

Predictors of increased transfusion requirements and optimizing transfusional support in patients on Extracorporeal membrane oxygenation (ECMO)

ECMO has an established role in neonatal, paediatric and adult patients with cardiac and/or respiratory failure who failed to respond to conventional therapies. It provides temporary cardiopulmonary support until the recovery of the patients or the institution of definitive treatment. Patients undergoing ECMO, especially adults, have high requirements for all blood components. High transfusional needs have been associated with increased mortality in the adults. Neonatal patients generally have lower overall transfusion requirements than the adults. The significant transfusion requirements among ECMO patients is contributed by increased bleeding from the need for systemic anticoagulation to reduce circuit thrombosis, activation and consumption of platelets and clotting factors, and anaemia from haemodilution and haemolysis. The need to prime the ECMO circuit with red cells may also account for part of the neonatal transfusion requirementsThere can be wide inter‐individual variations in the transfusion requirements of ECMO patients. Differences in pre‐determined transfusion triggers may account for differences in blood utilization between centers. Central cannulation can be associated with higher cannulation bleeding rates and blood utilization than peripheral cannulation. In neonates, factors associated with increased daily platelet transfusions include the use of venoarterial ECMO and the presence of concomitant sepsis and meconium aspiration. Neonates with sepsis or congenital diaphragmatic hernia may have the highest overall platelet transfusions due to longer ECMO duration. Neonates with intracranial haemorrhage were observed to require more platelet transfusions.In our retrospective analyses of adult ECMO patients in a cardiothoracic surgical unit in Singapore, there were positive correlations of total red cell, platelet and FFP transfusions with ECMO duration which in turn increased in non‐surgical or septic patients. On multivariate analyses, nadir haemoglobin of <7.5 g/dL associated with increased average daily red cell and FFP transfusions. Recent antiplatelet usage and maximum haemoblobin decline of >5.5 g/dl while on ECMO independently associated with increased average daily platelet transfusions. In addition, increased ECMO duration (which correlated negatively with nadir platelet count) was also independently associated with average daily transfusion of >3 platelet concentrate units. Bleeding was not an independent factor associated with any of the blood component utilization. Our findings suggest that the patients' haemoglobin levels and the perceived need to minimize coagulopathies among patients with significant anaemia and/or additional bleeding risks may have the greatest impact on clinicians' transfusion decisions in adult patients undergoing ECMO.Measures including the use of activated recombinant factor VII to reduce haemorrhage, and reduction in allogeneic blood transfusion with the use of an autotransfusion device during elective changes of ECMO systems have been reported to reduce transfusion requirements. Close collaboration between the transfusion service and the ECMO team is necessary to optimize the transfusion support of patients undergoing ECMO.

Early experiences with miniaturized extracorporeal life-support in the catheterization laboratory

Cardiocirculatory arrest during different types of interventions in the catheterization laboratory (cath-lab) requires mechanical cardiopulmonary resuscitation (CPR) to restore spontaneous circulation. However, mechanical chest compression leads to interruption of the procedure and can severely compromise the success of the percutaneous coronary intervention (PCI) or transcatheter aortic valve implantation (TAVI). Alternatives to mechanical chest compression are rare and mostly uncommon. The use of extracorporeal assistance for cardiopulmonary resuscitation (E-CPR) can be life-saving, but, up to now, it is not commonly and rapidly available in hospitals with cardiac-catheter laboratories but without cardiac-surgery departments. Here, we report our early experiences in using miniaturized extracorporeal membrane oxygenation (ECMO) systems for E-CPR in the cath-lab. We characterize the emergency uses and the bridging function of these simplified ECMO devices. Patients who developed cardiocirculatory arrest during PCI and TAVI procedures were treated with E-CPR using percutaneous veno-arterial extracorporeal life-support. To provide extracorporeal life-support, we used two types of miniaturized ECMO systems that can act independently from wall their connection points for power and oxygen supply and are suitable for use in the cath-lab. Between 2006 and 2011, E-CPR was used in 10 PCI and 4 TAVI patients. The mean age was 73.6 ± 8.8 years. In all patients, E-CPR could be established using percutaneous veno-arterial vessel access. On extracorporeal assistance, the return of beating heart circulation could be rapidly re-established in all patients. In the PCI group, the procedure was successfully completed in all patients while on ECMO. Two patients in the TAVI group were bridged on ECMO to surgical aortic valve replacement. In the clinical follow-up, seven patients (50%) survived to hospital discharge. Miniaturized ECMO systems can be safe and highly effective in restoring circulation and gas exchange in patients with cardiocirculatory failure in the cath-lab. Additionally, the PCI and TAVI procedures can be finished successfully on ECMO, otherwise the patients can be bridged to cardiac surgery. Especially for patients in need of cardiac surgery, patient transfer to extracorporeal assistance can be more easily processed.

