Artificial organs
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Translational research is a useful tool to provide scientific evidence for cannula selection during extracorporeal life support (ECLS). The objective of this study was to evaluate four Avalon Elite bi-caval dual lumen cannulas and nine femoral arterial cannulas in terms of flow range, circuit pressure, pressure drop, and hemodynamic energy transmission in a simulated adult ECLS model. A veno-venous ECLS circuit was used to evaluate four Avalon Elite bi-caval dual lumen cannulas (20, 23, 27, and 31 Fr), and a veno-arterial ECLS circuit was used to evaluate nine femoral arterial cannulas (15, 17, 19, 21, and 23 Fr). ⋯ Maquet at 4 L/min: 17 Fr-43.6 vs. 44.4%, 19 Fr-31.0 vs. 31.4%, 21 Fr-20.8 vs. 22.4%) at high flow rates when compared with the Maquet cannulae. The results for this study provided valuable hemodynamic characteristics of all evaluated adult cannulas with human blood in order to guide ECLS cannula selection in clinical practice. Use of larger cannulas are suggested for VV- and VA-ECLS.
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The objective of this study is to evaluate the hemodynamic characteristics of two femoral arterial cannulae in terms of circuit pressure, pressure drop, and hemodynamic energy transmission under non-pulsatile and pulsatile modes in a simulated adult extracorporeal life support (ECLS) system. The ECLS circuit consisted of i-cor diagonal pump and console (Xenios AG, Heilbronn, Germany), an iLA membrane ventilator (Xenios AG), an 18 Fr or 16 Fr femoral arterial cannula (Xenios AG), and a 23/25 Fr Estech remote access perfusion (RAP) femoral venous cannula (San Ramon, CA, USA). The circuit was primed with lactated Ringer's solution and packed red blood cells to achieve a hematocrit of 35%. ⋯ The pressure drops and percentages of THE loss across two cannulae tested using human blood were higher compared to the manufacturer's data tested using water. The cannula size should be chosen to match the expected flow rate. In addition, this novel i-cor ECLS system can provide non-pulsatile and ECG-synchronized pulsatile flow without significantly increasing the cannula pressure drop and hemodynamic energy loss.
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Measurement of lactate concentrations during cardiac surgery with cardiopulmonary bypass (CPB) is a reliable monitoring tool for the assessment of the adequacy of perfusion, and a predictor of poor outcome. However, increased lactate production, which is multifactorial (anaerobic metabolism, hyperglycemia), increased lactate load by packed red blood cell (PRBC) transfusions, and decreased lactate clearance may all result in hyperlactatemia. The aim of this study was to estimate the clearance of lactate in infants undergoing surgery with CPB, using the lactate load from the PRBCs transfusions received during CPB. ⋯ Lactate clearance increased significantly with age. The half-life of lactate in infants is comparable with that reported in adults with CPB, and lactate clearance is higher. Knowing the high lactate content of PRBCs, lactate clearance rather than absolute concentration is potentially a better indicator of the adequacy of perfusion during CPB in infants.
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The objective of this study is to compare hemodynamic performances under different pulsatile control algorithms between Medos DeltaStream DP3 and i-cor diagonal pumps in simulated pediatric and adult ECLS systems. An additional pilot study was designed to test hemolysis using two pumps during 12h-ECLS. The experimental circuit consisted of parallel combined pediatric and adult ECLS circuits using an i-cor pump head and either an i-cor console or Medos DeltaStream MDC console, a Medos Hilite 2400 LT oxygenator for the pediatric ECLS circuit, and a Medos Hilite 7000 LT oxygenator for the adult ECLS circuit. ⋯ Although high pulsatile amplitudes delivered higher levels of hemodynamic energy to the patient, the high rotational speeds increased the risk of hemolysis. Use of proper pulsatile amplitude settings and intermittent pulsatile mode are suggested to achieve better pulsatility and decrease the risk of hemolysis. Further optimized pulsatile control algorithms are needed.
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Comparative Study
Minimally Invasive Left Ventricular Assist Device Implantation: A Comparative Study.
Left ventricular assist device (LVAD) is now a routine therapy for advanced heart failure. Minimally invasive approach via thoracotomy for LVAD implantation is getting popular due to its potential advantage over the conventional sternotomy approach in terms of reduced risk at re-operation due to sternal sparing. We compared the approaches (thoracotomy and sternotomy) to determine the superiority. ⋯ There was no significant difference between the groups in terms of postoperative hemodynamic parameters, laboratory markers, bleeding and requirement of blood products, intensive care unit, and hospital stay or complications of LVAD surgery. There were no significant differences in terms of long-term survival (Log-Rank P = 0.953), however, thoracotomy, compared to sternotomy approach, incurred significantly less requirement of temporary right ventricular assist (4 vs. 19.4%, P = 0.041). Minimally invasive bilateral thoracotomy approach for LVAD implantation in addition to benefits of sternal sparing avoids dilatation of right ventricle and reduces chances of right ventricular failure requiring temporary right ventricular assist.