Types Of Extracorporeal Membrane Oxygenation Research Articles

Extra-Corporeal Membrane Oxygenation in Pregnancy.

Extracorporeal membrane oxygenation (ECMO) is a cardiac or pulmonary function support system that is used in cases of refractory organ failure in addition to conventional treatment. Currently, Level I evidence is not yet available, which reflects improved outcomes with ECMO in pregnant women, the use in pregnancy should be indicated in selected cases and only in specialized centers. We searched articles in the most important scientific databases from 2009 until 31 December 2023 consulting also the site ClinicalTrials.com to find out about studies that have been recently conducted or are currently ongoing. We matched the combination of the following keywords: "ECMO and pregnancy", "H1N1 and pregnancy", "COVID-19 and pregnancy", "ARDS and pregnancy", "ECMO and pregnancy AND (cardiac arrest)". We selected the following number of articles for each keyword combination: "ECMO and pregnancy" (665 articles); "ECMO and influenza H1N1" (384 articles); "pregnancy and influenza H1N1" (1006 articles); "pregnancy and ARDS" (2930 articles); "ECMO and pregnancy and ARDS and influenza H1N1" (24 articles); and "[ECMO and pregnancy AND (cardiac arrest)]" (74 articles). After careful inspection, only 43 papers fitted our scope. There are two types of ECMO: venous-venous (VV-ECMO) and venous-arterial (VA-ECMO). The first-one is necessary to cope with severe hypoxia: oxygen-depleted blood is taken from the venous circulation, oxygenated, and carbon dioxide removed from the extracorporeal circuit and returned to the same venous system. The VA-ECMO is a type of mechanical assistance to the circulatory system that allows to put the failing organ at rest by ensuring adequate oxygenation and systemic de-oxygenation, avoiding multi-organ failure. The main indications for ECMO support in pregnant women are cardiogenic shock, acute respiratory distress syndrome (ARDS), pulmonary embolism, and eclampsia. There are also fetal indications for ECMO, and they are fetal distress, hypoxic-ischemic encephalopathy (HIE), and twin-to-twin transfusion syndrome (TTTS). Until now, based on the outcomes of the numerous clinical studies conducted, ECMO has been shown to be a successful therapeutic strategy in cases where medical treatment has been unsuccessful. In well-selected pregnant patients, it appears to be safe and associated with a low risk of maternal and fetal complications. The aim of this review is to report the main properties of ECMO (VV and VA) and the indications for its use in pregnant women.

Safety of low-dose anticoagulation in extracorporeal membrane oxygenation using the Permanent Life Support System: a retrospective observational study.

Bleeding and thrombosis are major complications associated with high mortality in extracorporeal membrane oxygenation (ECMO) management. Anticoagulant therapy should be adequate to reduce thrombosis. However, related studies are limited. We retrospectively reviewed all patients supported with ECMO at a single institution between January 2014 and July 2022 and included those on all types of ECMO using the Permanent Life Support System. Patients were classified into two groups according to their measured mean activated partial thromboplastin time (aPTT) during ECMO management: a high-anticoagulation (AC) group (aPTT, ≥55 seconds; n=52) and a low-AC group (aPTT, <55 seconds; n=79). The primary outcome was thrombotic or bleeding events during ECMO. We identified 10 patients with bleeding; significantly more of these patients were in the high-AC group (n=8) than in the low-AC group (15.4% vs. 2.5%, p=0.01). However, thrombus events and oxygenator change-free times were not significantly different between the two groups. Four patients in the high-AC group died of bleeding complications (brain hemorrhage, two; hemopericardium, one; and gastrointestinal bleeding, one). One patient in the low-AC group developed a thrombus and died of ECMO dysfunction due to circuit thrombosis. Heparin did not significantly improve thrombotic outcomes. However, maintaining an aPTT of ≥55 seconds was a significant risk factor for bleeding events, especially those associated with mortality.

Failing Fontan cardiovascular support: Review.

