Want to take quizzes and track your credits?
Does routine prophylactic low-dose oxygen supplementation after acute stroke improve functional outcome?
In this randomized clinical trial, 8003 patients with acute stroke were randomized within 24 hours of admission to 3 days of continuous oxygen, nocturnal oxygen, or control. After 3 months, there was no significant difference in death and disability for the combined oxygen groups compared with control (odds ratio, 0.97) or for the continuous oxygen group compared with the nocturnal oxygen group (odds ratio, 1.03).
Routine low-dose oxygen did not improve outcomes in nonhypoxic patients after acute stroke.
Hypoxia is common in the first few days after acute stroke, is frequently intermittent, and is often undetected. Oxygen supplementation could prevent hypoxia and secondary neurological deterioration and thus has the potential to improve recovery.
To assess whether routine prophylactic low-dose oxygen therapy was more effective than control oxygen administration in reducing death and disability at 90 days, and if so, whether oxygen given at night only, when hypoxia is most frequent, and oxygen administration is least likely to interfere with rehabilitation, was more effective than continuous supplementation.
Design, Setting, and Participants
In this single-blind randomized clinical trial, 8003 adults with acute stroke were enrolled from 136 participating centers in the United Kingdom within 24 hours of hospital admission if they had no clear indications for or contraindications to oxygen treatment (first patient enrolled April 24, 2008; last follow-up January 27, 2015).
Participants were randomized 1:1:1 to continuous oxygen for 72 hours (n = 2668), nocturnal oxygen (21:00 to 07:00 hours) for 3 nights (n = 2667), or control (oxygen only if clinically indicated; n = 2668). Oxygen was given via nasal tubes at 3 L/min if baseline oxygen saturation was 93% or less and at 2 L/min if oxygen saturation was greater than 93%.
Main Outcomes and Measures
The primary outcome was reported using the modified Rankin Scale score (disability range, 0 [no symptoms] to 6 [death]; minimum clinically important difference, 1 point), assessed at 90 days by postal questionnaire (participant aware, assessor blinded). The modified Rankin Scale score was analyzed by ordinal logistic regression, which yields a common odds ratio (OR) for a change from one disability level to the next better (lower) level; OR greater than 1.00 indicates improvement.
A total of 8003 patients (4398 (55%) men; mean [SD] age, 72  years; median National Institutes of Health Stroke Scale score, 5; mean baseline oxygen saturation, 96.6%) were enrolled. The primary outcome was available for 7677 (96%) participants. The unadjusted OR for a better outcome (calculated via ordinal logistic regression) was 0.97 (95% CI, 0.89 to 1.05; P = .47) for oxygen vs control, and the OR was 1.03 (95% CI, 0.93 to 1.13; P = .61) for continuous vs nocturnal oxygen. No subgroup could be identified that benefited from oxygen. At least 1 serious adverse event occurred in 348 (13.0%) participants in the continuous oxygen group, 294 (11.0%) in the nocturnal group, and 322 (12.1%) in the control group. No significant harms were identified.
Conclusions and Relevance
Among nonhypoxic patients with acute stroke, the prophylactic use of low-dose oxygen supplementation did not reduce death or disability at 3 months. These findings do not support low-dose oxygen in this setting.
ISRCTN Identifier: ISRCTN52416964
Sign in to take quiz and track your certificates
JN Learning™ is the home for CME and MOC from the JAMA Network. Search by specialty or US state and earn AMA PRA Category 1 CME Credit™ from articles, audio, Clinical Challenges and more. Learn more about CME/MOC
Corresponding Author: Christine Roffe, MD, Institute for Science and Technology in Medicine, Keele University, Guy Hilton Research Centre, Thornburrow Drive, Stoke-on-Trent, Staffordshire ST4 7QB, United Kingdom (email@example.com).
Accepted for Publication: August 12, 2017.
Correction: This article was corrected on November 14, 2017, for an incorrect SI conversion factor in Table 1, several incorrect 99% CIs in Table 2, an incorrect P value in Figure 3, and for minor typographical errors.
Author Contributions: Drs Roffe and Bishop had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Concept and design: Roffe, Gray.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Roffe, Sim, Ives, Ferdinand, Gray.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Sim, Bishop, Ives, Gray.
Obtained funding: Roffe, Gray.
Administrative, technical, or material support: Roffe, Nevatte, Sim.
