ScvO2与 Pcv －aCO2在外科感染性休克液体复苏中的临床研究

Central venous oxygen saturation and central venous-to-arterial carbon dioxide difference in guiding fluid resuscitation of surgical septic shock

目的：探讨通过监测ScvO2与Pcv－aCO2能否更好地指导外科感染性休克患者早期液体复苏治疗。方法外科术后感染性休克患者46例，根据6 h复苏前后动脉及上腔静脉血气变化，分析ScvO2、Pcv－aCO2与Lac、BE及CO的相关性。依照预后分为生存组和死亡组，比较两组的ScvO2、Pcv－aCO2。按ScvO2与Pcv－aCO2分组，比较乳酸清除率、机械通气时间、住ICU时间及28 d病死率。结果 ScvO2、Pcv－aCO2与Lac、BE有部分相关性，与CO有相关性。 T0、T6的ScvO2与Pcv－aCO2呈负相关。依据预后分组，经过6 h复苏后生存组的Pcv－aCO2优于死亡组，但ScvO2比较差异无统计学意义。6 h复苏后ScvO2＞70％组内根据Pcv－aCO2是否达标分组，组间6 h乳酸清除率、28 d病死率比较差异有统计学意义（P＝0.018，P＝0．001）。6 h复苏后Pcv－aCO2＜6 mm Hg组内根据ScvO2是否达标分组，组间6 h乳酸清除率比较差异亦有统计学意义（P＝0．024）。经6 h复苏后Pcv－aCO2对预后具有中等判断能力（AUROC＝0．758）。将入选患者经6 h复苏后的ScvO2分为低ScvO2组（＜70％）、中ScvO2组（70％～80％）和高ScvO2组（＞80％），三组28 d病死率比较差异无统计学意义（P＝0.070）。结论 ScvO2与Pcv－aCO2均可作为外科感染性休克早期评价复苏疗效的有效指标，两者均达标的患者6 h乳酸清除率最高。但ScvO2达标Pcv－aCO2≥6 mm Hg时，提示复苏不充分。联合ScvO2与Pcv－aCO2更有利于指导感染性休克的复苏治疗。

Objective To determine whether central venous -to -arterial carbon dioxide P（cv-aCO2） and central venous oxygen saturation （ScvO2） could be sufficient guides early during fluid resuscitation in surgical septic shock patients .Methods Forty six postoperative septic shock patients were surveyed in this study .According to artery and superior vena cava blood gas , during both the beginning of resuscitation （T0） and in the 6th hour of resuscitation （T6）, the correlation of cardiac output between ScvO 2 , Pcv -aCO2 and lactic acid, Base excess could be determined .Patients were divided into survival group and terminal group by the prognosis .Then, ScvO2 and Pcv -aCO2 levels were determine and compared between groups .Then they were divided into groups according to ScvO 2 and Pcv-aCO2 , and compared lactate clearance rate , mechanical ventilation time , ICU stay and 28-day mortality.Results There was a moderate correlation among ScvO 2, Pcv-aCO2 and lactic acid, Base excess , and there was a strong correlation between ScvO 2 , Pcv-aCO2 and cardiac output .Patients were divided into survival group and terminal group by the prognosis . After continuous 6 hour resuscitation, there was significant differences in the amount Pcv -aCO2 between the two groups , but＆amp;nbsp;there was no significant difference in the amount ScvO 2 .All enrolled patients who had ScvO 2 were greater than 70%after 6 hour resuscitation , they were divided into two groups , based on whether the patientsT6 Pcv-aCO2 was less than 6 mm Hg （ low gap group ） or greater than or equal to 6 mmHg （ high gap group ） .There was significant difference in the clearance of lactate and 28 d mortality （ P=0.018,P=0.001）.All enrolled patients who had Pcv -aCO2 less than 6 mm Hg after 6 hour resuscitation were divided into two groups , based on whether the patients T6 ScvO2 was less than 70%（low gap group） or greater than or equal to 70%（high gap group）.There were significant differences in the clearance of lactate （ P =0.024 ）.T6 Pcv -aCO2 concentration also helped prognostic ability （AUROC=0.758）.All enrolled patients were divided into lower ScvO 2 group （ 〈70%）, middle ScvO2 group （70%to 80%）, and higher ScvO2 group （ 〉80%） after 6 hour resuscitation, there was no significant difference in 28 d mortality （χ2 Value =5.319, P =0.070 ）.Conclusion The combination of ScvO2 and Pcv-aCO2 may guide the shock resuscitation .The clearance of lactate was the highest in the group of patients achieving the goals of both ScvO 2 〈70% and Pcv-aCO2 〈6 mm Hg. Septic patients targeting only ScvO 2 may still have inappropriate tissue perfusion , especially when Pcv-aCO2≥6 mm Hg, which indicates insufficient resuscitation .Combined ScvO 2 and Pcv-aCO2 to guide resuscitation of septic shock could be better affect the patient＇s prognosis .