Severe hyperlactaemia in intensive care patients is most often due to underlying sepsis or septic, cardiogenic or haemorrhagic shock. Hyperlactaemia is an independent predictor of death in various groups of critically ill patients. With serum lactate values > 10 mmol/l 80 % of the patients die in intensive care, and if the severe lactic acidosis persists for 48 hours, all patients die. Increased lactate levels require immediate diagnostic work-up and classification. The new sepsis definition requires a serum lactate > 2 mmol/l for septic shock with adequate volume substitution and vasopressor administration in order to achieve a mean arterial pressure in persistent hypotension ≥ 65 mmHg. The 1-hour bundle of the Surviving Sepsis Campaign published in 2018 recommends as a first measure the determination of the lactate serum concentrations, and increased values should be closely monitored. In addition, blood culture sampling, broad-spectrum antibiotics, fluid resuscitation and vasopressor administration are recommended within the first hour. Large amounts of crystalloids should be given for increased lactate levels (≥ 4 mmol/l) and refractory hypotension, the administration of fluids can be adjusted according to lactate clearance. Lactate metabolism is prolonged in patients with liver function impairment. Lactate levels on admission to intensive care are significantly associated with the number of failing organs and mortality in patients with cirrhosis. 12-hour lactate clearance has a strong predictive prognosis for survival in patients with baseline lactate levels above 5 mmol/l, the latter remains an independent predictor for the severity of the underlying disease even after correction. The greater the decrease in lactate during the initial therapy, the better the outcome.
