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

March 12, 2008
March 12, 2008
November 2004
July 2006   (final data collection date for primary outcome measure)
Event related Potentials (Amplitudes, latencies) at different clinically relevant sedation levels [ Time Frame: postoperative awakening ] [ Designated as safety issue: No ]
Same as current
No Changes Posted
  • 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 ]
Same as current
Not Provided
Not Provided
 
ERPS, BIS and Entropy for Neuromonitoring in ICU Patients
Auditory Event-Related Potentials, BIS-Index and Entropy for the Discrimination of Different Levels of Sedation in the ICU Patients

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.

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.

Observational
Observational Model: Case-Only
Time Perspective: Prospective
Not Provided
Not Provided
Non-Probability Sample

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

  • Deep Sedation
  • Electroencephalography
  • Event-Related Potentials
  • Evoked Potentials, Auditory
Not Provided
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Completed
20
September 2007
July 2006   (final data collection date for primary outcome measure)

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.
Both
18 Years and older
No
Contact information is only displayed when the study is recruiting subjects
Switzerland
 
NCT00639548
KIM-NMP4
No
Haenggi Matthias, Department of Intensive Care Medicine - Inselspital
University Hospital Inselspital, Berne
GE Healthcare
Not Provided
University Hospital Inselspital, Berne
March 2008

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP