Reduction of Intraoperative EEG Burst Suppression

Intraoperative burst suppression represents a non physiological EEG pattern. According to the literature and scientific knowledge, intraoperative burst suppression patterns might be caused either by hypotension resulting in a reduced cerebral circulation or by an oversedation of anesthetics correlating with a very deep level of hypnosis.

Some publications exist that discuss the occurrence of intraoperative burst suppression especially in elderly people (aged ≥ 60 years) as a predictor of postoperative delirium and postoperative cognitive dysfunction.

None of the studies however was able to prove a causal relationship between burst suppression and postoperative delirium. Contrary it might simply be an epiphenomenon.

Conducting this interventional trail primarily aims to prove whether specific anesthesiological interventions, such as the treatment of intraoperative hypotension in first line and/or the reduction of the concentration of anesthetics in second line, reduce intraoperative burst suppression. Hence it might be possible to investigate a possible casualty between burst suppression and postoperative delirium in a second trial.

Inclusion criteria

• Age ≥ 60 years
• Surgical interventions in general anesthesia (volatile or total intravenous anesthesia)
• expected surgery duration ≥ 1h
• American Society of Anesthesiologists (ASA) 1-4
• written informed consent prior to study participation

Exclusion criteria

• Neurological or psychiatric disorders
• hearing difficulty
• deafness
• neurosurgical (intra)cranial surgery
• pregnancy
• expected continuous mandatory ventilation after surgery