Portable miniaturized extracorporeal membrane oxygenation systems for H1N1-related severe acute respiratory distress syndrome: A case series

BackgroundTechnological advances improved the practice of “modern” extracorporeal membrane oxygenation (ECMO). In the present report, we describe the experience of a referral ECMO center using portable miniaturized ECMO systems for H1N1-related severe acute respiratory distress syndrome (ARDS). MethodsAn observational study of all patients with H1N1-associated ARDS treated with ECMO in Hospital S. João (Porto, Portugal) between November 2009 and April 2011 was performed. Extracorporeal membrane oxygenation support was established using either ELS or Cardiohelp systems (Maquet-Cardiopulmonary-AG, Hirrlingen, Germany). ResultsTen adult patients with severe ARDS secondary to H1N1 infection (Pao2/fraction of inspired oxygen, 69 mm Hg [56-84]; Murray score, 3.5 [3.5-3.8]) were included, and 60% survived to hospital discharge. Five patients were uneventfully transferred on ECMO from referring hospitals to our center by ambulance. Six patients were treated during the first postpandemic influenza season. All patients were treated with oseltamivir, and 1 received in addition zanamivir. Four patients received corticosteroids. Nosocomial infection was the most common complication (40%). Of the 4 deaths, 2 were caused by hemorrhagic shock; 1, by irreversible multiple organ failure; and 1, by refractory septic shock. ConclusionIn our experience, ECMO support was a valuable therapeutic option for H1N1-related severe ARDS. The use of portable miniaturized systems allowed urgent rescue of patients from referring hospitals and safe interhospital and intrahospital transport during ECMO support.

Peripheral Extracorporeal Membrane Oxygenation System as Salvage Treatment of Patients With Refractory Cardiogenic Shock: Preliminary Outcome Evaluation

The novel Permanent Life Support (PLS; Maquet, Jostra Medizintechnik AG, Hirrlingen, Germany) as peripheral veno-arterial extracorporeal membrane oxygenation (ECMO) support system has been investigated as treatment for patients with refractory cardiogenic shock (CS). Between January 2007 and July 2011, 73 consecutive adult patients were supported on peripheral PLS ECMO system at our institution (55 men; age 60.3 ± 11.6 years, range: 23-84 years). Indications for support were failure to wean from cardiopulmonary bypass in the setting of postcardiotomy (n = 50) and primary donor graft failure (n = 8), post-acute myocardial infarction CS (n = 12), and CS on chronic heart failure (n = 3). Mean support time was 10.9 ± 7.6 days (range: 2-34 days). Overall, 26 (35.6%) patients died on ECMO. Among survivors on ECMO, 44 (60.2%) patients were successfully weaned from support, and three (4.1%) were switched to a mid-long-term ventricular assist device. Thirty-three (45.2%) were successfully discharged. The following variables were significantly different if survivors and nonsurvivors on ECMO were compared: age (P = 0.04), female gender (P < 0.01), cardiopulmonary resuscitation before ECMO (P < 0.01), lactate level before ECMO (P = 0.01), number of platelets, fresh frozen plasma units, and packed red blood cells (PRBCs) transfused during ECMO support (P = 0.03, P = 0.02, and P < 0.01), blood lactate level (P = 0.01), and creatine kinase isoenzyme MB (CK-MB) relative index 72 h after ECMO initiation (P < 0.001), and multiple organ failure on ECMO (P < 0.01). Stepwise logistic regression identified blood lactate level and CK-MB relative index at 72 h after ECMO initiation, and number of PRBCs transfused on ECMO as significant predictors of mortality on ECMO (P = 0.011, odds ratio [OR] = 2.48; 95% confidence interval [CI] = 1.11-3.12; P = 0.012, OR = 2.81, 95% CI = 1.026-2.531; and P = 0.012, OR = 1.94, 95% CI = 1.02-5.21; respectively). Patients with an initial poor hemodynamic status could benefit by rapid peripheral installation of PLS ECMO. The blood lactate level, CK-MB relative index, and PRBCs transfused should be strictly monitored during ECMO support.

