He Huai-wu, Liu Da-wei, Long Yun, Wang Xiao-ting
Crit Care. 2013 Jun 20;17(3):R116. doi: 10.1186/cc12788.
The peripheral perfusion index (PI) is a noninvasive numerical value of peripheral perfusion, and the transcutaneous oxygen challenge test (OCT) is defined as the degree of transcutaneous partial pressure of oxygen (PtcO2) response to 1.0 FiO2. The value of noninvasive monitoring peripheral perfusion to predict outcome remains to be established in septic patients after resuscitation. Moreover, the prognostic value of PI has not been investigated in septic patients.
Forty-six septic patients, who were receiving PiCCO-Plus cardiac output monitoring, were included in the study group. Twenty stable postoperative patients were studied as a control group. All the patients inspired 1.0 of FiO2 for 10 minutes during the OCT. Global hemodynamic variables, traditional metabolic variables, PI and OCT related-variables were measured simultaneously at 24 hours after PiCCO catheter insertion. We obtained the 10 min-OCT ((PtcO2 after 10 minutes on inspired 1.0 oxygen)--(baseline PtcO2)), and the oxygen challenge index ((10 min-OCT)/(PaO2 on inspired 1.0 oxygen--baseline PaO2)) during the OCT.
The PI was significantly correlated with baseline PtcO2, 10 min-OCT and oxygen challenge index (OCI) in all the patients. The control group had a higher baseline PtcO2, 10 min-OCT and PI than the septic shock group. In the sepsis group, the macro hemodynamic parameters and ScvO2 showed no differences between survivors and nonsurvivors. The nonsurvivors had a significantly lower PI, 10 min-OCT and OCI, and higher arterial lactate level. The PI, 10 min-OCT and OCI predicted the ICU mortality with an accuracy that was similar to arterial lactate level. A PI<0.2 and a 10 min-OCT<66 mmHg were related to poor outcome after resuscitation.
The PI and OCT are predictive of mortality for septic patients after resuscitation. Further investigations are required to determine whether the correction of an impaired level of peripheral perfusion may improve the outcome of septic shock patients.
外周灌注指数（PI）是外周灌注的无创数值，经皮氧激发试验（OCT）定义为经皮氧分压（PtcO2）对1.0 FiO2的反应程度。复苏后脓毒症患者中，无创监测外周灌注以预测预后的价值仍有待确定。此外，PI在脓毒症患者中的预后价值尚未得到研究。
研究组纳入46例接受PiCCO-Plus心输出量监测的脓毒症患者。选取20例术后病情稳定的患者作为对照组。在OCT期间，所有患者吸入1.0 FiO2持续10分钟。在插入PiCCO导管24小时后，同时测量整体血流动力学变量、传统代谢变量、PI和OCT相关变量。我们在OCT期间获得了10分钟OCT（吸入1.0氧气10分钟后的PtcO2 - 基线PtcO2）和氧激发指数（（10分钟OCT）/（吸入1.0氧气时的PaO2 - 基线PaO2））。
所有患者中，PI与基线PtcO2、10分钟OCT和氧激发指数（OCI）显著相关。对照组的基线PtcO2、10分钟OCT和PI高于脓毒症休克组。在脓毒症组中，宏观血流动力学参数和ScvO2在存活者和非存活者之间无差异。非存活者的PI、10分钟OCT和OCI显著更低，动脉血乳酸水平更高。PI、10分钟OCT和OCI预测ICU死亡率的准确性与动脉血乳酸水平相似。PI<0.2和10分钟OCT<66 mmHg与复苏后预后不良相关。
PI和OCT可预测复苏后脓毒症患者的死亡率。需要进一步研究以确定纠正外周灌注受损水平是否可改善脓毒症休克患者的预后。
