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Thorax Jan 1974, 121-124. A method of providing long-term pulmonary support without the use of an artificial oxygenator or systemic heparinization was investigated. Three groups of...
, 121-124. A method of providing long-term pulmonary support without the use of an artificial oxygenator or systemic heparinization was investigated. Three groups of experiments were performed. Group I determined the bypass flow and blood oxygenator requirements of apnoeic animals supported by venovenous bypass. Group II and III experiments evaluated two different methods of oxygenating apnoeic test animals from adjacent parabiotic support animals. It was determined that a venovenous bypass ratio equal to cardiac output and a Po of venous return blood of 150 mmHg was required to maintain satisfactory blood gases. These parameters were provided by support animals and sustained total respiratory support of the test animals for 48 hours.
Topics: Animals; Carbon Dioxide; Cardiac Catheterization; Cardiac Output; Dogs; Extracorporeal Circulation; Femoral Artery; Jugular Veins; Oxygen; Oxygenators; Parabiosis; Partial Pressure
PubMed: 4825543
DOI: 10.1136/thx.29.1.121 -
American Journal of Surgery Apr 1984The new Travenol oxygenator is composed of 80 parallel blood pathways. Microporous membrane separates the blood and gas compartments. The membrane surface area is 3 m2,...
The new Travenol oxygenator is composed of 80 parallel blood pathways. Microporous membrane separates the blood and gas compartments. The membrane surface area is 3 m2, with a pore size of 0.01 microns. Venous blood drains directly from the patient through the oxygenator, then through an integral heat exchanger and into a reservoir, from which a single arterial pump returns the blood to the patient. The advantage of this configuration of membrane oxygenator is simplicity of setup and operation. A disadvantage that we have observed is an apparent variation in resistance to blood flow through the oxygenator during clinical perfusion. Construction changes in a later version of the oxygenator have reduced the resistance to flow through the blood pathway. This device has been used for 20 perfusions at moderate hypothermia (mean 31.8 degrees C) in patients up to 2.1 m2 body surface area for up to 313 minutes. Blood flow was 2.1 to 5.6 liters/min, partial arterial oxygen pressure 100 to 394 torr, partial arterial carbon dioxide pressure 19 to 57 torr (mean 37 torr) and, arterial pH 7.29 to 7.56 (mean 7.41). Oxygen transfer was as high as 230 ml/min. This integral oxygenator-heat exchanger-reservoir is operated like a bubble oxygenator, with direct venous drainage through the device and a single pump, but it uses a membrane oxygenator for gas exchange to eliminate the detrimental effects of bubbles.
Topics: Adult; Aged; Carbon Dioxide; Cardiac Surgical Procedures; Cardiopulmonary Bypass; Humans; Middle Aged; Oxygen; Oxygenators, Membrane
PubMed: 6424487
DOI: 10.1016/0002-9610(84)90003-5 -
ASAIO Journal (American Society For... 2008Although microporous polypropylene hollow fiber oxygenators are standard devices used for extracorporeal membrane oxygenation (ECMO), they have limitations such as... (Clinical Trial)
Clinical Trial
Extracorporeal membrane oxygenation with a poly-methylpentene oxygenator (Quadrox D). The experience of a single Italian centre in adult patients with refractory cardiogenic shock.
Although microporous polypropylene hollow fiber oxygenators are standard devices used for extracorporeal membrane oxygenation (ECMO), they have limitations such as development of plasma leakage. Poly-methylpentene (PMP) is a new material used for the last generation of oxygenators. We reviewed our experience with a new PMP oxygenator (Quadrox D) and a centrifugal pump (RotaFlow) used to support adult patients with refractory cardiogenic shock. Between January 2000 and April 2007, 25 patients required ECMO for primary or postcardiotomy cardiogenic shock. Eighteen patients were analyzed [mean age 60.2 years; 11 (61%) men; 7 (39%) women]. Nine patients (50%) suffered primary cardiogenic shock. Cardiopulmonary resuscitation was applied in 11 patients (61%) with a mean duration time of 31.5 minutes. Mean ECMO duration time was 7.1 +/- 6.3 days (range, 1-27 days). Intra-aortic balloon pump was used in 13 patients (72.2%) with a mean duration time of 7.7 +/- 5 (range, 2-17 days). Twelve patients (66.7%) survived on ECMO and five patients (27.8%) were discharged. Our results indicate the PMP oxygenator and the centrifugal pump provided acceptable results in terms of surviving on ECMO and discharge. Patients with an initial catastrophic hemodynamic status could benefit by means of a rapid institution of ECMO with PMP oxygenators.
