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Akif Ündar - One of the best experts on this subject based on the ideXlab platform.
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in vitro evaluation of capiox fx05 and rx05 Oxygenators in neonatal cardiopulmonary bypass circuits with varying venous reservoir and vacuum assisted venous drainage levels
Artificial Organs, 2020Co-Authors: Shyama Sathianathan, Shigang Wang, Allen R Kunselman, Rafay Nasir, Akif ÜndarAbstract:The purpose of this study was to evaluate the hemodynamic properties and microemboli capture associated with different vacuum-assisted venous drainage (VAVD) vacuum levels and venous reservoir levels in a neonatal cardiopulmonary bypass circuit. Trials were conducted in 2 parallel circuits to compare the performance of Capiox Baby RX05 oxygenator with separate AF02 arterial filter to Capiox FX05 oxygenator with integrated arterial filter. Arterial cannula flow rate to the patient was held at 500 mL/min and temperature maintained at 32°C, while VAVD vacuum levels (0 mm Hg, -15 mm Hg, -30 mm Hg, -45 mm Hg, -60 mm Hg) and venous reservoir levels (50 mL, 200 mL) were evaluated in both Oxygenators. Hemodynamic parameters measuring flow, pressure, and total hemodynamic energy were made in real time using a custom-made data acquisition system and Labview software. Nearly 10 cc bolus of air was injected into the venous line and gaseous microemboli detected using an Emboli Detection and Classification Quantifier. Diverted blood flow via the arterial filter's purge line and mean pressures increased with increasing VAVD levels (P < 0.01). Mean pressures were lower with lower venous reservoir levels and were greater in RX05 groups compared to FX05 (P < 0.01). Microemboli detected at the preoxygenator site increased with higher VAVD vacuum levels and lower venous reservoir levels (P < 0.01). The amount of microemboli captured by the FX05 oxygenator with integrated arterial filter was greater than by the RX05 oxygenator alone, although both Oxygenators were able to clear microemboli before reaching the pseudo-patient.
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in vitro comparison of pediatric Oxygenators with and without integrated arterial filters in maintaining optimal hemodynamic stability and managing gaseous microemboli
Artificial Organs, 2018Co-Authors: Morgan K Moroi, Shigang Wang, Allen R Kunselman, Madison Force, Akif ÜndarAbstract:The purpose of this study was to compare the Capiox FX15 oxygenator with integrated arterial filter to the Capiox RX15 oxygenator with separate Capiox AF125 arterial filter in terms of hemodynamic properties and gaseous microemboli (GME) capturing. Trials were conducted at varying flow rates (2.0 L/min, 3.0 L/min, 4.0 L/min), temperatures (30°C, 35°C), and flow modalities (pulsatile, nonpulsatile). Pressure and flow waveforms were recorded using a custom-made data acquisition system. GME data were recorded using an Emboli Detection and Classification Quantifier after injecting a 5 mL air bolus into the venous line. Maximum instantaneous pre-oxygenator flows reached 7.4 L/min under pulsatile conditions when the roller pump was set to a flow rate of 4 L/min. Mean pressure drops were slightly greater in the FX15 group (P < 0.0001), and the diverted flow from the arterial purge line was slighter greater in the FX15 group at 3 L/min and 4 L/min (P < 0.0001). There was a slight generation of surplus hemodynamic energy (SHE) at the pre-oxygenator site for both Oxygenators under "nonpulsatile mode." However, higher pre-oxygenator SHE levels were recorded for both groups with "pulsatile mode." The RX15 and FX15 groups were both able to remove all microemboli from the circuit at 2 L/min and 3 L/min in "nonpulsatile mode." Microemboli were delivered to the patient at 4 L/min with pulsatile flows in both groups. The RX15 oxygenator with separate AF125 arterial filter and FX15 oxygenator with integrated arterial filter performed similarly in terms of hemodynamic performance and microemboli capturing. Pulsatile flows at 4 L/min produced instantaneous flow rates that surpassed the documented maximum flow rates of the Oxygenators and might have contributed to the delivery of GME to the pseudo-patient.
