Extracorporeal Membrane Oxygenation System Research Articles

Adoption of Augmented Reality in Educational Programs for Nurses in Intensive Care Units of Tertiary Academic Hospitals: Mixed Methods Study.

In the wake of challenges brought by the COVID-19 pandemic to conventional medical education, the demand for innovative teaching methods has surged. Nurse training, with its focus on hands-on practice and self-directed learning, encountered significant hurdles with conventional approaches. Augmented reality (AR) offers a potential solution to addressing this issue. The aim of this study was to develop, introduce, and evaluate an AR-based educational program designed for nurses, focusing on its potential to facilitate hands-on practice and self-directed learning. An AR-based educational program for nursing was developed anchored by the Kern six-step framework. First, we identified challenges in conventional teaching methods through interviews and literature reviews. Interviews highlighted the need for hands-on practice and on-site self-directed learning with feedback from a remote site. The training goals of the platform were established by expert trainers and researchers, focusing on the utilization of a ventilator and extracorporeal membrane oxygenation system. Intensive care nurses were enrolled to evaluate AR education. We then assessed usability and acceptability of the AR training using the System Usability Scale and Technology Acceptance Model with intensive care nurses who agreed to test the new platform. Additionally, selected participants provided deeper insights through semistructured interviews. This study highlights feasibility and key considerations for implementing an AR-based educational program for intensive care unit nurses, focusing on training objectives of the platform. Implemented over 2 months using Microsoft Dynamics 365 Guides and HoloLens 2, 28 participants were trained. Feedback gathered through interviews with the trainers and trainees indicated a positive reception. In particular, the trainees mentioned finding AR particularly useful for hands-on learning, appreciating its realism and the ability for repetitive practice. However, some challenges such as difficulty in adapting to the new technology were expressed. Overall, AR exhibits potential as a supplementary tool in nurse education. To our knowledge, this is the first study to substitute conventional methods with AR in this specific area of critical care nursing. These results indicate the multiple principal factors to take into consideration when adopting AR education in hospitals. AR is effective in promoting self-directed learning and hands-on practice, with participants displaying active engagement and enhanced skill acquisition. ClinicalTrials.gov NCT05629663; https://clinicaltrials.gov/study/NCT05629663.

Clinical Practice of Pre-Assembling and Storing of Extracorporeal Membrane Oxygenation Systems

According to the Extracorporeal Life Support Organization (ELSO) guidelines, pre-assembled and already primed extracorporeal membrane oxygenation (ECMO) systems can be safely stored for up to 30 days under specific conditions. This study gives a detailed overview of existing pre-assembly practices. An anonymous online survey was conducted among chief perfusionists at German ECMO centers. Forty-four of a total of 83 ECMO centers (53%) completed the survey. Thirty-three percent do not preassemble ECMO systems. Seventy-seven percent (n = 34) reported having preassembled ECMO systems readily available (30% dry preassembly/20% wet preassembly/27% wet preassembly with circulation). Half of the participating centers (50%) reported having a standard operating procedure (SOP) and the majority (57%) of chief perfusionists expressed a need for an evidence-based SOP. A maximum storage time for wet preassembled ECMO systems is established in 88% of departments. On average, wet preassembled systems are discarded after 20 days, which is below the ELSO’s safe limit of 30 days. Overall, this survey reveals a heterogeneous approach regarding the practice of provisioning preassembled ECMO systems. The demand for an evidence-based SOP for the preassembly and storing of ECMO systems becomes evident, necessitating the determination of hygienic standards, regular training, and a reliable maximum storage period.

Early thrombus detection in the extracorporeal membrane oxygenation circuit by noninvasive real-time ultrasonic sensors

Thrombus formation in extracorporeal membrane oxygenation (ECMO) remains a major concern as it can lead to fatal outcomes. To the best of our knowledge, there is no standard non-invasive method for quantitatively measuring thrombi. This study’s purpose was to verify thrombus detection in an ECMO circuit using novel, non-invasive ultrasonic sensors in real-time, utilizing the fact that the ultrasonic velocity in a thrombus is known to be higher than that in the blood. Ultrasonic sensors with a customized chamber, an ultrasonic pulse-receiver, and a digital storage oscilloscope (DSO) were used to set up the measuring unit. The customized chamber was connected to an ECMO circuit primed with porcine blood. Thrombi formed from static porcine blood were placed in the circuit and ultrasonic signals were extracted from the oscilloscope at various ECMO flow rates of 1–4 L/min. The ultrasonic signal changes were successfully detected at each flow rate on the DSO. The ultrasonic pulse signal shifted leftward when a thrombus passed between the two ultrasonic sensors and was easily detected on the DSO screen. This novel real-time non-invasive thrombus detection method may enable the early detection of floating thrombi in the ECMO system and early management of ECMO thrombi.