Although all congenital heart defects (CHD) present unique challenges, univentricular CHD are especially challenging given the difficulty of passively perfusing pulmonary blood flow. Three surgical procedures are required within the first years of life, with the final completing a Fontan circulation in which the inferior vena cava is connected to the pulmonary artery and previously connected superior vena cava. This allows passive venous return to the pulmonary circulation then flow into the single ventricle for systemic circulation. Although a Fontan provides successful palliation for two to three decades, many complications can arise as pulmonary resistance must remain low to allow adequate forward flow. Eventually, the failing Fontan circulation requires temporary support as the patient awaits a heart transplant. We reviewed PubMed, Google Scholar, and U. Kentucky library for different techniques evaluated to support a failing Fontan circulation. Multiple technologies have been developed as a bridge to transplant to decrease morbidity. Innovative types of extracorporeal membrane oxygenation, ventricular assist devices, and total artificial hearts have been attempted in laboratory settings as well as in Fontan patients with varying degrees of success. This article emphasizes the strengths and weaknesses of each technology in the context of Fontan physiology. The end game for these patients remains a heart transplant. Without easy access to donors, each of the options discussed is a potential bridge to limit morbidity and mortality until a suitable donor heart becomes available.

Acute Kidney Injury During Extracorporeal Membrane Oxygenation: VA ECMO Versus VV ECMO.

Acute kidney injury (AKI) has been reported to be one of the most common complications in patients receiving extracorporeal membrane oxygenation (ECMO), yet variations in AKI between different types of ECMO remain unclear. This meta-analysis systematically compares AKI/severe AKI in adult patients requiring different types of ECMO. Two authors independently performed a literature search using PubMed, Web of Science, and Embase, encompassing publications up until April 20, 2020 (inclusive). The number of AKI patients, including patients who required/did not require renal replacement therapy (RRT), and deceased patients with AKI/severe AKI, who received different types of ECMO were collated and analyzed using STATA. The results indicated that there were no significant differences in the risk of AKI/severe AKI among different types of ECMO. However, the presence of AKI and severe AKI during veno-arterial (VA) ECMO was more strongly associated with mortality. Although mortality rates related to AKI/severe AKI during VV ECMO are high, the occurrence of AKI/severe AKI during VA ECMO should be given greater attention, as these instances are considered strong indicators of patient deterioration and even death. Additional studies are needed to corroborate these findings.

Terapia nutricional no paciente adulto em oxigenação por membrana extracorpórea: revisão de literatura

Introduction: Extracorporeal membrane oxygenation (ECMO) provides partial or total cardiopulmonary support to patients with severe, acute and reversible cardiac or pulmonary failure. Despite the increasing use of the technique in adult patients, information on nutritional care is scarce. The objective was to investigate available data on the nutritional support of adult patients using ECMO in order to assist in the development of institutional protocols. Methods: A narrative review of the literature was led in order to showing the management of nutritional support, reasons for low nutritional adequacy, nutritional needs and the role of nutrition in ECMO complications. Results: Search strategies identified studies published up to October 11th, 2019. Only primary studies, indexed in the MEDLINE, Scopus and Web of Science data bases were evaluated, resulting in the inclusion of 11 studies. There is evidence that early enteral nutrition is safe and well tolerated and can be initiated via the gastric route. Gastrointestinal dysfunction with high gastric residual volumes is a common finding. However, there is positive evidence of treatment with prokinetic drugs, with the option of using a nasojejunal tube and parenteral nutrition. It is possible to achieve nutritional adequacy (&gt;80%), which is associated with lower mortality. However, malnutrition is recurrent, among the main reasons is the interruption of the diet for therapeutic/diagnostic procedures. Supplemental parenteral nutrition is an important strategy, but it requires special care with the associated administration of glucose and fats. Data on nutritional needs are controversial, as well as the differences in nutritional support and intercurrences between types of ECMO (VA and VV). Conclusion: It is concluded that although most studies are observational retrospective, the evidence shows that nutrition is safe, well tolerated and is associated with lower mortality of patients on ECMO.

Extracorporeal Membrane Oxygenation as a Bridge to Lung Transplant: Considerations for Critical Care Nursing Practice.

Candidates waiting for lung transplant are sicker now than ever before. Extracorporeal membrane oxygenation has become useful as a bridge to lung transplant for these critically ill patients. Critical care nurses must be prepared to care for the increasing number of lung transplant patients who require this advanced support method. To provide critical care nurses with the foundational knowledge essential for delivering quality care to this high-acuity transplant patient population. This review describes the types of extracorporeal membrane oxygenation (venovenous and venoarterial), provides an overview of the indications and contraindications for extracorporeal membrane oxygenation, and discusses the role of clinical bedside nurses in the treatment of patients requiring extracorporeal membrane oxygenation as a bridge to lung transplant.

Extracorporeal membrane oxygenation in the pediatric population - who should go on, and who should not.

