title: [Significance of central venous-to-arterial carbon dioxide difference for early goal-directed therapy in septic patients].
abstract: OBJECTIVE
  To determine whether central venous-to-arterial carbon dioxide tension difference (Pcv-aCO(2)) could still be used as a goal of fluid resuscitation in septic patients who already had ScvO2 greater than 70% after early resuscitation.
  
  
  METHODS
  A prospective observational study was performed on 56 septic patients admitted to the Intensive Care Unit (ICU) in a single University Hospital, who already had ScvO2 greater than 70% after early resuscitation. They were divided into two groups, based on whether the patients' initial Pcv-aCO2 was less than 6 mmHg (low gap group) or greater than or equal to 6 mmHg (high gap group). The following data were collected at 0, 12, and 24 hours (T(0), T(12), T(24)) after study inclusion: hemodynamic indices [mean blood pressure (MAP), heart rate (HR), cardiac output (CO), central venous pressure (CVP)], perfusion-related indexes [ScvO(2), Pcv-aCO2, serum lactate (Lac), Lac clearance rate], organ function- related indices [oxygenation index (PaO2/FiO(2)), serum creatinine (SCr), creatine kinase (CK-MB)], APACHE II score, SOFA score, and 24 hours amounts of fluid infusion.
  
  
  RESULTS
  Twenty patients (42.9%) with initial Pcv-aCO(2) ≥ 6 mmHg were included in the high gap group and another thirty-two patients were included in the low gap group. At T12 and T24, ScvO(2) and CO were significantly higher, and Lac and SCr were significantly lower in low gap patients than high gap patients (P<0.05). At T(12) and T(24), Lac clearance rate was significantly higher (P<0.05), and 24-hours amounts of fluid infusion was significantly less [(3449.47 ± 695.41) mL vs (4070.66 ± 757.43) mL, P= 0.002] for the low gap group than for the high gap group, as well as the descrease of SOFA score at T(24) (P<0.05). There was no significant difference of APACHE II score between the 2 groups (P<0.05). CO and Pcv-aCO(2) values were inversely correlated (P< 0.05).
  
  
  CONCLUSIONS
  Septic patients targeting only ScvO(2) may still have inappropriate tissue perfusion, especially when Pcv-aCO2 ≥6 mmHg, which indicates insufficient resuscitation. When ScvO(2) > 70% has achieved after early resuscitation, Pcv-aCO2 can still be used as a goal of fluid resuscitation in septic patients .
authors.affiliation: Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha 410008, China.
authors.forename: Lina
authors.initials: L
authors.lastname: Zhang
authors.forename: Yuhang
authors.initials: Y
authors.lastname: Ai
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Liu
authors.forename: Xinhua
authors.initials: X
authors.lastname: Ma
authors.forename: Guangfeng
authors.initials: G
authors.lastname: Ming
authors.forename: Shuangping
authors.initials: S
authors.lastname: Zhao
authors.forename: Daomiao
authors.initials: D
authors.lastname: Xu
mesh_terms: D000328:Adult; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood*; D002496:Central Venous Pressure; D005260:Female; D005440:Fluid Therapy; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018805:Sepsis / Q000097:blood* / Q000503:physiopathology / Q000628:therapy*; D012720:Severity of Illness Index; D014683:Vena Cava, Superior
chemical_list: D002245:Carbon Dioxide