-
PloS One 2022Current methods for identification of oxygenator clotting during prolonged extracorporeal life support include visual inspection, evaluation of oxygenator resistance and...
Current methods for identification of oxygenator clotting during prolonged extracorporeal life support include visual inspection, evaluation of oxygenator resistance and oxygen exchange performance, and assessment of clotting-related laboratory parameters. However, these observations do not provide a quantitative assessment of oxygenator clot formation. By measuring changes in the dynamic oxygenator blood volume this study aimed to evaluate the relation to oxygenator resistance and oxygen transfer performance. Sixty-seven oxygenators were studied during adult extracorporeal life support. Oxygenator blood volume, oxygenator resistance, and oxygen transfer efficiency were monitored. Oxygenator blood volume decreased with increasing runtime (r = -0.462; p <0.001). There was a statistically significant, fair negative correlation between oxygenator blood volume and oxygenator resistance (r = -0.476; p<0.001) in all oxygenators, which became stronger analyzing only exchanged oxygenators (r = -0.680; p<0.001) and oxygenators with an oxygenator blood volume <187 mL (r = 0.831; p<0.001). No relevant correlation between oxygenator blood volume and O2 transfer was found. Oxygenator blood volume declined over time and was clearly associated with an increasing oxygenator resistance during prolonged extracorporeal life support, though O2 transfer was less affected.
Topics: Adult; Blood Volume; Carbon Dioxide; Extracorporeal Membrane Oxygenation; Female; Humans; Male; Middle Aged; Monitoring, Physiologic; Oxygen; Oxygenators; Regional Blood Flow
PubMed: 35108345
DOI: 10.1371/journal.pone.0263360 -
Journal of Cardiothoracic and Vascular... May 1997The natural lung is the organ responsible for oxygen and carbon dioxide exchange between the blood and the outside environment. This function is accomplished by the... (Review)
Review
The natural lung is the organ responsible for oxygen and carbon dioxide exchange between the blood and the outside environment. This function is accomplished by the large surface area and high permeability of the gas exchange interface, the alveolar-capillary membrane. These same features are fundamental to the design of an artificial lung, or oxygenator. Additional lung-like features essential to the design of an ideal oxygenator include the ability to achieve balanced oxygen and carbon dioxide exchange with minimal blood damage and blood activation. The purpose of this review is to present the past and current developments of the oxygenator designs in terms of the structural and functional features of the natural lung as well as the limitations in the ability to mimic the features of the lung because of the lack of appropriate technology.
Topics: Capillaries; Carbon Dioxide; Equipment Design; Hemorheology; Humans; Lung; Oxygen; Oxygenators; Oxygenators, Membrane; Permeability; Pulmonary Alveoli; Pulmonary Gas Exchange
PubMed: 9161895
DOI: 10.1016/s1053-0770(97)90096-3 -
Targeted Oncology Dec 2012Hypoxia is a critical hallmark of solid tumors and involves enhanced cell survival, angiogenesis, glycolytic metabolism, and metastasis. Hyperbaric oxygen (HBO)... (Review)
Review
Hypoxia is a critical hallmark of solid tumors and involves enhanced cell survival, angiogenesis, glycolytic metabolism, and metastasis. Hyperbaric oxygen (HBO) treatment has for centuries been used to improve or cure disorders involving hypoxia and ischemia, by enhancing the amount of dissolved oxygen in the plasma and thereby increasing O(2) delivery to the tissue. Studies on HBO and cancer have up to recently focused on whether enhanced oxygen acts as a cancer promoter or not. As oxygen is believed to be required for all the major processes of wound healing, one feared that the effects of HBO would be applicable to cancer tissue as well and promote cancer growth. Furthermore, one also feared that exposing patients who had been treated for cancer, to HBO, would lead to recurrence. Nevertheless, two systematic reviews on HBO and cancer have concluded that the use of HBO in patients with malignancies is considered safe. To supplement the previous reviews, we have summarized the work performed on HBO and cancer in the period 2004-2012. Based on the present as well as previous reviews, there is no evidence indicating that HBO neither acts as a stimulator of tumor growth nor as an enhancer of recurrence. On the other hand, there is evidence that implies that HBO might have tumor-inhibitory effects in certain cancer subtypes, and we thus strongly believe that we need to expand our knowledge on the effect and the mechanisms behind tumor oxygenation.
