经皮组织氧负荷试验预测感染性休克患者液体复苏达标的临床价值

摘要

目的 评价经皮组织氧负荷试验(oxygen challenge test,OCT)预测感染性休克患者液体复苏效果的临床价值.方法 前瞻性观察性研究,选择2015-01 ～ 2016-06收住南京大学医学院附属鼓楼医院重症医学科的54例感染性休克患者,入院后进行规范化治疗.于液体复苏前、复苏后6h实施OCT,同时进行经皮氧分压(transcutaneous oxygen pressure,PtcO2)、平均动脉压(MAP)、动脉血乳酸(Lac)、中心静脉血氧饱和度(ScvO2)等血流动力学监测.计算6h乳酸清除率(lactate clearance rate,LRC),根据复苏后6 h LRC分为高清除组(6 h LRC≥10％,n=32)和低清除组(6 h LRC＜ 10％,n=22),比较2组患者复苏后6 h OCT、PtcO2、ScvO2的变化,绘制受试者工作特征曲线(ROC),比较其评估液体复苏达标价值.结果 复苏前2组患者血流动力学指标、氧代谢指标比较差异无统计学意义;复苏后6h高清除组Lac(mmol/L)低于低清除组(3.3±3.2 vs.7.3 ±4.1,P=0.010),PtcO2(mm Hg)高于低清除组(88.2±29.2 vs.54.0±25.9,P=0.004),氧负荷试验(mm Hg)高于低清除组(90.9 ±57.5 vs.40.0 ±19.8,P=0.010),复苏后6h2组ScvO2比较差异无统计学意义[(76.6±6.5)％vs.(77.7±7.5)％,P=0.686].复苏前后OCT均与同时期Lac呈显著负相关,复苏后6 h OCT与LRC呈显著正相关,复苏后ScvO2与LRC无相关性.复苏后6 h OCT的曲线下面积(AUC)为0.836,＞6 h PtcO2的AUC为0.768,6 h ScvO2的AUC最小为0.416,6 h OCT预测6 h LRC≥10％的最佳临界值为61 mm Hg,其敏感度71.9％,特异度90.9％.结论 经皮氧负荷试验与感染性休克患者液体复苏前后Lac和LRC有良好的相关性,可以预测感染性休克患者的液体复苏效果..%Objective To evaluate the clinical value of oxygen challenge test (OCT) in predicting the effect of fluid resuscitation in patients with septic shock.Methods A prospective observational study was conducted.54 patients with septic shock admitted to intensive care unit (ICU) of Affiliated Hospital of Nanjing University Medical School from January 2015 to June 2016 were enrolled and given the standard treatment in accordance with the 2014 Chinese severe sepsis/septic shock treatment guidelines.OCT,transcutaneous oxygen pressure (PtcO2),mean arterial pressure (MAP),arterial blood lactic acid (Lac),central venous oxygen saturation (ScvO2) and other hemodynamic monitoring before and 6 h after fluid resuscitation were recorded,and the 6 h lactate clearance rate (LRC) was calculated.The patients were divided into high clearance group (n =32) with 6 h LRC ≥ 10％ and low clearance group (n =22) with 6 h LRC ＜ 10％.OCT,PtcO2 and ScvO2 after resuscitation were compared between 2 groups.The receiver-operating characteristics (ROC) analysis was performed to predict the effect of fluid resuscitation of the variables OCT,PtcO2 and ScvO2 after resuscitation.Results Before resuscitation,the hemodynamic parameters,tissue oxygen metabolism parameters had no significant differences in both groups.Six hours after resuscitation,arterial blood lactic acid is lower in the low clearance group [(3.3 ± 3.2) mmol/L vs.(7.3 ±4.1) mmol/L,P =0.010] than the high clearance group,PtcO2 and OCT was higher in the low clearance group [PtcO2:(88.2 ± 29.2) mm Hg vs.(54.0 ±25.9) mmol/L,P=0.004;OCT:(90.9±57.5) mmHgvs.(40.0±19.8) mmHg,P=0.010],ScvO2 of 6 h after resuscitation in the 2 groups had no significant difference [(76.6％ ±6.5) ％ vs.(77.7％ ± 7.5) ％,P =0.686)].OCT was significantly negatively correlated with Lac of the same period before and after resuscitation.OCT after 6 h resuscitation and 6 h LRC was significantly and positively correlated,and no correlation between ScvO2 and LRC after resuscitation.The AUC of 6 h OCT (0.836) was greater than 6 h PtcO2 (0.768),while the AUC of 6 h ScvO2 was the smallest (0.416).The best cutoff value of 6 h OCT for the predicting of 6 h LRC ≥ 10％ was 61 mm Hg,with the sensitivity 71.9％ and the specificity 90.9％.Conclusion OCT is well correlated with arterial blood lactate and lactate clearance rate in septic shock before and after fluid resuscitation,and can be used to evaluate the effect of fluid resuscitation in patients with septic shock.