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in vitro evaluation of pediatric hollow fiber membrane Oxygenators on hemodynamic performance and gaseous microemboli handling an international multicenter multidisciplinary approach
Artificial Organs, 2017Co-Authors: Shigang Wang, Allen R Kunselman, Luiz Fernando Caneo, Fabio Biscegli Jatene, Marcelo B Jatene, Idagene A Cestari, Akif ÜndarAbstract:The objective of this study was to compare the hemodynamic performances and gaseous microemboli (GME) handling ability of two pediatric Oxygenators in a simulated pediatric cardiopulmonary bypass (CPB) model and the importance of adding an arterial filter in the circuit. The circuit consisted of a Braile Infant oxygenator or a Maquet Quadrox-I Pediatric oxygenator without integrated arterial filter (parallel arrangement), 1/4 in. ID tubing A-V loop, and a 12-Fr arterial cannula, primed with lactated Ringer's solution and packed red blood cells. Trials were conducted at flow rates ranging from 500 to 2000 mL/min (500 mL/min increment) at 35°C and 28°C. Real-time pressure and flow data were recorded using a custom-based data acquisition system. For GME testing, 5 cc of air was manually injected into the venous line. GME were recorded using the Emboli Detection and Classification Quantifier (EDAC) System. An additional experiment using a separate arterial filter was conducted. There was no difference in the mean circuit pressure, pressure drop, total hemodynamic energy level, and energy loss between the two Oxygenators. The venous line pressures were higher in the Braile than in the Quadrox group during all trials (P <0.01). GME count and volume at pre-/post oxygenator and pre-cannula sites in the Quadrox were lower than the Braile group at high flow rates (P < 0.05). In the additional experiment, an arterial filter captured a significant number of microemboli at all flow rates. The Braile Infant oxygenator has a matched hemodynamic characteristic with the Quadrox-i Pediatric oxygenator. The Quadrox-i has a better GME handling ability compared with the Braile Infant oxygenator. Regardless of type of oxygenator an additional arterial filter decreases the number of GME.
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in vitro evaluation of two types of neonatal Oxygenators in handling gaseous microemboli and maintaining optimal hemodynamic stability during cardiopulmonary bypass
Brazilian Journal of Cardiovascular Surgery, 2016Co-Authors: Neelima Marupudi, Allen R Kunselman, Shigang Wang, Luiz Fernando Caneo, Fabio Biscegli Jatene, Akif ÜndarAbstract:Objective: Usually only FDA-approved Oxygenators are subject of studies by the international scientific community. The objective of this study is to evaluate two types of neonatal membrane Oxygenators in terms of transmembrane pressure gradient, hemodynamic energy transmission and gaseous microemboli capture in simulated cardiopulmonary bypass systems. Methods: We investigated the Braile Infant 1500 (Braile Biomedica, Sao Jose do Rio Preto, Brazil), an oxygenator commonly used in Brazilian operating rooms, and compared it to the Dideco Kids D100 (Sorin Group, Arvada, CO, USA), that is an FDA-approved and widely used model in the USA. Cardiopulmonary bypass circuits were primed with lactated Ringer's solution and packed red blood cells (Hematocrit 40%). Trials were conducted at flow rates of 500 ml/min and 700 ml/min at 35oC and 25oC. Real-time pressure and flow data were recorded using a custom-based data acquisition system. For gaseous microemboli testing, 5cc of air were manually injected into the venous line. Gaseous microemboli were recorded using the Emboli Detection and Classification Quantifier. Results: Braile Infant 1500 had a lower pressure drop (P<0.01) and a higher total hemodynamic energy delivered to the pseudopatient (P<0.01). However, there was a higher raw number of gaseous microemboli seen prior to oxygenator at lower temperatures with the Braile oxygenator compared to the Kids D100 (P<0.01). Conclusion: Braile Infant 1500 oxygenator had a better hemodynamic performance compared to the Dideco Kids D100 oxygenator. Braile had more gaseous microemboli detected at the pre-oxygenator site under hypothermia, but delivered a smaller percentage of air emboli to the pseudopatient than the Dideco oxygenator.
