“灰色地带”液体反应性的预测指标：通过增加潮气量暂时增加脉压变异度。

Predictor of fluid responsiveness in the 'grey zone': augmented pulse pressure variation through a temporary increase in tidal volume.

机构信息

Department of Anaesthesiology and Pain Medicine, Samsung Medical Centre, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 06351, Republic of Korea.

出版信息

Br J Anaesth. 2017 Jul 1;119(1):50-56. doi: 10.1093/bja/aex074.

DOI:10.1093/bja/aex074

PMID:28974059

Abstract

BACKGROUND

Pulse pressure variation (PPV) is widely used as a predictor of fluid responsiveness. However, a previous study has suggested a 'grey zone' between 9 and 13% in which PPV would be inconclusive to predict fluid responsiveness. Considering PPV is based on cardiopulmonary interactions, we evaluated whether an augmented PPV using a temporary increase in tidal volume (V T ) from 8 to 12 ml kg -1 has the predictability for fluid responsiveness in patients within the grey zone.

METHODS

Adult patients requiring general anaesthesia were enrolled. During the period when PPV was within the range of 9-13%, haemodynamic variables such as stroke volume index (SVI) and PPV with an 8 ml kg -1 tidal volume ventilation (PPV8) were obtained before and after volume expansion (6 ml kg -1 ) under mechanical ventilation. Augmented PPV induced by 2-min ventilation with a V T of 12 ml kg -1 (PPV12) was also recorded immediately before volume loading. The patients whose SVI increased ≥10% after volume expansion were considered responders.

RESULTS

In 38 enrolled patients, 20 were responders. Receiver operating characteristic curve analysis showed PPV12 had an excellent predictability for fluid responsiveness {area under the curve [AUC]=0.935 [95% confidence interval (CI) 0.805-0.989]; sensitivity 95%; specificity 72%; P <0.0001}. The optimal threshold for PPV12 was >17%. However, PPV8 failed to show significant predictability [AUC=0.668 (95% CI 0.497-0.812); sensitivity 65%; specificity 61%; P =0.06].

CONCLUSION

In mechanically ventilated patients, our augmented PPV successfully predicted fluid responsiveness in the previously suggested grey zone.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02653469.

摘要

背景

脉压变异度（PPV）被广泛用作预测液体反应性的指标。然而，先前的一项研究表明，在 9%至 13%之间存在一个“灰色地带”，在此范围内，PPV 无法确定是否能够预测液体反应性。鉴于 PPV 是基于心肺相互作用的，我们评估了在灰色地带内的患者中，使用临时增加潮气量（V T ）从 8 至 12ml/kg 是否可以增强 PPV 来预测液体反应性。

方法

纳入需要全身麻醉的成年患者。在 PPV 处于 9-13%范围内的期间内，在机械通气下，通过 6ml/kg 的容量扩张，在容量扩张（6ml/kg）前后获得血流动力学变量，如每搏指数（SVI）和 8ml/kg 潮气量通气的 PPV（PPV8）。在进行容量加载之前，还记录了通过 2 分钟通气（V T 为 12ml/kg）诱导的增强 PPV（PPV12）。将 SVI 在容量扩张后增加≥10%的患者视为有反应者。

结果

在 38 名纳入的患者中，有 20 名是有反应者。受试者工作特征曲线分析显示，PPV12 对液体反应性具有极好的预测性{曲线下面积（AUC）=0.935[95%置信区间（CI）0.805-0.989]；灵敏度 95%；特异性 72%；P<0.0001}。PPV12 的最佳阈值>17%。然而，PPV8 未能显示出显著的预测性[AUC=0.668（95%CI 0.497-0.812）；灵敏度 65%；特异性 61%；P=0.06]。