Bloodstream Infection caused by Corynebacterium striatum in COVID-19 patient

Objectives: Recent research recognized coryneform bacteria as emerging opportunistic pathogens. Corynebacterium striatum appears as a significant pathogen in immunocompromised and immunocompetent patients. Methods: In this paper, we report a case of an adult COVID-19 patient with C. striatum bloodstream infection. In addition, we reviewed clinical cases of bloodstream infection caused by Corynebacterium spp, mainly C. striatum. Results: We present a 43-year-old patient hospitalized due to bilateral pneumonia caused by a SARS-CoV-2 infection. During hospitalization, the patient was connected to a veno-venous extracorporeal membrane oxygenation (ECMO) circuit. C. striatum was isolated in seven sets of blood cultures sampled over seven consecutive days. Based on identification done by MALDI- ToF, empirical therapy with vancomycin was initiated. Identification was confirmed by 16S ribosomal RNA gene sequencing. Although central venous catheter was replaced, C. striatum was persistently isolated in blood cultures in the following days. Although replacement of the ECMO cannula would be recommended, the procedure was not performed due to the severe patient's condition. Fosfomycin was added to vancomycin as salvage therapy in order to reorganize the structure of the biofilm and enable better penetration and efficacy of vancomycin which resulted in sterile blood cultures in the following days. Conclusion: During the last decades, there have been many examples of bloodstream infections caused by skin contaminants. Although the central venous catheter is most commonly described as a route of entry of the skin microbiota in the bloodstream, other catheters such as pleural catheter and ECMO system, should not be neglected. It is well known that bacterial cells often form a biofilm on the surface of different medical devices such as central venous catheters, endoscopes, and urinary catheters. Fosfomycin has the potential to penetrate the biofilm, transform the biofilm structure and potentially increase the concentration of other antimicrobial agents in the biofilm.

Bloodstream Infection caused by Corynebacterium striatum in COVID-19 patient

Objectives: Recent research recognized coryneform bacteria as emerging opportunistic pathogens. Corynebacterium striatum appears as a significant pathogen in immunocompromised and immunocompetent patients. Methods: In this paper, we report a case of an adult COVID-19 patient with C. striatum bloodstream infection. In addition, we reviewed clinical cases of bloodstream infection caused by Corynebacterium spp, mainly C. striatum. Results: We present a 43-year-old patient hospitalized due to bilateral pneumonia caused by a SARS-CoV-2 infection. During hospitalization, the patient was connected to a veno-venous extracorporeal membrane oxygenation (ECMO) circuit. C. striatum was isolated in seven sets of blood cultures sampled over seven consecutive days. Based on identification done by MALDI- ToF, empirical therapy with vancomycin was initiated. Identification was confirmed by 16S ribosomal RNA gene sequencing. Although central venous catheter was replaced, C. striatum was persistently isolated in blood cultures in the following days. Although replacement of the ECMO cannula would be recommended, the procedure was not performed due to the severe patient's condition. Fosfomycin was added to vancomycin as salvage therapy in order to reorganize the structure of the biofilm and enable better penetration and efficacy of vancomycin which resulted in sterile blood cultures in the following days. Conclusion: During the last decades, there have been many examples of bloodstream infections caused by skin contaminants. Although the central venous catheter is most commonly described as a route of entry of the skin microbiota in the bloodstream, other catheters such as pleural catheter and ECMO system, should not be neglected. It is well known that bacterial cells often form a biofilm on the surface of different medical devices such as central venous catheters, endoscopes, and urinary catheters. Fosfomycin has the potential to penetrate the biofilm, transform the biofilm structure and potentially increase the concentration of other antimicrobial agents in the biofilm.

