摘要目的:探讨早期液体复苏后血乳酸（Lac）联合中心静脉-动脉血二氧化碳分压差与动脉-中心静脉血氧含量差比值（Pcv-aCO 2/Ca-cvO 2）对脓毒性休克患者预后的预测价值。 方法:选择2017年1月至2019年12月兰州大学第二医院重症医学科收治的97例脓毒性休克患者。收集复苏前及复苏6 h桡动脉和上腔静脉血气分析结果，计算Pcv-aCO 2/Ca-cvO 2比值。根据28 d预后将患者分为死亡组和存活组，比较两组患者一般资料、急性生理学与慢性健康状况评分Ⅱ（APACHEⅡ）、序贯器官衰竭评分（SOFA）、临床治疗情况、6 h乳酸清除率（LCR）、重症监护病房（ICU）住院时间以及复苏前后血流动力学和氧代谢指标；采用多因素Cox回归法分析脓毒性休克患者28 d死亡的危险因素，通过受试者工作特征曲线（ROC）评价死亡相关危险因素对预后的预测价值。 结果:①与存活组比较，死亡组患者APACHEⅡ评分和SOFA评分更高〔APACHEⅡ评分（分）：23.96±4.31比17.70±3.92，SOFA评分（分）：12.74±2.80比9.23±2.43，均 P<0.01〕，机械通气及连续性肾脏替代治疗（CRRT）比例更高〔机械通气：85.2%（23/27）比50.0%（35/70），CRRT：51.9%（14/27）比25.7%（18/70），均 P<0.05〕，6 h补液量更多（L：2.92±0.24比2.63±0.25， P<0.01），6 h LCR更低〔（11.61±7.76）%比（27.67±13.71）%， P<0.01〕，ICU住院时间更短（d：6.37±2.70比7.67±2.31， P<0.05）。②与存活组比较，死亡组复苏前平均动脉压（MAP）更低〔mmHg（1 mmHg＝0.133 kPa）：52.63±4.35比55.74±3.01， P<0.01〕，Lac和Pcv-aCO 2/Ca-cvO 2比值更高〔Lac（mmol/L）：7.13±1.75比5.22±1.36，Pcv-aCO 2/Ca-cvO 2比值：1.67±0.29比1.48±0.22，均 P<0.01〕；死亡组复苏6 h MAP仍显著低于存活组（mmHg：62.59±4.80比66.71±3.91， P<0.01），而中心静脉压（CVP）、Lac、Pcv-aCO 2及Pcv-aCO 2/Ca-cvO 2比值明显高于存活组〔CVP（mmHg）：10.74±1.40比8.80±0.75，Lac（mmol/L）：6.36±1.86比3.90±1.95，Pcv-aCO 2（mmHg）：7.59±2.02比4.34±1.37，Pcv-aCO 2/Ca-cvO 2比值：1.87±0.51比1.03±0.27，均 P<0.01〕。③多因素Cox回归分析显示，复苏前及复苏6 h Lac和Pcv-aCO 2/Ca-cvO 2比值是脓毒性休克患者28 d死亡的独立危险因素〔复苏前Lac：相对危险度（ RR）＝1.434，95%可信区间（95% CI）为1.070～1.922， P＝0.016；复苏6 h Lac： RR＝1.564，95% CI为1.202～2.035， P＝0.001；复苏前Pcv-aCO 2/Ca-cvO 2比值： RR＝2.828，95% CI为1.108～4.207， P＝0.038；复苏6 h Pcv-aCO 2/Ca-cvO 2比值： RR＝4.386，95% CI为2.842～5.730， P＝0.000〕。④ ROC曲线分析显示，复苏6 h Lac和Pcv-aCO 2/Ca-cvO 2比值对脓毒性休克患者预后均有预测价值，ROC曲线下面积（AUC）分别为0.849（95% CI为0.762～0.914）和0.905（95% CI为0.828～0.955），二者联合对脓毒性休克患者预后的预测价值明显大于Lac〔AUC（95% CI）：0.976（0.923～0.996）比0.849（0.762～0.914）， Z＝3.354， P＝0.001〕，敏感度为97.14%，特异度为88.89%。 结论:Lac和Pcv-aCO 2/Ca-cvO 2比值是脓毒性休克患者28 d死亡的独立危险因素，二者联合可以更准确地评估脓毒性休克患者的预后。

abstractsObjective:To evaluate the prognostic value of arterial lactate (Lac) combined with central venous-to-arterial carbon dioxide difference to arterial-to-central venous oxygen content difference ratio (Pcv-aCO 2/Ca-cvO 2) in patients with septic shock following early fluid resuscitation. Methods:A total of 97 patients with septic shock admitted to intensive care unit (ICU) of Lanzhou University Second Hospital from January 2017 to December 2019 were enrolled. The Pcv-aCO 2/Ca-cvO 2 ratio was calculated from blood gas analysis of radial artery and superior vena cava which was performed before resuscitation and at 6 hours of resuscitation at the same time. The patients were divided into death group and survival group according to the 28-day prognosis. The baseline data, acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) score, sequential organ failure score (SOFA), clinical therapy, lactate clearance rate (LCR) at 6 hours, the length of ICU stay, hemodynamics and oxygen metabolism parameters before and after resuscitation were compared between the two groups. Risk factors were analyzed by multivariate Cox regression for 28-day mortality of patients with septic shock. The receiver operating