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evaluation of capiox rx25 and quadrox i adult hollow fiber membrane Oxygenators in a simulated cardiopulmonary bypass circuit
Artificial Organs, 2016Co-Authors: Shigang Wang, Allen R Kunselman, Akif ÜndarAbstract:The Capiox RX25 and Quadrox-i Adult Oxygenators are commonly used in clinical adult cardiopulmonary bypass circuits. This study was designed to test the effectiveness of two adult Oxygenators in order to evaluate gaseous microemboli (GME) trapping capability and hemodynamic performance. A simulated adult CPB circuit was used and primed with Ringer's lactate and packed red blood cells (hematocrit 25%). All trials were conducted at flow rates of 2-5 L/min (1 L/min increments) with a closed and open arterial filter purge line at 35°C. The postcannula pressure was maintained at 100 mm Hg. After a 5 cc of bolus air was introduced into the venous line, an Emboli Detection and Classification system was used to detect and classify GME at the preoxygenator, postoxygenator, and precannula sites. At the same time, real-time pressure and flow data were recorded, and hemodynamic energy was calculated using a custom-made data acquisition system and Labview software. Our results showed that the oxygenator pressure drops of Quadrox-i Adult oxygenator were lower than Capiox RX25 at all flow rates. The Quadrox-i Adult oxygenator retained more hemodynamic energy across the oxygenator. Both Oxygenators could trap the majority of GME, but Capiox RX25 did better than the Quadrox-i Adult oxygenator. No GME was delivered to the pseudo patient at all flow rates in the Capiox group. The Capiox RX25 venous reservoir could capture more GME at lower flow rates, while the Quadrox-i Adult venous reservoir performed better at higher flow rates. An open arterial filter purge line reduced GME slightly in the Capiox group, but GME increased in the Quadrox group. The Quadrox-i Adult oxygenator is a low-resistance, high-compliance oxygenator. The GME handling ability of Capiox RX25 performed well under our clinical setting. Further optimized design for the venous/cardiotomy reservoir is needed.
Shigang Wang - One of the best experts on this subject based on the ideXlab platform.
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pumping o2 with no n2 an overview of hollow fiber membrane Oxygenators with integrated arterial filters
Current Topics in Medicinal Chemistry, 2020Co-Authors: Anxin Liu, Zhiquan Sun, Qier Liu, Ning Zhu, Shigang WangAbstract:The advancement of cardiac surgery benefits from the continual technological progress of cardiopulmonary bypass (CPB). Every improvement in the CPB technology requires further clinical and laboratory tests to prove its safety and effectiveness before it can be widely used in clinical practice. In order to reduce the priming volume and eliminate a separate arterial filter in the CPB circuit, several manufacturers developed novel hollow-fiber membrane Oxygenators with integrated arterial filters (IAF). Clinical and experimental studies demonstrated that an oxygenator with IAF could reduce total priming volume, blood donor exposure and gaseous microemboli delivery to the patient. It can be easily set up and managed, simplifying the CPB circuit without sacrificing safety. An oxygenator with IAF is expected to be more beneficial to the patients with low body weight and when using a minimized extracorporeal circulation system. The aim of this review manuscript was to discuss briefly the concept of integration, the current Oxygenators with IAF, and the in-vitro / in-vivo performance of the Oxygenators with IAF.
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in vitro evaluation of capiox fx05 and rx05 Oxygenators in neonatal cardiopulmonary bypass circuits with varying venous reservoir and vacuum assisted venous drainage levels
Artificial Organs, 2020Co-Authors: Shyama Sathianathan, Shigang Wang, Allen R Kunselman, Rafay Nasir, Akif ÜndarAbstract:The purpose of this study was to evaluate the hemodynamic properties and microemboli capture associated with different vacuum-assisted venous drainage (VAVD) vacuum levels and venous reservoir levels in a neonatal cardiopulmonary bypass circuit. Trials were conducted in 2 parallel circuits to compare the performance of Capiox Baby RX05 oxygenator with separate AF02 arterial filter to Capiox FX05 oxygenator with integrated arterial filter. Arterial cannula flow rate to the patient was held at 500 mL/min and temperature maintained at 32°C, while VAVD vacuum levels (0 mm Hg, -15 mm Hg, -30 mm Hg, -45 mm Hg, -60 mm Hg) and venous reservoir levels (50 mL, 200 mL) were evaluated in both Oxygenators. Hemodynamic parameters measuring flow, pressure, and total hemodynamic energy were made in real time using a custom-made data acquisition system and Labview software. Nearly 10 cc bolus of air was injected into the venous line and gaseous microemboli detected using an Emboli Detection and Classification Quantifier. Diverted blood flow via the arterial filter's purge line and mean pressures increased with increasing VAVD levels (P < 0.01). Mean pressures were lower with lower venous reservoir levels and were greater in RX05 groups compared to FX05 (P < 0.01). Microemboli detected at the preoxygenator site increased with higher VAVD vacuum levels and lower venous reservoir levels (P < 0.01). The amount of microemboli captured by the FX05 oxygenator with integrated arterial filter was greater than by the RX05 oxygenator alone, although both Oxygenators were able to clear microemboli before reaching the pseudo-patient.
