Outcome among VF/VT patients in the LINC (LUCAS IN cardiac arrest) trial-A randomised, controlled trial.

INTRODUCTION: The LINC trial evaluated two ALS-CPR algorithms for OHCA patients, consisting of 3min' mechanical chest compression (LUCAS) cycles with defibrillation attempt through compressions vs. 2min' manual compressions with compression pause for defibrillation. The PARAMEDIC trial, using 2min' algorithm found worse outcome for patients with initial VF/VT in the LUCAS group and they received more adrenalin compared to the manual group. We wanted to evaluate if these algorithms had any outcome effect for patients still in VF/VT after the initial defibrillation and how adrenalin timing impacted it.

METHOD: Both groups received manual chest compressions first. Based on non-electronic CPR process documentation, outcome, neurologic status and its relation to CPR duration prior to the first detected return of spontaneous circulation (ROSC), time to defibrillation and adrenalin given were analysed in the subgroup of VF/VT patients.

RESULTS: Seven hundred and fifty-seven patients had still VF/VT after initial chest compressions combined with a defibrillation attempt (374 received mechanical CPR) or not (383 received manual CPR). No differences were found for ROSC (mechanical CPR 58.3% vs. manual CPR 58.6%, p=0.94), or 6-month survival with good neurologic outcome (mechanical CPR 25.1% vs. manual CPR 23.0%, p=0.50). A significant difference was found regarding the time from start of manual chest compression to the first defibrillation (mechanical CPR: 4 (2-5) min vs manual CPR 3 (2-4) min, P<0.001). The time from the start of manual chest compressions to ROSC was longer in the mechanical CPR group.

CONCLUSIONS: No difference in short- or long-term outcomes was found between the 2 algorithms for patients still in VF/VT after the initial defibrillation. The time to the 1st defibrillation and the interval between defibrillations were longer in the mechanical CPR group without impacting the overall outcome. The number of defibrillations required to achieve ROSC or adrenalin doses did not differ between the groups.