[1
]
Warwick Clinical Trials Unit, University of Warwick, Coventry, UK; Heart of England
NHS Foundation Trust, Birmingham, UK. Electronic address: g.d.perkins@warwick.ac.uk.
[2
]
Warwick Clinical Trials Unit, University of Warwick, Coventry, UK.
[3
]
Surrey Peri-operative Anaesthesia Critical care collaborative Research Group, Faculty
of Health and Medical Sciences, University of Surrey, Guildford, UK.
[4
]
Surrey Peri-operative Anaesthesia Critical care collaborative Research Group, Faculty
of Health and Medical Sciences, University of Surrey, Guildford, UK; South Central
Ambulance Service NHS Foundation Trust, Otterbourne, UK; NIHR Southampton Respiratory
Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton
Hampshire.
[5
]
Warwick Clinical Trials Unit, University of Warwick, Coventry, UK; University of Oxford,
Oxford, UK.
[6
]
West Midlands Ambulance Service NHS Foundation Trust, Brierley Hill, UK.
[7
]
Warwick Clinical Trials Unit, University of Warwick, Coventry, UK; West Midlands Ambulance
Service NHS Foundation Trust, Brierley Hill, UK.
[8
]
Welsh Ambulance Services NHS Trust, Denbighshire, Wales, UK.
[9
]
South Central Ambulance Service NHS Foundation Trust, Otterbourne, UK.
[10
]
North East Ambulance Service NHS Foundation Trust, Newcastle upon Tyne, UK; Royal
Victoria Infirmary, Newcastle upon Tyne, UK.
[11
]
North East Ambulance Service NHS Foundation Trust, Newcastle upon Tyne, UK.