Topics: Adult; Aged; Alkenes; Extracorporeal Membrane Oxygenation; Female; Heart-Assist Devices; Humans; Italy; Male; Middle Aged; Oxygen; Oxygenators; Oxygenators, Membrane; Polymers; Postoperative Complications; Shock, Cardiogenic
PubMed: 18204321
DOI: 10.1097/MAT.0b013e31815ff27e -
The Journal of Extra-corporeal... Sep 2016Gaseous microemboli (GME) are an abnormal physiological occurrence during cardiopulmonary bypass and extracorporeal membrane oxygenation (ECMO). Several studies have...
Gaseous microemboli (GME) are an abnormal physiological occurrence during cardiopulmonary bypass and extracorporeal membrane oxygenation (ECMO). Several studies have correlated negative sequelae with exposure to increased amounts of GME. Hypobaric oxygenation is effective at eliminating GME in hollow-fiber microporous membrane oxygenators. However, hollow-fiber diffusion membrane oxygenators, which are commonly used for ECMO, have yet to be validated. The purpose of this study was to determine if hypobaric oxygenation, compared against normobaric oxygenation, can reduce introduced GME when used on diffusion membrane oxygenators. Comparison of a sealed Quadrox-iD with hypobaric sweep gas (.67 atm) vs. an unmodified Quadrox-iD with normal atmospheric sweep gas (1 atm) in terms of GME transmission during continuous air introduction (50 mL/min) in a recirculating in vitro circuit, over a range of flow rates (3.5, 5 L/min) and crystalloid prime temperatures (37°C, 28°C, and 18°C). GME were measured using three EDAC Doppler probes positioned pre-oxygenator, post-oxygenator, and at the arterial cannula. Hypobaric oxygenation vs. normobaric oxygenation significantly reduced hollow-fiber diffusion membrane oxygenator GME transmission at all combination of pump flows and temperatures. There was further significant reduction in GME count between the oxygenator outlet and at the arterial cannula. Hypobaric oxygenation used on hollow-fiber diffusion membrane oxygenators can further reduce GME compared to normobaric oxygenation. This technique may be a safe approach to eliminate GME during ECMO.
Topics: Blood Component Removal; Cardiopulmonary Bypass; Embolism, Air; Equipment Design; Equipment Failure Analysis; Humans; In Vitro Techniques; Oxygen; Oxygenators, Membrane
PubMed: 27729706
DOI: No ID Found -
Perfusion May 1994
Review
Topics: Carbon Dioxide; Humans; Oxygen; Oxygenators
PubMed: 7949574
DOI: 10.1177/026765919400900308 -
The Journal of Extra-corporeal... Sep 2000This study compares the gas transfer capacity, the blood trauma, and the blood path resistance of the hollow-fiber membrane oxygenator Dideco D 903 with a surface area...
This study compares the gas transfer capacity, the blood trauma, and the blood path resistance of the hollow-fiber membrane oxygenator Dideco D 903 with a surface area of 1.7 m2 (oxygenator 1.7) versus a prototype built on the same principles but with a surface area of 2 m2 (oxygenator 2). Six calves (mean body weight: 68.2 +/- 3.2 kg) were connected to cardiopulmonary bypass (CPB) by jugular venous and carotid arterial cannulation, with a mean flow rate of 4 l/min for 6 h. They were randomly assigned to oxygenator 1.7 (N = 3) or 2 (N = 3). After 7 days, the animals were sacrificed. A standard battery of blood samples was taken before the bypass, throughout the bypass, and 24 h, 48 h, and 7 days after the bypass. The oxygenator 2 group showed significantly better total oxygen and carbon dioxide transfer values throughout the perfusion (p < .001 for both comparison). Hemolytic parameters (lactate dehydrogenase and free plasma hemoglobin) exhibited a slight but significant increase after 5 h of bypass in the oxygenator 1.7 group. The pressure drop through the oxygenator was low in both groups (range, 43-74 mmHg). With this type of hollow-fiber membrane oxygenator, an increased surface of gas exchange from 1.7 m2 to 2 m2 improves gas transfer, with a limited impact on blood trauma and no increase of blood path resistance.
