Einfluss der Impella-Mikroaxialpumpe auf den Renal Resistive Index (RRI) als Marker für die renale Funktion

The prerenal acute kidney failure after infarct-induced cardiogenic shock is still a frequent complication with high mortality. At the moment there are only a few therapeutic approaches to reduce the prevalence and lethality of this complication. Temporary hemodynamic support of the circulatory system by means of a mechanical pump system is one of the possible approaches. The study by Flaherty and colleagues from 2017 already showed the positive effects of mechanical cardiac support using an Impella-microaxial-pump in hospitalized critically ill patients. The Impella-systems belong to the intracorporeal left ventricular mechanical cardiac support systems. The systems support the cardiac system by means of continuous blood transport from the left ventricle into the aorta and lead to an improvement in the perfusion of all organs. Previous studies examined the improvement of renal perfusion with the support of the cardiac output by means of an Impella-microaxial-pump. These studies used only the blood analysis of creatinine and diuresis of the patient to detect renal problems. Our study was the first one to use sonographic RRI detection to demonstrate the positive influence of mechanical cardiac support on the renal system. The sonographic measurement of the RRI can show the hemodynamic influence of the Impella-microaxial-pump more specifically and without interference of other factors than the blood analysis of the creatinine. Our results showed a significant decrease of the RRI by increasing the cardiac output by the use of mechanical cardiac assistance. An increase of the Impella-performance by +0.5 L/min showed a significant (p <0.001) reduction of the RRI by 0.07 (9.6%). The increase of the performance to +1.0 L/min even resulted in a significant (p <0.001) reduction in the RRI by 0.115 (15.74%). The positive influence of the Impella-microaxialpump on renal perfusion could therefore also be demonstrated by means of RRI detection and should be considered a possible approach to reducing renal complications in cardiogenic shock.