Membrane oxygenator longevity was higher in argatroban-treated patients undergoing vvECMO.

BACKGROUND: In severe acute respiratory distress syndrome (ARDS), venovenous extracorporeal membrane oxygenation (vvECMO) can be a lifesaver. However, anticoagulation therapy is mandatory because the nonendothelial extracorporeal surface increases the risk of thromboembolic problems. Heparin is still the most common anticoagulant, but argatroban could be an alternative. This work investigates whether argatroban offers a therapeutic advantage over heparin during vvECMO. METHODS: We performed a retrospective cohort study of patients who underwent vvECMO for severe ARDS and received heparin or argatroban as anticoagulation therapy. Demographic variables, intensive care unit (ICU) treatment and outcome parameters were evaluated. The primary outcome parameter was the operating time of the membrane oxygenator normalized to the duration of vvECMO treatment. Secondary outcome parameters were transfusion requirements normalized to the duration of vvECMO therapy. RESULTS: Fifty seven patients from January 2019 to February 2021 underwent vvECMO and were included in this study. Thirty three patients received heparin and 24 patients argatroban as anticoagulatory therapy. The groups did not differ in demographics, ICU scoring systems, or comorbidities. Platelet counts and partial prothrombin time did not differ between the two groups during the first 6 days of vvECMO. The argatroban group had lower requirements for red blood cells, platelets and fresh frozen plasma. The mean runtime of the individual membrane oxygenator increased from 12.3 days (heparin group) to 16.6 days in the argatroban group. CONCLUSIONS: Our findings suggest that argatroban can be considered as anticoagulant during vvECMO.

Mortality rate in patients with SAR-COV-2 infection treated with extracorporeal membrane oxygenator: A systematic review and meta-analysis.

BACKGROUND: Extracorporeal membrane oxygenator (ECMO) is one of the life-saving modalities for the treatment of multiple organs dysfunction, particularly the heart and the lungs. OBJECTIVE: To evaluate the benefit of ECMO for the treatment of SAR-COV-2 infection and its outcomes, complications, and mortality rate. METHODS: A comprehensive search for articles was performed using MEDLINE and SCOPUS from December 2019 to December 2020. Two independent reviewers selected eligible studies, extracted the data, assessed the quality of the studies, reviewed the full study protocols, and reported the findings according to the PRISMA protocol. The meta-analyses were performed using the Comprehensive Meta-Analysis software version 2.0. RESULTS: Pooled data from 57 studies was analyzed. There were 7,035 patients with SAR-COV-2 infection with event rate of ECMO treatment was 58.10% (95%CI: 43.70-71.20). The mortality rate was 16.66% (95%CI: 11.49-23.53). The mean mortality rate of ECMO supported patients was 35.60% (95%CI: 30.60 to 41.00). Thirty-one percent (95%CI: 24.50-38.40) of the patients had venous thromboembolic events, 30.90% (95%CI: 17.90-47.80) of the patients had ECMO circuit thrombosis, and 24.50% (95%CI: 12.50-42.40) of the patients had bleeding. In the subgroup analysis, the mortality rate was higher among patients who were treated with ECMO, the pooled odds ratio was 4.47 (95%CI: 2.39-8.35, p < 0.001), and was significantly higher in Asia with an odds ratio of 7.88 (95%CI: 2.40-25.85, p = 0.001). CONCLUSION: Mortality rate among patients who received ECMO therapy was high. A system of care, including patient selection, resource management and referral system, can impact the outcomes of ECMO therapy.

IoT-based mock oxygenator for extracorporeal membrane oxygenation simulator.

BACKGROUND: Training is an essential aspect of providing high-quality treatment and ensuring patient safety in any medical practice. Because extracorporeal membrane oxygenation (ECMO) is a complicated operation with various elements, variables, and irregular situations, doctors must be experienced and knowledgeable about all conventional protocols and emergency procedures. The conventional simulation approach has a number of limitations. The approach is intrinsically costly since it relies on disposable medical equipment (i.e., oxygenators, heat exchangers, and pumps) that must be replaced regularly due to the damage caused by the liquid used to simulate blood. The oxygenator, which oxygenates the blood through a tailored membrane in ECMO, acts as a replacement for the patient's natural lung. For the context of simulation-based training (SBT) oxygenators are often expensive and cannot be recycled owing to contamination issues. METHODS: Consequently, it is advised that the training process include a simulated version of oxygenators to optimize reusability and decrease training expenses. Toward this goal, this article demonstrates a mock oxygenator for ECMO SBT, designed to precisely replicate the real machine structure and operation. RESULTS: The initial model was reproduced using 3D modeling and printing. Additionally, the mock oxygenator could mimic frequent events such as pump noise and clotting. Furthermore, the oxygenator is integrated with the modular ECMO simulator using cloud-based communication technology that goes in hand with the internet of things technology to provide remote control via an instructor tablet application. CONCLUSIONS: The final 3D modeled oxygenator body was tested and integrated with the other simulation modules at Hamad Medical Corporation with several participants to evaluate the effectiveness of the training session.

Hemocompatibility challenge of membrane oxygenator for artificial lung technology.

The artificial lung (AL) technology is one of the membrane-based artificial organs that partly augments lung functions, i.e. blood oxygenation and CO2 removal. It is generally employed as an extracorporeal membrane oxygenation (ECMO) device to treat acute and chronic lung-failure patients, and the recent outbreak of the COVID-19 pandemic has re-emphasized the importance of this technology. The principal component in AL is the polymeric membrane oxygenator that facilitates the O2/CO2 exchange with the blood. Despite the considerable improvement in anti-thrombogenic biomaterials in other applications (e.g., stents), AL research has not advanced at the same rate. This is partly because AL research requires interdisciplinary knowledge in biomaterials and membrane technology. Some of the promising biomaterials with reasonable hemocompatibility - such as emerging fluoropolymers of extremely low surface energy - must first be fabricated into membranes to exhibit effective gas exchange performance. As AL membranes must also demonstrate high hemocompatibility in tandem, it is essential to test the membranes using in-vitro hemocompatibility experiments before in-vivo test. Hence, it is vital to have a reliable in-vitro experimental protocol that can be reasonably correlated with the in-vivo results. However, current in-vitro AL studies are unsystematic to allow a consistent comparison with in-vivo results. More specifically, current literature on AL biomaterial in-vitro hemocompatibility data are not quantitatively comparable due to the use of unstandardized and unreliable protocols. Such a wide gap has been the main bottleneck in the improvement of AL research, preventing promising biomaterials from reaching clinical trials. This review summarizes the current state-of-the-art and status of AL technology from membrane researcher perspectives. Particularly, most of the reported in-vitro experiments to assess AL membrane hemocompatibility are compiled and critically compared to suggest the most reliable method suitable for AL biomaterial research. Also, a brief review of current approaches to improve AL hemocompatibility is summarized. STATEMENT OF SIGNIFICANCE: The importance of Artificial Lung (AL) technology has been re-emphasized in the time of the COVID-19 pandemic. The utmost bottleneck in the current AL technology is the poor hemocompatibility of the polymer membrane used for O2/CO2 gas exchange, limiting its use in the long-term. Unfortunately, most of the in-vitro AL experiments are unsystematic, irreproducible, and unreliable. There are no standardized in-vitro hemocompatibility characterization protocols for quantitative comparison between AL biomaterials. In this review, we tackled this bottleneck by compiling the scattered in-vitro data and suggesting the most suitable experimental protocol to obtain reliable and comparable hemocompatibility results. To the best of our knowledge, this is the first review paper focusing on the hemocompatibility challenge of AL technology.

Injection of Recombinant Tissue Plasminogen Activator into Extracorporeal Membrane Oxygenators Postpones Oxygenator Exchange in COVID-19.

