Hyperlactataemia, a marker of poor prognosis in intensive care patients, is most frequently found in cases of acute circulatory failure ;however, it may be due to factors other than cellular hypoxia. The level of blood lactate is determined by the balance between its production and its elimination, which can be influenced by various factors. For example, the influence of medication on blood lactate levels should not be underestimated, whether in anaesthesiology, with the use of propofol, or with certain anti-retrovirals in HIV seropositive patients. And in oncology, blood lactate can derive from anaerobic metabolism, characteristic of tumour cells. The differential diagnosis of hyperlactataemia can, therefore, sometimes be more complex than initially thought.SCOPUS: re.jinfo:eu-repo/semantics/publishe