Cameli Matteo, Bigio Elisa, Lisi Matteo, Righini Francesca M, Galderisi Maurizio, Franchi Federico, Scolletta Sabino, Mondillo Sergio
Department of Medical Biotechnologies, University of Siena, Italy.
Unit of Cardiovascular Diseases, University of Siena, Italy.
Clin Physiol Funct Imaging. 2015 Sep;35(5):344-50. doi: 10.1111/cpf.12168. Epub 2014 Jun 5.
Pulse pressure variation (PPV) is a dynamic index of fluid responsiveness. This parameter helps clinicians in improving haemodynamic status while avoiding potential fluid overload. Echocardiographic indices, such as E/E' ratio and left atrial (LA) strain by speckle tracking echocardiography (STE), are used to estimate left ventricular (LV) filling pressures. This study aimed at exploring the relationship between PPV and echocardiographic indices of LV filling pressures in critically ill patients.
Twenty-two patients (mean age of 50.9 ± 21.6, male/female = 15/7) admitted to intensive care unit, and requiring mechanical ventilation and invasive arterial pressure monitoring, were studied. In all patients, two independent operators assessed simultaneously PPV, using a pulse contour method, mean E/E' ratio and peak atrial longitudinal strain (PALS) by means of STE. PALS values were obtained by averaging LA segments measured in the 4-chamber and 2-chamber views (global PALS).
A significant negative correlation was found between mean E/E' ratio and PPV (R(2) = -0.76; P<0.001). A positive correlation between global PALS and PPV was found (R(2) = 0.80, P<0.001). Mean global PALS of 26.2% demonstrated excellent accuracy (Area Under Roc Curve = 0.86, P<0.001), and good sensitivity (92%) and specificity (86%) in predicting a PPV >15%.
In a group of mechanically ventilated patients PPV, derived from pulse contour analysis, and echocardiographic preload parameters were well correlated. Global PALS by STE provided better estimation of PPV than mean E/E' ratio. PALS seems a potential alternative to PPV in assessing fluid responsiveness in critically ill patients.
脉压变异（PPV）是液体反应性的动态指标。该参数有助于临床医生改善血流动力学状态，同时避免潜在的液体过载。超声心动图指标，如E/E'比值和斑点追踪超声心动图（STE）测量的左心房（LA）应变，用于估计左心室（LV）充盈压。本研究旨在探讨重症患者中PPV与LV充盈压超声心动图指标之间的关系。
研究了22例入住重症监护病房、需要机械通气和有创动脉压监测的患者（平均年龄50.9±21.6岁，男/女=15/7）。在所有患者中，两名独立操作人员同时使用脉搏轮廓法评估PPV，通过STE评估平均E/E'比值和心房纵向峰值应变（PALS）。PALS值通过平均在四腔心和两腔心视图中测量的LA节段获得（整体PALS）。
平均E/E'比值与PPV之间存在显著负相关（R²=-0.76；P<0.001）。发现整体PALS与PPV之间存在正相关（R²=0.80，P<0.001）。平均整体PALS为26.2%，在预测PPV>15%时显示出优异的准确性（曲线下面积=0.86，P<0.001），以及良好的敏感性（92%）和特异性（86%）。
在一组机械通气患者中，通过脉搏轮廓分析得出的PPV与超声心动图预负荷参数密切相关。与平均E/E'比值相比，STE测量的整体PALS对PPV的估计更好。在评估重症患者的液体反应性方面，PALS似乎是PPV的潜在替代指标。