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in vitro comparison of pediatric Oxygenators with and without integrated arterial filters in maintaining optimal hemodynamic stability and managing gaseous microemboli
Artificial Organs, 2018Co-Authors: Morgan K Moroi, Shigang Wang, Allen R Kunselman, Madison Force, Akif ÜndarAbstract:The purpose of this study was to compare the Capiox FX15 oxygenator with integrated arterial filter to the Capiox RX15 oxygenator with separate Capiox AF125 arterial filter in terms of hemodynamic properties and gaseous microemboli (GME) capturing. Trials were conducted at varying flow rates (2.0 L/min, 3.0 L/min, 4.0 L/min), temperatures (30°C, 35°C), and flow modalities (pulsatile, nonpulsatile). Pressure and flow waveforms were recorded using a custom-made data acquisition system. GME data were recorded using an Emboli Detection and Classification Quantifier after injecting a 5 mL air bolus into the venous line. Maximum instantaneous pre-oxygenator flows reached 7.4 L/min under pulsatile conditions when the roller pump was set to a flow rate of 4 L/min. Mean pressure drops were slightly greater in the FX15 group (P < 0.0001), and the diverted flow from the arterial purge line was slighter greater in the FX15 group at 3 L/min and 4 L/min (P < 0.0001). There was a slight generation of surplus hemodynamic energy (SHE) at the pre-oxygenator site for both Oxygenators under "nonpulsatile mode." However, higher pre-oxygenator SHE levels were recorded for both groups with "pulsatile mode." The RX15 and FX15 groups were both able to remove all microemboli from the circuit at 2 L/min and 3 L/min in "nonpulsatile mode." Microemboli were delivered to the patient at 4 L/min with pulsatile flows in both groups. The RX15 oxygenator with separate AF125 arterial filter and FX15 oxygenator with integrated arterial filter performed similarly in terms of hemodynamic performance and microemboli capturing. Pulsatile flows at 4 L/min produced instantaneous flow rates that surpassed the documented maximum flow rates of the Oxygenators and might have contributed to the delivery of GME to the pseudo-patient.
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in vitro evaluation of pediatric hollow fiber membrane Oxygenators on hemodynamic performance and gaseous microemboli handling an international multicenter multidisciplinary approach
Artificial Organs, 2017Co-Authors: Shigang Wang, Allen R Kunselman, Luiz Fernando Caneo, Fabio Biscegli Jatene, Marcelo B Jatene, Idagene A Cestari, Akif ÜndarAbstract:The objective of this study was to compare the hemodynamic performances and gaseous microemboli (GME) handling ability of two pediatric Oxygenators in a simulated pediatric cardiopulmonary bypass (CPB) model and the importance of adding an arterial filter in the circuit. The circuit consisted of a Braile Infant oxygenator or a Maquet Quadrox-I Pediatric oxygenator without integrated arterial filter (parallel arrangement), 1/4 in. ID tubing A-V loop, and a 12-Fr arterial cannula, primed with lactated Ringer's solution and packed red blood cells. Trials were conducted at flow rates ranging from 500 to 2000 mL/min (500 mL/min increment) at 35°C and 28°C. Real-time pressure and flow data were recorded using a custom-based data acquisition system. For GME testing, 5 cc of air was manually injected into the venous line. GME were recorded using the Emboli Detection and Classification Quantifier (EDAC) System. An additional experiment using a separate arterial filter was conducted. There was no difference in the mean circuit pressure, pressure drop, total hemodynamic energy level, and energy loss between the two Oxygenators. The venous line pressures were higher in the Braile than in the Quadrox group during all trials (P <0.01). GME count and volume at pre-/post oxygenator and pre-cannula sites in the Quadrox were lower than the Braile group at high flow rates (P < 0.05). In the additional experiment, an arterial filter captured a significant number of microemboli at all flow rates. The Braile Infant oxygenator has a matched hemodynamic characteristic with the Quadrox-i Pediatric oxygenator. The Quadrox-i has a better GME handling ability compared with the Braile Infant oxygenator. Regardless of type of oxygenator an additional arterial filter decreases the number of GME.
