Close correlation between arterial and central venous lactate concentrations of children in shock: A cross-sectional study

Highlight•Arterial lactate is widely used to guide therapy in children with shock.•Central venous saturation is a valuable tool for monitoring in patients with shock.•Central venous lactate is practical to estimate arterial lactate concentration.

BackgroundArterial lactate (aLact) has been widely used to guide therapeutic decisions in children with shock. We evaluated the feasibility of central venous lactate (cvLact) in assessing aLact among children with shock.MethodsPairs of arterial and central venous samples for lactate concentrations were collected simultaneously during the shock and hemodynamically stable states. The results were analyzed by using a Cobas 8000 analyzer.ResultsSixty-four blood paired samples were collected from 48 patients. The overall correlation between central venous and arterial lactate concentrations was r = 0.962, p < 0.0001, r2 = 0.965. The regression equation was aLact = (0.978 × cvLact) − 0.137. A similar correlation was found between central venous and arterial lactate concentrations during the states of shock and stable hemodynamics (r = 0.970, p < 0.0001, r2 = 0.966 and r = 0.935, p < 0.0001, r2 = 0.962, respectively). The mean difference between central venous and arterial lactate concentrations was 0.20 mmol/l (95% CI: 0.08 to 0.32) and the limits of agreement were − 0.74 mmol/l (95% CI: − 0.94 to − 0.53) and 1.13 (95% CI: 0.93 to 1.34).ConclusionsIn situations of shock where a central venous catheter is required, samples from a central vein present an acceptable and timely alternative to arterial samples for quantitating lactate concentrations.