The goal of this clinical trial is to learn if transcranial alternating current stimulation can shorten the duration of delirium in intensive care setting. The main question it aims to answer:
* Is it possible to shorten the duration of delirium with transcranial alternating current stimulation?
Researchers will compare experimental treatment to sham.
Participants will receive experimental or sham treatment on maximum of two days depending on their delirium status. Duration of delirium is recorded and reported as "days alive and free of delirium".
Delirium in intensive care and duration of delirium for more than 24 hours. Delirium is defined as 4 or more points on ICDSC and -1 or more points on RASS.
Under 18 years of age, pregnancy, delirium tremens, epilepsy or history of seizures any time before first trial intervention, active psychotic disease, infection of central nervous system, acute intoxication, traumatic brain injury, stroke, intracranial bleeding and implanted electronic devices.