Research Centre for Emergency Medicine, Institute of Clinical Medicine, Aarhus University, Nørrebrogade 44, Building 30, 1st Floor, 8000, Århus C, Denmark,
J Clin Monit Comput. 2014 Aug;28(4):341-9. doi: 10.1007/s10877-013-9528-4. Epub 2013 Nov 8.
Monitoring that can predict fluid responsiveness is an unsettled matter for spontaneously breathing patients. Based on the convincing results with dynamic monitoring based on preload variations induced by mechanical ventilation, we hypothesised that the extra systolic post-ectopic beat could constitute a similar intermittent preload shift inducing a brief variation in blood pressure and that the magnitude of this variation could predict the hemodynamic response to volume expansion in sedated pigs. Ten pigs were sedated and hemodynamically monitored and four intravascular volume shifts were made: blood depletion (25% of estimated blood volume; 660 ml), retransfusion (of 500 ml depleted blood), and two sequential volume expansions (500 ml colloid each). Between volume shifts, supraventricular and ventricular extra systoles were induced by a pacemaker. Hemodynamic variables such as pulse pressure (PP) and pre-ejection period (PEP) were determined for each heart beat and the hemodynamic changes in the post-ectopic beats compared to sinus beats was extracted (e.g. ∆PP and ∆PEP) and used to predict fluid responsiveness of subsequent volume expansions which was determined by receiver operating characteristic (ROC) curves. Ventricular extra systoles were generally useful for fluid responsiveness prediction (ROC areas >0.65). ∆PEP variables best predicted fluid responsiveness: ∆PEP derived from arterial pressure curve and ECG had ROC area of 0.84 and sensitivity of 0.77 and specificity of 0.71; ∆PEP derived from plethysmographic curve and ECG had ROC area of 0.79 and sensitivity of 0.71 and specificity of 0.70. However, ∆PP was not a useful variable in this study (ROC area <0.65). Hemodynamic analysis of post ectopic beats may be a feasible method for fluid responsiveness prediction.
监测能够预测液体反应性的方法对于自主呼吸患者来说仍然存在争议。基于机械通气引起的前负荷变化的动态监测具有令人信服的结果，我们假设异位心搏后的额外收缩期可以构成类似的间歇性前负荷转移，引起短暂的血压变化，并且这种变化的幅度可以预测镇静猪容量扩张的血流动力学反应。10 头猪接受镇静和血流动力学监测，并进行了 4 次血管内容量转移：血液耗竭（估计血容量的 25%；660ml）、再输血（500ml 耗竭血液）和两次连续容量扩张（各 500ml 胶体）。在容量转移之间，通过起搏器诱导室上性和室性异位搏动。确定每个心跳的脉搏压（PP）和射血前期（PEP）等血流动力学变量，并提取异位心搏与窦性心搏相比的血流动力学变化（例如，∆PP 和 ∆PEP），并用于预测随后的容量扩张的液体反应性，通过接收者操作特征（ROC）曲线确定。室性异位搏动通常可用于预测液体反应性（ROC 区域>0.65）。∆PEP 变量最能预测液体反应性：从动脉压力曲线和心电图得出的 ∆PEP 的 ROC 面积为 0.84，灵敏度为 0.77，特异性为 0.71；从容积描记曲线和心电图得出的 ∆PEP 的 ROC 面积为 0.79，灵敏度为 0.71，特异性为 0.70。然而，在这项研究中，∆PP 不是一个有用的变量（ROC 区域<0.65）。异位心搏后的血流动力学分析可能是预测液体反应性的一种可行方法。
