Division of Pulmonary and Critical Care Medicine, Thomas Jefferson University, Philadelphia, PA, USA.
J Intensive Care Med. 2011 Mar-Apr;26(2):116-24. doi: 10.1177/0885066610384192.
Both occult hypoperfusion and volume overload are associated with increased morbidity and mortality in critically ill patients. Accurately predicting fluid responsiveness (FRes) allows for optimization of cardiac performance while avoiding fluid overload and prolonged mechanical ventilation.
To simultaneously assess the ability to predict FRes using the stroke volume variation (SVV) obtained with the Vigileo/Flotrac monitor and inferior vena cava respiratory variation (ΔIVC) measured by standard echocardiography ([ECHO) during mechanical ventilation.
We included medical intensive care unit (ICU) patients undergoing mechanical ventilation that required vasopressors, had worsening organ function, and that were well adapted to the ventilator. We excluded patients requiring escalating doses of vasopressors, hemodialysis, with ascites and patients with atrial fibrillation or a heart rate >120/min. Stroke volume index (SVI) and SVV were obtained from the Vigileo monitor whereas ΔIVC was obtained with ECHO (M-mode). Doppler ECHO was used to measure SVI and used to determine FRes (defined by SVI increase ≥ 10%). A data set was obtained before and 30 minutes after a 10-minute fluid challenge (FC) with 500 mL of saline.
In all, 25 patients were prospectively enrolled over an 8-month period. A total of 12 patients had acute respiratory distress syndrome (ARDS), 3 had a cardiac arrest, and 10 had sepsis. The patients' mean age was 61.36 years (±13.7), study enrollment since ICU admission was 3.4 days (±3.39), the Sequential Organ Failure Assessment (SOFA) score was 12.44 (±2.59), and the tidal volume 8.6 mL/kg (±1.68). Of the 25 patients, 8 (32%) were FRes. The correlation coefficient between the baseline ΔIVC and percentage increase in SVI (by ECHO) after an FC was R(2) = .51 with a receiver operating characteristic (ROC) curve of 0.81 while that for the baseline SVV by Vigileo was R(2) = .12 with an ROC curve of 0.57. The mean SVI bias between ECHO and Vigileo was -2 mL/m(2), the precision was -18 to 14 and the mean error was 46%.
ECHO assessment of the IVC variation during mechanical ventilation may prove to be a useful technique to predict FRes and guide fluid resuscitation in the ICU. The SVV obtained with the Vigileo monitor failed to predict FRes likely due to lack of calibration and the use of a complex algorithm that may be unreliable in patients with sepsis.
隐匿性低灌注和容量过负荷均与危重症患者的发病率和死亡率增加相关。准确预测液体反应性（FRes）可优化心功能，同时避免液体过负荷和延长机械通气时间。
同时评估使用 Vigileo/Flotrac 监测仪获得的每搏量变异度（SVV）和标准超声心动图测量的下腔静脉呼吸变异度（ΔIVC）预测 FRes 的能力，这两种方法均在机械通气时使用。
我们纳入了正在接受机械通气、需要升压药物、器官功能恶化且对呼吸机适应良好的重症监护病房（ICU）患者。排除了需要逐渐增加升压药物剂量、需要血液透析、有腹水和患有心房颤动或心率＞120 次/分钟的患者。通过 Vigileo 监测仪获得心排量指数（SVI）和 SVV，通过超声心动图（M 模式）获得 ΔIVC。多普勒超声心动图用于测量 SVI，并用于确定 FRes（定义为 SVI 增加≥10%）。在 10 分钟盐水负荷 500ml 后 30 分钟前，获得一组数据。
在 8 个月的时间内，前瞻性纳入了 25 名患者。共有 12 名患者患有急性呼吸窘迫综合征（ARDS），3 名患者发生心脏骤停，10 名患者患有败血症。患者的平均年龄为 61.36 岁（±13.7），自入住 ICU 以来的研究纳入时间为 3.4 天（±3.39），序贯器官衰竭评估（SOFA）评分为 12.44（±2.59），潮气量为 8.6ml/kg（±1.68）。在 25 名患者中，有 8 名（32%）为 FRes。FC 后基线 ΔIVC 与 ECHO 检测到的 SVI 百分比增加之间的相关系数为 R（2）=.51，ROC 曲线为 0.81，而通过 Vigileo 获得的基线 SVV 的 R（2）=.12，ROC 曲线为 0.57。ECHO 和 Vigileo 之间的平均 SVI 偏差为 2ml/m（2），精密度为-18 至 14，平均误差为 46%。
机械通气期间通过超声心动图评估下腔静脉变异度可能是一种有用的技术，可以预测 FRes，并指导 ICU 中的液体复苏。通过 Vigileo 监测仪获得的 SVV 无法预测 FRes，这可能是由于缺乏校准和使用可能在脓毒症患者中不可靠的复杂算法所致。
