Testing the effects of low levels of blood oxygen and movement of the accuracy of portable vital signs monitors
| ISRCTN | ISRCTN61535692 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN61535692 |
| Secondary identifying numbers | 251711 |
- Submission date
- 28/05/2019
- Registration date
- 10/06/2019
- Last edited
- 19/07/2023
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Other
Plain English summary of protocol
Background and study aims
Despite best efforts, there is continuing evidence that a proportion of hospitalised patients worsen, sometimes due to reversible causes. Failure to identify and act on indicators of worsening acute illness in hospital wards is a problem that has been known for more than 10 years. “Track and Trigger” scoring systems are used in practice to check “standard" vital signs. These are pulse rate, respiratory rate, blood pressure, oxygen level and temperature. These are taken at timed intervals based on a protocol which is selected based on the clinical condition of the patient. Intermittent application of vital sign monitoring devices can be time-consuming. As a result the correct frequency of observations is often missed. Continuous vital sign monitoring within the ward environment is not currently workable, but it’s believed to increase the timely detection of patient deterioration. Wearable ambulatory monitoring systems (AMS) may provide an alternative continuous monitoring system which may improve the early detection of irregular physical and biological parameters. AMS would allow patients to be more mobile and have less discomfort. The aim of this study is to test whether the devices will be able to give correct readings and be suitable for clinical use. This is to ensure that AMS kits give accurate and reliable readings. To achieve this these kits need to be rigorously tested on 30 healthy volunteers.
Who can participate?
Men and women aged 18 or over and in generally good health
What does the study involve?
Participants will be attached to a standard hospital monitor and the portable monitors being tested. A small tube will be inserted into their radial artery (called an arterial line). This will allow the study doctor to take blood samples during the study. Participants will be asked to follow a series of movements designed to mimic those commonly made by patients in hospital, such as drinking, standing and reading. They will then be asked to wear a tight-fitting mask attached to a machine. This will gradually lower the amount of oxygen in their blood. Throughout the study, blood samples will be taken from the arterial line to measure blood oxygen levels. At the end of the study the mask will be removed, oxygen levels returned to normal and the arterial line will be removed.
What are the possible benefits and risks of participating?
The risks involved in participation in this study are few. The procedures to be carried out in this study are generally well tolerated. The member of the research team carrying out these procedures will have done them a great number of times before and be technically skilled so as to minimise discomfort. Although rare, there is always a risk of minimal complications during arterial line placement and decreased oxygen exposure, for example bruising and fainting. Other rare complications of the arterial line can include temporary vascular occlusion, thrombosis, ischemia, hematoma formation, and local and catheter-related infection, sepsis and nerve damage. If symptoms become unpleasant, the testing will be stopped. These side effects should rapidly reverse following breathing normal room air.
Where is the study run from?
John Radcliffe Hospital (UK)
When is the study starting and how long is it expected to run for?
May 2018 to March 2022
Who is funding the study?
NIHR Oxford Biomedical Research Centre (UK)
Who is the main contact?
Dr Sarah Vollam
Sarah.vollam@ndcn.ox.ac.uk
Contact information
Public
Nuffield Department of Clinical Neurosciences, University of Oxford
Kadoorie Centre
Level 3
John Radcliffe Hospital
Oxford
OX3 9DU
United Kingdom
 ORCID ID |
0000-0003-2835-6271 |
|---|---|
| Phone | +44 (0)1865231440 |
| Sarah.vollam@ndcn.ox.ac.uk |
Study information
| Study design | Observational cross-sectional cohort study |
|---|---|
| Primary study design | Observational |
| Secondary study design | Cross sectional study |
| Study setting(s) | Other |
| Study type | Diagnostic |
| Participant information sheet | Not available in web format, please use contact details to request a participant information sheet |
| Scientific title | Virtual HDU: hypoxia study. Accuracy and validity testing of ambulatory monitoring system |
| Study acronym | vHDU-Hypoxia |
| Study objectives | The primary objective of the study is to determine the specificity and sensitivity of commercially available ambulatory vital-sign monitoring equipment for detection of hypoxia. This phase of the study will test the ambulatory monitoring equipment on healthy volunteers. |
| Ethics approval(s) | Approved 15/03/2019, East of Scotland Research Ethics Service REC 2 (Tayside Medical Science Centre, Residency Block Level 3, George Pirie Way, Ninewells Hospital and Medical School, Dundee DD1 9SY, Tel: +44 (0)1382 383878; Email: eosres.tayside@nhs.net), ref: 19/ES/0008 |
| Health condition(s) or problem(s) studied | Vital sign monitoring |