A new miniaturized extracorporeal membrane oxygenator with integrated rotary blood pump (Ilias): first results in a porcine model of lung injury

Extracorporeal membrane oxygenation (ECMO) is used for most severe acute respiratory distress syndrome cases in specialized centres. However, critically ill patients fulfilling ECMO criteria are often not suitable for transportation and currently available ECMO systems are not designed for emergency use or interhospital transfer. Therefore, a new miniaturized ECMO (Ilias; Figure ​Figure1)1) with only 5 kg weight was developed to reduce filling volume and simplify management. Figure 1 The Ilias prototype. Methods Acute lung injury was induced with repeated pulmonary saline infusion in 13 pigs until the Horowitz Index was <100 mmHg. Pigs were assigned to the following three groups: group 1 (n = 3), control group, conventional ventilation; group 2 (n = 5), standard venovenous ECMO (Maquet); group 3 (n = 5), Ilias group. Gas exchange, hemodynamics, hemolysis, and coagulation activation were examined over a period of 8 hours.

First experience with the new portable miniaturized extracorporeal membrane oxygenation system Cardiohelp for severe respiratory failure in adults

Aims: Over the last decade, technical improvements in extracorporeal membrane oxygenation (ECMO) equipment have reduced procedure-related complications, and have made ECMO an effective option for patients with acute respiratory distress syndrome (ARDS) if conventional therapy fails.

First experience with the new portable extracorporeal membrane oxygenation system Cardiohelp for severe respiratory failure in adults

Over the last decade, technical improvements in extracorporeal membrane oxygenation (ECMO) equipment have reduced procedure-related complications and have made ECMO an effective option for patients with acute respiratory distress syndrome (ARDS) if conventional therapy fails. In this report, we present our early experience with the Cardiohelp, a new portable miniaturized ECMO system, in 22 consecutive patients with ARDS. All patients were placed on venovenous ECMO. Cannulas were inserted percutaneously, employing the Seldinger technique. Data were collected prospectively. The median patient age was 47 years (36 to 61). Fifteen patients from regional hospitals were too unstable for conventional transport and were placed on Cardiohelp at the referring hospital and then transported to our institution. The patients were transported by ambulance (n=2) or helicopter (n=13) over a distance of 50-250 km. Cardiohelp support resulted in immediate improvement of gas exchange and highly protective ventilation. The median duration of support was 13 days (8 to 19). An exchange of the device was necessary in 9 patients. Sixteen patients (72.7%) were successfully weaned from ECMO and fifteen patients (68.2%) survived. Device-related complications were not observed. The compact portable ECMO device Cardiohelp is a highly effective method to secure vital gas exchange and to reduce further ventilator-induced lung injury in patients with acute respiratory failure. Crucial technical innovations and ease of device transport and implantation allow location-independent stabilization with consecutive inter-hospital transfer.

