Background

The plethysmography variability index (PVI) is a non-invasive, real-time, and automated parameter for evaluating fluid responsiveness, but it does not reliably predict fluid responsiveness during low tidal volume (V_T) ventilation. We hypothesized that in a ‘tidal volume challenge’ with a transient increase in tidal volume from 6 to 8 ml Kg^− 1, the changes in PVI could predict fluid responsiveness reliably.

Method

We performed a prospective interventional study in adult patients undergoing hepatobiliary or pancreatic tumor resections and receiving controlled low V_T ventilation. The values for PVI, perfusion index, stroke volume variation, and stroke volume index (SVI) were recorded at baseline V_T of 6 ml Kg^− 1, 1 min after the V_T challenge (8 ml Kg^− 1), 1 min after V_T 6 ml Kg^− 1 reduced back again, and then 5 min after crystalloid fluid bolus 6 ml kg^− 1 (actual body weight) administered over 10 min. The fluid responders were identified by SVI rise ≥ 10% after the fluid bolus.

Results

The area under the receiver operating characteristic curve for PVI value change (ΔPVI_6–8) after increasing V_T from 6 to 8 ml Kg^− 1 was 0.86 (95% confidence interval, 0.76–0.96), P < 0.001, 95% sensitivity, 68% specificity, and with best cut-off value of absolute change (ΔPVI_6–8) = 2.5%.

Conclusion

In hepatobiliary and pancreatic surgeries, tidal volume challenge improves the reliability of PVI for predicting fluid responsiveness and changes in PVI values obtained after tidal volume challenge are comparable to the changes in SVI.

中文翻译：

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潮气量挑战对肝胆胰手术中体积描记变异性指数可靠性的影响：一项前瞻性介入研究

背景

体积描记变异性指数 (PVI) 是用于评估液体反应性的无创、实时、自动化参数，但它不能可靠地预测低潮气量 (V T ) 通气期间的液体反应_性。我们假设，在潮气量从 6 ml Kg - 1 瞬时增加到 8 ml Kg ^{- 1 的}“潮气量挑战”中，PVI 的变化可以可靠地预测液体反应性。

方法

_{我们对接受肝胆或胰腺肿瘤切除术并接受受控低潮气量}通气的成年患者进行了一项前瞻性干预研究。PVI、灌注指数、每搏输出量变化和每搏输出量指数 (SVI) 的值在6 ml Kg ^{− 1的基线 V} _T、V _T激发后 1 分钟（8 ml Kg ^{− 1}）、1 分钟后记录V _T 6 ml Kg ^{− 1}再次减少，然后在 10 分钟内推注晶体液 6 ml kg ^{− 1}（实际体重）后 5 分钟。输液反应者通过输液后 SVI 上升 ≥ 10% 来确定。

结果

将 V _T从 6 ml Kg ^{− 1增加到 8 ml Kg − 1 后，PVI 值变化 (ΔPVI} _6–8 )的受试者工作特征曲线下面积为 0.86（95% 置信区间，0.76–0.96），P  < 0.001，95% 灵敏度，68% 特异性，绝对变化的最佳截止值 (ΔPVI _6–8 ) = 2.5%。

结论

在肝胆和胰腺手术中，潮气量挑战提高了 PVI 预测液体反应性的可靠性，潮气量挑战后获得的 PVI 值的变化与 SVI 的变化相当。