Clinical trial NCT03775356: Reduction of Intraoperative EEG Burst Suppression
Official title: Reduction of Intraoperative EEG Burst Suppression - Test of Efficacy
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Burst Suppression
EEG With Abnormally Slow Frequencies
Postoperative Delirium
Keywords: Intraoperative EEG based monitoring
Level of hypnosis
Burst suppression
Postoperative delirium
EEG-signal characteristics
Entropy
Lead sponsor: Technical University of Munich
Sponsor class: OTHER
First posted: 2018-12-13
Enrollment: 106
Sex: ALL
Minimum age (years): 60
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: Burst suppression (BS) is a not physiological pattern in the electroencephalogram (EEG). BS during general anesthesia is mainly seen as a sign for too deep hypnosis and may increase the risk of postoperative delirium (POD), a disturbance of consciousness arising within 24 hours after surgery. This monocentric, simple masked randomized study aims primarily to investigate, whether particular anesthesiological interventions reduce the occurrence of intraoperative burst suppression. The investigator initiated trial includes 66 patients (male and female) aged ≥ 60 years in two groups (intervention and control group). Secondary aims will be the correlation of burst suppression and mean arterial pressure, concentration of anesthetics and postoperative delirium.

Detailed description: 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.

Eligibility criteria: 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

Primary outcomes:
measure: Chance of the total, cumulative burst suppression rate.
timeFrame: During general anesthesia and within the intervention
Secondary outcomes:
measure: Burst suppression rate during induction.
timeFrame: During induction within the intervention
measure: Burst suppression rate during maintenance.
timeFrame: During maintenance within the intervention
measure: Mean arterial blood pressure.
timeFrame: During burst suppression within general anesthesia
measure: Endtidal anesthetic concentration (ETAC) and infusion rate of propofol.
timeFrame: During burst suppression within the intervention
measure: Specific characteristics of the EEG frequency spectrum during burst suppression
timeFrame: During burst suppression within general anesthesia
measure: Postoperative delirium.
timeFrame: Within the first three postoperative days
Other outcomes:
Locations:
city: München
country: Germany
facility: Klinikum rechts der Isar - Klinik fuer Anaesthesiologie und Intensivmedizin
state: Bayern
Study officials:
affiliation: Clinic director - Department of anesthesiology and intensive care
name: Gerhard Schneider, Prof. Dr.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Soehle M, Dittmann A, Ellerkmann RK, Baumgarten G, Putensen C, Guenther U. Intraoperative burst suppression is associated with postoperative delirium following cardiac surgery: a prospective, observational study. BMC Anesthesiol. 2015 Apr 28;15:61. doi: 10.1186/s12871-015-0051-7.
citation: Fritz BA, Kalarickal PL, Maybrier HR, Muench MR, Dearth D, Chen Y, Escallier KE, Ben Abdallah A, Lin N, Avidan MS. Intraoperative Electroencephalogram Suppression Predicts Postoperative Delirium. Anesth Analg. 2016 Jan;122(1):234-42. doi: 10.1213/ANE.0000000000000989.
citation: Radtke FM, Franck M, Lendner J, Kruger S, Wernecke KD, Spies CD. Monitoring depth of anaesthesia in a randomized trial decreases the rate of postoperative delirium but not postoperative cognitive dysfunction. Br J Anaesth. 2013 Jun;110 Suppl 1:i98-105. doi: 10.1093/bja/aet055. Epub 2013 Mar 28.
citation: Sessler DI, Sigl JC, Kelley SD, Chamoun NG, Manberg PJ, Saager L, Kurz A, Greenwald S. Hospital stay and mortality are increased in patients having a "triple low" of low blood pressure, low bispectral index, and low minimum alveolar concentration of volatile anesthesia. Anesthesiology. 2012 Jun;116(6):1195-203. doi: 10.1097/ALN.0b013e31825683dc.
citation: Georgii MT, Kreuzer M, Fleischmann A, Schuessler J, Schneider G, Pilge S. Targeted Interventions to Increase Blood Pressure and Decrease Anaesthetic Concentrations Reduce Intraoperative Burst Suppression: A Randomised, Interventional Clinical Trial. Front Syst Neurosci. 2022 Mar 4;16:786816. doi: 10.3389/fnsys.2022.786816. eCollection 2022.