Detecting low brain oxygen levels in patients undergoing non-cardiac surgery to assess its association with post-operative delirium

ISRCTN ISRCTN15439489
DOI https://doi.org/10.1186/ISRCTN15439489
Secondary identifying numbers 1.31
Submission date
29/08/2018
Registration date
06/11/2018
Last edited
22/03/2021
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Mental and Behavioural Disorders
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims (brief description of the disease or area of study, what are the objectives/aim of the study)

The aim is to explore the use of a novel monitor, during general anaesthesia and surgery, that non-invasively measures the levels of oxygen in the brain. We will also look for the uncommon complication of delirium occurring early in the postoperative period.

Who can participate? (what are the age range and gender of the participants, can they only participate if they have a certain condition or if they are healthy volunteers?)

Specific patients having surgery at this hospital will be approached.

What does the study involve? (what interventions will be compared, will all participants receive the same treatment?)

The use of a new monitor before, during and for one hour after surgery.

What are the possible benefits and risks of participating? (what can participants gain from enrolling, are there any side effects of the treatments and if so, what are the symptoms?)
No potential benefit. Trivial risk of having allergic to the adhesive on the sensor.

Where is the study run from? (what are the approximate number and names of centres taking part in this trial, if there is a lead centre, which one is it?)
Royal Surrey County Hospital NHS Foundation Trust

When is the study starting and how long is it expected to run for? (what is the anticipated start date and the approximate duration of the trial?)
September 2018 to January 2019

Who is funding the study? (who will be paying the costs that the trial will incur during its lifecycle?)
Medtronic, the manufacturer of the sensors and device.

Who is the main contact? (if this is the same as the contact in the record, please provide the name and email address only, if different to the contact in the record, please provide the name, position they hold at the institution/organisation and their email address)
Ben Creagh-Brown, bencb@nhs.net

Contact information

Dr Ben Creagh-Brown
Public

Royal Surrey County Hospital
Guildford
GU27XX
United Kingdom

ORCiD logoORCID ID 0000-0002-4397-1232

Study information

Study designProspective observational cohort study
Primary study designObservational
Secondary study designCohort study
Study setting(s)Hospital
Study typeDiagnostic
Participant information sheet Not available in web format, please use the contact details below to request a participant information sheet
Scientific titleUsing near-infrared spectroscopy to detect cerebral desaturation in non-cardiac surgery and assess its relationship with post-operative delirium– a pilot study
Study acronymCereOx
Study objectivesLow baseline cerebral oximetry values, or some metric of peri-operative cerebral desaturation may be more closely associated with post-operative delirium than other variables including systemic blood pressure.
Ethics approval(s)London - Bloomsbury Research Ethics Committee reviewed the above application on 21 June 2018. REC reference: 18/LO/1122
Health condition(s) or problem(s) studiedPostoperative delirium
InterventionMeasurement of cerebral oximetry, from entering the anaesthetic room to 1 hour after the end of surgery
Intervention typeDevice
Pharmaceutical study type(s)
Phase
Drug / device / biological / vaccine name(s)
Primary outcome measureThe following will be assessed once the final participant has finished the study (as these measurements require the total number of patients):
1. Proportion of patients enrolled in whom we acquired interpretable regional oxygen saturation (rScO2) data (%) is assessed: 100 X total number recruited with interpretable data / total number recruited
2. Proportion of patients enrolled in whom we acquired delirium data (%) is assessed: 100 X total number recruited with delirium data / total number recruited
Secondary outcome measuresFor each cohort of surgical patients, and the cohort as a whole, use descriptive statistics (proportion (%), or mean and standard deviation, or median and interquartile range – according to parametric or non-parametric distribution respectively):
1. Incidence of cerebral desaturation using three previously utilised definitions (as below). Cerebral saturation is assessed using a cerebral oximetry machine, recorded continuously during surgery and for 1 hour after surgery.
1.1. Any occurrence of a decrease of 10% from baseline
1.2. Any occurrence of a decrease of 20% from baseline
1.3. Any occurrence of an absolute value of regional oxygen saturation (rScO2) <50%
2. Average duration of relative desaturation - time with rScO2 ≤ 60%
3. Incidence of systemic hypotension using three common definitions (as below). Systolic hypotension is assessed using blood pressure readings taken during surgery. Baseline values will be obtained from the pre-operative clinic; however, if this is not possible then the pre-induction blood pressure will be used as a baseline.
3.1. Any occurrence of systolic blood pressure (BP) ≤20% of baseline
3.2. Any occurrence of systolic BP ≤30% of baseline
3.3. Any occurrence of systolic BP ≤40% of baseline
4. Average duration of systemic hypotension - time with mean arterial pressure (MAP) ≤20% of baseline
5. Incidence of hypoxaemia using three definitions (as below). Hypoxaemia will be assessed using saturation probe readings during surgery.
5.1. Any occurrence of blood oxygen saturation (SpO2) ≤ 88%
5.2. Any occurrence of SpO2 ≤ 90%
5.3. Any occurrence of SpO2 ≤ 92%
6. Average duration of hypoxaemia - time with SpO2 ≤ 90%
7. Utilisation of vasopressor drugs (α-agonists) - we will record either a vasopressor infusion or bolus is given during surgery, and if any are given during the recovery. Time administered, drug, dose and the Mean Arterial Pressure (obtained from the anaesthetic machine) will be recorded by the clinician
8. Baseline rScO2 values
9. The incidence of delirium during the postoperative in-patient stay (up to day 7), assessed using 4AT (clinic test for delirium)
10. For the cohort as a whole, compare the difference in variables listed above (1 to 8) between those who developed postoperative delirium and those who did not, using appropriate statistical test: Chi-squared for proportions, unpaired test-t for continuous parametrically-distributed variables, Mann-Whitney U test for continuous non-parametrically-distributed variables.
Overall study start date26/01/2018
Completion date01/02/2019

Eligibility

Participant type(s)Patient
Age groupSenior
SexBoth
Target number of participants60
Total final enrolment60
Key inclusion criteriaPatients:
1. Age ≥ 60
2. Able to provide informed consent

Surgical types:
1. Scheduled orthopaedic surgery (GA/sedation +/- regional)
2. Scheduled gastrointestinal surgery (open/closed)
3. Scheduled robotic urological or gynaecological surgery
4. Emergency laparotomy surgery
Key exclusion criteria1. Acute or chronic cognitive impairment, including delirium or dementia
2. Previous neurosurgery
3. Insufficient English language to discuss participation
Date of first enrolment03/09/2018
Date of final enrolment01/01/2019

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

Royal Surrey County Hospital
Egerton Road
Guildford
GU2 7XX
United Kingdom

Sponsor information

Royal Surrey County Hospital
Hospital/treatment centre

Egerton Road
Guildford
GU2 7XX
England
United Kingdom

Phone 01483 571122
Email k.penhaligon@nhs.net
Website www.royalsurrey.nhs.uk
ROR logo "ROR" https://ror.org/02w7x5c08

Funders

Funder type

Industry

Medtronic
Private sector organisation / For-profit companies (industry)
Alternative name(s)
Medtronic Inc.
Location
United States of America

Results and Publications

Intention to publish date01/07/2019
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryStored in repository
Publication and dissemination planPublish findings at conferences and as a manuscript in a peer-reviewed journal
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article 01/06/2021 22/03/2021 Yes No
HRA research summary 28/06/2023 No No

Editorial Notes

22/03/2021: The following changes were made to the trial record:
1. Publication reference added.
2. The total final enrolment was added.
25/02/2019: internal review.
23/11/2018: Internal review.