Supervision: Roffe, Ives, Gray.
Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Roffe reports receipt of a grant from the Research for Patient Benefit Programme and the Health Technology Assessment Programme of the National Institute for Health Research (NIHR), receipt of lecture and travel fees from Air Liqude, and independent membership on the data safety and monitoring committee of the PROOF trial. No other disclosures were reported.
Funder/Support: This project was funded by the NIHR Health Technology Assessment Programme (project number 09/104/21) and the Research for Patient Benefit Programme.
Role of the Funder/Sponsor: The NIHR had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Disclaimer: The views and opinions expressed herein are those of the authors and do not necessarily reflect those of the Health Technology Assessment, NIHR, the National Health Service (NHS), or the Department of Health. The Stroke Oxygen Study (SO2S) was sponsored by North Staffordshire Combined Healthcare NHS Trust.
SO2S Collaborators: Writing Committee: Christine Roffe, Tracy Nevatte, Julius Sim, Jon Bishop, Philip Ferdinand, Natalie Ives, and Richard Gray. Statistical Analysis: Jon Bishop, Julius Sim, Natalie Ives. Trial Management Group: Christine Roffe (Chair), Tracy Nevatte, Julius Sim, Richard Gray, Natalie Ives, Jon Bishop, Sarah Pountain, Peter and Linda Handy. Trial Steering Committee: Martin Dennis (Chair), Lalit Kalra, Sian Maslin-Prothero, Jane Daniels, Peta Bell, Richard Lindley. Data Safety and Monitoring Committee: Stephen Jackson (Chair), Thompson Robinson, Martyn Lewis. Trial Coordinating Center: Alison Buttery, Clare Gething, Joy Dale, Wendy Lawton, Chris Buckley, Eddie Skelson, Nicola Mellor, Kathryn McCarron, Jean Leverett, Emily Linehan, Stephanie Edwards, Terri Oliver, Loretto Thompson, Sian Edwards, Clare Lees and Jackie Richards. Study Team at Birmingham Clinical Trials Unit: Andrew Howman, Robert Hills, Nick Hilken, Samir Mehta and Chakanaka Sidile. Literature Searches: Frank Lally, Philip Ferdinand, Girish Muddegowda. Editorial Assistance: Frank Lally, David Roffe, Steve Alcock.Participating Centers and SO2S Collaborative Group Members (asterisks indicate principal investigator[s]; numeric values indicate the number of participants enrolled): Royal Stoke University Hospital, Stoke-on-Trent: K Finney, S Gomm, J Lucas, H Maguire, C Roffe* (478); St George’s Hospital, London: I Jones, L Montague, B Moynihan*, J O’Reilly, C Watchurst (288); The Royal Liverpool University Hospital, Liverpool: P Cox, G Fletcher, A Ledger, S Loharuka*, P Lopez, A Manoj* (257); Royal Bournemouth General Hospital, Bournemouth: O David, D Jenkinson*, J Kwan, E Rogers, E Wood (240); Kings College Hospital, London: A Davis, L Kalra*, E Khoromana, R Lewis, H Trainer (231); Leeds General Infirmary, Leeds: M Kambafwile, L Makawa, E Veraque, P Wanklyn*, D Waugh (204); Salford Royal Hospital, Salford: E Campbell, J Hardicre, V O’Loughlin, C Smith*, T Whittle (192); Southend Hospital, Southend: P Guyler*, P Harman, A Kumar Kundu, D Sinha, S Tysoe (188); Countess of Chester Hospital, Chester: S Booth, K Chatterjee*, H Eccleson, C Kelly, S Leason (176); The Royal Victoria Infirmary, Newcastle upon Tyne: A Barkat, J Davis, A Dixit*, M Fawcett, V Hogg (168); Royal Sussex County Hospital, Brighton: K Ali*, J Breeds, J Gaylard, J Knight, G Spurling (164); Musgrove Park Hospital, Taunton: S Brown, L Caudwell, L Dunningham, J Foot, M