| Intervention | Participants will visit the designated research facility for the study visit. On arrival, participants will be assessed for their suitability for the study. An arterial line will be inserted into their radial artery. They will be connected to a standard hospital monitor and the ambulatory monitors being tested. Throughout the study, data from all monitors will be recorded. In the movement phase, participants will follow a series of protocolised movements designed to replicate usual patient movements. Arterial blood samples will be taken at the end of each movement. During the hypoxia phase, participants will lie on a bed with a tight face mask delivering reduced levels of inhaled oxygen. Their blood oxygen levels will be monitored and arterial blood gases taken at intervals as their oxygen saturations decrease. Throughout the procedures, an anaesthetist will be present and their vital signs closely monitored for safety purposes. After the hypoxia phase, their blood oxygen levels will be normalised and the arterial line removed. They will remain with the study team until deemed to have recovered sufficiently to leave the research facility. |
| Intervention type | Device |
| Pharmaceutical study type(s) | |
| Phase | Not Applicable |
| Drug / device / biological / vaccine name(s) | Not provided at time of registration |
| Primary outcome measure | Specificity and sensitivity of currently available ambulatory vital-sign monitors will be assessed by comparing continuous oxygen saturation, pulse rate and breathing rate data from each ambulatory monitor with arterial blood oxygen saturation measured through blood gas analysis, respiratory rate derived from capnography and pulse rate derived from ‘usual care’ hospital grade pulse oximetry monitoring. Arterial oxygen saturation will be measured at incremental drops in SpO2, up to 80%. Respiratory rate and pulse rate will be measured continuously throughout testing. |
| Secondary outcome measures | The effects of movement on data acquisition by currently available ambulatory vital-sign monitors will be assessed by comparing continuous oxygen saturation, pulse rate and breathing rate data from each ambulatory monitor with arterial blood oxygen saturation measured through blood gas analysis, respiratory rate derived from capnography and pulse rate derived from ‘usual care’ hospital grade pulse oximetry monitoring. Arterial oxygen saturation will be measured after each movement is completed. Respiratory rate and pulse rate will be measured continuously throughout testing. |
| Overall study start date | 05/05/2018 |
| Completion date | 01/03/2022 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Sex | Both |
| Target number of participants | 30 |
| Total final enrolment | 29 |
| Key inclusion criteria | 1. Willing and able to give informed consent for participation in the study 2. Men and women aged 18 or over and in generally good health |
| Key exclusion criteria | 1. Allergies to adhesive dressings (such as bio-occlusive dressings or micropore) or local anesthesic (e.g. Lidocaine) 2. Intra-cardiac device (e.g. Permanent pacemaker) or previous wrist arterial line 3. Epilepsy 4. Angina, congenital heart disease or history of severe cardiopulmonary disease 5. History of anaemia (reported in the pre-screening telephone call) or Hb below 100 g/l on first test 6. Resting hypoxaemia (SpO2 <94%) or significant cardiopulmonary disease rendering exposure to alveolar hypoxia unsafe, as determined by the research physician 7. Pregnancy or breastfeeding 8. Clotting disorders and use of antiplatelet or anticoagulant medication (such as Aspirin) 9. Claustrophobia precluding spell in the hypoxic exposure |
| Date of first enrolment | 18/06/2019 |
| Date of final enrolment | 01/09/2019 |
Locations
Countries of recruitment
- England
- United Kingdom
Study participating centre
Kadoorie Centre
Headley Way
Oxford
OX3 9DU
United Kingdom
Sponsor information
University/education
Clinical Trials and Research Governance
Joint Research Office
Boundary Brook House
Churchill Drive
Headington
Oxford
OX3 7GB
England
United Kingdom
| Phone | +44 (0)1865289885 |
|---|---|
| ctrg@admin.ox.ac.uk | |
| Website | https://researchsupport.admin.ox.ac.uk/ctrg |
"ROR" |
https://ror.org/052gg0110 |
Funders
Funder type
Government
No information available
Results and Publications
| Intention to publish date | 05/12/2022 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Available on request |
| Publication and dissemination plan | Peer-reviewed journals at the end of data analysis. |
| IPD sharing plan | De-identified data will be held with the University of Oxford electronic archive for 5 years after the end of the study. Datasets will be large and focused on validation of monitor outputs. However, de-identified datasets may be made available to researchers on written request to the PI (Dr Peter Watkinson: peter.watkinson@ndcn.ox.ac.uk). |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Results article | results | 15/09/2021 | 21/09/2021 | Yes | No |
| Results article | 15/02/2022 | 16/02/2022 | Yes | No | |
| HRA research summary | 28/06/2023 | No | No | ||
| Protocol article | 12/01/2020 | 19/07/2023 | Yes | No |
Editorial Notes
19/07/2023: Publication reference added.
05/04/2022: The study contact has been updated and the plain English summary has been updated accordingly.
16/02/2022: Publication reference added.
21/09/2021: The following changes have been made:
1. Publication reference added.
2. The total final enrolment number has been added from the reference.
10/11/2020: The following changes were made to the trial record:
1. The overall trial end date was changed from 30/10/2019 to 01/03/2022.
2. The intention to publish date was changed from 05/12/2020 to 05/12/2022.
09/06/2020: The intention to publish date was changed from 10/12/2019 to 05/12/2020.
11/06/2019: Internal review.
10/06/2019: Trial's existence confirmed by Research Ethics Service.