Topics: Animals; Cell Hypoxia; Cell Respiration; Clinical Trials as Topic; Humans; Hyperbaric Oxygenation; Neoplasms; Oxygen
PubMed: 23054400
DOI: 10.1007/s11523-012-0233-x -
Artificial Organs Nov 2022Training is an essential aspect of providing high-quality treatment and ensuring patient safety in any medical practice. Because extracorporeal membrane oxygenation...
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.
Topics: Humans; Extracorporeal Membrane Oxygenation; Oxygenators; Simulation Training; Lung; Computer Simulation; Oxygenators, Membrane
PubMed: 35578949
DOI: 10.1111/aor.14318 -
Journal of Artificial Organs : the... 2004From the 1950s to the 1980s, the most widely used oxygenator in the clinical field was the disposable bubble oxygenator. However, membrane oxygenators have become the... (Review)
Review
From the 1950s to the 1980s, the most widely used oxygenator in the clinical field was the disposable bubble oxygenator. However, membrane oxygenators have become the preferred clinical choice over the years. In the United States, membrane oxygenators used in cardiopulmonary bypass operations account for the majority of clinical oxygenator use. Membrane oxygenators have an equal capability for oxygenating venous blood compared with other type of oxygenators such as the bubble type and film type; however, the membrane oxygenator requires a smaller volume for priming to achieve a sufficient gas transfer rate and results in less blood trauma such as hemolysis because it uses a similar mechanism to the natural lung. In the 1980s, the first capillary-type oxygenator adopted the system of intracapillary blood perfusion. However, this induced high pressure resistance in the module and caused hemolysis. Thus, at present, capillary oxygenators commonly adopt the system of extracapillary blood perfusion. Microporous hollow-fiber membranes are primarily used for short-term cardiopulmonary bypass application, whereas nonmicroporous hollow-fiber membranes are primarily used for long-term extracorporeal membrane oxgenation application.
Topics: Cardiopulmonary Bypass; Equipment Design; Extracorporeal Membrane Oxygenation; History, 20th Century; Humans; Oxygenators; Oxygenators, Membrane; Pulmonary Gas Exchange
PubMed: 15558331
DOI: 10.1007/s10047-004-0268-6 -
ASAIO Journal (American Society For... Oct 2022Extracorporeal membrane oxygenation (ECMO) has been advancing rapidly due to a combination of rising rates of acute and chronic lung diseases as well as significant...
Extracorporeal membrane oxygenation (ECMO) has been advancing rapidly due to a combination of rising rates of acute and chronic lung diseases as well as significant improvements in the safety and efficacy of this therapeutic modality. However, the complexity of the ECMO blood circuit, and challenges with regard to clotting and bleeding, remain as barriers to further expansion of the technology. Recent advances in microfluidic fabrication techniques, devices, and systems present an opportunity to develop new solutions stemming from the ability to precisely maintain critical dimensions such as gas transfer membrane thickness and blood channel geometries, and to control levels of fluid shear within narrow ranges throughout the cartridge. Here, we present a physiologically inspired multilayer microfluidic oxygenator device that mimics physiologic blood flow patterns not only within individual layers but throughout a stacked device. Multiple layers of this microchannel device are integrated with a three-dimensional physiologically inspired distribution manifold that ensures smooth flow throughout the entire stacked device, including the critical entry and exit regions. We then demonstrate blood flows up to 200 ml/min in a multilayer device, with oxygen transfer rates capable of saturating venous blood, the highest of any microfluidic oxygenator, and a maximum blood flow rate of 480 ml/min in an eight-layer device, higher than any yet reported in a microfluidic device. Hemocompatibility and large animal studies utilizing these prototype devices are planned. Supplemental Visual Abstract, http://links.lww.com/ASAIO/A769.
Topics: Animals; Biomimetics; Equipment Design; Microfluidics; Oxygen; Oxygenators
PubMed: 36194101
DOI: 10.1097/MAT.0000000000001647 -
The International Journal of Artificial... Nov 2022Oxygenator exchange during extracorporeal membrane oxygenation (ECMO) is a life-threatening procedure. D-dimer has been used to predict oxygenator failure, but it is a...
INTRODUCTION
Oxygenator exchange during extracorporeal membrane oxygenation (ECMO) is a life-threatening procedure. D-dimer has been used to predict oxygenator failure, but it is a parameter used a few days before oxygenator exchange. This study investigated parameters before and immediately after ECMO initiation that predict oxygenator exchange.
METHODS
This was a single-center, retrospective study of 28 patients who received veno-venous ECMO with heparin/silicone-coated polypropylene oxygenator (NSH-R HPO-23WH-C; Senko Medical Inc., Tokyo, Japan), due to acute respiratory failure, from April 2015 to March 2020. Clinical data before ECMO initiation and during the first 3 days on ECMO were compared between the patients with oxygenator exchange (exchange group) and those without oxygenator exchange (non-exchange group).
RESULTS
Nine (32%) patients required oxygenator exchange. The exchange group had significantly higher white blood cell count (WBC) (16,944 ± 2423/µL vs 10,342 ± 1442/µL, < 0.05) and Acute Physiology and Chronic Health Evaluation (APACHE) II score (31 ± 5 vs 25 ± 8, < 0.05) before ECMO initiation than the non-exchange group. The partial pressure of oxygen at the outlet of the oxygenator (PO) and activated partial thromboplastin time (aPTT) during the first 3 days on ECMO were significantly lower in the exchange group than in the non-exchange group.
CONCLUSIONS
High WBC and APACHE II score before ECMO initiation, low PO, and aPTT during the first 3 days on ECMO were associated with oxygenator exchange during veno-venous ECMO. These parameters could be used to avoid unexpected oxygenator exchange.
Topics: Extracorporeal Membrane Oxygenation; Heparin; Humans; Oxygen; Oxygenators; Polypropylenes; Retrospective Studies; Silicones
PubMed: 35982583
DOI: 10.1177/03913988221118382 -
The Surgical Clinics of North America Oct 1974
Review
Topics: Blood; Catheterization; Extracorporeal Circulation; Hematocrit; Heparin; Humans; Hydrogen-Ion Concentration; Intensive Care Units; Lung Diseases; Oxygen; Oxygenators, Membrane; Positive-Pressure Respiration; Pulmonary Circulation; Respiratory Insufficiency; Workforce
PubMed: 4608966
DOI: 10.1016/s0039-6109(16)40445-7 -
Annals of Biomedical Engineering Dec 2021Oxygenator thrombosis during extracorporeal membrane oxygenation (ECMO), is a complication that necessitates component replacement. ECMO centers monitor clot burden by...
Oxygenator thrombosis during extracorporeal membrane oxygenation (ECMO), is a complication that necessitates component replacement. ECMO centers monitor clot burden by intermittent measurement of pressure drop across the oxygenator. An increase in pressure drop at a preset flow rate suggests an increase in resistance/clot formation within the oxygenator. This monitoring method comes with inherent disadvantages such as monitoring gaps, and increased risk of air embolism and infection. We explored utilizing flow measurement, which avoids such risks, as an indicator of ECMO circuit obstructions. The hypothesis that flow rate through a shunt tube in the circuit will increase as distal resistances in the circuit increases was tested. We experimentally simulated controlled levels of oxygenator obstructions using glass microspheres in an ex vivo veno-venous ECMO circuit and measured the change in shunt flow rate using over the tube ultra-sound flow probes. A mathematical model was also used to study the effect of distal resistances in the ECMO circuit on shunt flow. Results of both the mathematical model and the experiments showed a clear and measurable increase in shunt flow with increasing levels of oxygenator obstruction. Therefore, flow monitoring appears to be an effective non-contact and continuous method to monitor for obstruction during ECMO.
