HD-tDCS is delivered on 10 consecutive weekdays, with two sessions per day (in the morning and in the afternoon). For each participant, a 3-mA current is applied via a center anode. The electric current was supplied to the active group and presented an acceleration time of 30 s, maintained at 3 mA for 30 min and then reduced for 30 s. And a maintenance dosage of dexmedetomidine (0.2 - 0.7 mcg/kg per hour).

HD-tDCS is delivered on 10 consecutive weekdays, with two sessions per day (in the morning and in the afternoon). For the simulated condition, the investigators maintained the same 30-second acceleration up to a total of 3 mA, followed immediately by a 30-second deceleration. And a maintenance dosage of dexmedetomidine (0.2 - 0.7 mcg/kg per hour).

Brain stimulation using active high definition transcranial direct current stimulation is applied simultaneously with the use of dexmedetomidine as a pharmacological treatment for delirium in critical illness patients with covid-19

delirium severity over the 28-day study period is measured using the CAM-ICU-7. Patients discharged before 28 days were considered without delirium.

defined as the total number of days that patients remained in the hospital from the date of randomization to the date of hospital discharge