Hospices Civils de Lyon, Department of Anesthesiology and Intensive Care, Louis Pradel Hospital, Claude Bernard Lyon 1 University, INSERM ERI 22, Lyon, France.
Br J Anaesth. 2011 Sep;107(3):329-35. doi: 10.1093/bja/aer165. Epub 2011 Jun 16.
Plethysmographic variability index (PVI) is an accurate predictor of fluid responsiveness in mechanically ventilated patients. However, the site of measurement of the plethysmographic waveform impacts its morphology and its respiratory variation. The goal of this study was to investigate the ability of PVI to predict fluid responsiveness at three sites of measurement (the forehead, ear, and finger) in mechanically ventilated patients under general anaesthesia.
We studied 28 subjects after induction of general anaesthesia. Subjects were monitored with a pulmonary artery catheter and three pulse oximeter sensors (the finger, ear, and forehead). Pulse pressure variation, central venous pressure, cardiac index (CI), and PVI measured at the forehead, ear, and finger (PVI(forehead), PVI(ear), and PVI(finger)) were recorded before and after fluid loading (FL). Subjects were responders to volume expansion if CI increased >15% after FL.
Areas under the receiver-operating curves to predict fluid responsiveness were 0.906, 0.880, and 0.836 for PVI(forehead), PVI(ear), and PVI(finger), respectively (P<0.05). PVI(forehead), PVI(ear), and PVI(finger) had a threshold value to predict fluid responsiveness of 15%, 16%, and 12% with sensitivities of 89%, 74%, and 74% and specificities of 78%, 74%, and 67%, respectively.
PVI can predict fluid responsiveness in anaesthetized and ventilated subjects at all three sites of measurement. However, the threshold values for predicting fluid responsiveness differ with the site of measurement. These results support the use of this plethysmographic dynamic index in the cephalic region when the finger is inaccessible or during states of low peripheral perfusion.
容积描记变异指数（PVI）是机械通气患者液体反应性的准确预测指标。然而，容积描记波形态的测量部位会影响其形态及其呼吸变化。本研究旨在探讨 PVI 在全身麻醉下机械通气患者三个测量部位（额头、耳朵和手指）预测液体反应性的能力。
我们研究了全身麻醉诱导后 28 名患者。患者使用肺动脉导管和三个脉搏血氧仪传感器（手指、耳朵和额头）进行监测。在液体负荷（FL）前后记录脉搏压变异、中心静脉压、心指数（CI）和额头、耳朵和手指处的 PVI（PVI（额头）、PVI（耳朵）和 PVI（手指））。如果 FL 后 CI 增加>15%，则认为患者对容量扩张有反应。
预测液体反应性的受试者工作特征曲线下面积分别为 0.906、0.880 和 0.836，用于 PVI（额头）、PVI（耳朵）和 PVI（手指）（P<0.05）。PVI（额头）、PVI（耳朵）和 PVI（手指）预测液体反应性的阈值分别为 15%、16%和 12%，敏感性分别为 89%、74%和 74%，特异性分别为 78%、74%和 67%。
PVI 可预测全身麻醉和机械通气患者所有三个测量部位的液体反应性。然而，预测液体反应性的阈值因测量部位而异。这些结果支持在手指不可及或外周灌注低时在头侧区域使用这种容积描记动态指数。
