The aims of fluid resuscitation are the achievement of an adequate cardiac output (CO) and sufficient mean arterial blood pressure (MAP) for the body to maintain tissue oxygenation. Noninvasive Ea dyn, defined as the PPV to SVV ratio, predicted the arterial blood pressure increase to fluid administration in spontaneously breathing, preload-dependent patients. A preinfusion Ea dyn value ≥1.06 (gray zone: 0.9–1.15) discriminated MAP-responders with a sensitivity and specificity of 88.2% (approximate 95% confidence interval, 64%–99%), respectively. Preinfusion Ea dyn predicted a positive MAP response to FC with an area under the receiver-operating characteristic curve of 0.92 ± 0.04 of standard error (95% confidence interval, 0.78–0.99 P < 0.0001).
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Preinfusion Ea dyn was significantly higher in MAP-responders (1.39 ± 0.41 vs 0.85 ± 0.23 P = 0.0001). Seventeen FCs (50%) induced a positive MAP response. Thirty-four FCs from 26 patients were studied. Ea dyn was continuously calculated from the PPV and SVV values obtained from the monitor. Patients were classified according to the increase in mean arterial blood pressure (MAP) after FC into MAP-responders (MAP increase ≥10%) and MAP-nonresponders (MAP increase <10%). Patients were included in the analysis if they were spontaneously breathing and had an increase in cardiac output ≥10% during an FC. Patients admitted postoperatively and monitored with the Nexfin monitor (BMEYE, Amsterdam, The Netherlands) were enrolled in the study. In this study, we assessed the effectiveness of Ea dyn to predict the arterial blood pressure response to a fluid challenge (FC) in preload-dependent, spontaneously breathing patients. Dynamic arterial elastance (Ea dyn), defined as the pulse pressure variation (PPV) to stroke volume variation (SVV) ratio, has been suggested as a predictor of the arterial pressure response to fluid administration.