characteristic (ROC) curve was plotted to assess the prognostic values of these factors for 28-day mortality. Results:① Compared with the survival group, the patients in the death group showed significantly higher levels of APACHEⅡ score (23.96±4.31 vs. 17.70±3.92) and SOFA score (12.74±2.80 vs. 9.23±2.43, both P < 0.01), significantly higher proportions of mechanical ventilation [85.2% (23/27) vs. 50.0% (35/70)] and continuous renal replacement therapy [CRRT; 51.9% (14/27) vs. 25.7% (18/70), both P < 0.05], a significantly more fluid replacement at 6 hours (L: 2.92±0.24 vs. 2.63±0.25, P < 0.01), a significantly lower level of LCR at 6 hours [(11.61±7.76)% vs. (27.67±13.71)%, P < 0.01], and a shorter length of ICU stay (days: 6.37±2.70 vs. 7.67±2.31, P < 0.05). ② Compared with the survival group, the patients before resuscitation in the death group showed a significantly lower level of mean arterial pressure [MAP (mmHg, 1 mmHg = 0.133 kPa): 52.63±4.35 vs. 55.74±3.01, P < 0.01], significantly higher levels of Lac and Pcv-aCO 2/Ca-cvO 2 ratio [Lac (mmol/L): 7.13±1.75 vs. 5.22±1.36, Pcv-aCO 2/Ca-cvO 2 ratio: 1.67±0.29 vs. 1.48±0.22, both P < 0.01]; and the patients at 6 hours of resuscitation in the death group showed a significantly lower level of MAP (mmHg: 62.59±4.80 vs. 66.71±3.91, P < 0.01), significantly higher levels of central venous pressure (CVP), Lac, Pcv-aCO 2 and Pcv-aCO 2/Ca-cvO 2 ratio [CVP (mmHg): 10.74±1.40 vs. 8.80±0.75, Lac (mmol/L): 6.36±1.86 vs. 3.90±1.95, Pcv-aCO 2 (mmHg): 7.59±2.02 vs. 4.34±1.37, Pcv-aCO 2/Ca-cvO 2 ratio: 1.87±0.51 vs. 1.03±0.27, all P < 0.01]. ③ Multivariate Cox regression analysis showed that the independent risk factors for 28-day mortality in patients with septic shock were Lac and Pcv-aCO 2/Ca-cvO 2 ratio whether before or at 6 hours of resuscitation [Lac before resuscitation: relative risk ( RR) = 1.434, 95% confidence interval (95% CI) was 1.070-1.922, P = 0.016; Lac at 6 hours of resuscitation: RR = 1.564, 95% CI was 1.202-2.035, P = 0.001; Pcv-aCO 2/Ca-cvO 2 ratio before resuscitation: RR = 2.828, 95% CI was 1.108-4.207, P = 0.038; Pcv-aCO 2/Ca-cvO 2 ratio at 6 hours of resuscitation: RR = 4.386, 95% CI was 2.842-5.730, P = 0.000]. ④ ROC curve analysis showed that Lac and Pcv-aCO 2/Ca-cvO 2 ratio at 6 hours of resuscitation had predictive value for the prognosis of patients with septic shock, the area under ROC curve (AUC) was 0.849 (95% CI was 0.762-0.914) and 0.905 (95% CI was 0.828-0.955), respectively. However, the predictive value of Lac combined with Pcv-aCO 2/Ca-cvO 2 ratio in patients with septic shock was significantly higher than Lac [AUC (95% CI): 0.976 (0.923-0.996) vs. 0.849 (0.762-0.914), Z = 3.354, P = 0.001], the sensitivity was 97.14%, and the specificity was 88.89%. Conclusions:Lac and Pcv-aCO 2/Ca-cvO 2 ratio are independent risk factors for predicting 28-day mortality in patients with septic shock. Lac combined with Pcv-aCO 2/Ca-cvO 2 ratio can assess the prognosis of patients with septic shock more accurately.