Novel combination of impella and extra corporeal membrane oxygenation as a bridge to full recovery in fulminant myocarditis.

A 31-year-old male was transferred to our hospital with severe heart failure due to viral myocarditis. He progressed to multiorgan failure requiring intubation and maximal doses of multiple vasopressors. Circulatory support was provided with an Impella device as a bridge to an extracorporeal membrane oxygenation (ECMO) system. On full mechanical cardiovascular support, the patient's hemodynamic status improved and ECMO and Impella were explanted after 48 hours. Three days later, he was extubated and continued on to a full recovery. There are no specific therapies for fulminant myocarditis but first-line treatment is supportive care. ECMO is commonly used in patients with severe heart failure. In severe systolic dysfunction, left ventricular decompression is required to reduce myocardial wall stress, decrease myocardial oxygen requirements, and enhance the chances of recovery. The Impella, an active support system, is less invasive than classical decompressive techniques and is associated with lower requirements for blood products with fewer thromboembolic complications. This is the only case reported of the contemporary use of Impella and ECMO as a bridge to full recovery in an adult with myocarditis. It also presents a novel use of the Impella device in decompressing the left ventricle of an adult patient on ECMO.

Hematologic Complications Associated with Ventricular Assist Devices (VAD's) in 13 Children From a Single Center

Abstract▪2263▪This icon denotes a clinically relevant abstract Introduction:Mechanical circulatory support systems are used for the treatment of end-stage heart failure. In children, extracorporeal membrane oxygenation systems and centrifugal pumps have been used widely in the past, but are only suitable for short term use and intensive care is obligatory. The Berlin Heart is a VAD which is an extracorporeal pulsatile pneumatic system which can be placed as a bridge to transplant or recovery and allows patients to be mobile and to lead an almost normal life. As with placement of any mechanical device, aggressive anticoagulant therapy is needed due to the increased risk of thrombosis and therefore an increased risk of bleeding associated with the treatment. Here we report the complications seen in 13 children on VAD's from a single institution. Methods:Patient medical records were reviewed to obtain the information on complications and associated coagulation test results. Tests of hemostasis and thrombosis were performed in the authors' CAP accredited Coagulation Laboratory at the Children's Hospital of Michigan. Results:Thirteen children with a mean age of 42 months (range 3 weeks to 13 years) received a VAD as a bridge to transplant between 2006 and 2011. There were 7 males and 6 females, 9 were African American and 5 Caucasian. 10/13 patients were on ECMO for a short duration (1–15days) prior to VAD implantation. The duration of VAD implantation varied from 8 days to 8 months. 9/13 eventually received a heart transplant. Anticoagulation was monitored according to the Berlin Heart protocol. There were 4 deaths, all in infants <7months of age. Complications included thrombosis in 7 patients and bleeding in 5, some of whom had both. Time to thrombotic complications varied from day of implant to 14 days post implantation. Thrombotic complications included fibrin deposits in the VAD to strokes. Assessment of risk factors for thrombosis and bleeding showed that 3/10 patients were heterozygous for the MTHFR gene mutation, 1/10 had a low protein S and 2/10 had a low protein C. 5/7 patients with thrombosis had concurrent systemic or respiratory infections. ATIII was monitored and replaced to keep over 70% per protocol recommendations. Reactive thrombocytosis seen in some patients with thrombosis was associated with an increase in MA on thromboelastography despite administration of antiplatelet drugs. Bleeding complications varied from hemopericardium and intracranial hemorrhage to GI bleeding. Anticoagulation was monitored using thromboelastography with platelet mapping (monitoring antiplatelet agents), PTT and unfractionated (UFH level) or low molecular weight heparin levels respectively; UFH levels were found to be more useful for monitoring heparin anticoagulation than PTT. PTT was found to be low secondary to elevated Factor VIII activity resulting in poor correlation to heparin levels. Thromboelastography Platelet mapping assays were used to monitor aspirin and platelet ADP receptor antagonists, but did not correlate with traditional whole blood platelet aggregation studies. Conclusions:While thrombosis and bleeding complications are commonly seen in adult patients on VAD's, pediatric data in this population are limited and monitoring for the complications is inadequate. At our institution, infants who received VAD's had a poor outcome, but larger studies are needed to evaluate if there are complications unique to this age group. Current monitoring strategies are not always successful in predicting the occurrence of complications. Defects in fibrinolysis and increased thrombin generation may predispose to thrombotic manifestations. Tests to detect elevated thrombin generation and evaluation of fibrinolysis using modified thromboelastography may be useful to predict an increase in thrombotic potential which may assist us in improving the outcome. Disclosures:No relevant conflicts of interest to declare.