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in vitro evaluation of two types of neonatal Oxygenators in handling gaseous microemboli and maintaining optimal hemodynamic stability during cardiopulmonary bypass
Brazilian Journal of Cardiovascular Surgery, 2016Co-Authors: Neelima Marupudi, Allen R Kunselman, Shigang Wang, Luiz Fernando Caneo, Fabio Biscegli Jatene, Akif ÜndarAbstract:Objective: Usually only FDA-approved Oxygenators are subject of studies by the international scientific community. The objective of this study is to evaluate two types of neonatal membrane Oxygenators in terms of transmembrane pressure gradient, hemodynamic energy transmission and gaseous microemboli capture in simulated cardiopulmonary bypass systems. Methods: We investigated the Braile Infant 1500 (Braile Biomedica, Sao Jose do Rio Preto, Brazil), an oxygenator commonly used in Brazilian operating rooms, and compared it to the Dideco Kids D100 (Sorin Group, Arvada, CO, USA), that is an FDA-approved and widely used model in the USA. Cardiopulmonary bypass circuits were primed with lactated Ringer's solution and packed red blood cells (Hematocrit 40%). Trials were conducted at flow rates of 500 ml/min and 700 ml/min at 35oC and 25oC. Real-time pressure and flow data were recorded using a custom-based data acquisition system. For gaseous microemboli testing, 5cc of air were manually injected into the venous line. Gaseous microemboli were recorded using the Emboli Detection and Classification Quantifier. Results: Braile Infant 1500 had a lower pressure drop (P<0.01) and a higher total hemodynamic energy delivered to the pseudopatient (P<0.01). However, there was a higher raw number of gaseous microemboli seen prior to oxygenator at lower temperatures with the Braile oxygenator compared to the Kids D100 (P<0.01). Conclusion: Braile Infant 1500 oxygenator had a better hemodynamic performance compared to the Dideco Kids D100 oxygenator. Braile had more gaseous microemboli detected at the pre-oxygenator site under hypothermia, but delivered a smaller percentage of air emboli to the pseudopatient than the Dideco oxygenator.
Allen R Kunselman - One of the best experts on this subject based on the ideXlab platform.
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in vitro evaluation of capiox fx05 and rx05 Oxygenators in neonatal cardiopulmonary bypass circuits with varying venous reservoir and vacuum assisted venous drainage levels
Artificial Organs, 2020Co-Authors: Shyama Sathianathan, Shigang Wang, Allen R Kunselman, Rafay Nasir, Akif ÜndarAbstract:The purpose of this study was to evaluate the hemodynamic properties and microemboli capture associated with different vacuum-assisted venous drainage (VAVD) vacuum levels and venous reservoir levels in a neonatal cardiopulmonary bypass circuit. Trials were conducted in 2 parallel circuits to compare the performance of Capiox Baby RX05 oxygenator with separate AF02 arterial filter to Capiox FX05 oxygenator with integrated arterial filter. Arterial cannula flow rate to the patient was held at 500 mL/min and temperature maintained at 32°C, while VAVD vacuum levels (0 mm Hg, -15 mm Hg, -30 mm Hg, -45 mm Hg, -60 mm Hg) and venous reservoir levels (50 mL, 200 mL) were evaluated in both Oxygenators. Hemodynamic parameters measuring flow, pressure, and total hemodynamic energy were made in real time using a custom-made data acquisition system and Labview software. Nearly 10 cc bolus of air was injected into the venous line and gaseous microemboli detected using an Emboli Detection and Classification Quantifier. Diverted blood flow via the arterial filter's purge line and mean pressures increased with increasing VAVD levels (P < 0.01). Mean pressures were lower with lower venous reservoir levels and were greater in RX05 groups compared to FX05 (P < 0.01). Microemboli detected at the preoxygenator site increased with higher VAVD vacuum levels and lower venous reservoir levels (P < 0.01). The amount of microemboli captured by the FX05 oxygenator with integrated arterial filter was greater than by the RX05 oxygenator alone, although both Oxygenators were able to clear microemboli before reaching the pseudo-patient.
