| 1. |
- Donker, Dirk W., et al.
(författare)
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Left ventricular unloading during veno-arterial ECMO : a review of percutaneous and surgical unloading interventions
- 2019
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Ingår i: Perfusion. - : Sage Publications. - 0267-6591 .- 1477-111X. ; 34:2, s. 98-105
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Forskningsöversikt (refereegranskat)abstract
- Short-term mechanical support by veno-arterial extracorporeal membrane oxygenation (VA ECMO) is more and more applied in patients with severe cardiogenic shock. A major shortcoming of VA ECMO is its variable, but inherent increase of left ventricular (LV) mechanical load, which may aggravate pulmonary edema and hamper cardiac recovery. In order to mitigate these negative sequelae of VA ECMO, different adjunct LV unloading interventions have gained a broad interest in recent years. Here, we review the whole spectrum of percutaneous and surgical techniques combined with VA ECMO reported to date.
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| 2. |
- Donker, Dirk W., et al.
(författare)
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Left Ventricular Unloading During Veno-Arterial ECMO : A Simulation Study
- 2019
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Ingår i: ASAIO journal (1992). - : Lippincott Williams and Wilkins. - 1058-2916 .- 1538-943X. ; 65:1, s. 11-20
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Tidskriftsartikel (refereegranskat)abstract
- Veno-arterial extracorporeal membrane oxygenation (VA ECMO) is widely used in cardiogenic shock. It provides systemic perfusion, but left ventricular (LV) unloading is suboptimal. Using a closed-loop, real-time computer model of the human cardiovascular system, cardiogenic shock supported by peripheral VA ECMO was simulated, and effects of various adjunct LV unloading interventions were quantified. After VA ECMO initiation (4 L/min) in cardiogenic shock (baseline), hemodynamics improved (increased to 85 mm Hg), while LV overload occurred (10% increase in end-diastolic volume [EDV], and 5 mm Hg increase in pulmonary capillary wedge pressure [PCWP]). Decreasing afterload (65 mm Hg mean arterial pressure) and circulating volume (-800 mL) reduced LV overload (12% decrease in EDV and 37% decrease in PCWP) compared with baseline. Additional intra-aortic balloon pumping only marginally decreased cardiac loading. Instead, adjunct Impella T enhanced LV unloading (23% decrease in EDV and 41% decrease in PCWP). Alternative interventions, for example, left atrial/ventricular venting, yielded substantial unloading. We conclude that real-time simulations may provide quantitative clinical measures of LV overload, depending on the degree of VA ECMO support and adjunct management. Simulations offer insights into individualized LV unloading interventions in cardiogenic shock supported by VA ECMO as a proof of concept for potential future applications in clinical decision support, which may help to improve individualized patient management in complex cardiovascular disease.
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| 3. |
- Karagiannidis, Christian, et al.
(författare)
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Impact of membrane lung surface area and blood flow on extracorporeal CO2 removal during severe respiratory acidosis
- 2017
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Ingår i: Intensive Care Medicine Experimental. - : Springer Science and Business Media LLC. - 2197-425X. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Veno-venous extracorporeal CO2 removal (vv-ECCO2R) is increasingly being used in the setting of acute respiratory failure. Blood flow rates through the device range from 200 ml/min to more than 1500 ml/min, and the membrane surface areas range from 0.35 to 1.3 m2. The present study in an animal model with similar CO2 production as an adult patient was aimed at determining the optimal membrane lung surface area and technical requirements for successful vv-ECCO2R.METHODS: Four different membrane lungs, with varying lung surface areas of 0.4, 0.8, 1.0, and 1.3m2 were used to perform vv-ECCO2R in seven anesthetized, mechanically ventilated, pigs with experimentally induced severe respiratory acidosis (pH 7.0-7.1) using a 20Fr double-lumen catheter with a sweep gas flow rate of 8 L/min. During each experiment, the blood flow was increased stepwise from 250 to 1000 ml/min.RESULTS: Amelioration of severe respiratory acidosis was only feasible when blood flow rates from 750 to 1000 ml/min were used with a membrane lung surface area of at least 0.8 m2. Maximal CO2 elimination was 150.8 ml/min, with pH increasing from 7.01 to 7.30 (blood flow 1000 ml/min; membrane lung 1.3 m2). The membrane lung with a surface of 0.4 m2 allowed a maximum CO2 elimination rate of 71.7 mL/min, which did not result in the normalization of pH, even with a blood flow rate of 1000 ml/min. Also of note, an increase of the surface area above 1.0 m2 did not result in substantially higher CO2 elimination rates. The pressure drop across the oxygenator was considerably lower (<10 mmHg) in the largest membrane lung, whereas the smallest revealed a pressure drop of more than 50 mmHg with 1000 ml blood flow/min.CONCLUSIONS: In this porcine model, vv-ECCO2R was most effective when using blood flow rates ranging between 750 and 1000 ml/min, with a membrane lung surface of at least 0.8 m2. In contrast, low blood flow rates (250-500 ml/min) were not sufficient to completely correct severe respiratory acidosis, irrespective of the surface area of the membrane lung being used. The converse was also true, low surface membrane lungs (0.4 m2) were not capable of completely correcting severe respiratory acidosis across the range of blood flows used in this study.
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| 4. |
- Strassmann, Stephan, et al.
(författare)
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Impact of sweep gas flow on extracorporeal CO2 removal (ECCO2R)
- 2019
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Ingår i: Intensive Care Medicine Experimental. - : SPRINGEROPEN. - 2197-425X. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Background: Veno-venous extracorporeal carbon dioxide (CO2) removal (vv-ECCO2R) is increasingly being used in the setting of acute respiratory failure. Blood flow rates range in clinical practice from 200mL/min to more than 1500mL/min, and sweep gas flow rates range from less than 1 to more than 10L/min. The present porcine model study was aimed at determining the impact of varying sweep gas flow rates on CO2 removal under different blood flow conditions and membrane lung surface areas.Methods: Two different membrane lungs, with surface areas of 0.4 and 0.8m(2), were used in nine pigs with experimentally-induced hypercapnia. During each experiment, the blood flow was increased stepwise from 300 to 900 mL/min, with further increases up to 1800 mL/min with the larger membrane lung in steps of 300 mL/min. Sweep gas was titrated under each condition from 2 to 8L/min in steps of 2 L/min. Extracorporeal CO2 elimination was normalized to a PaCO2 of 45 mmHg before the membrane lung.Results: Reversal of hypercapnia was only feasible when blood flow rates above 900mL/min were used with a membrane lung surface area of at least 0.8m(2). The membrane lung with a surface of 0.4m(2) allowed a maximum normalized CO2 elimination rate of 416mL/min with 8L/min sweep gas flow and 900mLbloodflow/min. The increase in sweep gas flow from 2 to 8L/min increased normalized CO2 elimination from 35 +/- 5 to 41 +/- 6 with 900mLbloodflow/min, whereas with lower blood flow rates, any increase was less effective, levelling out at 4Lsweepgasflow/min. The membrane lung with a surface area of 0.8 m(2) allowed a maximum normalized CO2 elimination rate of 101 +/- 12 mL/min with increasing influence of sweep gas flow. The delta of normalized CO2 elimination increased from 4 +/- 2 to 26 +/- 7 mL/min with blood flow rates being increased from 300 to 1800 mL/min, respectively.Conclusions: The influence of sweep gas flow on the CO2 removal capacity of ECCO2R systems depends predominantly on blood flow rate and membrane lung surface area. In this model, considerable CO2 removal occurred only with the larger membrane lung surface of 0.8m(2) and when blood flow rates of >= 900mL/min were used.
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