Dynamic and volumetric variables of fluid responsiveness fail during immediate postresuscitation period*

Objective Fluid therapy after resuscitation from cardiac arrest is challenging since both hypovolemia and fluid overload may cause circulatory failure. Therefore, prediction of fluid responsiveness is a major issue in optimizing hemodynamic therapy. The aim of the present study was to evaluate the performance of stroke volume variation, pulse pressure variation, variation of Doppler-derived velocity time integral, and global end-diastolic volume index to predict fluid responsiveness in the postcardiac arrest period. Design Prospective animal study. Setting University-affiliated research laboratory. Subjects Twenty anesthetized and ventilated Goettinger minipigs. Intervention Animals were equipped with a central venous catheter, a thermistor-tipped arterial catheter, and a transesophageal echo probe. Electrically induced cardiac arrest of 8 mins was followed by cardiopulmonary resuscitation. Hemodynamic measurements were performed before and after a two-step fluid bolus at baseline and both 1 and 4 hrs after return of spontaneous circulation. Fluid responsiveness was defined by an increase in stroke volume of at least 15%. Performance of variables was analyzed using receiver operator characteristics analysis. Measurement and main results Variables reliably indicated fluid responsiveness at baseline. Fifteen animals were successfully resuscitated. Left ventricular ejection fraction was significantly reduced 1 hr after return of spontaneous circulation (52.6% ± 6.4%; p < .01) compared with baseline (69.9% ± 5.3%). One hour after return of spontaneous circulation, fluid responsiveness could not be predicted by any variable. In contrast, pulse pressure variation, variation of the velocity time integral, and global end-diastolic volume index, but not stroke volume variation, were able to predict fluid responsiveness 4 hrs after return of spontaneous circulation, since area under the curve was 0.85 (p < .01), 0.94 (p < .01), 0.77 (p = .02), and 0.68 (p = .12), respectively. Conclusions Prediction of fluid responsiveness failed 1 hr after successful cardiopulmonary resuscitation from cardiac arrest. Four hours after return of spontaneous circulation, however, the variables pulse pressure variation, variation of the velocity time integral, and global end-diastolic volume index, but not stroke volume variation, enabled prediction of fluid responsiveness and may, therefore, be considered for subsequent hemodynamic optimization after successful cardiopulmonary resuscitation.