Topics: Blood Circulation; Equipment Failure; Extracorporeal Membrane Oxygenation; Humans; Models, Statistical; Oxygen; Oxygenators, Membrane
PubMed: 34705123
DOI: 10.1007/s10439-021-02878-w -
Journal of Cardiothoracic Surgery Mar 2023The management of the oxygenator can be prolonged in the long-term procedures especially during extracorporeal membrane oxygenation (ECMO) for bridge to transplant or...
BACKGROUND
The management of the oxygenator can be prolonged in the long-term procedures especially during extracorporeal membrane oxygenation (ECMO) for bridge to transplant or bridge to recovery. Long-term use often involves an overrun of the time of use with respect to certification of the oxygenating module of 14 days, for the maintenance of performance and efficiency of the oxygenator. The evaluation of the long-term oxygenator efficiency is complex and depends on the: patient pathology, ECMO configuration, the management of coagulation and anticoagulation, materials selection and circuit components, the structure, design and performance of the oxygenator. In this context we investgated the long-term performance of the A.L.ONE Eurosets ECMO oxygenator in relation to the parameters prodromal to replacement.
METHODS
We retrospectively collected eight years data from Anthea Hospital GVM Care & Research, Bari, Italy on the long-term use exceeding 14 days of Eurosets A.L.ONE ECMO Adult oxygenator in Polymetylpentene fiber, for ECMO procedures, including the procedures: Veno Arterial (VA) ECMO post-cardiotomy or not, veno-venous (VV) ECMO. The primary end points were the evaluation of Gas Transfer: oxygen partial pressure (PO) post oxygenator, Carbon dioxide partial pressure (PCO) post oxygenator, the oxygen transfer across the oxygenator membrane V'O, differential CO content across oxygenator; Pressure monitoring: oxygenator pressure Drop in relation to Blood flow rate (BFR) (ΔP); Hematologic values: Hemoglobin, Fibrinogen, Platelets, aPTT, D-Dimer, LDH.
RESULTS
Nine VA ECMO patients who used the oxygenator for 18.5 days and two VV ECMO patients who used the oxygenators for 17.2 days on the seventeenth days reported average values PaO (267 ± 29 mmHg); PaCO (34 ± 4 mmHg) with gas blender values set to 3.8 ± 0.6 L/min of air and a FiO of 78 ± 5%; the transfer across the oxygenator membrane V'O was 189 ± 43 (ml/min/m). The mean peak of partial pressure of carbon dioxide from the gas exhaust of oxygenator (PCO) was 38 ± 4 mmHg; differential CO across the oxygenator "pre-oxygenator PCO-post-oxygenator PCO" (18 ± 6 mmHg); the mean blood flow rate (BFR) 4.5 ± 0.6 (L/minute); the pump revolution per minutes mean maximum rate was 4254 ± 345 (RPM); the mean pressure drop (ΔP) was 76 ± 12 mmHg; the mean peak of d-dimers (DDs) was 23.6 ± 0.8 mg / dL; the mean peak of LDH was 230 ± 55 (mg/dl); fibrinogen mean peak 223 ± 40 (mg/dl).
CONCLUSIONS
The performance of the Eurosets A.L.ONE ECMO Adult polymethylpentene fiber oxygenator in our experience has proven efficiency in terms of O uptake and CO removal, blood fluid dynamics, metabolic compensation and heat exchange in the long-term treatment. The device was safe without iatrogenic problems over a period of 14 days in the patients undergoing ECMO VA and in all patients undergoing VV ECMO with continuous administration of anticoagulation therapy.
Topics: Humans; Adult; Extracorporeal Membrane Oxygenation; Carbon Dioxide; Retrospective Studies; Oxygenators, Membrane; Oxygen
PubMed: 36998079
DOI: 10.1186/s13019-023-02190-9