Artificial organs
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Comparative Study
Platelet function during cardiopulmonary bypass using multiple electrode aggregometry: comparison of centrifugal and roller pumps.
Blood trauma may be lower with centrifugal pumps (CPs) than with roller pumps (RPs) during cardiopulmonary bypass (CPB), because, unlike RPs, CPs do not compress the tubing, and shear stress is considered lower in CPs than in RPs. However, relative platelet function remains unclear. Using multiple electrode aggregometry (MEA), we compared platelet function with CP and RP. ⋯ Platelet function, evaluated with MEA, was lowest 30 min after CPB was started but did not decrease over time in either group. As assessed by MEA, platelet function using CP and RP did not differ significantly. Platelet dysfunction was caused mainly by initial contact with foreign materials and may not be dependent on type of pump.
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Extracorporeal membrane oxygenation (ECMO) is a temporary mechanical circulatory assist method that offers circulatory as well as respiratory support efficiently via peripheral access; however, it is liable to complications. Limb ischemia is one of the notorious complications of ECMO but can be avoided utilizing a proper distal limb perfusion method. A retrospective study of patients undergoing peripheral venoarterial (VA) ECMO for various reasons between June 2010 and December 2012 was performed. ⋯ The mean cannula size was significantly greater than the mean introducer sheath size (11.1 ± 1.3 vs. 7.0 ± 1.1 Fr). Use of a distal-perfusion cannula is a most reliable method of limb perfusion in peripheral VA-ECMO. The cannula can ensure adequate and smooth perfusion of the limb owing to its large caliber, its less turbulent flow, the ability it provides to monitor the flow, and the option to attach a side port.
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Near-infrared spectroscopy (NIRS) is a noninvasive method used to evaluate tissue oxygenation. We evaluated the relationship between cerebral and renal NIRS parameters during transcatheter intervention and adverse events in the catheterization room. Between January 1 and May 31, 2012, 123 of 163 pediatric patients undergoing cardiac catheterization were followed by NIRS. ⋯ When arrhythmia developed, NIRS values fell simultaneously, while the development of a desaturation problem was heralded by NIRS falling 10-15 s earlier than changes in pulse oxymetry; on improving saturation, NIRS returned to earlier values 10-15 s before pulse oxymetry readings. NIRS monitoring may provide an early warning with regard to complications likely to develop during a procedure. A fall of 9% in cranial NIRS values, or of 21% in renal measurements, should raise clinician awareness.
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A mechanical blood pump specifically designed to increase pressure in the great veins would improve hemodynamic stability in adolescent and adult Fontan patients having dysfunctional cavopulmonary circulation. This study investigates the impact of axial-flow blood pumps on pressure, flow rate, and energy augmentation in the total cavopulmonary circulation (TCPC) using a patient-specific Fontan model. The experiments were conducted for three mechanical support configurations, which included an axial-flow impeller alone in the inferior vena cava (IVC) and an impeller with one of two different protective stent designs. ⋯ Retrograde flow was neither observed nor measured from the TCPC junction into the SVC. All of the pump configurations enhanced the rate of power gain of the cavopulmonary circulation by adding energy and rotational force to the fluid flow. We measured an enhancement of forward flow into the TCPC junction, reduction in IVC pressure, and only minimally increased pulmonary arterial pressure under conditions of pump support.
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Severe blood loss in victims of trauma creates an exaggerated inflammatory background that contributes to the development of intravascular coagulopathy and multiple organ dysfunction syndrome. We hypothesized that treatment with diphenyldifluoroketone EF24, an inhibitor of nuclear factor kappa-B, would have salutary effects in hemorrhagic shock. The objective of this study was to investigate the effect of EF24 on the expression of the interleukin-1 receptor (IL-1R) superfamily in a rat model of hypovolemic shock. ⋯ Simultaneously, the pulmonary expression of ST2 and SIGIRR (the putative down-regulators of the pro-inflammatory IL-1R pathway) was increased in EF24-treated hemorrhaged rats. The concentration of hemorrhage-induced TNF-α and IL-6 in lung tissue homogenates was also reduced by EF24 treatment. These results confirm our previous in vitro observations in lipopolysaccharide-stimulated dendritic cells that EF24 beneficially modulates the IL-1R pathway and suggest that it could be investigated as an adjunct therapeutic in managing inflammation associated with hemorrhagic shock.