Mathematical models for predicting arterial blood gas and arterial lactate have recently be published (PMID 27543529; see the citations section). The aim of the study is to externally validate these models in a multicenter (11 centres in France) cohort of intensive care unit patients suffering from acute circulatory failure. For the peru pose of the study, patients will undergo concomitent central venous/arterial blood sampling from 1 to 4 times during their intensive cafe unit stay. Clinical characteristics of the patients and central venous blood gas and lactate values will be used to predicted arterial values according to previously published formula. Predicted and actual arterial values of each variable of interest (pH, PaCO2, SaO2, lactate) will then be compared.
Predicting arterial lactate and blood gas values with sufficient accuracy by simply analyzing central venous blood would be interesting in intensive care unit patients in whom the insertion of an arterial catheter or arterial punctures could be avoided. This prospective study aims at externally validating published mathematical models built to predict arterial values from central venous blood analysis.