Influence of Covid-19 disease on hemostasis dynamics during extracorporeal membrane oxygenation (ECMO)1.

COVID-19 causes a considerable degradation of pulmonary function to the point of an acute respiratory distress syndrome (ARDS). Over the course of the disease the gas exchange capability of the lung can get impaired to such an extent that extracorporeal membrane oxygenation (ECMO) is needed as a life-saving intervention. In patients COVID-19 as well as ECMO may cause severe coagulopathies which manifest themselves in micro and macro thrombosis. Previous studies established D-dimers as a marker for critical thrombosis of the ECMO system while on admission increased D-dimers are associated with a higher mortality in COIVD-19 patients. It is therefore crucial to determine if COVID-19 poses an increased risk of early thrombosis of the vital ECMO system. 40 patients who required ECMO support were enrolled in a retrospective analysis and assigned into 2 groups. The COVID group consist of 20 COVID-19 patients who required ECMO support (n = 20), whereas 20 ECMO patients without COVID-19 were assigned to the control group. D-dimers, fibrinogen, antithrombin III (AT III), lactate dehydrogenase (LDH) and platelet count were analysed using locally weighted scatterplot smoothing and MANOVAs. The analysis of both groups shows highly significant differences in the dynamics of hemostasis. The increase in D-dimers that is associated with thrombosis of the ECMO systems occurs in COVID-19 patients around 2 days earlier (p = 2,8115 10-11) while fibrinogen is consumed steadily. In the control group fibrinogen levels increase rapidly after ten days with a plateau phase of around five days (p = 1,407 10-3). Both groups experience a rapid increase in AT III after start of support by ECMO (p = 5,96 10-15). In the COVID group platelet count decreased from 210 giga/l to 130 giga/l within eight days, while in the same time span in the control group platelets decreased from 180 giga/l to 105 giga/l (p = 1,1 10-15). In both groups a marked increase in LDH beyond 5000 U/l occurs (p = 3,0865 10-15). The early increase in D-dimers and decrease in fibrinogen suggests that COVID-19 patients bear an increased risk of early thrombosis of the ECMO system compared to other diseases treated with ECMO. Additionally, the control group shows signs of severe inflammation 10 days after the start of ECMO which were absent in COVID-19 patients.

Installed strategy and clinical observation of self-made extracorporeal membrane oxygenation system in the treatment of critically ill patients

To summarize the strategy and method for the treatment of critically ill patients with self-made extracorporeal membrane oxygenation (ECMO) system. A observative study was conducted. Fifty-six patients with ECMO assisted support in Fuwai Central China Cardiovascular Disease Hospital from December 2020 to December 2021 were enrolled. According to the clinical situation of the patients and the wishes of the family, conventional ECMO package (conventional group) or self-made ECMO package (self-made group) was chosen. In the conventional group, the disposable ECMO package was used to install the machine, pre charge and exhaust the air. In the self-made group, the disposable consumables commonly used in extracorporeal circulation during cardiac surgery (including centrifugal pump heads, membrane oxygenation, tubes, connectors, etc.) were used to create a self-made ECMO system. Based on the patient's situation, personalized tube model selection and length control were carried out. The preparation time, auxiliary time, auxiliary method, total pre charge volume, free hemoglobin (FHb) levels after 2 hours of ECMO operation and operating costs, as well as changes in hemodynamics, arterial blood gas analysis, and blood indicators within 48 hours after ECMO placement in the two groups were recorded. The occurrence of adverse events related to the ECMO system during ECMO adjuvant therapy in two groups was simultaneously observed. Fifty-six patients were enrolled finally, with 28 cases in the conventional group and 28 cases in the self-made group, and all successfully completed the operation of ECMO. There was no statistically significant difference in ECMO system preparation time, auxiliary time, auxiliary method, and FHb levels after 2 hours of ECMO operation between the conventional group and the self-made group [preparation time (minutes): 13±4 vs. 15±5, auxiliary time (hours): 287±34 vs. 276±42, veno-arterial ECMO (cases): 22 vs. 24, veno-venous ECMO (cases): 6 vs. 4, FHb after 2 hours of ECMO operation (mg/L): 226±67 vs. 253±78, all P > 0.05]. However, the total pre charge volume and operating costs in the self-made group were significantly lower than those in the conventional group [total pre charge volume (mL): 420±25 vs. 650±10, operating costs (ten thousand yuan): 3.8±0.4 vs. 6.7±0.3, both P < 0.01]. The hemodynamics, arterial blood gas analysis, and blood indicators of patients in the two groups were relatively stable within 48 hours after ECMO operation, and most of the indicators between the two groups showed no statistically significant differences. The hemoglobin (Hb) levels at 12, 24, and 48 hours after the machine transfer in the self-made group were significantly higher than those in the conventional group (g/L: 128.5±23.7 vs. 117.5±24.3 at 12 hours, 121.3±31.3 vs. 109.6±33.2 at 24 hours, 118.5±20.1 vs. 105.2±25.7 at 48 hours, all P < 0.05). Both groups of patients did not experience any adverse event related to the ECMO system, such as membrane pulmonary infiltration, joint detachment, and massive hemolysis, during the ECMO assisted treatment process. When implementing ECMO for critically ill patients in clinical practice, a self-made ECMO system with disposable consumables commonly used in extracorporeal circulation during cardiac surgery can be used for cardiopulmonary function assistance support, thereby saving patients medical costs and alleviating their dependence on disposable ECMO package in clinical practice.

