Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, China.
Shock. 2017 Nov;48(5):551-557. doi: 10.1097/SHK.0000000000000893.
It is a great challenge for physician to assess the relationship between O2 delivery and O2 consumption in septic shock patients with high ScvO2. Recently, the venous-to-arterial CO2 difference/arterial-central venous O2 difference ratio (P(v-a)CO2/C(a-v)O2) has shown potential for reflecting anaerobic metabolism. Therefore, we evaluated the value of using the P(v-a)CO2/C(a-v)O2 ratio to predict mortality and assess anaerobic metabolism in septic shock patients with high ScvO2 (≥ 80%).
This was a clinical investigation of septic shock patients on the P(v-a)CO2/C(a-v)O2 ratio in the intensive care unit (ICU) department. The patients' arterial and central venous blood gas levels were measured simultaneously at enrollment (T0) and 24 h (T24) after resuscitation.
A total of 61 patients with high ScvO2 at T24 after resuscitation were selected for analysis. The ICU mortality rate in the septic shock patients was 20% (12/61). The nonsurvivors had a significantly higher P(v-a)CO2, P(v-a)CO2/C(a-v) O2 ratio, arterial lactate level and lower lactate clearance at T24 after resuscitation. The P(v-a)CO2/C(a-v)O2 ratio had the biggest the areas under the receiver operating characteristic (AUC) for predicting ICU mortality. For predicting ICU mortality, a threshold of P(v-a)CO2/C(a-v)O2 ratio ≥1.6 was associated with a sensitivity of 83% and a specificity of 63%. Multivariate analysis showed P(v-a)CO2/C(a-v)O2 ratio at both T0 (RR 5.597, P = 0.024) and T24 (RR 5.812, P = 0.031) was an independent predictor of ICU mortality. Including the ratio into the regression model showed a bigger AUC than without the ratio (0.886 vs. 0.833).
The P(v-a)CO2/C(a-v)O2 ratio is an independent predictor of ICU mortality in septic shock patients with high ScvO2 after resuscitation. It is worthy of consideration to recruit microcirculation to correct the high ratio in high ScvO2 case.
对于高中心静脉血氧饱和度（ScvO2）的脓毒性休克患者，评估氧输送与氧消耗之间的关系是医师面临的一大挑战。最近，静脉-动脉二氧化碳分压差/动脉-中心静脉血氧差比值（P（v-a）CO2/C（a-v）O2）已显示出反映无氧代谢的潜力。因此，我们评估了使用 P（v-a）CO2/C（a-v）O2 比值来预测死亡率和评估高 ScvO2（≥80%）脓毒性休克患者无氧代谢的价值。
这是一项在重症监护病房（ICU）部门评估脓毒性休克患者 P（v-a）CO2/C（a-v）O2 比值的临床研究。在复苏后 24 小时（T24）同时测量患者的动脉和中心静脉血气水平。
共纳入复苏后 T24 时高 ScvO2 的 61 例患者进行分析。脓毒性休克患者 ICU 死亡率为 20%（12/61）。与存活者相比，死亡患者在复苏后 T24 时的 P（v-a）CO2、P（v-a）CO2/C（a-v）O2 比值、动脉血乳酸水平更高，乳酸清除率更低。P（v-a）CO2/C（a-v）O2 比值预测 ICU 死亡率的受试者工作特征曲线（ROC）下面积最大。预测 ICU 死亡率时，P（v-a）CO2/C（a-v）O2 比值≥1.6 的阈值与 83%的敏感性和 63%的特异性相关。多变量分析显示，T0 时的 P（v-a）CO2/C（a-v）O2 比值（RR 5.597，P=0.024）和 T24 时的 P（v-a）CO2/C（a-v）O2 比值（RR 5.812，P=0.031）均为 ICU 死亡率的独立预测因素。将比值纳入回归模型比不纳入比值时的 AUC 更大（0.886 比 0.833）。
复苏后高 ScvO2 的脓毒性休克患者 P（v-a）CO2/C（a-v）O2 比值是 ICU 死亡率的独立预测因素。考虑招募微循环来纠正高 ScvO2 病例中的高比值是值得的。
