Dynamic arterial elastance (Ea dyn ), the ratio between pulse pressure variation (PPV) and stroke volume variation (SVV), has been suggested as a dynamic parameter relating pressure and flow. We aimed to determine the effects of endotoxic septic shock and hemodynamic resuscitation on Ea dyn in an experimental study in 18 New Zealand rabbits. Animals received placebo (SHAM, n = 6) or intravenous lipopolysaccharide (E. Coli 055:B5, 1 mg⋅kg – 1 ) with or without (EDX-R, n = 6; EDX, n = 6) hemodynamic resuscitation (fluid bolus of 20 ml⋅kg – 1 and norepinephrine for restoring mean arterial pressure). Continuous arterial pressure and aortic blood flow measurements were obtained simultaneously. Cardiovascular efficiency was evaluated by the oscillatory power fraction [%Osc: oscillatory work/left ventricular (LV) total work] and the energy efficiency ratio (EER = LV total work/cardiac output). Ea dyn increased in septic animals (from 0.73 to 1.70; p = 0.012) and dropped after hemodynamic resuscitation. Ea dyn was related with the %Osc and EER [estimates: −0.101 (−0.137 to −0.064) and −9.494 (−11.964 to −7.024); p < 0.001, respectively]. So, the higher the Ea dyn, the better the cardiovascular efficiency (lower %Osc and EER). Sepsis resulted in a reduced %Osc and EER, reflecting a better cardiovascular efficiency that was tracked by Ea dyn . Ea dyn could be a potential index of cardiovascular efficiency during septic shock.
Background: Dynamic arterial elastance (Ea dyn ), the ratio between pulse pressure variation (PPV) and stroke volume variation (SVV), has been suggested as a functional parameter that is a surrogate of arterial load. We aimed to determine the effects of endotoxic septic shock and hemodynamic resuscitation on Ea dyn . Results: Experimental randomized study in a university animal research laboratory with 18 New Zealand rabbits. Animals received placebo (SHAM, n=6) or intravenous lipopolysaccharide (LPS, Escherichia coli serotype 055:B5, 1 mg·kg -1 ) with or without (EDX-R, n=6; EDX-NR, n=6) hemodynamic resuscitation (fluid bolus of 20 ml·kg -1 and norepinephrine for restoring mean arterial pressure). Continuous arterial pressure and aortic blood flow measurements were obtained simultaneously. Cardiovascular efficiency was evaluated by the oscillatory power fraction (%Osc: oscillatory work / left ventricular (LV) total work) and the energy efficiency ratio (EER = LV total work/cardiac output). The LPS-induced endotoxic shock produced a hyperdynamic shock with high cardiac output and arterial hypotension. Ea dyn increased in septic animals (from 0.73 to 1.70; p=0.012) and dropped after hemodynamic resuscitation. Ea dyn was related with the %Osc and EER [estimates: -0.101 (-0.137 – -0.064) and -9.494 (-11.964 – -7.024); p<0.001, respectively]. So, the higher the Ea dyn, the better the cardiovascular efficiency (lower %Osc and EER). Conclusions: In this experimental model, Ea dyn increased during endotoxic septic shock and decreased with hemodynamic resuscitation. Sepsis resulted in a reduced oscillatory power fraction and lowered EER, reflecting a better cardiovascular efficiency that was tracked by Ea dyn . Ea dyn could be a potential index of cardiovascular efficiency during septic shock.
En diversas ocasiones Pietro Laureano nos ha explicado como una serie de gotas de agua, primorosamente conducidas, pueden dar lugar a un pequeño oasis, al inicio, o convertirse después, en asentamientos como Petra, Shibaz, o tantos otros monumentos de piedra y arena, que encontramos en Capadocia, en el Sahara o en Yemen. Incluso el más remoto desierto, monumento de la naturaleza, puede devenir un rico paisaje cultural incorporando el trabajo humano, siempre que se puedan captar y conducir hábilmente unas pocas gotas de agua, mediante sofisticadas canalizaciones esculpidas perseverantemente en la tierra. Son estas mismas gotas de agua las que están a la base de tantos paisajes culturales, epopeyas seculares en diversos rincones del planeta, desde Gobi al Yucatán, pasando por los qanats que confirieron vida a tantas ciudades persas; o mucho más cerca, en Mattera
ResumenEl presente artículo trata de condensar la experiencia fruto del intercambio académico de ideas sobre la incorporación de la noción de "paisaje cultural" como instrumento de planeamiento urbano y territorial en un pequeño pueblo de tradición rural del interior de China llamado Daxu. En el contexto del acelerado proceso de transformación urbana y territorial propio del gran país asiático, se afronta la problemática de incorporar el concepto de "paisaje cultural" como eje de las actuaciones del máster plan de este municipio rural, con el objetivo de ayudar a un desarrollo local sostenible. Palabras clavePaisaje cultural. Intercambio académico. Planeamiento urbano y territorial. China. Exchanges on the notion of cultural landscape: the experience in the city of Daxu [Jianghua County, Hunan] China AbstractThis article tries to summarize the experience of an academic exchange on the incorporation of "cultural landscape" notion as an instrument for urban and regional planning in a small Chinese village called Daxu. In the context of Chinese's accelerated urban and territorial transformation process, this experience tackles the problem of incorporating the concept of "cultural landscape" in this rural municipality master plan in order to create a sustainable local development.
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