title: Comparison of lactate values obtained from different sites and their clinical significance in patients with severe sepsis.
abstract: OBJECTIVE
  The ideal site for lactate collection has not been clearly established. This study aimed to evaluate associations between lactate levels in arterial blood (Lart), peripheral venous blood (Lper) and central venous blood (Lcen) in patients with severe sepsis or septic shock.
  
  
  METHODS
  Cross-sectional analytical study in an tertiary university hospital.
  
  
  METHODS
  Samples from patients with a central venous catheter and from healthy volunteers (control group) were collected. Blood was drawn simultaneously for measurements of Lart, Lper and Lcen, and the first sample was collected less than 24 hours after the onset of organ dysfunction. The results were analyzed using Pearson correlation, Bland-Altman and McNemar tests.
  
  
  RESULTS
  A total of 238 samples were collected from 32 patients. The correlation results were r = 0.79 (P < 0.0001) for Lart/Lper and r = 0.84 (P < 0.0001) for Lart/Lcen. Bland-Altman showed large limits of agreement: -3.2 ± 4.9 (-12.8 to 6.4) and -0.8 ± 5.9 (-12.5 to 10.8), for Lper and Lcen respectively. In the control group, there was greater correlation (r = 0.9009, P = 0.0004) and agreement: -0.7 ± 1.2 (-3.1 to 1.7). Regarding clinical intervention, there was good agreement between Lart/Lcen (96.3%; three disagreements), with worst results for Lart/Lper (87.0%) with 10 cases of disagreement (P = 0.04). In eight patients (80.0%) Lper was higher than Lart.
  
  
  CONCLUSIONS
  Lcen, and not Lper, can replace Lart with good correlation and clinical agreement. Lper tends to overestimate Lart, thus leading to unnecessary therapeutic interventions.
authors: Intensive Care Unit, Universidade Federal de São Paulo-Escola Paulista de Medicina, São Paulo, Brazil.
authors: Ana Paula Metran
authors: AP
authors: Nascente
authors: Murillo
authors: M
authors: Assunção
authors: Carla Janaina
authors: CJ
authors: Guedes
authors: Flávio Geraldo Rezende
authors: FG
authors: Freitas
authors: Bruno Franco
authors: BF
authors: Mazza
authors: Miriam
authors: M
authors: Jackiu
authors: Flávia Ribeiro
authors: FR
authors: Machado
mesh_terms: D000328:Adult; D000368:Aged; D001158:Arteries; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D018805:Sepsis / Q000097:blood* / Q000503:physiopathology; D018709:Statistics, Nonparametric; D013997:Time Factors; D014680:Veins
chemical_list: D019344:Lactic Acid