Topics: Animals; Carbon Dioxide; Cardiopulmonary Bypass; Cattle; Medical Laboratory Science; Membranes, Artificial; Oxygen; Oxygenators, Membrane; United States
PubMed: 11146960
DOI: No ID Found -
Artificial Organs Nov 1994Major clinically relevant findings have been extracted and summarized from the database developed from the international multicenter clinical trials of the intravascular...
Major clinically relevant findings have been extracted and summarized from the database developed from the international multicenter clinical trials of the intravascular oxygenator (IVOX) as a means for augmenting the deficient blood gas transfer of patients in advanced acute respiratory failure (ARF). Between February 1990 and May 1993, a total of 164 IVOX devices were utilized in 160 clinical trial patients who were hypoxemic and/or hypercarbic while receiving closed system positive pressure mechanical ventilator support at or exceeding generally accepted minimum safe levels of intensity. The average rates of oxygen and carbon dioxide transfer into and out of circulating venous blood by means of the IVOX device varied from 40-70 ml/min. Evidence of patient benefit during IVOX utilization includes improvement in blood gas partial pressures associated with decreased intensity of mechanical ventilation, improved hemodynamics in patients with mechanical ventilator depressed cardiovascular function, and decreased indices of lung dysfunction. Clinically recognized IVOX-related complications or adverse events were reported in 24.5% of the clinical trials patients. At necropsy examination of 68 clinical trials patients who died during or after IVOX utilization, forensic pathologists reported 4 cases in which IVOX utilization could have been a primary or contributing cause of death. Significant IVOX device mechanical and/or performance malfunction problems were recognized in 29 (17.7%) of the IVOX devices utilized in clinical trials. IVOX clinical trials data collected and analyzed to date indicate IVOX utilization has a favorable risk/benefit ratio in patients in severe, acute, potentially reversible ARF.
Topics: Acute Disease; Carbon Dioxide; Cause of Death; Clinical Protocols; Clinical Trials as Topic; Equipment Failure; Heart; Hemodynamics; Hemorrhage; Humans; Hypercapnia; Hypoxia; Information Systems; Lung; Multicenter Studies as Topic; Oxygen; Oxygenators; Partial Pressure; Platelet Count; Positive-Pressure Respiration; Prostheses and Implants; Respiratory Insufficiency; Survival Rate
PubMed: 7864735
DOI: 10.1111/j.1525-1594.1994.tb03334.x -
Artificial Organs Oct 2009For the need for respiratory support for patients with acute or chronic lung diseases to be addressed, a novel integrated maglev pump-oxygenator (IMPO) is being...
For the need for respiratory support for patients with acute or chronic lung diseases to be addressed, a novel integrated maglev pump-oxygenator (IMPO) is being developed as a respiratory assist device. IMPO was conceptualized to combine a magnetically levitated pump/rotor with uniquely configured hollow fiber membranes to create an assembly-free, ultracompact system. IMPO is a self-contained blood pump and oxygenator assembly to enable rapid deployment for patients requiring respiratory support or circulatory support. In this study, computational fluid dynamics (CFD) and computer-aided design were conducted to design and optimize the hemodynamics, gas transfer, and hemocompatibility performances of this novel device. In parallel, in vitro experiments including hydrodynamic, gas transfer, and hemolysis measurements were conducted to evaluate the performance of IMPO. Computational results from CFD analysis were compared with experimental data collected from in vitro evaluation of the IMPO. The CFD simulation demonstrated a well-behaved and streamlined flow field in the main components of this device. The results of hydrodynamic performance, oxygen transfer, and hemolysis predicted by computational simulation, along with the in vitro experimental data, indicate that this pump-lung device can provide the total respiratory need of an adult with lung failure, with a low hemolysis rate at the targeted operating condition. These detailed CFD designs and analyses can provide valuable guidance for further optimization of this IMPO for long-term use.