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in vitro comparison of pediatric Oxygenators with and without integrated arterial filters in maintaining optimal hemodynamic stability and managing gaseous microemboli
Artificial Organs, 2018Co-Authors: Morgan K Moroi, Shigang Wang, Allen R Kunselman, Madison Force, Akif ÜndarAbstract:The purpose of this study was to compare the Capiox FX15 oxygenator with integrated arterial filter to the Capiox RX15 oxygenator with separate Capiox AF125 arterial filter in terms of hemodynamic properties and gaseous microemboli (GME) capturing. Trials were conducted at varying flow rates (2.0 L/min, 3.0 L/min, 4.0 L/min), temperatures (30°C, 35°C), and flow modalities (pulsatile, nonpulsatile). Pressure and flow waveforms were recorded using a custom-made data acquisition system. GME data were recorded using an Emboli Detection and Classification Quantifier after injecting a 5 mL air bolus into the venous line. Maximum instantaneous pre-oxygenator flows reached 7.4 L/min under pulsatile conditions when the roller pump was set to a flow rate of 4 L/min. Mean pressure drops were slightly greater in the FX15 group (P < 0.0001), and the diverted flow from the arterial purge line was slighter greater in the FX15 group at 3 L/min and 4 L/min (P < 0.0001). There was a slight generation of surplus hemodynamic energy (SHE) at the pre-oxygenator site for both Oxygenators under "nonpulsatile mode." However, higher pre-oxygenator SHE levels were recorded for both groups with "pulsatile mode." The RX15 and FX15 groups were both able to remove all microemboli from the circuit at 2 L/min and 3 L/min in "nonpulsatile mode." Microemboli were delivered to the patient at 4 L/min with pulsatile flows in both groups. The RX15 oxygenator with separate AF125 arterial filter and FX15 oxygenator with integrated arterial filter performed similarly in terms of hemodynamic performance and microemboli capturing. Pulsatile flows at 4 L/min produced instantaneous flow rates that surpassed the documented maximum flow rates of the Oxygenators and might have contributed to the delivery of GME to the pseudo-patient.
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in vitro evaluation of pediatric hollow fiber membrane Oxygenators on hemodynamic performance and gaseous microemboli handling an international multicenter multidisciplinary approach
Artificial Organs, 2017Co-Authors: Shigang Wang, Allen R Kunselman, Luiz Fernando Caneo, Fabio Biscegli Jatene, Marcelo B Jatene, Idagene A Cestari, Akif ÜndarAbstract:The objective of this study was to compare the hemodynamic performances and gaseous microemboli (GME) handling ability of two pediatric Oxygenators in a simulated pediatric cardiopulmonary bypass (CPB) model and the importance of adding an arterial filter in the circuit. The circuit consisted of a Braile Infant oxygenator or a Maquet Quadrox-I Pediatric oxygenator without integrated arterial filter (parallel arrangement), 1/4 in. ID tubing A-V loop, and a 12-Fr arterial cannula, primed with lactated Ringer's solution and packed red blood cells. Trials were conducted at flow rates ranging from 500 to 2000 mL/min (500 mL/min increment) at 35°C and 28°C. Real-time pressure and flow data were recorded using a custom-based data acquisition system. For GME testing, 5 cc of air was manually injected into the venous line. GME were recorded using the Emboli Detection and Classification Quantifier (EDAC) System. An additional experiment using a separate arterial filter was conducted. There was no difference in the mean circuit pressure, pressure drop, total hemodynamic energy level, and energy loss between the two Oxygenators. The venous line pressures were higher in the Braile than in the Quadrox group during all trials (P <0.01). GME count and volume at pre-/post oxygenator and pre-cannula sites in the Quadrox were lower than the Braile group at high flow rates (P < 0.05). In the additional experiment, an arterial filter captured a significant number of microemboli at all flow rates. The Braile Infant oxygenator has a matched hemodynamic characteristic with the Quadrox-i Pediatric oxygenator. The Quadrox-i has a better GME handling ability compared with the Braile Infant oxygenator. Regardless of type of oxygenator an additional arterial filter decreases the number of GME.