The role of extracorporeal membrane oxygenation (ECMO), a method of providing cardiorespiratory support in instances of cardiac or respiratory failure, in neonates and children continues to expand and evolve. This review details the current landscape of ECMO as it applies to neonates and children. Specifically, this review provides the most recent evidence for which patients should be considered for the various forms of ECMO including venovenous ECMO, venoarterial-ECMO, and extracorporeal cardiopulmonary resuscitation. Specific topics to be discussed include indications and contraindications for the different types of ECMO in neonates and children, anticoagulation strategies and ways to monitor end-organ function, outcomes specific to the different types and populations with a focus on meaningful survival to discharge and neurologic outcomes, and consideration of special populations such as low birth weight infants, traumatically injured patients, and children who received recent bone marrow transplants. This review also discusses still unanswered questions surrounding the most appropriate use of ECMO as its role and applications continue to evolve. With rapidly increasing utilization of ECMO, neonatologists and pediatricians should be aware of the most recent evidence guiding its indications, applications, and limitations.

Unexpectedly Good Neurological Outcome after Prolonged Cardiac Arrest

Backgoround: Generally, neurological outcome of patients who have achieved return of spontaneous circulations (ROSC) with abnormal blood tests date and some severe organ complications is extremely poor. Because we experienced a case of good neurological outcome using two different types of extracorporeal membrane oxygenation (ECMO) in spite of prolonged cardiac arrest, we reported this case and reviewed the literature. Case presentation: A 36-year-old male suddenly collapsed at bar after drinking. Initial ECG showed ventricular fibrillation (VF) and subsequently underwent advanced cardiovascular life support. On admission, the ECG still showed VF, but pupillary light reflex was faintly present. Then, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support was established 54 minutes after collapse. Blood tests showed lactate was 15.8 mmol/l and NH3 of 251 μg/dl. To improve respiratory function after cardiogenic shock, we changed to veno-venous ECMO (VV-ECMO) and removed superabundant fluid using continuous hemodiafiltration. Patient was discharged on day-26 after a full functional recovery. Conclusion: In severe respiratory disorder, it would be more effective to change to VV-ECMO after recovering from cardiogenic shock while removing superabundant fluid using continuous hemodiafiltration. In predicting the neurological outcome of a post cardiac arrest patient, the presence of a pupillary light reflex may be more significant than NH3 and lactate.

Clinical implications of the initial SAPS II in veno-arterial extracorporeal oxygenation.

Prediction of survival and weaning probability in VA ECMO (veno-arterial extracorporeal membrane oxygenation) patients could be of great benefit for real-time decision making on VA ECMO initiation in critical ill patients. We investigated whether the SAPS II score would be a real-time determinant for VA ECMO initiation and could be a predictor of survival and weaning probability in patients on VA ECMO. Between January 1, 2010 and December 31, 2014, VA ECMO was carried out on 135 adult patients suffering from primary cardiogenic shock. To avoid selection bias, we excluded respiratory failure patients treated with VV or other types of ECMO. Successful VA ECMO weaning was defined as weaning, followed by stable survival for more than 48 hours. Survival after VA ECMO was defined as successful weaning and treatment of the underlying medical condition, followed by discharge without any further events. A total of 135 patients consisted of 41 women and 94 men, with a mean age of 59.4±16.5 years. Fifty-three patients had successful weaning, and 35 survived and were discharged uneventfully. Compared to the non-survivors, the survivors showed a lower SAPS II (67.77±20.79 vs. 90.29±13.31, P<0.001), a lower SOFA score (12.63±3.49 vs. 15.33±2.28, P<0.001), a lower predicted death rate (71.12±30.51 vs. 94.00±9.36, P<0.001), a higher initial ipH (7.14±0.22 vs. 6.98±0.15, P<0.001), and a lower initial lactate level (7.09±4.93 vs. 12.11±4.84, P<0.001). The average duration of hospital stay in the successful vs. failed weaning groups was 33.43±27.41 vs. 6.35±8.71 days, and the average duration of ICU stay in the successful vs. failed weaning groups was 20.60±16.88 vs. 5.39±5.95 days. By multivariate logistic regression analysis of initial parameters for VA ECMO assistance, the simplified acute physiology score II (SAPS II) (OR =1.1019, P=0.0389), ipH (OR =0.0010, P=0.0452), and hospital stay (OR =0.8140, P=0.001) had an association with in-hospital mortality on VA ECMO. The initial SAPS II score [area under the curve (AUC) =0.821] demonstrated significantly superior prediction of VA ECMO mortality than age (AUC =0.697), SOFA score (AUC =0.701), ipH (AUC =0.551), and the other parameters. By multivariable CoX regression analysis of survival, only the SAPS II score proved to have statistical significance (hazard ratio, 1.0423; 95% CI, 1.0083-1.0775; P=0.01). Although the precise predictive scoring systems for VA ECMO still remains one of the most difficult challenges to ECMO physicians, the SAPS II score could provide valuable information on prognosis to patient himself, family members and caretakers, and might help physicians increase the survival rate and might avoid a waste of healthcare resources.