Hussain* (156); Bristol Royal Infirmary, Bristol: J Chambers, P Murphy*, M Osborn, A Steele (151); Royal Preston Hospital, Preston: S Duberley, C Gilmour, B Gregary, S Punekar*, S Raj (148); University Hospital Aintree, Liverpool: J Atherton, R Durairaj*, T Fluskey, Z Mellor, V Sutton (148); Birmingham Heartlands Hospital, Birmingham: P Carr, J McCormack, D Sandler*, C Stretton, K Warren (143); Pennine Acute Hospital, Rochdale: L Harrison, L Johnson, R Namushi*, N Saravanan, N Thomas (133); Queen’s Hospital, Burton: J Birch, R Damant, B Mukherjee* (131); University Hospital Coventry, Walsgrave: L Aldridge, P Kanti Ray*, S Nyabadza, C Randall, H Wright (129); Wansbeck Hospital, Northumberland: C Ashbrook-Raby, A Barkat, R Lakey, C Price*, G Storey (124); Royal Devon and Exeter Hospital, Wonford: L Barron, A Bowring, H Eastwood, M James*, S Keenan (113); Royal United Hospital, Bath: J Avis, D Button, D Hope, B Madigan, L Shaw* (113); Royal Cornwall Hospital, Treliske: K Adie, G Courtauld, F Harrington, C Schofield (112); Queen Elizabeth the Queen Mother Hospital, Margate: G Gunathilagan*, S Jones, G Thomas (105); York Hospital, York: J Coyle*, N Dyer, S Howard, M Keeling, S Williamson (105); University Hospital of North Durham, Durham: E Brown, S Bruce, B Esisi*, R Hayman, E Roberts (99); Derriford Hospital, Plymouth: C Bailey, B Hyams, A Mohd Nor*, N Persad (96); Selly Oak Hospital (Acute), Birmingham: J Hurley, E Linehan, J McCormack, J Savanhu, D Sims* (92); Whiston Hospital, Prescot: R Browne, S Dealing, V Gowda* (89); Torbay District General Hospital, Torbay: C Bailey, P Fitzell, C Hilaire, D Kelly*, S Szabo (88); Charing Cross Hospital, London: E Beranova, J Pushpa-Rajah, T Sachs, P Sharma*, V Tilley (87); Leighton Hospital, Crewe: N Gautam, C Maity*, R Miller, C Mustill, M Salehin*, A Walker (87); Kent & Canterbury Hospital, Canterbury: H Baht, I Burger*, L Cowie, T Irani, A Thomson (84); New Cross Hospital, Wolverhampton: P Bourke, K Fotherby*, D Morgan, K Preece (84); Northwick Park Hospital, Harrow: L Burgess, D Cohen*, M Mpelembue (83); Barnsley District General Hospital, Barnsley: M Albazzaz*, R Bassi, C Dennis, K Hawley, S Johnson-Holland (82); Blackpool Victoria Hospital, Blackpool: H Goddard, J Howard, C Jeffs, J Mcilmoyle*, A Strain (82); North Tyneside General Hospital, North Shields: J Dickson, K Mitchelson, C Price*, V Riddell, A Smith (79); Eastbourne District General Hospital, Eastbourne: C Athulathmudali*, E Barbon (76); Warrington Hospital, Warrington: K Bunworth, L Connell, G Delaney-Sagar, K Mahawish*, O Otaiku*, H Whittle (75); Princess Royal Hospital, Haywards Heath: R Campbell*, A Nyarko (71); City Hospitals, Sunderland: S Crawford, C Gray*, D Gulliver, R Lakey, N Majmudar*, S Rutter (69); William Harvey Hospital, Ashford: L Cowie, D Hargroves*, T Webb (69); Stepping Hill Hospital, Stockport: A Brown, H Cochrane, S Krishnamoorthy*, J McConniffe (66); The James Cook University Hospital, Middlesborough: D Broughton*, K Chapman, L Dixon, A Surendran (66); Northampton General Hospital (Acute), Northampton: M Blake*, F Faola, A Kannan, P Lai, B Vincent (59); Leicester General Hospital, Leicester: M Dickens, D Eveson, S Khan, R Marsh, A Mistri*,(57); Rotherham District General Hospital, Rotherham: J Harris, J Howe, K McNulty, J Okwera* (56); St Peter’s Hospital, Chertsey: R Nari*, E Young (56); Macclesfield District General Hospital, Macclesfield: A Barry, B Menezes, M Sein*, H Rooney, L