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in vitro evaluation of two types of neonatal Oxygenators in handling gaseous microemboli and maintaining optimal hemodynamic stability during cardiopulmonary bypass
Brazilian Journal of Cardiovascular Surgery, 2016Co-Authors: Neelima Marupudi, Allen R Kunselman, Shigang Wang, Luiz Fernando Caneo, Fabio Biscegli Jatene, Akif ÜndarAbstract:Objective: Usually only FDA-approved Oxygenators are subject of studies by the international scientific community. The objective of this study is to evaluate two types of neonatal membrane Oxygenators in terms of transmembrane pressure gradient, hemodynamic energy transmission and gaseous microemboli capture in simulated cardiopulmonary bypass systems. Methods: We investigated the Braile Infant 1500 (Braile Biomedica, Sao Jose do Rio Preto, Brazil), an oxygenator commonly used in Brazilian operating rooms, and compared it to the Dideco Kids D100 (Sorin Group, Arvada, CO, USA), that is an FDA-approved and widely used model in the USA. Cardiopulmonary bypass circuits were primed with lactated Ringer's solution and packed red blood cells (Hematocrit 40%). Trials were conducted at flow rates of 500 ml/min and 700 ml/min at 35oC and 25oC. Real-time pressure and flow data were recorded using a custom-based data acquisition system. For gaseous microemboli testing, 5cc of air were manually injected into the venous line. Gaseous microemboli were recorded using the Emboli Detection and Classification Quantifier. Results: Braile Infant 1500 had a lower pressure drop (P<0.01) and a higher total hemodynamic energy delivered to the pseudopatient (P<0.01). However, there was a higher raw number of gaseous microemboli seen prior to oxygenator at lower temperatures with the Braile oxygenator compared to the Kids D100 (P<0.01). Conclusion: Braile Infant 1500 oxygenator had a better hemodynamic performance compared to the Dideco Kids D100 oxygenator. Braile had more gaseous microemboli detected at the pre-oxygenator site under hypothermia, but delivered a smaller percentage of air emboli to the pseudopatient than the Dideco oxygenator.
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evaluation of capiox rx25 and quadrox i adult hollow fiber membrane Oxygenators in a simulated cardiopulmonary bypass circuit
Artificial Organs, 2016Co-Authors: Shigang Wang, Allen R Kunselman, Akif ÜndarAbstract:The Capiox RX25 and Quadrox-i Adult Oxygenators are commonly used in clinical adult cardiopulmonary bypass circuits. This study was designed to test the effectiveness of two adult Oxygenators in order to evaluate gaseous microemboli (GME) trapping capability and hemodynamic performance. A simulated adult CPB circuit was used and primed with Ringer's lactate and packed red blood cells (hematocrit 25%). All trials were conducted at flow rates of 2-5 L/min (1 L/min increments) with a closed and open arterial filter purge line at 35°C. The postcannula pressure was maintained at 100 mm Hg. After a 5 cc of bolus air was introduced into the venous line, an Emboli Detection and Classification system was used to detect and classify GME at the preoxygenator, postoxygenator, and precannula sites. At the same time, real-time pressure and flow data were recorded, and hemodynamic energy was calculated using a custom-made data acquisition system and Labview software. Our results showed that the oxygenator pressure drops of Quadrox-i Adult oxygenator were lower than Capiox RX25 at all flow rates. The Quadrox-i Adult oxygenator retained more hemodynamic energy across the oxygenator. Both Oxygenators could trap the majority of GME, but Capiox RX25 did better than the Quadrox-i Adult oxygenator. No GME was delivered to the pseudo patient at all flow rates in the Capiox group. The Capiox RX25 venous reservoir could capture more GME at lower flow rates, while the Quadrox-i Adult venous reservoir performed better at higher flow rates. An open arterial filter purge line reduced GME slightly in the Capiox group, but GME increased in the Quadrox group. The Quadrox-i Adult oxygenator is a low-resistance, high-compliance oxygenator. The GME handling ability of Capiox RX25 performed well under our clinical setting. Further optimized design for the venous/cardiotomy reservoir is needed.
William R Wagner - One of the best experts on this subject based on the ideXlab platform.
