title: High central venous-to-arterial CO2 difference/arterial-central venous O2 difference ratio is associated with poor lactate clearance in septic patients after resuscitation.
abstract: OBJECTIVE
  Recently, the central venoarterial carbon dioxide difference/arterial-central venous oxygen difference (P(v-a)CO2/C(a-v)O2) ratio has been suggested as an additional indicator of anaerobic metabolism. We investigated the relationship between the P(v-a)CO2/C(a-v)O2 ratio and 8-hour lactate clearance (LC) in septic patients after resuscitation.
  
  
  RESULTS
  We prospectively obtained 168 sets of measurements from 84 septic patients. The arterial and central venous blood gases were measured simultaneously at enrollment and 8 hours after resuscitation. The P(v-a)CO2/C(a-v)O2 (r = -0.24, P = .028) at T8 was negatively correlated with 8-hour LC after resuscitation in all patients. The patients with 8-hour LC ≥ 10% exhibited significantly lower P(v-a)CO2/C(a-v)O2 ratios and intensive care unit mortality after resuscitation than the patients with 8-hour LC < 10%. The area under the receiver operating characteristic curve of the P(v-a)CO2/C(a-v)O2 ratio for the detection of LC ≥ 10% was the greatest and was significantly better than that of the central venous oxygen saturation and similar to that of the P(v-a)CO2. Moreover, a P(v-a)CO2/C(a-v)O2 < 1.23 at T8 is related to poor 8-hour LC rate (LC ≥ 10%) in the patients with normalized central venous oxygen saturation values (≥70%) after resuscitation.
  
  
  CONCLUSIONS
  The high P(v-a)CO2/C(a-v)O2 ratio is associated with poor LC after resuscitation. The P(v-a)CO2/C(a-v)O2 ratio may provide useful information for assessing the LC potential and optimizing the LC rate.
authors.affiliation: Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors.forename: Huai-wu
authors.initials: HW
authors.lastname: He
authors.affiliation: Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China. Electronic address: tjmuhhw@163.com.
authors.forename: Da-wei
authors.initials: DW
authors.lastname: Liu
authors.affiliation: Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Long
authors.affiliation: Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors.forename: Xiao-ting
authors.initials: XT
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D019344:Lactic Acid / Q000097:blood* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012151:Resuscitation / Q000379:methods; D012772:Shock, Septic / Q000097:blood* / Q000401:mortality / Q000628:therapy
chemical_list: D002245:Carbon Dioxide; D019344:Lactic Acid
keywords: Central venous oxygen saturation; Lactate clearance; Oxygen debt; Tissue perfusion