PMID- 33653685 OWN - NLM STAT- MEDLINE DCOM- 20210311 LR - 20210316 IS - 1756-1833 (Electronic) IS - 0959-8138 (Print) IS - 0959-8138 (Linking) VI - 372 DP - 2021 Mar 2 TI - High flow oxygen and risk of mortality in patients with a suspected acute coronary syndrome: pragmatic, cluster randomised, crossover trial. PG - n355 LID - 10.1136/bmj.n355 [doi] LID - n355 AB - OBJECTIVE: To determine the association between high flow supplementary oxygen and 30 day mortality in patients presenting with a suspected acute coronary syndrome (ACS). DESIGN: Pragmatic, cluster randomised, crossover trial. SETTING: Four geographical regions in New Zealand. PARTICIPANTS: 40 872 patients with suspected or confirmed ACS included in the All New Zealand Acute Coronary Syndrome Quality Improvement registry or ambulance ACS pathway during the study periods. 20 304 patients were managed using the high oxygen protocol and 20 568 were managed using the low oxygen protocol. Final diagnosis of ST elevation myocardial infarction (STEMI) and non-STEMI were determined from the registry and ICD-10 discharge codes. INTERVENTIONS: The four geographical regions were randomly allocated to each of two oxygen protocols in six month blocks over two years. The high oxygen protocol recommended oxygen at 6-8 L/min by face mask for ischaemic symptoms or electrocardiographic changes, irrespective of the transcapillary oxygen saturation (SpO(2)). The low oxygen protocol recommended oxygen only if SpO(2) was less than 90%, with a target SpO(2) of less than 95%. MAIN OUTCOME MEASURE: 30 day all cause mortality determined from linkage to administrative data. RESULTS: Personal and clinical characteristics of patients managed under both oxygen protocols were well matched. For patients with suspected ACS, 30 day mortality for the high and low oxygen groups was 613 (3.0%) and 642 (3.1%), respectively (odds ratio 0.97, 95% confidence interval 0.86 to 1.08). For 4159 (10%) patients with STEMI, 30 day mortality for the high and low oxygen groups was 8.8% (n=178) and 10.6% (n=225), respectively (0.81, 0.66 to 1.00) and for 10 218 (25%) patients with non-STEMI was 3.6% (n=187) and 3.5% (n=176), respectively (1.05, 0.85 to 1.29). CONCLUSION: In a large patient cohort presenting with suspected ACS, high flow oxygen was not associated with an increase or decrease in 30 day mortality. TRIAL REGISTRATION: ANZ Clinical Trials ACTRN12616000461493. CI - (c) Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. FAU - Stewart, Ralph A H AU - Stewart RAH AUID- ORCID: 0000-0002-6167-1225 AD - Green Lane Cardiovascular Service, Auckland City Hospital, Private Bag 92024, Auckland 1030, New Zealand rstewart@adhb.govt.nz. AD - Department of Medicine, University of Auckland, New Zealand. FAU - Jones, Peter AU - Jones P AD - Emergency Medicine Research, Auckland City Hospital, New Zealand. AD - Department of Surgery, University of Auckland, New Zealand. FAU - Dicker, Bridget AU - Dicker B AD - St John Auckland and Paramedicine Department, Auckland University of Technology, New Zealand. FAU - Jiang, Yannan AU - Jiang Y AD - National Institute for Health Innovation, University of Auckland, New Zealand. FAU - Smith, Tony AU - Smith T AD - St John Ambulance, Auckland, New Zealand. FAU - Swain, Andrew AU - Swain A AD - Wellington Free Ambulance, Wellington, New Zealand. FAU - Kerr, Andrew AU - Kerr A AD - Department of Cardiology, Middlemore Hospital, Otahuhu, Aukland, New Zealand. AD - Section of Epidemiology and Biostatistics, University of Auckland, New Zealand. FAU - Scott, Tony AU - Scott T AD - Cardiology Department, Northshore Hospital, Takapuna, Auckland, New Zealand. FAU - Smyth, David AU - Smyth D AD - Canterbury District Health Board, Christchurch, New Zealand. FAU - Ranchord, Anil AU - Ranchord A AD - Cardiology Department, Capital and Coast District Health Board, Wellington Hospital, New Zealand. FAU - Edmond, John AU - Edmond J AD - Southern District Health Board, Dunedin and Dunedin School of Medicine, University of Otago, Dunedin, New Zealand. FAU - Than, Martin AU - Than M AD - Department of Emergency Medicine, Christchurch Hospital, New Zealand. FAU - Webster, Mark AU - Webster M AD - Green Lane Cardiovascular Service, Auckland City Hospital, Private Bag 92024, Auckland 1030, New Zealand. AD - Department of Medicine, University of Auckland, New Zealand. FAU - White, Harvey D AU - White HD AD - Green Lane Cardiovascular Service, Auckland City Hospital, Private Bag 92024, Auckland 1030, New Zealand. AD - Department of Medicine, University of Auckland, New Zealand. FAU - Devlin, Gerard AU - Devlin G AD - Hauroa Tairawhiti, Gisborne and Heart Foundation of New Zealand, Gisborn, New Zealand. LA - eng PT - Journal Article PT - Pragmatic Clinical Trial PT - Randomized Controlled Trial PT - Research Support, Non-U.S. Gov't DEP - 20210302 PL - England TA - BMJ JT - BMJ (Clinical research ed.) JID - 8900488 SB - IM MH - Acute Coronary Syndrome/diagnosis/*mortality/*therapy MH - Aged MH - Clinical Protocols MH - Cluster Analysis MH - Cross-Over Studies MH - Female MH - Hospitalization MH - Humans MH - Male MH - Middle Aged MH - New Zealand MH - *Oxygen Inhalation Therapy MH - Survival Rate PMC - PMC7923953 COIS- Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: support from the National Heart Foundation of New Zealand (grant No 1649) and from the Health Research Council of New Zealand clinical practitioner fellowships to RAHS and MT; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years ; no other relationships or activities that could appear to have influenced the submitted work. EDAT- 2021/03/04 06:00 MHDA- 2021/03/12 06:00 PMCR- 2021/03/02 CRDT- 2021/03/03 05:38 PHST- 2021/03/03 05:38 [entrez] PHST- 2021/03/04 06:00 [pubmed] PHST- 2021/03/12 06:00 [medline] PHST- 2021/03/02 00:00 [pmc-release] AID - ster060486 [pii] AID - 10.1136/bmj.n355 [doi] PST - epublish SO - BMJ. 2021 Mar 2;372:n355. doi: 10.1136/bmj.n355.