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predicting membrane oxygenator pressure drop using computational fluid dynamics
Artificial Organs, 2002Co-Authors: Kenneth L Gage, Mark J Gartner, Greg W Burgreen, William R WagnerAbstract:: Three-dimensional computational fluid dynamic (CFD) simulations of membrane Oxygenators should allow prediction of spatially dependent variables and subsequent shape optimization. Fiber bed complexity and current computational limitations require the use of approximate models to predict fiber drag effects in complete device simulations. A membrane oxygenator was modified to allow pressure measurement along the fiber bundle in all cardinal axes. Experimental pressure drop information with water perfusion was used to calculate the permeability of the fiber bundle. A three-dimensional CFD model of a commercial membrane oxygenator was developed to predict pressure drops throughout the device. Darcy's Law was used to account for the viscous drag of the fibers and was incorporated as a momentum loss term in the conservation equations. Close agreement was shown between experimental and simulated pressure drops at lower flow rates, but the simulated pressure drops were lower than experimental results at higher flows. Alternate models of fiber drag effects and flow field visualization are suggested as means to potentially improve the accuracy of the flow simulation. Computational techniques coupled with experimental verification offer insight into model validity and show promise for the development of accurate three-dimensional simulations of membrane Oxygenators.
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modeling flow effects on thrombotic deposition in a membrane oxygenator
Artificial Organs, 2000Co-Authors: Mark J Gartner, Kenneth L Gage, Carl R Wilhelm, Charlene M Fabrizio, William R WagnerAbstract:: The hypothesis that regions of low blood velocity in a membrane oxygenator, as predicted by computational fluid dynamics (CFD), would correspond with regions of clinical thrombotic deposition was investigated. Twenty heparin-coated Oxygenators were sectioned following use in adult extracorporeal membrane oxygenation. The activated clotting time (ACT) was maintained at approximately 180 s via heparin infusion throughout the support period. Cross-sections were systematically photographed, and slides made to allow image projection upon a digitizing pad. Thrombotic deposition was traced to allow creation of a device cross-section image with an overlaid color scale representing thrombotic deposition frequency. A two-dimensional CFD model was developed to predict blood velocities throughout the oxygenator cross-section. Direct spatial comparisons were made between maps of CFD modeled blood speed and thrombotic deposition. Theoretical oxygenator design modification was performed within the CFD model to investigate flow paths which might minimize regions of low blood velocity. CFD results demonstrated that low velocity regions qualitatively matched regions with a high incidence of thrombotic deposition. Thrombotic deposition was also correlated to longer perfusion periods. This technique of coupling clinical data and CFD offers the potential to relate flow characteristics to thrombotic deposition and represents a potentially powerful new methodology for the optimization of oxygenator flow-related biocompatibility.
Van Willem Oeveren - One of the best experts on this subject based on the ideXlab platform.
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pressure drop shear stress and activation of leukocytes during cardiopulmonary bypass a comparison between hollow fiber and flat sheet membrane Oxygenators
Artificial Organs, 2000Co-Authors: Pw Boonstra, Reindert Graaff, Aa Rijnsburger, H Mungroop, Van Willem OeverenAbstract:The membrane oxygenator is known to be superior to the bubble oxygenator, but little information is available about the difference between the hollow fiber and flat sheet membrane Oxygenators with regard to pressure drop, shear stress, and leukocyte activation. In this study, we compared these 2 types of membrane Oxygenators in patients undergoing cardiopulmonary bypass (CPB) surgery with special focus on leukocyte activation and pressure drop across the Oxygenators. Plasma concentration of elastase, a marker indicating leukocyte activation, increased to 593+/-68% in the flat sheet oxygenator group versus 197+/-42% in the hollow fiber oxygenator group (p<0.01) at the end of CPB compared to their respective baseline concentrations before CPB. Pressure drop across the oxygenator was significantly higher in the flat sheet group than in the hollow fiber group throughout the entire period of CPB (p<0.01). High pressure drop across the oxygenator as well as the calculated shear stress was positively correlated with the release of elastase at the end of CPB (r = 0.760, p<0.01, r = 0.692, p<0.01). However, this positive correlation existed in the flat sheet oxygenator but not in the hollow fiber oxygenator. Clinically, both membrane Oxygenators have satisfactory performance in O2 and CO2 transfer. These results suggest that a higher pressure drop across the flat sheet oxygenator is associated with more pronounced activation of leukocytes in patients undergoing cardiopulmonary bypass.
