Clinical trial NCT00434382: Neuronal Mechanisms of Sensory Processing During General Anesthesia
Official title: Neuronale Mechanismen Der Sensorischen Reizverarbeitung in Der Narkose
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: General Anesthesia
Keywords: auditory evoked potentials
sensory processing
monitoring
general anesthesia
Lead sponsor: Ludwig-Maximilians - University of Munich
Sponsor class: OTHER
Collaborators: name: CareFusion
name: German Federal Ministry of Education and Research
First posted: 2007-02-13
Enrollment: 768
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: SUPPORTIVE_CARE

Brief summary: The ability of Mid Latency Auditory Evoked Potentials for a routine monitoring of sensory suppression should be evaluated during a wide spectrum of clinically common forms general anesthesia.

Detailed description: Up to now there is no fully functional and precise technique for accurate assessment for monitoring the degree of unconsciousness during general anaesthesia. Previous studies and results obtained during the project regarding the effect of anaesthetics on single neurons and small neuronal networks indicate that it would be most promising to use a method directly correlating to the integrity of the relevant functional systems. As one goal of the project it was formulated to develop and test a new system for recording and analysis of mid latency auditory evoked potentials (MLAEP), suitable to be used in the clinical surrounding of an operation theatre. Step by step an investigational system was developed, that after obtaining legal approvement was functional in a broad spectrum of cases. In a multicenter study the including 4 clinical centres and 426 patients the reliability of the system was proved. Even under the hard conditions of the OR the apparatus was able to record the signals with sufficient reliability and precision. A clear correlation of MLAEP parameters with clinically defined states of consciousness could be identified. Differences in the effect of the used combinations of general anaesthetics and opioids were identified. An algorithm for automatic analysis of the signals was developed, to allow users with limited knowledge of interpretation of MLAEP signals to use them for monitoring anaesthesia.

Eligibility criteria: Inclusion Criteria:

* Male and female patients
* Scheduled for elective urological, gynaecological or general surgery
* ASA status I or II
* Age 18 to 65

Exclusion Criteria:

* ASA status above II
* Operative procedures involving the neurocranium, neck or require other neurophysiologic monitoring
* Inability to communicate freely in the german language
* Major hearing deficit
* Regular centrally acting medication including drug abuse within 3 months prior to the investigation
* Participant of an other clinical investigation
* Lacking or withdrawal of written informed consent

Primary outcomes:
measure: Intraoperative signs of inadequate anesthesia
measure: Postoperative recall of events
measure: MLAEP parameters
Secondary outcomes:
Other outcomes:
Locations:
city: Friedrichshafen
country: Germany
facility: Krankenhaus Friedrichshafen
city: Heidelberg
country: Germany
facility: Klinik für Anaesthesia am Universitaetsklinikum Heidelber
city: Lubeck
country: Germany
facility: Klinik fuer Anaesthesiologie am Universitätsklinikum Schleswig Holstein, Campus Luebeck
city: Munich
country: Germany
facility: Klinik fuer Anaesthesiologie der Ludwigs-Maximilians-Universitaet Muenchen
Study officials:
affiliation: Klinik fuer Anaesthesiologie, Ludwig-Maximilians-Universitaet Muenchen
name: Michael AM Daunderer, M.D.,Ph.D.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Scheller BC, Daunderer M, Pipa G. General anesthesia increases temporal precision and decreases power of the brainstem auditory-evoked response-related segments of the electroencephalogram. Anesthesiology. 2009 Aug;111(2):340-55. doi: 10.1097/ALN.0b013e3181acf7c0.