Extracorporeal Membrane Oxygenation in Adults - Variants, Complications during Therapy, and the Role of Radiological Imaging.

Background Extracorporeal membrane oxygenation (ECMO) and extracorporeal life support (ECLS) as respiratory and circulatory assist therapies are gaining in importance in the treatment of critically ill patients. Depending on the place of cannulation - veno-venous for ECMO and veno-arterial for ECLS - distinct changes in hemodynamics will occur. In this review we describe the different types of ECMO and ECLS systems, the typical cannula placement and frequent complications under therapy. The most suitable imaging modalities will be presented and typical hemodynamic pitfalls in contrast-enhanced computed tomography or angiography will be elucidated. Methods The review is based on a literature search in PubMed with the terms "ECMO" and/or "ECLS" and/or "extracorporeal life support" and/or "imaging" and/or "complications". Statistical data was taken from the ECMO register of the "Extracorporeal Life Support Organization (ELSO)". Results Critical illness- and therapy-associated complications are common so that imaging, particularly computed tomography, becomes increasingly important. Following veno-venous cannulation in ECMO, the normal sequential blood flow is preserved, so that no contrast enhancement irregularities should be expected when the right timing and an adequate amount of contrast agent are selected. After veno-arterial cannulation in ECLS, different artifacts like pseudo-filling defects, pseudomembranes and irregular/low contrast enhancement of heart and pulmonary vessels can be found, depending on the site of cannulation and the residual cardiac function. Key points · Cannula placement is usually documented by radiography.. · Computed tomography is appropriate in the face of inconclusive cannula placement and probable complications.. · In veno-venous ECMO, no contrast enhancement artifacts are to be expected.. · Veno-arterial ECLS leads to pseudo-filling defects, pseudomembranes and irregular contrast enhancement of heart and pulmonary vessels.. Citation Format · Beck L, Burg MC, Heindel W et al. Extracorporeal Membrane Oxygenation in Adults - Variants, Complications during Therapy, and the Role of Radiological Imaging. Fortschr Röntgenstr 2017; 189: 119 - 127.

Experience of Early Conditioning on Extracorporeal Membrane Oxygenation (ECMO) Therapy as Bridge to Transplantation or Recovery

SESSION TITLE: ECMO Posters SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, October 28, 2015 at 01:30 PM - 02:30 PM PURPOSE: Critical illness and immobility is considered a major determinant of morbidity and mortality associated with ECMO support for severe cardiorespiratory failure. Early conditioning of the ECMO patients with help of physical and occupational therapy has been shown to improve short term as well as long term outcomes. METHODS: Retrospective analysis of patients bridged to transplantation with ECMO at a single tertiary care center with an active lung and heart transplantation program. We are reporting our experience of the ECMO patients who received multidisciplinary comprehensives active rehabilitation with aim for transplantation. RESULTS: Between September 2012 and October 2014; eight patients were managed with active physical therapy (PT) during ECMO support. The median (IQR) age was 24 (8-51) years, and 5 (63 %) were female. Veno-arterial ECMO was used in five patients (63%) and veno-venous in three (37%). Avalon canula was used in three and others were managed by central cannulation. Cardiac decompensation due to cardiomyopathy was the primary reason for ECMO in four patients, and ARDS and pulmonary hypertension in others. The median (IQR) ECMO duration was 115 days (19-148). All but one patient were liberated from invasive mechanical ventilation while receiving ECMO. The median (IQR) first PT day was 13 (2-22) and the median (IQR) best PT day from the first was 43 (3-76). During PT sessions all patients (100%) were ambulated (five >100 yards) and only two were on vasopressor on the first PT day. ECMO circuit related complication observed in one patient and patient related complication in 63%. Five patients (63%) bridged to transplant (2 lungs, 2 heart and one combined), two died prior to transplant and one recovered. Of the five patients (63%) surviving to discharge, three discharged to acute rehabilitation and two went to home. The median (IQR) total ICU days were 129(27-210) and the post-transplant ICU days were 37(6-80). CONCLUSIONS: Multidisciplinary approach for early conditioning in ECMO patients is safe and improves short term transplant outcomes. The impact of active rehabilitation during ECMO on transplant outcomes needs larger study. CLINICAL IMPLICATIONS: Early mobilisation is feasible irrespective of the types of ECMO by which patients are supported for cardiorespiratory failure. Given the advancement in technology for safer practice, and increase use of ECMO in crtitically ill patients, it's worth to share the experience from established centers to achieve the goal for better patient care. DISCLOSURE: The following authors have nothing to disclose: Pramod Guru, Keith Bryant, Tammy Friedrich, Jeffrey Riley, Dawit Haile, Machael Nemergut, Richard Daly, Gregory Schears No Product/Research Disclosure Information

