The severity of minimal dialysis disequilibrium syndrome (DDS) is currently detected and graded clinically using clinical criteria. Bispectral Index (BIS), an electroencephalographic (EEG) derived parameter is widely used in anesthesia and Critical Care setting to detect effects of anesthetic/hypnotic drugs. The aim of our study was to assess the discriminative power of BIS monitoring to accurately detect DDS.

Design: A consecutive, clinical, validation study. Setting: Medical University of Graz (Graz, Austria). Patients: Twenty consecutive patients undergoing first hemodialysis are enrolled at Medical University of Graz, Haemodialysis Unit. Agitated patients or patients who fell asleep during the recording are excluded from the final analysis.

During the first dialysis session of approximately 3 h, patients were observed for signs of disequilibrium; headaches, dizziness, nausea, vomiting, if they become obtunded, have visual impairments or cramps. Accordingly patients were divided into 2 groups; the "DDS group" of patients who experienced one of the DDS symptoms of headaches, dizziness, nausea, vomiting, become obtunded, have visual impairments or cramps and patients who do not experience any of the DDS symptoms in the "non-DDS group" An assigned nephrologist will assess the physical and mental status of the patients.

Inclusion Criteria:

• First Time renal Dialysis

Exclusion Criteria:

• subjects' consumption of sedatives/hypnotics psychotropic drugs, or concomitant neurological disorders affecting mental state such as hepatic encephalopathy, stroke, stupor or dementia and renal transplant patients.

First Time renal Dialysis