To discuss the suitable haemodynamic monitoring for critically ill patients with shock.

For the basic initial monitoring, recent studies emphasized the importance of clinical signs of hypoperfusion and arterial pressure. This basic monitoring is not sufficient in patients resisting to initial treatment. Echocardiography does not allow multidaily measurements and has limitations, for measuring right or left ventricular preload. For a more continuous monitoring, noninvasive and minimally invasive tools are insufficiently reliable, as recently confirmed, and informative. The most invasive techniques, transpulmonary thermodilution and the pulmonary arterial catheter are more suitable. Their effect on outcome is lacking, although recent studies showed their benefit in acute heart failure. For assessing tissue oxygenation, recent publications better defined the meaning of the indices derived from the partial pressure of carbon dioxide. The integration of all data by artificial intelligence is the subject of early research in critical care.

For monitoring critically ill patients with shock, minimally or noninvasive systems are not reliable or informative enough. In the most severe patients, a reasonable monitoring policy can combine continuous monitoring by transpulmonary thermodilution systems or the pulmonary arterial catheter, with an intermittent assessment with ultrasound and measurement of tissue oxygenation.