Coronavirus disease 2019 (COVID-19) has drastically increased the number of patients requiring extracorporeal life support. We investigate the efficacy and safety of low-dose recombinant tissue-type plasminogen activator (rtPA) injection into exhausted oxygenators to delay exchange in critically ill COVID-19 patients on veno-venous extracorporeal membrane oxygenation (V-V ECMO). Small doses of rtPA were injected directly into the draining section of a V-V ECMO circuit. We compared transmembrane pressure gradient, pump head efficiency, membrane arterial partial oxygen pressure, and membrane arterial partial carbon dioxide pressure before and after the procedure. Bleeding was compared with a matched control group of 20 COVID-19 patients on V-V ECMO receiving standard anticoagulation. Four patients received 16 oxygenator instillations with rtPA at 5, 10, or 20 mg per dose. Administration of rtPA significantly reduced transmembrane pressure gradient (Δ pm = 54.8 ± 18.1 mmHg before vs . 38.3 ± 13.3 mmHg after, p < 0.001) in a dose-dependent manner (Pearson's R -0.63, p = 0.023), allowing to delay oxygenator exchange, thus reducing the overall number of consumed oxygenators. rtPA increased blood flow efficiency η (1.20 ± 0.28 ml/revolution before vs . 1.24 ± 0.27 ml/r, p = 0.002). Lysis did not affect membrane blood gases or systemic coagulation. Minor bleeding occurred in 2 of 4 patients (50%) receiving oxygenator lysis as well as 19 of 20 control patients (95%). Lysis of ECMO oxygenators effectively delays oxygenator exchange, if exchange is indicated by an increase in transmembrane pressure gradient. Application of lysis did not result in higher bleeding incidences compared with anticoagulated patients on V-V ECMO for COVID-19.

Lean Ad hoc Extracorporeal Membrane Oxygenation Systems for COVID-19.

Coronavirus disease (COVID-19) is overwhelming hospitals with patients requiring respiratory support, including ventilators and Extracorporeal Membrane Oxygenation (ECMO). Bottlenecks in device availability may contribute to mortality, and limited device availability even in ECMO centers has led to rationing recommendations. Therefore, we explored options for ad hoc construction of venovenous ECMO using readily available components, essentially, large cannulas, membrane oxygenators, and blood pumps. As thousands of certified cardiac Impella pumps are distributed worldwide, we assembled lean ECMO by embedding Impella pumps coaxially in tubes, combined with standard gas exchangers. Ad hoc integration of Impella blood pumps with gas exchange modules, large-bore venous cannulas, regular ECMO tubing, Y-pieces, and connectors led to lean ECMO systems with stable performance over several days. Oxygenation of 2.5-5 L of blood per minute is realistic. Benefit/risk analysis appears favorable if a patient needs respiratory support but required support systems in a center are exhausted. Ad hoc assembly of venovenous ECMO is feasible using Impella blood pumps, results in stable blood flow across gas exchange modules, and thus may offer another opportunity to oxygenate, "recover the lungs" and hopefully save lives in selected patients with severe COVID-19 disease even when conventional life support equipment is exhausted. The lean design also yields inspirations for future ECMO systems.

A Simple Approach for Gas Blender on Extracorporeal Membrane Oxygenation in Resource Shortage Context.

With the massive influx of patients during COVID-19 pandemic into intensive care unit, resources have quickly been stretched to the limit, including extracorporeal membrane oxygenation (ECMO). Gas blender attached to ECMO is used to allow precise adjustment of characteristics of fresh gas flow, that is, blood oxygen delivery and carbon dioxide removal. To cope with the gas blender shortage, we describe a back-up system set up in our French tertiary referral ECMO center using air and oxygen flowmeters. A table has been created to facilitate medical prescription but also nurse monitoring. This extraordinary situation forces physicians to adapt medical devices, and that could be useful in future viral pandemics.