Does Bispectral index monitoring during anesthesia provide benefit for elderly patients?

ISRCTN ISRCTN42029636
DOI https://doi.org/10.1186/ISRCTN42029636
Secondary identifying numbers N/A
Submission date
23/02/2015
Registration date
17/03/2015
Last edited
16/03/2015
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Surgery
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
Bispectral index (BIS) is a method used to monitor the depth of anesthesia. Administration of anesthetics in response to individual need as estimated BIS has been associated with reduced risk of awareness, reduced consumption of anesthetics, faster emergence from anesthesia and reduced incidence of postoperative nausea and vomiting. Although controversial, an impact on long-term mortality has been proposed. There are neuro-monitoring devices available but they are not used routinely, which shows that it is still not clear whether these technologies actually provide sufficient benefit to be cost effective. This aim of this study is to provide a carefully controlled global view on BIS monitoring during anesthesia that will be relevant to patients, anesthesia providers and the community.

Who can participate?
Patients 70 years or older undergoing major, elective, non-cardiac surgery.

What does the study involve?
BIS is recorded for all participants.
Then participants are randomly allocated to one of two groups: “open group” or “concealed group”,
BIS is available for guiding administration of anesthetics for participants in the “open group”. BIS data is recorded for subsequent analysis for participants in the "concealed" group.
A third group of age and gender matched people not undergoing surgery is recruited in order to correct cognitive testing results in the two study groups (for random variation over time and learning effect).

What are the possible benefits and risks of participating?
Participants allocated to the “open group” may benefit from more individualized administration of anaesthesics. Participants allocated to the “concealed” group will receive standard care.
Application of BIS electrodes is not associated with any risk. Risks with BIS monitoring have not been demonstrated.

Where is the study run from?
Länssjukhuset, Kalmar (Sweden)

When is the study starting and how long is it expected to run for?
From February 2004 to October 2010

Who is funding the study?
Medical Research Council of South East Sweden

Who is the main contact?
Dr Rolf Sandin
rolf.sandin@ltkalmar.se

Contact information

MD, PhD Rolf Sandin
Scientific

Hospital administration, Länssjukhuset
Kalmar
39185
Sweden

Study information

Study designSingle-center randomized controlled study
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Hospital
Study typeOther
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific titleA prospective, randomized evaluation of utility of Bispectral index monitoring in elderly surgical patients
Study objectivesThe hypothesis is that mean BIS values would be closer to a predefined target of 50 and significantly different from when no data from BIS monitoring is available, and that this anticipated difference in BIS between groups should be significantly related to improved outcome. Twenty-five outcome variables were allocated to one of three meaningful domains which constitute primary outcome. These domains are postoperative cognitive decline, perioperative cardiovascular compromise, and a socio-economic oriented domain.
We anticipate that potential benefits from individualized BIS guided anesthesia would be most obvious in the elderly population undergoing long procedures. Therefore we conduct this investigation in patients 70 years or older undergoing major, elective, non-cardiac surgery.
Ethics approval(s)Regionala Etikprövningsnämnden i Linköping (IRB at Linköping University, Linköping, Sweden), 27/04/2005, reference number M25-5.
Health condition(s) or problem(s) studiedImproved outcome after anesthesia by more precise administration of anesthetics in relation to individual need as assessed by bispectral index monitoring.
InterventionIn study groups Bispectral index is recorded in all subjects but only available for guiding administration of anesthetics in the "open" group as opposed to the "concealed" group in which data is recorded for subsequent analysis.
Additional control patients not undergoing surgery were recruited to establish the learning effect and natural variation in performance over time in the cognitive testing for postoperative cognitive dysfunction.
Intervention typeDevice
Pharmaceutical study type(s)
Phase
Drug / device / biological / vaccine name(s)
Primary outcome measurePostoperative cognitive dysfunction day 7 after surgery, global cardio-vascular outcome score (based on 10 subparameters), and global socio-economic outcome score ( based on 8 subparameters)
Secondary outcome measuresIntraoperative blood loss, net fluid and blood balance, urine production first 6 h postoperatively, postoperative hypoxemia (defined as SpO2 below 90%), increase in C-reactive protein postoperative day 3, weight gain postoperative day 3, awareness, 7 subparameters reflecting postoperative cognitive decline as described by Moller et al. (Lancet 1998; 351: 857-61), increase in Troponin-I 12-24 h after surgery, increase in Troponin-I 72 h after surgery, average intraoperative mean arterial blood pressure, duration of heart rate deviating >20% from baseline intraoperatively, duration of heart rate deviating >20% from baseline postoperatively, duration of systolic arterial blood pressure deviating >20% from baseline intraoperatively, duration of systolic arterial blood pressure deviating >20% from baseline postoperatively, duration of intraoperative inotropic support, number of patients given inotropic support postoperatively, duration of inotropic support postoperatively, age corrected average MAC-fraction of sevoflurane administered during anesthesia, duration of stay at the postoperative care unit, number of påatioents admitted to the ICU postoperatively, duration of sotal stay at the postoperative care unit and intensive care unit, length of hospital stay, number of patients being discharged to home, 30-day survival, 1-year survival.
Overall study start date20/02/2004
Completion date21/10/2010

Eligibility

Participant type(s)Patient
Age groupAdult
SexBoth
Target number of participants50 patients in each of the two study groups and 25 age matched control patients not undergoing surgery (control for cognitive testing).
Key inclusion criteria1. Aged over 70, both gender
2. Anticipated duration of surgery over 90 minutes
3. Being able to communicate in Swedish
4. No overt hearing or reading difficulties
Key exclusion criteria1. Unstable medical condition starting after inclusion but prior to surgery
2. Psychiatric disease
3. Reoperation
4. Lost to follow-up
5. Result from mini mental state examination <23
Date of first enrolment01/04/2006
Date of final enrolment30/10/2009

Locations

Countries of recruitment

  • Sweden

Study participating centre

Länssjukhuset
Kalmar
S-39185
Sweden

Sponsor information

Medical Research Council of South East Sweden - Forskningsrådet i Sydöstra Sverige (FORSS)
Research council

Forskningsrådet i Sydöstra Sverige
Linköping
58191
Sweden

Phone +46101037655
Email lena.lindgren@regionostergotland.se
Website www.fou.nu

Funders

Funder type

Research council

Medical Research Council of South East Sweden - Forskningsrådet i Sydöstra Sverige (FORSS)

No information available

Results and Publications

Intention to publish date31/05/2015
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryAvailable on request
Publication and dissemination planThe results are intended to be published in a major scientific journal in the field of anesthesiology.
IPD sharing plan