EBQ:Paramedic Trial

Under Review Journal Club Article

Perkins GD. et al.. "Mechanical versus manual chest compression for out-of-hospital cardiac arrest (PARAMEDIC): a pragmatic, cluster randomised controlled trial". Lancet. 2015. 385(9972):947-55.
PubMed Full text PDF

Clinical Question

Does prehospital LUCAS-2 mechanical CPR improve survival from out-of-hospital cardiac arrest?

Conclusion

The use of LUCAS-2 in non-traumatic, out-of-hospital cardiac arrests did not show improvement over manual CPR in patient survival to 30 days.

Major Points

• Survival to 30 days had no difference with 6% (LUCAS-2) vs. 7% (control)
• No difference in ROSC, survival of event, survival to 3 months, or survival to 12 months
• Decreased favorable neurologic outcome (CPC 1 or 2) in LUCAS-2 group

Study Design

Pragmatic, cluster randomized, controlled trial

Population

91 ambulance stations (selected for being urban and semi-urban) from 4 UK National Health Service (NHS) Ambulance Services (West Midlands, North East England, Wales, South Central).

Patient Demographics

• No major differences in baseline characteristics
  • Mean age ~71 years
  • 63% male
  • ~87% presumed cardiac etiology
  • ~82% arrests occurred at home
  • ~62% witnessed arrests
  • ~44% bystander CPR performed before EMS arrival
  • ~6.4 minute response time from call to EMS arrival
  • ~82% given IV medications
  • ~46% intubated
  • ~67% transported to hospital

Inclusion Criteria

• Vehicle included in trial is first on scene
• Patient in cardiac arrest outside of a hospital
• Resuscitation attempted
• Known or believed to be ≥18 years of age

Exclusion Criteria

• Cardiac arrest caused by trauma
• Known or apparent pregnancy

Interventions

• LUCAS-2 mechanical chest compression device during CPR (intervention group)
• Manual chest compressions per standard resuscitation guidelines (control group)
• Both groups received standard advanced life support care including defibrillation and drug administration
• Randomization occurred at the cluster level (ambulance vehicle)

Outcomes

Primary Outcome

• 30-day survival: mechanical CPR 6% vs manual CPR 7% (adjusted OR 0.86, 95% CI 0.64-1.15)

Secondary Outcomes

• ROSC at hospital handover: mechanical 32% vs manual 31%
• Survival to hospital discharge: mechanical 5.8% vs manual 6.8%
• Favorable neurological outcome at 3 months (CPC 1-2): mechanical 5.0% vs manual 5.2%
• No significant difference in any secondary outcome

Criticisms

• Cluster randomization at ambulance level may introduce bias if crew experience varies between vehicles
• Time from cardiac arrest to LUCAS deployment was variable and may have reduced compression quality during transition
• The study was pragmatic in design, meaning variation in how the device was deployed could affect results
• A numerical (non-significant) trend toward worse outcomes with mechanical CPR was concerning
• Crossover between groups was permitted when clinically indicated, potentially diluting treatment effects

Funding

• National Institute for Health Research (NIHR) Health Technology Assessment Programme (UK)
• Physio-Control/Jolife AB provided LUCAS-2 devices

See Also

LINC Trial