EBQ:LINC Trial

Complete Journal Club Article

Rubertsson, Sten et al. "Mechanical Chest Compressions and Simultaneous Defibrillation vs Conventional Cardiopulmonary Resuscitation in Out-of-Hospital Cardiac Arrest (The LINC Randomized Trial)". JAMA. 2014. 311(1):53-61.
PubMed Full text PDF

Clinical Question

Does an algorithm combining mechanical chest compression and defibrillation provide a short term survival benefit in out-of-hospital cardiac arrest (OHCA) when compared to a traditional algorithm of manual chest compressions and defibrillation.

Conclusion

There was no 4-hour survival benefit in the mechanical vs. manual CPR algorithm.

Major Points

*The LUCAS mechanical CPR 

Design

• Multicenter randomized clinical trial of patients with OHCA
• 2589 patients with OHCA between 2008-2013
• 4 Swedish, 1 British, and 1 Dutch ambulance service

Inclusion Criteria

• Age >18
• Out of Hospital Cardiac Arrest

Exclusion Criteria

• Traumatic Cardiac Arrest (including hanging)
• Age < 18 years old
• Known pregnancy
• Body size too large or small to fit the LUCAS compression device
• Defibrillation before the LUCAS arrived on scene
• Patients with cardiac arrest witnessed by the EMS crew and received return of spontaneous circulation (ROSC) after immediate defibrilation

Baseline Patient Characteristics

Mechanical vs Manual CPR age: 69 vs 69.1 male: 67% vs 66% heart disease: 65% vs 63% pulmonary disease: 64% vs 69% respiratory arrest: 59% vs 47% witnessed arrest: 66% vs 65% bystander CPR: 57% vs 55% Initial rhythm:

V. fib 29% vs 30%

PEA 20% vs 20%

Asystole 47% vs 46%

Time to ROSC from start of CPR: 17min vs 14min

Interventions

Mechanical CPR algorithm:

1. Immediate manual CPR until the mechanical device was deployed
2. Mechanical compressions for 3 min
3. First defibrillation shock delivered without rhythm check at 90 sec
4. Rhythm check after 3 min
5. If shockable rhythm at 3 min then new 3 min cycle begun with shock at new 90 sec mark
6. if no shockable rhythm then 3 min of mechanical CPR with no defibrillation until next 3min rhythm check

Manual CPR algorithm

• In accordance with the 2005 European Resuscitation Council guidelines

Paramedics were trained at initiation of trial and ever 6 months in the mechanical algorithm

Post Resuscitation care

• Patients were treated with hypothermia (32C-34C) for 24hours regardless of initial ECG rhythm.

Outcome

Mechanical CPR vs Manual CPR

Primary Outcomes

4 hour survival: 23.6% vs 23.7% (P>.99%)

Secondary Outcomes

Arrival at emergency department with pulse: 28.2% vs 27.7% Survival to discharge from ICU:

CPC score 1-2 on hospital discharge: 8.3% vs. 7.8%

6month survivals with CPC score 1-2: 8.5% v 7.6%

Chest compression fraction: 0.84 vs 0.78

Adverse Outcomes

LUCAS group:

• Airway bleeding: 1
• Splenic rupture: 1
• Pneumothorax: 1
• Migration on Chest: 1

Thoracic vertebral fracture and flail chest not directly related to LUCAS

Manual group:

• Flail chest: 2
• Abdominal Aortic aneurysm: 1
• Pneumothorax: 1

Criticisms

*The study is more about comparing a unique algorithm that prioritizes chest compressions over defibrilation and just so happens to use a mechanical compression device

• The study is industry sponsored by Physio-Control and Jolife AB with the lead author receiving consulting fees from Physio-Control
• Inference regarding the use of mechanical vs manual compressions is limited since a different resuscitation algorithm was used for the two arms

Funding

Institutional grants from Uppsala University and by Physio-Control/Jolife AB