Extracorooreal membrane oxvgenation treatment of a child with fulminant myocarditis

Objective To report the clinical experience of extracorporeal membrane oxygenation (ECMO)in the emergency management of fulminant myocarditis.Methods The patient,an 11 year-old boy,had fever for 4 day and abdominal pain,vomiting for 1 day and anuria for 12 hours.Electrocardiogram showed Ⅲ atrial-ventricular block,multifocal ventricular rhythm,bundle branch block,convulsivum multifocal ventricular tachycardia,extensive low voltage,ST-T elevation at lead Ⅰ,AVR,V1,V2,V3;and there were ST-T intrusion,T wave inversion at lead Ⅱ,Ⅲ,AVR,AVF,V4～5.Blood creatine kinase was 2 161 U/L,reatine kinase isoenzyme 109 U/L,α-hydroxybutyrate dehydrogenase 612 U/L,lactate dehydrogenase 696 U/L,troponin Ⅰ 22.1 U/L.Echocardiogram showed right atrium 4.4 mm,right ventricular 2.3 mm,severe tricuspid valve regurgitation,left ejection fraction 33％,left ventricular fractional shortening 15％,ventricular wall motion dyssynchrony.Blood lactate was 4.0 mmol/L.The patient's condition was still unstable after using dobutamin,dopamine,milrinone,furosemide,large dose methylprednisolone,intravenous human immunoglobin,phosphocreatine and so on.ECMO was used for cardio-pulmonary support.It is necessary to monitoring the consciousness,temperature,heart rate,respiration,blood pression,SaO2,urinary volume,ariterial blood gas,blood electrolytes,blood lactate,blood glucose,liver function,renal function,blood routine,activated clotting time(ACT),lower extremity blood supply and so on.ACT was maintained at 160～200 s.Heparin was used persistently[5～10 U/(kg·min)].Results ECMO system had been successfully used for 7 days.The cardiac function of the patient was improved significantly.There was no complication,such as hemorrhage,infection,and embolism.Heart arrest in the patient occurred three times,ventricular fibrillation and ventricular flutter occurred one time respectively during ECMO.The rhythm was recovered by electric defibrillation and antiarrhythmic drugs.On day 20,the patient was discharged.At the time of hospital discharge,the patient demonstrated good activity,with normal myocardial enzymes.The echocardiogram showed the size of the cardiac chambers and the contractile function of the myocardia were normal.Electrocardiogram showed Ⅰ degree atrial-ventricular block,complete right bundle branch block.Two weeks later,the electrocardiogram demonstrated complete right bundle branch block.Echocardiogram showed septal thickening(0.9 cm).Two months later,the electrocardiogram was just as that of two weeks before.Echocardiogram showed septal thickening(0.7 cm).The children had no symptom after he was discharged and acted without limitation.Conclusion ECMO is a kind of effective treatment for fulminant myocarditis.The key to desirable therapeutic effect is the timing of its application. Key words: Extracorporeal membrane oxygenation ; Fulminant myocarditis ; Children

