Maintaining organ perfusion is the key to successful intensive care medicine. Shock is the most dangerous microcirculatory disorder and one of the most hazardous and lethal conditions of critically ill patients still showing high mortality rates. However, there are still ongoing controversies, how to assess microcirculation, how to predict outcome in time and how to guide specific therapy. Macrocirculation does not reflect microcirculation. Microcirculation reflects organ perfusion and correlates with the outcome. There is growing evidence that microcirculatory parameters are powerful tools to predict the outcome after cardiac arrest. Several guidelines use it as a target to guide therapy, but these recommendations base only on supporting evidence of low quality. Lactate is a late reflector of reduced organ perfusion and is of limited value for time-critical decision-making and their value as a therapeutic target. Sublingual sidestream dark-field (SDF) - measurement is a non-invasive method that reliably reflects organ perfusion. The last generation of microcirculation assessment tools are easy to use hand-held devices that use an automatic algorithm. In consequence, microcirculation has become a directly detectable physiological compartment. However, systematic investigations about this technology in shock are still lacking. DAMIS determines the value of directly assessed microcirculation on outcome in different types of shock. Therefore, this multicenter study will recruit up to 200 patients in shock. After the first measurement, patients will be randomized either to intervention or to control. The intervention consists in knowing microcirculatory parameters. A checklist will assist the treating physicians of the interventional group in explaining microcirculatory values and offering possible treatment options. Patients in the control group will be measured as well, but results will not be communicated to the treating physician.

Inclusion Criteria:

1. Older than 18 years

2. Admitted to the ICU in state of shock at the time point of admission to ICU or in the first 3 hours defined as

   • the need to use vasopressors, -dilatators, fluids to maintain mean arterial pressure > 65 mmHg
   • AND lactate > 2 mmol/l

Exclusion Criteria:

1. Younger than 18 years
2. Anatomic reasons that inhibit sublingual measurement
3. Lack of informed consent
4. more than 4 hours after ICU admission

Sublingual SDF-Measurement at admission and after 24h, with or without communication and interpreting checklist to the treating physician