Effect of extracorporeal membrane oxygenation combined with ulinastatin

This study aims to investigate the clinical efficacy of combining extracorporeal membrane oxygenation (ECMO) with ulinastatin in the treatment of severe pneumonia (SP) with respiratory failure, using an immuno-magnetic bead-based ELISA method. A total of 40 patients with SP complicated by respiratory failure who were admitted to the respiratory department of our hospital from January 2019 to December 2022, were selected. They were divided into the control group (n = 20) and the ECMO group (n = 20). The control group received conventional therapy such as mechanical ventilation, anti-infection, anticoagulation, and maintaining acid-base balance. The ECMO group established an ECMO system and injected ulinastatin intravenously based on conventional therapy. After 7 days of treatment, arterial blood was collected for blood gas analysis and pulmonary function index. The level of inflammatory factors was determined using the immunomagnetic bead-ELISA method. Flow cytometry was used to assess T lymphocyte subsets and clinical efficacy between the two groups. The ECMO group exhibited significantly shorter length of hospital stay and mechanical ventilation duration compared to the control group. Moreover, pulmonary function indexes (FEV1, FVC, PEF) and blood gas indexes were superior in the ECMO group than those in the control group. Additionally, the ECMO group exhibited significantly reduced levels of PCT, IL6, and CRP, and elevated CD3+% and CD4+% values compared to the control group. In conclusion, the combined therapy demonstrates efficacy in the treatment of patients with SP and respiratory failure, and the immunomagnetic bead-based ELISA method enhances detection efficiency and reduces errors.

Twelve-year trends in unprotected left main coronary artery occlusion: insights from a real-world multicentre study.

Acute myocardial infarction (AMI) resulting from unprotected left main coronary artery (LMCA) occlusion and subtotal occlusion is a life-threatening condition. Although AMI management has improved in the past two decades, there is limited information on recent trends in patient characteristics, management, and outcomes for acute unprotected LMCA-related AMI. This study aims to assess such trends over a 12year period. This retrospective multicentre study includes patients with unprotected LMCA occlusion/subtotal occlusion admitted to three tertiary hospitals between 2008 and 2020. The patients were divided into two groups based on the chronology of presentation: a 'past group' (January 2008 to December 2014) and a 'contemporary group' (January 2015 to December 2020). The study compares clinical characteristics, management approaches, and outcomes between the two groups. The study includes 128 patients, with 51 (40%) in the 'past group' and 77 (60%) in the 'contemporary group'. Baseline risk factors did not show statistically significant differences between the two groups, except for hypertension (49% vs. 74%; P=0.005). Chest pain was more frequent in the 'past group' (98% vs. 89%; P=0.014), and a trend towards more cardiac arrests was observed in the 'contemporary group' (18% vs. 31%; P=0.087). Revascularization type did not differ significantly (P=0.419), but manual thrombectomy was less frequently used (41% vs. 23%; P=0.032) and stent implantation showed a trend towards higher rates (66% vs. 78%; P=0.150) in the 'contemporary cohort'. There was a gradual shift from bare-metal to drug-eluting stents, with a significantly higher percentage of ticagrelor/prasugrel loading in the 'contemporary cohort' (5% vs. 79%; P<0.001). The use of mechanical circulatory support (MCS), although not statistically significant, was higher among patients in the 'past group' (67% vs. 51%; P=0.073). The type of MCS differed significantly between groups, with a decrease in intra-aortic balloon pump use (67% vs. 42%; P=0.005) and an increase in veno-arterial extracorporeal membrane oxygenation (4% vs. 22%; P=0.005) and Impella system (0% vs. 3%) over time. Survival analysis showed no significant differences (P=0.599; log-rank test) in all-cause mortality between the different time groups, with the long-term survival rate being approximately 30%. In our real-world population, despite the progressive use of newer drugs and more advanced devices over time, patients with unprotected LMCA occlusion/subtotal occlusion remain a subpopulation with poor prognosis.