Wilkinson (55); Manor Hospital, Walsall: S Hurdowar, K Javaid*, K Preece (54); Bradford Royal Infirmary, Bradford: R Bellfield, B Hairsine, L Johnston, C Patterson*, S Williamson (53); Luton & Dunstable Hospital, Luton: F Justin, S Sethuraman*, L Tate (50); Royal Blackburn Hospital, Blackburn: A Bell, M Goorah, N Goorah*, A Sangster (50); University College Hospital, London: N Bhupathiraju, L Latter, P Rayson, R Simister*, R Uday Erande (50); Addenbrooke’s Hospital, Cambridge: N Butler, D Day, E Jumilla, J Mitchell, E Warburton* (48); Queen Alexandra Hospital, Portsmouth: T Dobson, C Edwards, J Hewitt*, L Hyatt, D Jarret* (47); North Devon District Hospital, Barnstaple: G Belcher, M Dent*, F Hammonds, J Hunt, C Vernon (45); Solihull Hospital, Solihull: A Carter, K Elfandi*, S Stafford (45); Pilgrim Hospital, Boston: A Hardwick, D Mangion*, S Marvova* (44); Norfolk & Norwich University Hospital, Norwich: J Jagger, P Myint*, G Ravenhill, N Shinh*, E Thomas, N Wyatt (41); Gloucestershire Royal Hospital, Gloucester: P Brown, F Davis, D Dutta*, J Turfrey, D Ward (40); Royal Surrey County Hospital, Guildford: O Balazikova, A Blight*, C Lawlor, K Pasco (39); Southport & Formby District General Hospital, Southport: M Marshall, P McDonald*, H Terrett (39); Bishop Auckland General Hospital, Bishop Auckland: E Brown, A Mehrzad* (35); Airedale General Hospital, Keighley: R Bellfield, P Garnett, B Hairsine, S Mawer*, M Smith*, S Williamson (34); Calderdale Royal Hospital, Halifax: C Button, J Greig, B Hairsine, A Nair, P Rana*, I Shakir* (34); Doncaster Royal Infirmary, Doncaster: P Anderton, D Chadha*, L Holford, D Walstow (34); East Surrey Hospital, Redhill Y Abousleiman*, S Collins, A Jolly, B Mearns* (34); Medway Maritime Hospital, Gillingham: P Akhurst, B Bourne, S Burrows, S Sanmuganathan*, S Thompson (34); Royal Derby Hospital, Derby: T England*, A Hedstrom, M Mangoyana, M Memon*, L Mills, K Muhiddin*, I Wynter (33); Wycombe General Hospital, High Wycombe: A Benford, M Burn*, A Misra, S Pascall (33); The Princess Royal Hospital, Telford: R Campbell*, N Motherwell (32); Harrogate District Hospital, Harrogate: S Appleby, S Brotheridge*, J Strover (30); Peterborough City Hospital, Peterborough: S D’Souza, P Owusu-Agyei*, S Subramonian, N Temple (30); West Cumberland Hospital, Whitehaven: R Jolly, O Orugun* (30); Colchester General Hospital, Colchester: M Keating, R Saksena*, A Wright (29); Royal Hampshire County Hospital, Winchester: D Ardern, C Eglinton, R Honney, N Smyth*, J Wilson (29); Dorset County Hospital, Dorchester: S Breakspear, L O’Shea, H Prosche*, S Sharpe (27); Frimley Park Hospital, Frimley: S Atkinson, B Clarke*, L Moore (27); Royal Hallamshire Hospital, Sheffield: S Duty, K Harkness, M Randall*, E Richards, K Stocks (27); Yeovil District Hospital, Yeovil: S Board, C Buckley, D Hayward, K Rashed*, R Rowland-Axe (25); Poole General Hospital, Poole: C Dickson, L Gleave, S Ragab* (24); Frenchay Hospital, Bristol: N Baldwin*, S Hierons, H Skuse, L Whelan (22); Princess Alexandra Hospital, Harlow: L Brown, M Burton, A Daniel, S Hameed*, S Mansoor* (22); West Suffolk Hospital, Bury St Edmunds: A Azim*, M Krasinska, J White (22); The Ulster Hospital, Dundonald: M Power*, B Wroath (21); Watford General Hospital, Watford: D Collas*, S Sundayi, E Walker (21); Southampton General Hospital, Southampton: M Brown, G Durward*, V Pressly, B Watkins, N Weir*, D Whittaker (20); Craigavon Area Hospital, Portadown: C Douglas, M