Distal limb perfusion: Achilles' heel in peripheral venoarterial extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO) is a temporary mechanical circulatory assist method that offers circulatory as well as respiratory support efficiently via peripheral access; however, it is liable to complications. Limb ischemia is one of the notorious complications of ECMO but can be avoided utilizing a proper distal limb perfusion method. A retrospective study of patients undergoing peripheral venoarterial (VA) ECMO for various reasons between June 2010 and December 2012 was performed. All patients were evaluated by our multidisciplinary team for suitability as candidates for ECMO. A peripheral VA-ECMO circuit was implanted via groin: inflow cannula in the femoral vein, an outflow cannula and distal-perfusion cannula, or an introducer sheath in the femoral artery. During the study period, 83 patients underwent various types of ECMO; 45 received peripheral VA-ECMO. Distal limb perfusion was achieved with an introducer sheath (6-8 Fr) in 13 cases and with a distal-perfusion cannula (10-12 Fr) in 32 cases. Nine (20%) patients developed signs of ischemia; five (11.2%) were treated conservatively, while four (8.8%) required surgical intervention. One patient required a below-knee amputation. The incidences of limb ischemia and limb ischemia requiring surgical intervention were significantly higher for the introducer sheath compared with the cannula (30.6 vs. 15.6% and 15.4 vs. 6.25%, respectively). Moreover, the patients supported on ECMO with a distal-perfusion cannula spent a significantly longer time on ECMO compared with the ones in whom an introducer sheath was used (11.9 ± 9.1 vs. 7.7 ± 4.3 days). The mean cannula size was significantly greater than the mean introducer sheath size (11.1 ± 1.3 vs. 7.0 ± 1.1 Fr). Use of a distal-perfusion cannula is a most reliable method of limb perfusion in peripheral VA-ECMO. The cannula can ensure adequate and smooth perfusion of the limb owing to its large caliber, its less turbulent flow, the ability it provides to monitor the flow, and the option to attach a side port.

Adult Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO), sometimes used interchangeably with extracorporeal life support, is a therapy that artificially supports pulmonary and/or cardiac organ systems. Venous blood is continuously withdrawn from a patient and passed across a membrane that can support both oxygenation and removal of carbon dioxide; blood is then reinfused back into the patient via venous or arterial access. A pump in the circuit can augment cardiac output, if necessary. Initial treatment with ECMO had discouraging outcomes, but recent experience with acute respiratory distress syndrome and the H1N1 influenza A pandemic in 2009 have led to a resurgence in popularity and additional research into this technique. At this time, treatment with ECMO is limited to highly specialized centers with well-trained practitioners. ECMO continues to be used primarily as a salvage technique in severe critical illness. This review will discuss the indications, complications, and types of ECMO. A guide to the clinical use of ECMO concludes the review.

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

The Treatment of Adult Respiratory Distress Syndrome (ARDS) Using Extracorporeal Membrane Oxygenation (ECMO)

Extracorporeal Membrane Oxygenation (ECMO) support to tissue oxygenation has been shown to improve survival in patients with life threatening respiratory distress syndrome or cardiac failure. Extracorporeal life support such as ECMO, including extracorporeal CO2 removal (ECCO2R), is used as temporary support until successful recovery of organs. A recently published multicentre randomized controlled trial, known as the CESAR (conventional ventilation or extracorporeal membrane oxygenation for severe adult respiratory failure) trial, was the first trial to demonstrate the utility of ECMO in acute respiratory distress syndrome (ARDS). During the 2009 influenza A (H1N1) pandemic, there were many reports of patients with severe ARDS related to H1N1 infection treated with ECMO. These reports revealed a high survival rate and effectiveness of ECMO. In this review, we explain the indication of ECMO clinical application, the practical types of ECMO, and complications associated with ECMO. In addition, we explain recent new ECMO technology and management of patients during ECMO support.