The Jena Method: Perfusionist Independent, Standby Wet-Primed Extracorporeal Membrane Oxygenation (ECMO) Circuit for Immediate Catheterization Laboratory and/or Hybrid Operating Room Deployment.

Background: The timely initiation of extracorporeal membrane oxygenation (ECMO) is crucial for providing life support. However, delays can occur when perfusionists are not readily available. The Jena Method aims to address this issue by offering a wet-primed ECMO system that can be rapidly established without the perfusionist's presence. Methods: The goal was to ensure prompt ECMO initiation while maintaining patient safety. The method focuses on meeting hygienic standards, safe primed storage of the circuit, staff training, and providing clear step-by-step instructions for the ECMO unit. Results: Since implementing the Jena Method in 2015, 306 patients received VA-ECMO treatment. Bacterial tests confirmed the sterility of the primed ECMO circuits during a 14-day period. The functionality of all the components of the primed ECMO circuit after 14 days, especially the pump and oxygenator, were thoroughly checked and no malfunction was found to this day. To train staff for independent ECMO initiation, a step-by-step system involves safely bringing the ECMO unit to the intervention site and establishing all connections. This includes powering up, managing recirculation, de-airing the system, and preparing it for cannula connection. A self-developed picture-based guide assists in this process. New staff members learn from colleagues and receive quarterly training sessions by perfusionists. After ECMO deployment, the perfusionist provides a new primed system for a potential next patient. Conclusions: Establishing a permanently wet-primed on-demand extracorporeal life support circuit without direct perfusionist support is feasible and safe. The Jena Method enables rapid ECMO deployment and has the potential to be adopted in emergency departments as well.

The outcomes of a standardized protocol for extracorporeal mechanical circulatory support selection-left ventricular challenge protocol.

There are no criteria for surgical mechanical circulatory system (MCS) selection for acute heart failure. Since 2021, we have utilized cardiopulmonary bypass system to assess patients' heart and lung condition to inform surgical MCS selection. we aimed to retrospectively analyze the outcomes of treatments administered using our protocol. We analyzed the data of 19 patients who underwent surgical MCS implantation. We compared patients' characteristics across the biventricular-assist device (BiVAD), central Y-Y extracorporeal membrane oxygenation (ECMO), central ECMO, and left VAD (LVAD) systems. Patients' diagnoses included fulminant myocarditis (47.4%), dilated cardiomyopathy (21.1%), acute myocardial infarction (15.8%), infarction from aortic dissection (5.3%), doxorubicin-related cardiomyopathy (5.3%), and tachycardia-induced myocarditis (5.3%). Eight patients (42.1%) underwent LVAD implantation, 1 (5.2%) underwent central ECMO, 4 (21.1%) underwent BiVAD implantation, and 6 (31.6%) underwent central Y-Y ECMO. 48h after surgery, both the pulmonary arterial and right atrial pressures were effectively controlled, with median values being 19.0mmHg and 9.0mmHg, respectively. No patients transitioned from LVAD to BiVAD in the delayed period. Cerebrovascular events occurred in 21.1%. Successful weaning was achieved in 11 patients (57.9%), and 5 patients (26.3%) were converted to durable LVAD. Two-year cumulative survival was 84.2%. Our protocol showed good results for device selection in patients with heart failure, and device selection according to this protocol enabled good control of the pulmonary and systemic circulations.