McCormick*, M McParland (19); Royal Lancaster Infirmary, Lancaster: C Culmsee, P Kumar* (18); Basildon Hospital, Basildon: M Bondoc, B Hadebe, R Rangasami*, I Udeozor, U Umansankar* (17); Birmingham City Hospital, Sandwell: F Kinney, S Hurdowar, S Ispoglou*, S Kausar* (17); City Hospital, Nottingham: P Cox, A Ferguson, D Havard, F Shelton, A Shetty* (16); Antrim Area Hospital, Antrim: C Edwards, C McGoldrick, A Thompson, D Vahidassr* (15); Pinderfields General Hospital, Wakefield: G Bateman, P Datta*, A Needle (15); Royal Albert Edward Infirmary, Wigan: P Farren, S Herath* (15); Good Hope Hospital, Sutton Coldfield: I Memon*, S Montgomery (13); Hereford County Hospital, Hereford: S Black, S Holloman, C Jenkins*, F Price (13); South Tyneside District General Hospital, South Shields: M Duffy, J Graham, J Scott (13); Broomfield Hospital, Chelmsford: A Lyle, F Mcneela, K Swan, J Topliffe, V Umachandran* (12); Wythenshawe Hospital, Wythenshawe: B Charles, E Gamble*, S Mawn (11); Warwick Hospital, Warwick: M Dean, B Thanvi* (10); Ipswich Hospital, Ipswich: M Chowdhury*, J Ngeh, S Stoddart (9); Kettering General Hospital, Kettering: K Ayes*, J Kessell (9); Nevill Hall Hospital, Abergavenny: B Richard*, E Scott (9); Princess Royal University Hospital, Orpington: L Ajayo, E Khoromana, E Parvathaneni, B Piechowski-Jozwiak*, L Sztriha* (9); Scarborough General Hospital, Scarborough: L Brown, K Deighton, E Elnour, J Paterson*, E Temlett (9); Hull Royal Infirmary, Hull: A Abdul-Hamid*, J Cook, K Mitchelson (8); King’s Mill Hospital, Sutton-in-Ashfield: M Cooper*, I Wynter (8); The Royal London Hospital, London: P Gompertz*, O Redjep, J Richards, R Uday Erande (8); Trafford General Hospital, Manchester: S Anwar*, A Ingram, S McGovern, S Musgrave*, L Tew (8); Altnagelvin Area Hospital, Londonderry: J Corrigan*, C Diver-Hall, M Doherty, M McCarron* (7); Darent Valley Hosptial, Dartford: P Aghoram*, T Daniel, S Hussein, S Lord (7); Royal Berkshire Hospital, Reading: N Mannava, A van Wyk* (6); Arrowe Park Hospital, Wirral: J Barrett*, R Davies*, A Dodd, D Lowe*, P Weir (5); Basingstoke and North Hampshire Hospital, Basingstoke: D Dellafera, E Giallombardo* (5); Lincoln County Hospital, Lincoln: S Arif, R Brown, S Leach* (5); Hexham General Hospital, Hexham: C Price*, V Riddell (4); Manchester Royal Infirmary, Manchester: J Akyea-Mensah, J Simpson* (4); Salisbury District Hospital, Salisbury: T Black*, C Clarke, M Skelton (4); Croydon University Hospital, Croydon: J Coleman, E Lawrence* (3); Russells Hall Hospital, Dudley: A Banerjee*, A Boyal, A Gregory (3); Worthing Hospital, Worthing: S Ivatts*, M Metiu (3); Bedford Hospital, Bedford: A Elmarimi*,S Hunter (2); James Paget Hospital, Great Yarmouth: H Benton, M Girling, P Harrison*, H Nutt, S Mazhar Zaidi*, C Whitehouse (2); St Richard’s Hospital, Chichester: G Blackman, S Ivatts* (2); Erne Hospital, Fermanagh: M Doherty, J Kelly* (1); University Hospital Lewisham, Lewisham: M Patel* (1); Bronglais General Hospital, Aberystwyth: P Jones* (0); Hillingdon Hospital, Hillingdon: A Parry* (0); Kingston Hospital, Kingston upon Thames: L Choy* (0); Morriston Hospital, Morriston: M Wani* (0); North Middlesex Hospital, Enfield: T Adesina, A David, R Luder* (0); Staffordshire District General Hospital, Stafford: A Oke* (0); St Helier Hospital, Carshalton: V Jones*, P O’Mahony, C Orefo (0); Whipps Cross University Hospital, London: R Simister* (0).
You currently have no searches saved.