Service d'Anesthésie Réanimation 1, Hôpital Pellegrin, CHU Bordeaux, Place Amélie Raba-Léon, 33076 Bordeaux Cedex, France.
Crit Care. 2009;13(6):R195. doi: 10.1186/cc8195. Epub 2009 Dec 7.
Passive leg raising (PLR) is a simple reversible maneuver that mimics rapid fluid loading and increases cardiac preload. The effects of this endogenous volume expansion on stroke volume enable the testing of fluid responsiveness with accuracy in spontaneously breathing patients. However, this maneuver requires the determination of stroke volume with a fast-response device, because the hemodynamic changes may be transient. The Vigileo monitor (Vigileo; Flotrac; Edwards Lifesciences, Irvine, CA, USA) analyzes systemic arterial pressure wave and allows continuous stroke volume monitoring. The aims of this study were (i) to compare changes in stroke volume induced by passive leg raising measured with the Vigileo device and with transthoracic echocardiography and (ii) to compare their ability to predict fluid responsiveness.
Thirty-four patients with spontaneous breathing activity and considered for volume expansion were included. Measurements of stroke volume were obtained with transthoracic echocardiography (SV-TTE) and with the Vigileo (SV-Flotrac) in a semi-recumbent position, during PLR and after volume expansion (500 ml saline). Patients were responders to volume expansion if SV-TTE increased > or = 15%.
Four patients were excluded. No patients received vasoactive drugs. Seven patients presented septic hypovolemia. PLR-induced changes in SV-TTE and in SV-Flotrac were correlated (r2 = 0.56, P < 0.0001). An increase in SV-TTE > or = 13% during PLR was predictive of response to volume expansion with a sensitivity of 100% and a specificity of 80%. An increase in SV-Flotrac > or =16% during PLR was predictive of response to volume expansion with a sensitivity of 85% and a specificity of 90%. There was no difference between the area under the ROC curve for PLR-induced changes in SV-TTE (AUC = 0.96 +/- 0.03) or SV-Flotrac (AUC = 0.92 +/- 0.05). Volume expansion-induced changes in SV-TTE correlated with volume expansion-induced changes in SV-Flotrac (r2 = 0.77, P < 0.0001). In all patients, the highest plateau value of SV-TTE recorded during PLR was obtained within the first 90 s following leg elevation, whereas it was 120 s for SV-Flotrac.
PLR-induced changes in SV-Flotrac are able to predict the response to volume expansion in spontaneously breathing patients without vasoactive support.
被动抬腿（PLR）是一种简单的可逆转操作，可模拟快速液体负荷并增加心脏前负荷。这种内源性容量扩张对每搏量的影响使我们能够在自主呼吸的患者中准确地测试液体反应性。然而，这种操作需要使用快速响应设备来确定每搏量，因为血流动力学变化可能是短暂的。Vigileo 监护仪（Vigileo；Flotrac；爱德华生命科学公司，加利福尼亚州欧文，美国）分析系统动脉压力波，并允许连续监测每搏量。本研究的目的是：（i）比较被动抬腿引起的每搏量变化，通过 Vigileo 设备与经胸超声心动图测量；（ii）比较它们预测液体反应性的能力。
纳入 34 例具有自主呼吸活动且考虑容量扩张的患者。在半卧位时，通过经胸超声心动图（SV-TTE）和 Vigileo（SV-Flotrac）获得每搏量测量值，在 PLR 和容量扩张后（500ml 生理盐水）。如果 SV-TTE 增加≥15%，则患者对容量扩张有反应。
排除了 4 名患者。没有患者接受血管活性药物。7 例患者出现脓毒性低血容量。SV-TTE 和 SV-Flotrac 诱导的 PLR 变化相关（r2=0.56，P<0.0001）。PLR 期间 SV-TTE 增加≥13%可预测对容量扩张的反应，其敏感性为 100%，特异性为 80%。PLR 期间 SV-Flotrac 增加≥16%可预测对容量扩张的反应，其敏感性为 85%，特异性为 90%。SV-TTE 诱导的 PLR 变化的 ROC 曲线下面积（AUC）无差异（AUC=0.96±0.03）或 SV-Flotrac（AUC=0.92±0.05）。SV-TTE 诱导的容量扩张变化与 SV-Flotrac 诱导的容量扩张变化相关（r2=0.77，P<0.0001）。在所有患者中，PLR 期间记录的 SV-TTE 的最高平台值在抬腿后 90s 内获得，而 SV-Flotrac 则为 120s。
在没有血管活性支持的情况下，SV-Flotrac 诱导的 PLR 变化能够预测自主呼吸患者对容量扩张的反应。