A novel tunable polypropylene hollow fiber membrane with gradient structure for extracorporeal membrane oxygenation applications

High gas permeability and excellent resistance to plasma leakage are expected from polypropylene (PP) hollow fiber membranes (HFMs) used in extracorporeal membrane oxygenation (ECMO) systems. This study successfully prepared a novel PP HFMs with tunable and gradient structures using oleic acid (OA) and methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate (RhodiasolvⓇ PolarClean) (PL) as binary diluents via the hybrid induced phase separation (HIPS) method. The phase-separation behavior of the PP-OA/PL system was studied using a phase diagram and the resultant membrane structure. As the concentration of PL in the binary diluents increased, the phase separation mechanism changed from solid–liquid (S–L) to liquid–liquid (L–L), and the structure of PP HFMs changed from crystalline to cellular or bi-continuous. Moreover, the effects of PP concentration and air gap distance on the membrane structure and performance were investigated. In particular, the obtained HFMs showed a clear gradient configuration. The results showed that when the PP concentration, OA to PL mass ratio, and air gap were set to 35 wt%, 7/3, and 10 mm, respectively, the PP HFM exhibited the optimal performance with a high N2 permeability of 23.42 ± 0.98 ml/(min cm2 bar) and resistance to simulated plasma leakage of 4300 min.

Post-Mortem Extracorporeal Membrane Oxygenation Perfusion Rat Model: A Feasibility Study.

The development of biomedical soft- or hardware frequently includes testing in animals. However, large efforts have been made to reduce the number of animal experiments, according to the 3Rs principle. Simultaneously, a significant number of surplus animals are euthanized without scientific necessity. The primary aim of this study was to establish a post-mortem rat perfusion model using extracorporeal membrane oxygenation (ECMO) in surplus rat cadavers and generate first post vivo results concerning the oxygenation performance of a recently developed ECMO membrane oxygenator. Four rats were euthanized and connected post-mortem to a venous-arterial ECMO circulation for up to eight hours. Angiographic perfusion proofs, blood gas analyses and blood oxygenation calculations were performed. The mean preparation time for the ECMO system was 791 ± 29 s and sufficient organ perfusion could be maintained for 463 ± 26 min, proofed via angiographic imaging and a mean femoral arterial pressure of 43 ± 17 mmHg. A stable partial oxygen pressure, a 73% rise in arterial oxygen concentration and an exponentially increasing oxygen extraction ratio up to 4.75 times were shown. Considering the 3Rs, the established post-mortal ECMO perfusion rat model using surplus animals represents a promising alternative to models using live animals. Given the preserved organ perfusion, its use could be conceivable for various biomedical device testing.

Abstract 244: Geospatial Access to Extracorporeal Membrane Oxygenation in the United States

Introduction: Extracorporeal Membrane Oxygenation (ECMO) is a form of complete cardiopulmonary support which has been associated with improved survival in both severe acute respiratory distress syndrome and refractory cardiac arrest. ECMO is a resource-intensive therapy limited to specialized centers in urban environments, restricting its availability in suburban and rural areas. We examined the proportion of the U.S. population within a 15-minute, 30-minute, and 45-minute drivetime area to an ECMO-capable center. Methods: Using geographic information systems (GIS), we created shapefiles with polygons representing 15, 30, and 45-minute drivetime areas to ECMO-capable centers. Census block group centroids were then overlaid to determine the proportion of the population with access to ECMO-capable centers. Results: We found that 22%, 52%, and 67% of the U.S. population live within 15, 30, and 45 minutes of ECMO-capable centers, respectively. One hundred and ten million people, more than one third of the U.S. population, live further than 45 minutes away from an ECMO-capable center. Puerto Rico, Wyoming, North Dakota, and Alaska have 0% population access. Texas, California, and Florida have the highest number of people with low access (9, 8, and 5 million, respectively). Conclusion: Population access to ECMO-capable centers in the U.S. is highly variable and limits time-dependent interventions, which are essential for successful deployment of extracorporeal cardiopulmonary resuscitation in refractory cardiac arrest. Our GIS model can be used for future planning of ECMO systems to optimize access for the U.S. population or to comparatively evaluate proposals to improve access.

