Depth of Anaesthesia and Postoperative Cognitive Decline in Patients Undergoing Heart Surgery

October 21, 2019 updated by: King's College Hospital NHS Trust

Effect of Depth of Anaesthesia on Postoperative Cognitive Decline in Patients Undergoing Coronary Artery Bypass Graft Surgery - a Prospectively Randomized Controlled Study

Post-Operative Cognitive Decline (POCD) is common after cardiac surgery and associated with increased morbidity and mortality. The pathophysiology of POCD is only poorly understood. Causes include hypoperfusion, microemboli and the systemic inflammatory response, which result in a reduction of cerebral oxygen delivery.

Cerebral oxygenation can be monitored non-invasively by measuring frontal lobe oxygen saturation (rSO2).

The bispectral index (BIS) of the electroencephalogram is widely known to measure depth of anaesthesia, and there is a high correlation between BIS, a dimensionless calculated number between 0 and 100, and clinical criteria of sedation. With BIS below 60 recall is extremely low.

The investigators demonstrated recently that inappropriately high levels of anaesthesia may be associated with poorer long-term outcomes in cognition after non-cardiac surgery (Ballard et al. 2012). Whether optimisation of the depth of anaesthesia and cerebral oxygenation has an effect on postoperative cognitive function in patients undergoing cardiac surgery is unknown.

The investigators hypothesize that the incidence of POCD in elderly patients (> 65 years old) at 6 weeks is less with mildly deep anaesthesia (BIS 50 +- 10) and optimised rSO2 (interventions when rSO2 drops below 15% of baseline reading) when compared with current practice (BIS blinded anaesthesia, reflecting moderately to highly deep anaesthesia and blinded rSO2 measurements).

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

88

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
    • Denmark Hill
      • London, Denmark Hill, United Kingdom, SE5 9RS
        • King's College Hospital NHS Foundation Trust

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

65 years and older (Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • patients undergoing elective coronary artery bypass graft surgery
  • patients at 65 years of age and older

Exclusion Criteria:

  • diseases of the central nervous system including dementia
  • inadequate knowledge of English
  • a current or past psychiatric illness
  • current use of tranquilizers or antidepressants
  • severe visual, auditory, or motor handicap

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
No Intervention: Current practice (BIS and rSO2 blinded)
Experimental: Targeted intra-operative depth of anaesthesia
Other: Targeted intra-operative depth of anaesthesia
The intervention group receives isoflurane at a concentration that results in a BIS value between 40-60 intra-operatively.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Incidence of postoperative cognitive decline after bypass surgery
Time Frame: Six weeks after bypass surgery
Six weeks after bypass surgery

Secondary Outcome Measures

Outcome Measure
Time Frame
Incidence of postoperative cognitive decline 5 days and 1 year after bypass surgery
Time Frame: Five days and one year postoperatively
Five days and one year postoperatively
Difference in degree of postoperative cognitive decline at 5 days, 6 weeks or 1 year after bypass surgery
Time Frame: 5days, 6 weeks or 1 year postoperatively
5days, 6 weeks or 1 year postoperatively
Postoperative Delirium
Time Frame: 3-5 days postoperatively
3-5 days postoperatively
Postoperative central nervous system and myocardial biochemical markers
Time Frame: up to 48 hours postoperatively
up to 48 hours postoperatively

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

King's College Hospital NHS Trust

Investigators

  • Principal Investigator: David Green, FRCA, MBA, King's College Hospital NHS Trust

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 1, 2014

Primary Completion (Actual)

January 1, 2016

Study Completion (Actual)

January 1, 2017

Study Registration Dates

First Submitted

December 4, 2012

First Submitted That Met QC Criteria

December 5, 2012

First Posted (Estimate)

December 6, 2012

Study Record Updates

Last Update Posted (Actual)

October 22, 2019

Last Update Submitted That Met QC Criteria

October 21, 2019

Last Verified

January 1, 2013

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • KHC11-001

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Postoperative Delirium

Clinical Trials on Targeted intra-operative depth of anaesthesia

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Netherlands

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe