title: Combination of arterial lactate levels and venous-arterial CO2 to arterial-venous O 2 content difference ratio as markers of resuscitation in patients with septic shock.
abstract: OBJECTIVE
  To evaluate the prognostic value of the Cv-aCO2/Da-vO2 ratio combined with lactate levels during the early phases of resuscitation in septic shock.
  
  
  METHODS
  Prospective observational study in a 60-bed mixed ICU. One hundred and thirty-five patients with septic shock were included. The resuscitation protocol targeted mean arterial pressure, pulse pressure variations or central venous pressure, mixed venous oxygen saturation, and lactate levels. Patients were classified into four groups according to lactate levels and Cv-aCO2/Da-vO2 ratio at 6 h of resuscitation (T6): group 1, lactate ≥2.0 mmol/L and Cv-aCO2/Da-vO2 >1.0; group 2, lactate ≥2.0 mmol/L and Cv-aCO2/Da-vO2 ≤1.0; group 3, lactate <2.0 mmol/L and Cv-aCO2/Da-vO2 >1.0; and group 4, lactate <2.0 mmol/L and Cv-aCO2/Da-vO2 ≤1.0.
  
  
  RESULTS
  Combination of hyperlactatemia and high Cv-aCO2/Da-vO2 ratio was associated with the worst SOFA scores and lower survival rates at day 28 [log rank (Mantel-Cox) = 31.39, p < 0.0001]. Normalization of both variables was associated with the best outcomes. Patients with a high Cv-aCO2/Da-vO2 ratio and lactate <2.0 mmol/L had similar outcomes to hyperlactatemic patients with low Cv-aCO2/Da-vO2 ratio. The multivariate analysis revealed that Cv-aCO2/Da-vO2 ratio at both T0 (RR 3.85; 95 % CI 1.60-9.27) and T6 (RR 3.97; 95 % CI 1.54-10.24) was an independent predictor for mortality at day 28, as well as lactate levels at T6 (RR 1.58; 95 % CI 1.13-2.22).
  
  
  CONCLUSIONS
  Complementing lactate assessment with Cv-aCO2/Da-vO2 ratio during early stages of resuscitation of septic shock can better identify patients at high risk of adverse outcomes. The Cv-aCO2/Da-vO2 ratio may become a potential resuscitation goal in patients with septic shock.
authors: Intensive Care Unit, Fundación Valle Del Lili - Universidad ICESI, Av. Simón Bolívar Cra. 98, Cali, Colombia, gusospin@gmail.com.
authors: Gustavo A
authors: GA
authors: Ospina-Tascón
authors: Mauricio
authors: M
authors: Umaña
authors: William
authors: W
authors: Bermúdez
authors: Diego F
authors: DF
authors: Bautista-Rincón
authors: Glenn
authors: G
authors: Hernandez
authors: Alejandro
authors: A
authors: Bruhn
authors: Marcela
authors: M
authors: Granados
authors: Blanca
authors: B
authors: Salazar
authors: César
authors: C
authors: Arango-Dávila
authors: Daniel
authors: D
authors: De Backer
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood*; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood*; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D011379:Prognosis; D011446:Prospective Studies; D012151:Resuscitation; D018570:Risk Assessment; D012772:Shock, Septic / Q000097:blood* / Q000628:therapy*; D016019:Survival Analysis
chemical_list: D015415:Biomarkers; D002245:Carbon Dioxide; D019344:Lactic Acid; D010100:Oxygen