The patients of the group "sepsis" are measured several times with the non-invasive multi-spectral sonography (Sonovum "ACG-Diagnosesystem") (days 1, 3, 7 and 14). The patients of the group "control" are measured on days 1 and 3 with the system. A measurement takes 3 minutes. For this purpose two ultrasound heads are placed above the patient's ears and fixed with an all-head harness. The device is certified for CE application. There are no known health risks of ultrasound in humans.

Sepsis with multiorgan failure is one of the most common diseases in intensive care units and is at the top of the world of causes of death. In addition to increasingly serious sepsis by multidrug-resistant pathogens, neurological symptoms are frequently recorded in the systemic manifestation of the disease pattern. Septic encephalopathy (SE) is usually an early cerebral sign of the developing sepsis, often before other clinically as well as diagnostically detectable findings such as fever ascent, hypotonia or laboratory chemical infections. Therefore, the SE is a clinically important parameter, also because after the sepsis, cerebral functional restrictions such as cognitive disorders can persist in the long term.

Therefore, on day 1, 3, 7 and 14 the patients are measured with the ACG-system as well as determined different scores of the patients: CAM-ICU (Confusion Assessment Method - Intensive Care Unit) and ICDSC (Intensive Care Delirium Screening Checklist) for the neurological outcome; Apache (Acute Physiology And Chronic Health Evaluation) II for mortality and SOFA (Sepsis-related Organ Failure Assessment Score) for organ failure.

Inclusion Criteria:

• Severe sepsis or septic shock
• Clinical suspicion of septic encephalopathy
• consent to the study by the patient or legal representative
• stay in intensive care unit for at least 24 hours without the presence of a septic disease and without clinical guidance for an SE

Exclusion Criteria:

• Inability to consent to participation in the research project or rejection by patients or legal representatives
• existence of other causes of delir other than sepsis (e.g., withdrawal)
• Infrequent prognosis (expected death in ≤ 12 hours despite maximum therapy)

• male or female, at least 18 years old
• Severe sepsis or septic shock
• Clinical suspicion of SE
• consent to the study by the patient or legal representative