Contact information
Type
Scientific
Primary contact
Dr Christine Roffe
ORCID ID
Contact details
SOS STudy
Stroke Research
Medical Illustrations
Royal Infirmary
Prince's Road
Hartshill
Stoke-on-Trent
ST4 7LN
United Kingdom
+44 (0)1782 555875
Christine.roffe@northstaffs.nhs.uk
Additional identifiers
EudraCT number
2006-003479-11
ClinicalTrials.gov number
Protocol/serial number
06/Q2604/109
Study information
Scientific title
The Stroke Oxygen Study: a multi-centre, prospective, randomised, open, blinded-endpoint study of routine oxygen treatment in the first 72 hours after a stroke
Acronym
SO2S
Study hypothesis
Main hypothesis:
Fixed dose oxygen treatment during the first three days after an acute stroke improves outcome.
Secondary hypothesis:
Restricting oxygen supplementation to night time only is more effective than continuous supplementation.
The pilot study of this trial can be found at ISRCTN12362720 (http://www.isrctn.com/ISRCTN12362720).
Ethics approval
Local Research Ethics Committee (Mellor House, Corporation Street, Stafford, ST16 3SR, UK), 31/10/2006, ref: 06/Q260/109. Protocol version 2 approved on 24/01/2007 and on 26/06/2008.
Study design
Multi-centre prospective randomised open blinded-endpoint study
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
Hospitals
Trial type
Treatment
Patient information sheet
Patient information can be found at http://www.so2s.co.uk/
Condition
Stroke, cerebral infarct, intracerebral haemorrhage, cerebrovascular disease
Intervention
Treatment group 1: no routine oxygen supplementation during the first 72 hours after randomisation.
Treatment group 2: oxygen per nasal cannula overnight (21:00 - 7:00) at a flow rate of 3 L/min (if baseline oxygen saturation is 93% or below) or at a flow rate of 2 L/min (if baseline oxygen saturation is greater than 93%) during the first three nights after randomisation.
Treatment group 3: oxygen per nasal cannula continuously (day and night) at a flow rate of 3 L/min (if baseline oxygen saturation is 93% or below) or a flow rate of 2 L/min (if baseline oxygen saturation is greater than 93%) during the first 72 hours after randomisation.
All patients will have regular observations of vital signs (blood pressure, heart rate, temperature and oxygen saturation) as per the local protocol of the stroke unit, but at least six-hourly. Treatment of any abnormal findings will be independent of trial allocation. Patients who require oxygen or changes in the dose of oxygen for clinical reasons at any time of the trial will be given the concentration of oxygen they require.
Intervention type
Drug
Phase
Not Applicable
Drug names
Oxygen
Primary outcome measure
Modified Rankin Scale score at 3 months
Secondary outcome measures
1. Secondary outcomes at 1 week:
1.1. Mortality
1.2. Number of patients with neurological deterioration (death or a greater than 4 point increase in the National Institutes of Health Stroke Scale [NIHSS])
1.3. Deaths
1.4. Highest oxygen saturation during the first 72 hours
1.5. Lowest oxygen saturation during the first 72 hours
2. Secondary outcomes at 3 months:
2.1. Mortality
2.2. Percentage of patients living at home
2.3. Ability to perform activities of daily living (Barthel index)
2.4. Quality of life (EuroQuol)
2.5. Extended Activities of Daily Living (Nottingham EADL score)
Overall trial start date
20/04/2008
Overall trial end date
01/11/2013
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
Adult patients (either sex) are eligible for trial inclusion if they were admitted with symptoms of an acute stroke within the preceding 24 hours, and if, in the doctors opinion, there is no clear indication for and no clear contraindication against oxygen treatment:
1. Potential indications for oxygen treatment could be:
1.1. Oxygen saturation on air less than 90%
1.2. Hypoxia associated with acute left ventricular failure
1.3. Severe pneumonia
1.4. Pulmonary embolus
1.5. Chronic respiratory failure patients treated with long term oxygen at home
2. Potential contraindications to fixed dose oxygen treatment could be:
2.1. Type 2 respiratory failure
2.2. Very severe hypoxia
3. Medical centres are eligible for participation in the study if they admit patients with acute stroke, are able to provide oxygen treatment and monitor oxygen saturation, and if there is a local researcher who will act as the principal investigator for the locality
Participant type
Patient
Age group
Adult
Gender
Both
Target number of participants
6000
Participant exclusion criteria
Patients will be excluded from the trial if:
1. The responsible doctor considers the patient to have definite indications for or contraindications to oxygen treatment at a rate of 2 - 3 L/min. The decision will be left to the responsible clinician
2. The stroke is not the main clinical problem
3. He/she has another serious life-threatening illness likely to lead to death within the next few months. This group of patients is excluded because it is unlikely that they are going to derive any benefit from the trial treatment
Recruitment start date
20/04/2008
Recruitment end date
01/11/2013
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Royal Infirmary
Stoke-on-Trent
ST4 7LN
United Kingdom
Sponsor information
Organisation
North Staffordshire Combined Healthcare NHS Trust (UK)
Sponsor details
Research & Development Department
North Staffordshire Combined Healthcare NHS Trust
Trust Headquarters
Bellringer Road
Trentham
Stoke-on-Trent
ST4 8HH
United Kingdom
+44 (0)1782 441687
r&d@northstaffs.nhs.uk
Sponsor type
Government
Website
http://www.nsch-tr.wmids.nhs.uk/site/show_page.php3?page_id=1
Funders
Funder type
Government
Funder name
North Staffordshire Combined Healthcare NHS Trust (UK)
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Funder name
Keele University
Alternative name(s)
Funding Body Type
private sector organisation
Funding Body Subtype
academic
Location
United Kingdom
Funder name
Research for Patient Benefit Programme
Alternative name(s)
NIHR Research for Patient Benefit Programme, RfPB
Funding Body Type
government organisation
Funding Body Subtype
National government
Location
United Kingdom
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
Publication list
2014 protocol in: http://www.ncbi.nlm.nih.gov/pubmed/24684940
2014 statistical analysis plan in: http://www.ncbi.nlm.nih.gov/pubmed/24939648
2017 results in: http://www.ncbi.nlm.nih.gov/pubmed/28973619
2018 results in: http://www.ncbi.nlm.nih.gov/pubmed/29595449
Publication citations
-
Protocol
Roffe C, Nevatte T, Crome P, Gray R, Sim J, Pountain S, Handy L, Handy P, The Stroke Oxygen Study (SO2S) - a multi-center, study to assess whether routine oxygen treatment in the first 72 hours after a stroke improves long-term outcome: study protocol for a randomized controlled trial., Trials, 2014, 15, 99, doi: 10.1186/1745-6215-15-99.
-
Statistical analysis plan
Sim J, Gray R, Nevatte T, Howman A, Ives N, Roffe C, Statistical analysis plan for the Stroke Oxygen Study (SO₂S): a multi-center randomized controlled trial to assess whether routine oxygen supplementation in the first 72 hours after a stroke improves long-term outcome., Trials, 2014, 15, 229, doi: 10.1186/1745-6215-15-229.