Closing the “Care in the Air” Capability Gap for Severe Lung Injury: The Landstuhl Acute Lung Rescue Team and Extracorporeal Lung Support

The success of US Air Force Critical Care Air Transport Teams (CCATT) in transporting critically ill and injured patients enabled changes in military medical force deployment and casualty care practice. Even so, a subset of casualties remains who exceed even CCATT capabilities for movement. These patients led to the creation of the Landstuhl Acute Lung Rescue Team (ALeRT) to close the "care in the air" capability gap. The ALeRT Registry was queried for the period between November 1, 2005, and June 30, 2010. Additionally, Landstuhl Regional Medical Center critical care patient transfers to host nation medical centers were reviewed for cases using extracorporeal lung support systems. For the review period, US Central Command activated the ALeRT on 40 occasions. The ALeRT successfully evacuated patients on 24 of 27 missions launched (89%). Three patients were too unstable for ALeRT evacuation. Of the 13 remaining activations, four patients died and nine patients improved sufficiently for standard CCATT movement. The ALeRT initiated pumpless extracorporeal lung assistance six times, but only once to facilitate evacuation. Two patients were supported with full extracorporeal membrane oxygenation support after evacuation due to progressive respiratory failure. ALeRT successfully transported 24 casualties from the combat zones to Germany. Without the ALeRT, these patients would have remained in the combat theater as significant consumers of limited deployed medical resources. Pumpless extracorporeal lung assistance is already within the ALeRT armamentarium, but has only been used for one aeromedical evacuation. Modern extracorporeal membrane oxygenation systems hold promise as a feasible capability for aeromedical evacuation.

Veno‐Venous Extracorporeal Membrane Oxygenation as a Bridge to and Support for Pulmonary Thromboendarterectomy in Misdiagnosed Chronic Thromboembolic Pulmonary Hypertension

Diagnostic delay in patients suffering massive pulmonary embolism (PE) on chronic thromboembolic pulmonary hypertension (CTEPH) has inevitably fatal consequences. Indications to pulmonary thromboendarterectomy (PTE) and extracorporeal membrane oxygenation (ECMO) are limited by severe comorbid conditions, some of which, as neurologic disease, absolutely contraindicate these procedures. We reported the clinical course of a severely diseased patient with a history of meningitis, psychosis and epilepsy, experiencing acute massive pulmonary embolism complicated by acute respiratory failure, successfully treated by ECMO and PTE. A 51-year-old woman with massive PE complicating a misdiagnosed CTEPH needed mechanical ventilation because of acute respiratory insufficiency. Thoracic computed tomography (CT) scan demonstrated PE, and brain CT showed multiple cerebral and cerebellar ischemic lesions. Veno-venous ECMO assistance was instituted despite CT imaging. She recovered from acute respiratory insufficiency by means of veno-venous ECMO. Weaning from ECMO was however impossible until surgical exploration demonstrated an underlying chronic CTEPH, which was successfully addressed by PTE, switching the ECMO system to a standard cardiopulmonary bypass. Postoperative course was uneventful and the patient was discharged home in healthy condition. Despite the fact that the cost-effective ratio should always be considered in advanced life support, expanding the commonly accepted selection criteria for expensive procedures might be advisable in selected acute life-threatening cases, in view of the possibility to unexpectedly save lives.

Extracorporeal Membrane Oxygenation in 108 Patients with Low Cardiac Output – a Single-Center Experience