Cardiac oxygenation by extracorporeal membrane oxygenation in exteriorized fetal lambs

OBJECTIVE: The purpose of this study was to determine the degree of cardiac oxygenation produced by different routes of extracorporeal membrane oxygenation in fetal lambs submerged in warm saline solution. STUDY DESIGN: Seven fetal lambs ranging in age from 113 to 133 days of gestation were delivered by cesarean section and oxygenated with extracorporeal membrane oxygenation. To maintain the patency of the ductus arteriosus, prostaglandin E 1 was continuously infused intravenously to the fetus. Initially the extracorporeal membrane oxygenation route was from the right atrium to the carotid artery. Then the extracorporeal membrane oxygenation route was changed to flow from the right atrium to the umbilical vein. The fetus was kept in a warm saline solution bath, and the fetal circulation was maintained. Extracorporeal membrane oxygenation flow ranged between 100 and 200 ml/min throughout the experiment. Simultaneous blood samples were taken during both types of extracorporeal membrane oxygenation from the following points in the fetal circulation: premembrane (least oxygenated blood leaving the fetus from the right atrium), postmembrane (oxygenated blood returning to the fetus), the carotid artery, and the left ventricle. The respiratory gases and pH of each sample were measured. Six fetuses received nonradioactive colored microspheres injected into the oxygenated blood returning to the fetus flow before returning to the fetuses during both types of extracorporeal membrane oxygenation. After the animals were killed, microspheres were counted in the myocardium separately taken from the right and left atria and the right and left ventricles to determine cardiac blood flow. RESULTS: During right atrium to carotid artery extracorporeal membrane oxygenation, left ventricle PO 2 remained low as postmembrane PO 2 increased; these values were not significantly correlated ( r = 0.234, p = 0.61). During right atrium to umbilical vein extracorporeal membrane oxygenation, left ventricle and postmembrane PO 2 exhibited a significant positive correlation ( r = 0.855, p = 0.014). When the extracorporeal membrane oxygenation route was switched from the right atrium to carotid artery to the right atrium to umbilical vein, there was a significant increase in left ventricle PO 2 and a decrease in left ventricle PCO 2 , whereas the respiratory gases and pH remained unchanged at other sites in the circulation. Microsphere counts were consistently higher during right atrium to umbilical vein extracorporeal membrane oxygenation than during right atrium to carotid artery extracorporeal membrane oxygenation in all four samples from different parts of myocardium ( p < 0.001 by paired t test). CONCLUSION: More effective cardiac oxygenation is provided by right atrium to umbilical vein extracorporeal membrane oxygenation than by right atrium to carotid artery extracorporeal membrane oxygenation. (A M J O BSTET G YNECOL 1996;174:864-70.)

Preliminary studies of the effects of extracorporeal membrane oxygenator on the disposition of common pediatric drugs.

There is an increased use of extracorporeal membrane oxygenation (ECMO) in the last 15 years for critically ill neonates. While receiving ECMO therapy, the critically ill infant needs various medications. We performed an in vitro study to evaluate the potential effect of the membrane oxygenator on drug extraction. Two closed ECMO circuits were set up at rates of 320 ml/min. One circuit was new and the other was used clinically for 5 days. Morphine at 8 ng/ml, gentamicin 10 micrograms/ml, vancomycin 40 micrograms/ml, phenobarbital 20 micrograms/ml, and phenytoin 20 micrograms/ml were injected into the circuit at 1-h intervals. Blood samples were drawn from the circuit at 10, 30, 60, and 240 minutes after injection. In the new circuit, drugs were eliminated as follows: vancomycin 36%, gentamicin 10%, phenobarbital 17%, phenytoin 43%, morphine 36%. In the used system, levels fell to a much smaller extent: vancomycin 11%, phenobarbital 6%, gentamicin 0%, phenytoin 0%, and morphine 16%. In a child receiving 20 micrograms/kg/h infusion of morphine, steady-state concentrations of 68.2 ng/ml fell to 11.6 ng/ml after changing the membrane. Our data indicate that the ECMO is associated with lowering of the concentrations of commonly used medications and that this process may depend partially on how new the membrane is. Before these changes may lead to new dosing guidelines for small children receiving ECMO, more experiments with new and used systems are warranted, as well as with different types of ECMO.