Topics: Adult; Animals; Computer Simulation; Computer-Aided Design; Equipment Design; Extracorporeal Membrane Oxygenation; Hemolysis; Hemorheology; Humans; Magnetics; Materials Testing; Oxygen; Oxygenators, Membrane; Pressure; Respiratory Insufficiency; Rotation; Sheep; Stress, Mechanical; Time Factors
PubMed: 19681842
DOI: 10.1111/j.1525-1594.2009.00807.x -
ASAIO Journal (American Society For... 1997The authors have synthesized a novel fluorinated polyimide to develop a membrane material for oxygenators and fabricated polyimide hollow fibers for use in an...
The authors have synthesized a novel fluorinated polyimide to develop a membrane material for oxygenators and fabricated polyimide hollow fibers for use in an intravascular oxygenator. A dry/wet phase inversion process has been applied to a spinning process to prepare an asymmetric polyimide hollow fiber. The outer surface of the hollow fiber consists of an ultrathin, dense skin layer, with a calculated apparent thickness of approximately 60 nm. The fiber diameter was 800 microns with a wall thickness of 130 microns. The asymmetric hollow fiber has two advantages because (a) the hollow fiber does not produce plasma leakage due to the dense skin layer of the surface and (b) O2 and CO2 transfer rates through the hollow fiber are enhanced due to the ultrathin skin layer and are significantly larger than those of presently available membrane oxygenators. The blood compatibility of the polyimide hollow fiber without heparinization has been evaluated in vitro. Deformation and aggregation of platelets adherent to the fibers were not observed, and the polyimide suppressed platelet activation. The polyimide significantly reduced the production of anaphylatoxin and also suppressed complement activation.
Topics: Carbon Dioxide; Equipment Design; Evaluation Studies as Topic; Humans; In Vitro Techniques; Membranes, Artificial; Oxygen; Oxygenators; Platelet Adhesiveness; Polymers; Textiles
PubMed: 9360091
DOI: No ID Found -
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi =... Dec 2009Intravenous membrane oxygenator (IVOX), an artificial lung usually located in vena caval system, can provide extra oxygen outside the lung for patients suffering from...
Intravenous membrane oxygenator (IVOX), an artificial lung usually located in vena caval system, can provide extra oxygen outside the lung for patients suffering from respiratory failure. However, gas exchange areas of IVOX are limited because of confined space in caval system. The increase of the diameter of IVOX may impede the return of venous blood to heart, and result in serious low blood pressure. Thus, it is important to increase the efficiency of IVOX by reducing the diffusive resistance of boundary layers. In the present study, the hollow member fiber of IVOX was weaved in braids; we tested the oxygen transfer efficiency and blood flow resistance of this IVOX in vitro. The results showed that the total transferred oxygen, the oxygen transfer rate and blood resistance increased with the increase of blood flow. The oxygen volume transferred by the IVOX and the oxygen transfer rate were (55.97 +/- 0.51) ml/min and (127.19 +/- 0.66) ml/(min x m)2 respectively at the blood flow of 5 L/min and hemoglobin of 120 g/L. They were significantly higher than those at 4 L/min and 3.5 L/min, respectively. The pressure drop also increased from (11.87 +/- 1.57) cmH2O at 3.5 L/min of blood flow to (18.53 +/- 0.99) cmH2O at 4 L/min and 19.77+/- 0.51 cmH2O at 5 L/min. However, they are safe to the patients (< 20 cmH2O). These results suggest that this braid type of IVOX can safely provide 20%-30% oxygen outside the lung for an adult patient.
Topics: Animals; Carbon Dioxide; Hemoglobin A; Oxygen; Oxygenators, Membrane; Regional Blood Flow; Swine
PubMed: 20095500
DOI: No ID Found