Safety and Efficacy of Extracorporeal Membrane Oxygenation Heating Units.

Patient temperature during extracorporeal membrane oxygenation (ECMO) is commonly managed by dedicated heating units (HUs) that are integrated into ECMO circuitry. Currently, no HU has received approval for ECMO by the FDA in the United States. Older FDA-approved HUs have been implicated in life-threatening patient infections and are no longer manufactured or available for use in the United States. We performed laboratory tests to evaluate the safety and efficacy of the Micro-Temp and the HTP-1500 HU systems that are potentially suitable for use in ECMO and describe our initial experience with the HTP-1500 HU after being placed in clinical service. Both units demonstrated similar heating efficacy, with the HTP-1500 achieving steady-state temperature approximately 5 h earlier than the Micro-Temp. Microorganisms were detected in the water compartment of all HUs prior to and after performing the manufacturer's recommended cleaning procedure, and after implementation of the HTP-1500 into clinical use we observed a decrease in the rate of bloodstream infection/ECMO days which did not reach statistical significance. Based on the results of this analysis and our institutional experience, we believe that integration of the HTP-1500 HU, an easily replaceable HU, into ECMO systems may reduce the risk of bacterial contamination and thus nosocomial infection when the devices are cleaned and maintained according to manufacturer's guidelines.

Experience in applied veno-arterial extracorporeal membrane oxygenation to support catheter ablation of malignant ventricular tachycardia

BackgroundAn electrical storm due to malignant ventricular tachycardia (VT) is a life-threatening condition that requires catheter ablation (CA). Most VT arrhythmias evolve over time after acute myocardial infarction, coronary artery bypass grafting, or chronic heart failure. Clinically, only radiofrequency ablation can identify and block all arrhythmia origin points. The procedure necessitates continuous VT induction in patients, resulting in hemodynamic instability; therefore, extracorporeal membrane oxygenation (ECMO) support is required. Earlier studies have reported substantial mortality rates; however, our results are significantly more favorable. In this study, we combined the minimally invasive extracorporeal circulation (MiECC) approach with ECMO to preserve an appropriate ECMO flow rate, thus reducing intraoperative left heart afterload. We report 21 cases illustrating the usefulness of modified veno-arterial (VA)-ECMO in this scenario. MethodsData of 21 patients supported by the modified VA-ECMO system (MiECC approach combined with the ECMO system) during VT CA in the Wuhan Asia Heart Hospital between June 2020 and July 2021 were reviewed retrospectively. ResultsSuccessful ablation was achieved in 20 out of 21 patients (95%). The median time for ECMO implantation was 206 min. Only two patients experienced complications post-treatment. All patients made complete recovery and were discharged. All patients were alive at the 1-year-follow-up. ConclusionsOur modified VA-ECMO system helped restore systemic circulation in patients experiencing an electrical storm, thus achieving greater electrical stability during VT CA. Pre-insertion of VA-ECMO can achieve even better results.

Computational fluid dynamics-based design and invitro characterization of a novel pediatric pump-lung.

Although extracorporeal membrane oxygenation (ECMO) has been used to provide temporary support for pediatric patients suffering severe respiratory or cardiac failure since 1970, ECMO systems specifically designed for pediatric patients, particularly for long-term use, remain an unmet clinical need. We sought to develop a new pediatric ECMO system, that is, pediatric pump-lung (PPL), consisting of a unique cylinder oxygenator with an outside-in radial flow path and a centrifugal pump. Computational fluid dynamics was used to analyze the blood fluid field for optimized biocompatible and gas exchange performances in terms of flow characteristics, hemolysis, and gas transfer efficiency. Ovine blood was used for invitro hemolysis and gas transfer testing. Both the computational and experimental data showed that the pressure drop through the PPL's oxygenator is significantly low, even at a flow rate of more than 3.5 L/min. The PPL showed better hemolysis performance than a commercial ECMO circuit consisting of the Quadrox-iD pediatric oxygenator and the Rotaflow pump at a 3.5 L/min flow rate and 250 mm Hg afterload pressure. The oxygen transfer rate of the PPL can reach over 200 mL/min at a flow rate of 3.5 L/min. The PPL has the potential to provide adequate blood pumping and excellent respiratory support with minimal risk of hemolysis for a wide range of pediatric patients.

