ERPS, BIS and Entropy for Neuromonitoring in ICU Patients

This study has been completed.
Sponsor:
Collaborator:
GE Healthcare
Information provided by:
University Hospital Inselspital, Berne
ClinicalTrials.gov Identifier:
NCT00639548
First received: March 12, 2008
Last updated: NA
Last verified: March 2008
History: No changes posted
  Purpose

Most critically ill patients receive sedative and analgesic drugs to attenuate discomfort and pain. The excessive use of sedatives and analgesics has undesirable effects for patients. Whereas undersedation is mostly easy to identify, oversedation with its associated problems is more difficult to recognize. Stopping sedation daily helps to avoid gross oversedation, but this is not always possible. Monitoring the depth of sedation is difficult and is currently based on clinical assessment and the use of clinical scoring systems. These scoring systems cannot be applied continuously, they are subjective and the level of consciousness can be altered when sedation is assessed.

Several methods based on the electroencephalogram have been tested to avoid these problems, but the results have been disappointing so far, so the BIS Monitor an dthe Entropy monitor.We have previously shown that the time-locked cortical response to standard external stimuli (long-latency auditory evoked potentials or event-related potentials; ERPs) can discriminate between clinically relevant light to moderate and deep sedation levels in healthy volunteers, when sedation is induced with a combination of propofol or midazolam with remifentanil.

We therefore hypothesized that ERPs may be used to monitor the depth of sedation in ICU patients as well. As the first step to test this hypothesis, we evaluated the use of ERPs to assess the level of sedation in patients undergoing elective major surgery and admitted to the ICU for short term postoperative mechanical ventilation.


Condition
Deep Sedation
Electroencephalography
Event-Related Potentials
Evoked Potentials, Auditory

Study Type: Observational
Study Design: Observational Model: Case-Only
Time Perspective: Prospective
Official Title: Auditory Event-Related Potentials, BIS-Index and Entropy for the Discrimination of Different Levels of Sedation in the ICU Patients

Further study details as provided by University Hospital Inselspital, Berne:

Primary Outcome Measures:
  • Event related Potentials (Amplitudes, latencies) at different clinically relevant sedation levels [ Time Frame: postoperative awakening ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • BIS-Index at different clinically relevant sedation levels [ Time Frame: postoperative awaakening ] [ Designated as safety issue: No ]
  • Entropy at different clinically relevant sedation levels [ Time Frame: postoperative awakening ] [ Designated as safety issue: No ]

Enrollment: 20
Study Start Date: November 2004
Study Completion Date: September 2007
Primary Completion Date: July 2006 (Final data collection date for primary outcome measure)
Detailed Description:

Most critically ill patients receive sedative and analgesic drugs to attenuate discomfort and pain. The excessive use of sedatives and analgesics prolongs time on mechanical ventilation, the incidence of nosocomial pneumonia, time spent in the intensive care unit, and increases costs. Strategies to reduce the use of sedatives and analgesics may improve the outcome. Whereas undersedation is mostly easy to identify, oversedation with its associated problems is more difficult to recognize, but should be avoided. While stopping sedation daily helps to avoid gross oversedation, this is not always possible, e.g. due to unstable condition of the patient. Also, accumulation of sedatives and analgesics may occur rapidly, especially in patients with renal and/or liver dysfunction. Monitoring the depth of sedation is difficult and is currently based on clinical assessment and the use of clinical scoring systems. These scoring systems cannot be applied continuously, they are subjective and the level of consciousness can be altered when sedation is assessed.

Several methods based on the electroencephalogram have been tested to avoid these problems, but the results have been disappointing so far. A relatively new method of processed EEG is Entropy®. Entropy is a non-linear statistic parameter which describes the order of random repetitive signals. In patients it translates the anesthesia-induced "calmer", more synchronized EEG into a single parameter. Spectral entropy can reproducibly indicate the hypnotic effects of propofol, thiopental and different anesthetic gases. The most popular method of processed EEG for assessment of sedation is the bispectral index (BIS-Index®). While BIS has been tested and validated for the use in the operation room with different anesthetics, data on its use in the ICU setting at less deep levels of sedation are controversial. The multiple concomitant medications and heterogeneity of underlying pathologies present a further challenge to the use of neuromonitoring in the ICU.

We have previously shown that the time-locked cortical response to standard external stimuli (long-latency auditory evoked potentials or event-related potentials; ERPs) can discriminate between clinically relevant light to moderate and deep sedation levels in healthy volunteers, when sedation is induced with a combination of propofol or midazolam with remifentanil.

We therefore hypothesized that ERPs may be used to monitor the depth of sedation in ICU patients as well. As the first step to test this hypothesis, we evaluated the use of ERPs to assess the level of sedation in patients undergoing elective major surgery and admitted to the ICU for short term postoperative mechanical ventilation.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

patients required an elective thoracic surgical intervention under general anesthesia and who were scheduled to the ICU for postoperative care

Criteria

Inclusion Criteria:

  • 18 Years or older

Exclusion Criteria:

  • ASA class III or higher history of adverse events during former surgery or anesthesia, neurological impairment in the medical history hearing abnormalities.
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00639548

Locations
Switzerland
Departement of Intensive Care Medicine - University Hospital Bern - Inselspital
Bern, Switzerland, 3010
Sponsors and Collaborators
University Hospital Inselspital, Berne
GE Healthcare
  More Information

Publications:
Responsible Party: Haenggi Matthias, Department of Intensive Care Medicine - Inselspital
ClinicalTrials.gov Identifier: NCT00639548     History of Changes
Other Study ID Numbers: KIM-NMP4
Study First Received: March 12, 2008
Last Updated: March 12, 2008
Health Authority: Switzerland: Ethikkommission

Keywords provided by University Hospital Inselspital, Berne:
Deep Sedation
EEG
Event-Related Potentials
Evoked potentials, auditory
BIS-Index
Entropy
ICU

ClinicalTrials.gov processed this record on October 21, 2014