(Es)ketamine exerts a circulatory supportive effect by increasing blood pressure, heart rate, and cardiacCardiac output. The cardiovascular effects are dependent on the dosage and are differently pronounced for ketamine and esketamine. The dose dependency can be influenced or eliminated by various severe disorders. (Es)ketamine also causes changes at the microvascular level and can, for example, cause better hemorrhage tolerance, arteriolar vasoconstriction, and avoidance of macromolecular leakage in the event of a hemorrhage. However, when ketamine is used in severe shock, increased episodes of hypotension may also be observed. When (es)ketamine is added to other anesthetic drugs with cardio-depressant features in general anesthesia induction, blood pressure drops can be better reduced or avoided. This is not at the expense of limiting the microcirculation and does not cause any measurable disturbance of hemodynamic coherence. Nonetheless, the limited microcirculatory data available and the inconsistent measurement methods used in the studies do not yet allow to draw any clear conclusions on possible beneficial effects of (es)ketamine on the microcirculation.