title: Mechanical versus manual chest compression for out-of-hospital cardiac arrest (PARAMEDIC): a pragmatic, cluster randomised controlled trial.
abstract: BACKGROUND
  Mechanical chest compression devices have the potential to help maintain high-quality cardiopulmonary resuscitation (CPR), but despite their increasing use, little evidence exists for their effectiveness. We aimed to study whether the introduction of LUCAS-2 mechanical CPR into front-line emergency response vehicles would improve survival from out-of-hospital cardiac arrest.
  
  
  METHODS
  The pre-hospital randomised assessment of a mechanical compression device in cardiac arrest (PARAMEDIC) trial was a pragmatic, cluster-randomised open-label trial including adults with non-traumatic, out-of-hospital cardiac arrest from four UK Ambulance Services (West Midlands, North East England, Wales, South Central). 91 urban and semi-urban ambulance stations were selected for participation. Clusters were ambulance service vehicles, which were randomly assigned (1:2) to LUCAS-2 or manual CPR. Patients received LUCAS-2 mechanical chest compression or manual chest compressions according to the first trial vehicle to arrive on scene. The primary outcome was survival at 30 days following cardiac arrest and was analysed by intention to treat. Ambulance dispatch staff and those collecting the primary outcome were masked to treatment allocation. Masking of the ambulance staff who delivered the interventions and reported initial response to treatment was not possible. The study is registered with Current Controlled Trials, number ISRCTN08233942.
  
  
  RESULTS
  We enrolled 4471 eligible patients (1652 assigned to the LUCAS-2 group, 2819 assigned to the control group) between April 15, 2010 and June 10, 2013. 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 group (104 [6%] of 1652 patients) and in the manual CPR group (193 [7%] of 2819 patients; adjusted odds ratio [OR] 0·86, 95% CI 0·64-1·15). No serious adverse events were noted. Seven clinical adverse events were reported in the LUCAS-2 group (three patients with chest bruising, two with chest lacerations, and two with blood in mouth). 15 device incidents occurred during operational use. No adverse or serious adverse events were reported in the manual group.
  
  
  CONCLUSIONS
  We noted no evidence of improvement in 30 day survival with LUCAS-2 compared with manual compressions. On the basis of ours and other recent randomised trials, widespread adoption of mechanical CPR devices for routine use does not improve survival.
  
  
  BACKGROUND
  National Institute for Health Research HTA - 07/37/69.
authors.affiliation: 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.
authors.forename: Gavin D
authors.initials: GD
authors.lastname: Perkins
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.
authors.forename: Tom
authors.initials: T
authors.lastname: Quinn
authors.affiliation: 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.
authors.forename: Charles D
authors.initials: CD
authors.lastname: Deakin
authors.affiliation: Warwick Clinical Trials Unit, University of Warwick, Coventry, 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; 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.
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: Welsh Ambulance Services NHS Trust, Denbighshire, Wales, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Whitfield
authors.affiliation: Welsh Ambulance Services NHS Trust, Denbighshire, Wales, UK.
authors.forename: Amanda
authors.initials: A
authors.lastname: Williams
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: John J M
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: Warwick Clinical Trials Unit, University of Warwick, Coventry, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Gates
mesh_terms: D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D016000:Cluster Analysis; D004632:Emergency Medical Services / Q000379:methods; D004634:Emergency Medical Technicians; D004739:England; D005260:Female; D006336:Heart Massage / Q000379:methods; D006801:Humans; D008297:Male; D058687:Out-of-Hospital Cardiac Arrest / Q000628:therapy*; D016896:Treatment Outcome; D014852:Wales