Relationship Between Bispectral Index (BIS) and Spectral Entropy (SpEn) During Desflurane Anaesthesia

Intraoperative Awareness Clinical Trial

Official title:

Relationship Between Bispectral Index (BIS) and Spectral Entropy (SpEn) During Desflurane Anaesthesia

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01868178
• Other study ID #: A 935/2007
• Status: Completed
• Phase: N/A
• First received: November 12, 2012
• Last updated: May 30, 2013
• Start date: September 2008
• Est. completion date: January 2009

Study information

• Verified date: May 2013
• Source: Catholic University of the Sacred Heart
• Contact: n/a
• Is FDA regulated: No
• Health authority: Italy: Ethics Committee
• Study type: Observational

Clinical Trial Summary

The aim of this study was to estimate the relationship between BIS and Spectral Entropy values and any explicit or implicit memory or dreams recall during desflurane anaesthesia.

Description:

During the last decade, an increasing number of monitor systems were developed designed to assess the depth of anesthesia.

Awareness is a rare occurrence of explicit recalls during anaesthesia with an incidence of 0,18% and the use of cerebral monitoring prevents about 50% of these events.

Different stages of awareness should be defined and implicit memorization is subconscious awareness without explicit recall and possible implicit recall with an incidence greater than awareness.

To assess implicit recalls, a large number of test can be used, for example the "word stem completation test" and the "free recall association test". These result easy to use and reliable in detect implicit memory.

Bispectral Index (BIS) and Spectral Entropy (SpEn) has been proposed, in recent years, as electroencephalographic monitors of anaesthesia depth.

The bispectral index is a monitor of anaesthetic depth approved by the Food and Drug Administration in the USA. The BIS monitor reports a dimensionless number between 0 (complete EEG inactivity) and 100 (awake state); BIS values from 40 to 60 are thought to be suitable for general anaesthesia. Spectral Entropy acquires the electroencephalograph (EEG) and frontal electromyography (FEMG) signals which are processed into three parameters: State Entropy (SE), Response Entropy (RE) and Burst Suppression Ratio (BSR).

SE is computed over the EEG dominant part of the spectrum (0.8-32 Hz), and therefore primarily should reflect the cortical state of the patient and results useful to assess hypnotic effects of drugs .

RE is computed over a frequency range from 0.8 to47 Hz. It includes both the EEG-dominant and EMG-dominant part of the spectrum . The SE and RE values below 60 correlate with a low probability of consciousness. Also Bispectral Index provides BRS, an evaluation of burst suppression in which cerebral activity results suppressed.

BIS and Spectral Entropy are intended to decrease the risk of intraoperative awareness and to enable the anesthetist to reduce risk of the under- and overdosing of anesthetic agents and to ensure faster and more predictable wake-up and extubation.

Previous studies result contrasting in the correlation between these devices with lack in evaluation of implicit memory.

The aim of this study was to estimate the relationship between BIS and Spectral Entropy values and any explicit or implicit memory or dreams recall during desflurane anaesthesia.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 50
• Est. completion date: January 2009
• Est. primary completion date: January 2009
• Accepts healthy volunteers: No
• Gender: Female
• Age group: 30 Years to 60 Years

Eligibility

Inclusion Criteria:

• American society of anesthesiologist physical status I-II

• Italian native speakers

Exclusion Criteria:

• Psychiatric or neurologic diseases

• Acoustic impairment

• Obesity (Body Mass Index > 30)

• Substance dependence.

Study Design

Observational Model: Case-Only, Time Perspective: Prospective

Related Conditions & MeSH terms

• Intraoperative Awareness

Intervention

Device:
• BIS and Spectral Entropy
The aim of the study was investigated the effectiveness of Spectral Entropy and BIS in avoiding awareness

Locations

Country	Name	City	State
Italy	Catholic University	Rome	Rm
Italy	Catholic University of Sacred Heart	Rome	Rm

Sponsors (1)

Lead Sponsor	Collaborator
Catholic University of the Sacred Heart

Country where clinical trial is conducted

Italy, 

References & Publications (10)

Brice DD, Hetherington RR, Utting JE. A simple study of awareness and dreaming during anaesthesia. Br J Anaesth. 1970 Jun;42(6):535-42. — View Citation

Domino KB, Posner KL, Caplan RA, Cheney FW. Awareness during anesthesia: a closed claims analysis. Anesthesiology. 1999 Apr;90(4):1053-61. — View Citation

Ghoneim MM. Incidence of and risk factors for awareness during anaesthesia. Best Pract Res Clin Anaesthesiol. 2007 Sep;21(3):327-43. — View Citation

Heier T, Steen PA. Awareness in anaesthesia: incidence, consequences and prevention. Acta Anaesthesiol Scand. 1996 Oct;40(9):1073-86. Review. — View Citation

Kissin I. Depth of anesthesia and bispectral index monitoring. Anesth Analg. 2000 May;90(5):1114-7. — View Citation

Liu J, Singh H, White PF. Electroencephalographic bispectral index correlates with intraoperative recall and depth of propofol-induced sedation. Anesth Analg. 1997 Jan;84(1):185-9. — View Citation

Liu WH, Thorp TA, Graham SG, Aitkenhead AR. Incidence of awareness with recall during general anaesthesia. Anaesthesia. 1991 Jun;46(6):435-7. — View Citation

O'Connor MF, Daves SM, Tung A, Cook RI, Thisted R, Apfelbaum J. BIS monitoring to prevent awareness during general anesthesia. Anesthesiology. 2001 Mar;94(3):520-2. — View Citation

Paolo Martorano P, Falzetti G, Pelaia P. Bispectral index and spectral entropy in neuroanesthesia. J Neurosurg Anesthesiol. 2006 Jul;18(3):205-10. — View Citation

Ranta SO, Laurila R, Saario J, Ali-Melkkilä T, Hynynen M. Awareness with recall during general anesthesia: incidence and risk factors. Anesth Analg. 1998 May;86(5):1084-9. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	explicit and implicit memory and dreams recall.		after 24 h	Yes
Primary	BIS index		change from baseline at 15 min	Yes
Secondary	entropy values		24 h after emergency from anaesthesia	Yes