Mini-fluid challenge test predicts stroke volume and arterial pressure fluid responsiveness during spine surgery in prone position

Figures

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  Figure 1. Fluid challenge protocol. Continuous fluid challenge was performed by infusing 500 mL of colloid solution over 15 minutes. Hemodynamic measurements including heart rate, mean arterial pressure, systolic blood pressure, stroke volume, pulse pressure variation, stroke volume variation, and plethysmographic variability index were performed before fluid challenge (baseline), 1 minute after infusing the initial 100 mL during 1 minute (T1), and 1 minute after fluid challenge (T2).

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  Figure 2. Study flowchart.

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  Figure 3. Prediction of SV fluid responsiveness. Receiver operating characteristic curves were calculated for ΔSV100 (increase in SV induced by mini-fluid challenge) and baseline SV, PPV, SVV, and PVI. SV fluid responsiveness was defined as a 15% or greater increase in SV from baseline after fluid challenge with 500 mL of colloid. ∗denotes a significant difference between the AUROC of variables and that of ΔSV100 (P < .05). AUROC = area under the receiver operating curve, CI = confidence interval, PPV = pulse pressure variation, PVI = plethysmographic variability index, SV = stroke volume, SVV = stroke volume variation.

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  Figure 4. Prediction of arterial pressure fluid responsiveness. Receiver operating characteristic curves were calculated for ΔSBP100 (increase in SBP induced by mini-fluid challenge), ΔSV100 (increase in SV induced by mini-fluid challenge), and baseline Eadyn. Fluid responsiveness in arterial pressure was defined as a 15% or greater increase in MAP from baseline after fluid challenge with 500 mL of colloid. ∗denotes a significant difference between the AUROC of variables and that of ΔSBP100 (P < .05). AUROC = area under the receiver operating curve, CI = confidence interval, Eadyn = dynamic arterial elastance, MAP = mean arterial pressure, SBP = systolic blood pressure, SV = stroke volume.