title: Prehospital randomised assessment of a mechanical compression device in out-of-hospital cardiac arrest (PARAMEDIC): a pragmatic, cluster randomised trial and economic evaluation.
abstract: Mechanical chest compression devices may help to maintain high-quality cardiopulmonary resuscitation (CPR), but little evidence exists for their effectiveness. We evaluated whether or not the introduction of Lund University Cardiopulmonary Assistance System-2 (LUCAS-2; Jolife AB, Lund, Sweden) mechanical CPR into front-line emergency response vehicles would improve survival from out-of-hospital cardiac arrest (OHCA).
  
  
  
  Evaluation of the LUCAS-2 device as a routine ambulance service treatment for OHCA.
  
  
  
  Pragmatic, cluster randomised trial including adults with non-traumatic OHCA. Ambulance dispatch staff and those collecting the primary outcome were blind to treatment allocation. Blinding of the ambulance staff who delivered the interventions and reported initial response to treatment was not possible. We also conducted a health economic evaluation and a systematic review of all trials of out-of-hospital mechanical chest compression.
  
  
  
  Four UK ambulance services (West Midlands, North East England, Wales and South Central), comprising 91 urban and semiurban ambulance stations. Clusters were ambulance service vehicles, which were randomly assigned (approximately 1 : 2) to the LUCAS-2 device or manual CPR.
  
  
  
  Patients were included if they were in cardiac arrest in the out-of-hospital environment. Exclusions were patients with cardiac arrest as a result of trauma, with known or clinically apparent pregnancy, or aged < 18 years.
  
  
  
  Patients received LUCAS-2 mechanical chest compression or manual chest compressions according to the first trial vehicle to arrive on scene.
  
  
  
  Survival at 30 days following cardiac arrest; survival without significant neurological impairment [Cerebral Performance Category (CPC) score of 1 or 2].
  
  
  
  We enrolled 4471 eligible patients (1652 assigned to the LUCAS-2 device and 2819 assigned to control) between 15 April 2010 and 10 June 2013. A total of 985 (60%) patients in the LUCAS-2 group received mechanical chest compression and 11 (< 1%) patients in the control group received LUCAS-2. In the intention-to-treat analysis, 30-day survival was similar in the LUCAS-2 (104/1652, 6.3%) and manual CPR groups [193/2819, 6.8%; adjusted odds ratio (OR) 0.86, 95% confidence interval (CI) 0.64 to 1.15]. Survival with a CPC score of 1 or 2 may have been worse in the LUCAS-2 group (adjusted OR 0.72, 95% CI 0.52 to 0.99). No serious adverse events were noted. The systematic review found no evidence of a survival advantage if mechanical chest compression was used. The health economic analysis showed that LUCAS-2 was dominated by manual chest compression.
  
  
  
  There was substantial non-compliance in the LUCAS-2 arm. For 272 out of 1652 patients (16.5%), mechanical chest compression was not used for reasons that would not occur in clinical practice. We addressed this issue by using complier average causal effect analyses. We attempted to measure CPR quality during the resuscitation attempts of trial participants, but were unable to do so.
  
  
  
  There was no evidence of improvement in 30-day survival with LUCAS-2 compared with manual compressions. Our systematic review of recent randomised trials did not suggest that survival or survival without significant disability may be improved by the use of mechanical chest compression.
  
  
  
  The use of mechanical chest compression for in-hospital cardiac arrest, and in specific circumstances (e.g. transport), has not yet been evaluated.
  
  
  
  Current Controlled Trials ISRCTN08233942.
  
  
  
  This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full inHealth Technology Assessment; Vol. 21, No. 11. See the NIHR Journals Library website for further project information.
authors.affiliation: Warwick Clinical Trials Unit, University of Warwick, Coventry, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Gates
authors.affiliation: Warwick Clinical Trials Unit, University of Warwick, Coventry, UK.
authors.forename: Ranjit
authors.initials: R
authors.lastname: Lall
authors.affiliation: Surrey Peri-operative Anaesthesia Critical Care Collaborative Research Group, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK (current address: Faculty of Health, Social Care and Education, Kingston University London and St George's, University of London, London, UK).
authors.forename: Tom
authors.initials: T
authors.lastname: Quinn
authors.affiliation: South Central Ambulance Service NHS Foundation Trust, Otterbourne, UK.
authors.forename: Charles D
authors.initials: CD
authors.lastname: Deakin
authors.affiliation: Warwick Clinical Trials Unit, University of Warwick, Coventry, UK.|Heart of England NHS Foundation Trust, Birmingham, UK.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Cooke
authors.affiliation: Warwick Clinical Trials Unit, University of Warwick, Coventry, UK.
authors.forename: Jessica
authors.initials: J
authors.lastname: Horton
authors.affiliation: Warwick Clinical Trials Unit, University of Warwick, Coventry, UK.|Oxford Clinical Trials Research Unit, University of Oxford, Oxford, UK.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Lamb
authors.affiliation: Warwick Clinical Trials Unit, University of Warwick, Coventry, UK.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Slowther
authors.affiliation: Surrey Peri-operative Anaesthesia Critical Care Collaborative Research Group, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK (current address: Faculty of Health, Social Care and Education, Kingston University London and St George's, University of London, London, UK).
authors.forename: Malcolm
authors.initials: M
authors.lastname: Woollard
authors.affiliation: West Midlands Ambulance Service NHS Foundation Trust, Brierley Hill, UK.
authors.forename: Andy
authors.initials: A
authors.lastname: Carson
authors.affiliation: Warwick Clinical Trials Unit, University of Warwick, Coventry, UK.|West Midlands Ambulance Service NHS Foundation Trust, Brierley Hill, UK.
authors.forename: Mike
authors.initials: M
authors.lastname: Smyth
authors.affiliation: West Midlands Ambulance Service NHS Foundation Trust, Brierley Hill, UK.
authors.forename: Kate
authors.initials: K
authors.lastname: Wilson
authors.affiliation: West Midlands Ambulance Service NHS Foundation Trust, Brierley Hill, UK.
authors.forename: Garry
authors.initials: G
authors.lastname: Parcell
authors.affiliation: West Midlands Ambulance Service NHS Foundation Trust, Brierley Hill, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Rosser
authors.affiliation: Welsh Ambulance Services NHS Trust, St Asaph, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Whitfield
authors.affiliation: Welsh Ambulance Services NHS Trust, St Asaph, UK.
authors.forename: Amanda
authors.initials: A
authors.lastname: Williams
authors.affiliation: Welsh Ambulance Services NHS Trust, St Asaph, UK.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Jones
authors.affiliation: South Central Ambulance Service NHS Foundation Trust, Otterbourne, UK.
authors.forename: Helen
authors.initials: H
authors.lastname: Pocock
authors.affiliation: South Central Ambulance Service NHS Foundation Trust, Otterbourne, UK.
authors.forename: Nicola
authors.initials: N
authors.lastname: Brock
authors.affiliation: South Central Ambulance Service NHS Foundation Trust, Otterbourne, UK.
authors.forename: John Jm
authors.initials: JJ
authors.lastname: Black
authors.affiliation: North East Ambulance Service NHS Foundation Trust, Newcastle upon Tyne, UK.|Royal Victoria Infirmary, Newcastle upon Tyne, UK.
authors.forename: John
authors.initials: J
authors.lastname: Wright
authors.affiliation: North East Ambulance Service NHS Foundation Trust, Newcastle upon Tyne, UK.
authors.forename: Kyee
authors.initials: K
authors.lastname: Han
authors.affiliation: North East Ambulance Service NHS Foundation Trust, Newcastle upon Tyne, UK.
authors.forename: Gary
authors.initials: G
authors.lastname: Shaw
authors.affiliation: North East Ambulance Service NHS Foundation Trust, Newcastle upon Tyne, UK.
authors.forename: Laura
authors.initials: L
authors.lastname: Blair
authors.affiliation: Academic Unit of Health Economics, Leeds Institute of Health Sciences, University of Leeds, Leeds, UK.
authors.forename: Joachim
authors.initials: J
authors.lastname: Marti
authors.affiliation: Academic Unit of Health Economics, Leeds Institute of Health Sciences, University of Leeds, Leeds, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: Hulme
authors.affiliation: Department of Emergency Medicine Research, University of Alberta, Edmonton, AB, Canada.
authors.forename: Christopher
authors.initials: C
authors.lastname: McCabe
authors.affiliation: Academic Unit of Health Economics, Leeds Institute of Health Sciences, University of Leeds, Leeds, UK.
authors.forename: Silviya
authors.initials: S
authors.lastname: Nikolova
authors.affiliation: Academic Unit of Health Economics, Leeds Institute of Health Sciences, University of Leeds, Leeds, UK.
authors.forename: Zenia
authors.initials: Z
authors.lastname: Ferreira
authors.affiliation: Warwick Clinical Trials Unit, University of Warwick, Coventry, UK.|Heart of England NHS Foundation Trust, Birmingham, UK.
authors.forename: Gavin D
authors.initials: GD
authors.lastname: Perkins
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000552:Ambulances; D016887:Cardiopulmonary Resuscitation / Q000191:economics* / Q000295:instrumentation*; D003362:Cost-Benefit Analysis; D004632:Emergency Medical Services / Q000191:economics* / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008603:Mental Health; D008875:Middle Aged; D009483:Neuropsychological Tests; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality / Q000628:therapy*; D016037:Single-Blind Method; D013222:State Medicine / Q000191:economics; D016019:Survival Analysis; D006113:United Kingdom