For short-term ventricular and pulmonary support the extracorporeal membrane oxygenation (ECMO) system using the Bio-Medicus centrifugal pump (Medtronic®, Minneapolis, MN, USA) was applied in 108 patients with cardiac low-output. From December 1996 to July 2006 the ECMO was implanted in 108 patients (73 adult, mean age: 49.3±18.0 yrs and 35 children, mean age: 1.3 ± 2.7 yrs) with mostly postcardiotomy cardiac low output. The surgical procedures included congenital heart surgery (n=35), heart transplantation (HTx) (n=21), coronary artery bypass operation (CABG) and/or valvular operation (n=33), other operations (n=6) and 13 patients with ECMO support for bridge to recovery. The mean supporting time was 5.1±5.6 days. Overall, 30-day-survival was 40.2%. Best survival rates were seen after congenital heart surgery (24/35, 65.7%) and after HTx (9/21, 42.9%); the worst rates were in the group of CABG and/or valvular operations (5/33, 15.2%), only ECMO support (3/13, 23.1%) and other operations (1/6, 16.7%). Fifty-four patients died while supported by ECMO, 15 were weaned from ECMO but died in hospital, 39 patients were weaned and survived. Causes of death were multi-organ failure (40.6%), bleeding (23.2%), persistent cardiac low output (21.7%), thrombembolic events (8.7%), and graft failure (5.8%). Markers for adverse outcome were identified as older age, high body weight, increased AST/GOT levels, and lower thrombocyte count in adults; and as higher levels of serum creatinine in pediatric patients. ECMO support showed best results in pediatric patients after congenital heart surgery and in patients after HTx in contrast to multimorbid, older patients with often irreversible myocardial damage.

Mobile cardio-respiratory support in prehospital emergency medicine

Serious pulmonary and cardiac failure may be treated with extracorporeal membrane oxygenation (ECMO) when the conventional treatment fails. Improvements in extracorporeal circulation devices have allowed us to set up two specialized mobile units: a mobile cardiac assistance unit (MCAU) and a mobile respiratory assistance unit (MRAU). Their role is to provide ECMO at patient's bedside, and then to ensure inter-hospital transport (IHT). The aim of this study was to evaluate our experiences with the transportation of patients on ECMO. We performed two prospective observational studies, the first on IHT requiring MCAU during 3 years and the second on IHT requiring MRAU during 6 months. Thirty-two patients needed MCAU. The median age is 40 years. The median distance travelled is 45 km. The median time of arrival at patient bedside is 49 min. Causes of cardiac shock were: myocarditis (28.1%), acute heart failure of unknown aetiology (21.9%), drug-induced cardiovascular failure (18.8%), post-infarction cardiac failure (12.5%), post-cardiac surgery (12.5%) and refractory cardiac arrest (6.2%). Thirty days mortality was 40%. Eleven patients needed MRAU. The median age was 33 years. The median distance travelled is 40 km; the median time of arrival at patient bedside is 47 min. All patients had severe acute respiratory distress syndrome complicating severe H1N1 virus infection. Thirty days mortality was 65%. In both the cases, all transportations were uneventful. This study shows that mobile ECMO system can be successfully and quickly established at patient's bedside, and that transportation of patients on ECMO can be performed safely and without technical difficulties.

Myocardites aiguës

Myocarditis is defined as inflammation of the myocardium accompanied by myocellular necrosis. Acute myocarditis should be considered in patients who present with a recent onset of cardiac failure or arrhythmia. Fulminant myocarditis is a distinct entity characterized by the sudden onset of severe congestive heart failure or cardiogenic shock, usually following a flu-like illness. Parvovirus B19, human herpesvirus 6, coxsackievirus, and adenovirus are most frequently the viruses responsible for the disease. Treatment of myocarditis remains largely supportive, since immunosuppression has not been proven to be beneficial for acute lymphocytic myocarditis. Trials of antiviral therapies, or immunostimulants such as interferons, suggest a potential therapeutic role but require further investigation. Lastly, early recognition of patients rapidly progressing to refractory cardiac failure and their immediate transfer to a medical and surgical center which is experienced in mechanical circulatory support is warranted. In this setting, extracorporeal membrane oxygenation (ECMO) should be the first-line mechanical assistance. For highly unstable patients, the preferred option is a Mobile Cardiac Assistance Unit, that rapidly moves to primary care hospitals with a portable ECMO system and hooks it up before refractory multiorgan failure occurs.