Risk factors for cannula-associated arterial thrombosis following extracorporeal membrane oxygenation support: a retrospective study.

Hemostatic dysfunction during extracorporeal membrane oxygenation (ECMO) due to blood-circuit interaction and the consequences of shear stress imposed by flow rates lead to rapid coagulation cascade and thrombus formation in the ECMO system and blood vessels. We aimed to identify the incidence and risk factors for cannula-associated arterial thrombosis (CaAT) post-decannulation. A retrospective study of patients undergoing arterial cannula removal following ECMO was performed. We evaluated the incidence of CaAT and compared the characteristics, ECMO machine parameters, cannula sizes, number of blood products transfused during ECMO, and daily hemostasis parameters in patients with and without CaAT. Multivariate analysis identified the risk factors for CaAT. Forty-seven patients requiring venoarterial ECMO (VA-ECMO) or hybrid methods were recruited for thrombosis screening. The median Sequential Organ Failure Assessment score was 11 (interquartile range, 8-13). CaAT occurred in 29 patients (61.7%), with thrombosis in the superficial femoral artery accounting for 51.7% of cases. The rate of limb ischemia complications in the CaAT group was 17.2%. Multivariate analysis determined that the ECMO flow rate-body surface area (BSA) ratio (100 ml/min/m2) was an independent factor for CaAT, with an odds ratio of 0.79 (95% confidence interval, 0.66-0.95; P=0.014). We found that the incidence of CaAT was 61.7% following successful decannulation from VA-ECMO or hybrid modes, and the ECMO flow rate-BSA ratio was an independent risk factor for CaAT. We suggest screening for arterial thrombosis following VA-ECMO, and further research is needed to determine the risks and benefits of such screening.

The effects of nitric oxide on coagulation and inflammation in ex vivo models of extracorporeal membrane oxygenation and cardiopulmonary bypass.

Extracorporeal life support (ECLS) has extensive applications in managing patients with acute cardiac and pulmonary failure. Two primary modalities of ECLS, cardiopulmonary bypass (CPB) and extracorporeal membrane oxygenation (ECMO), include several similarities in their composition, complications, and patient outcomes. Both CPB and ECMO pose a high risk of thrombus formation and platelet activation due to the large surface area of the devices and bleeding due to system anticoagulation. Therefore, novel methods of anticoagulation are needed to reduce the morbidity and mortality associated with extracorporeal support. Nitric oxide (NO) has potent antiplatelet properties and presents a promising alternative or addition to anticoagulation with heparin during extracorporeal support. We developed two ex vivo models of CPB and ECMO to investigate NO effects on anticoagulation and inflammation in these systems. Sole addition of NO as an anticoagulant was not successful in preventing thrombus formation in the ex vivo setups, therefore a combination of low-level heparin with NO was used. Antiplatelet effects were observed in the ex vivo ECMO model when NO was delivered at 80 ppm. Platelet count was preserved after 480 min when NO was delivered at 30 ppm. Combined delivery of NO and heparin did not improve haemocompatibility in either ex vivo model of CPB and ECMO. Anti-inflammatory effects of NO in ECMO systems have to be evaluated further.

Predicting Survival in Extracorporeal Membrane Oxygenation Patients With Optical Microcirculation Sensing

In this study, we propose a novel method to use functional near-infrared spectroscopy (NIRS) to monitor patients' lower limb microcirculation with extracorporeal membrane oxygenation (ECMO). We controlled the ECMO system's speed and measured hemodynamics using NIRS devices which attached to both calves at approximately 60% of the tibia length. Features from the collected blood oxygen data were extracted and utilized as machine learning inputs for classification. The patients were divided into two groups based on discharge and mortality. In venovenous (VV) ECMO, we found that the construction of the classification model based on the characteristics of this type with better discriminating ability can effectively distinguish the two groups.