Resumen de Mechanical Chest Compressions and Simultaneous Defibrillation vs Conventional Cardiopulmonary Resuscitation in Out-of-Hospital Cardiac Arrest The LINC Randomized Trial
Sten Rubertsson, Erik Lindgren, David Smekal, Ollie Östlund
Importance A strategy using mechanical chest compressions might improve the poor outcome in out-of-hospital cardiac arrest, but such a strategy has not been tested in large clinical trials.
Objective To determine whether administering mechanical chest compressions with defibrillation during ongoing compressions (mechanical CPR), compared with manual cardiopulmonary resuscitation (manual CPR), according to guidelines, would improve 4-hour survival.
Design, Setting, and Participants Multicenter randomized clinical trial of 2589 patients with out-of-hospital cardiac arrest conducted between January 2008 and February 2013 in 4 Swedish, 1 British, and 1 Dutch ambulance services and their referring hospitals. Duration of follow-up was 6 months.
Interventions Patients were randomized to receive either mechanical chest compressions (LUCAS Chest Compression System, Physio-Control/Jolife AB) combined with defibrillation during ongoing compressions (n = 1300) or to manual CPR according to guidelines (n = 1289).
Main Outcomes and Measures Four-hour survival, with secondary end points of survival up to 6 months with good neurological outcome using the Cerebral Performance Category (CPC) score. A CPC score of 1 or 2 was classified as a good outcome.
Results Four-hour survival was achieved in 307 patients (23.6%) with mechanical CPR and 305 (23.7%) with manual CPR (risk difference, –0.05%; 95% CI, –3.3% to 3.2%; P > .99). Survival with a CPC score of 1 or 2 occurred in 98 (7.5%) vs 82 (6.4%) (risk difference, 1.18%; 95% CI, –0.78% to 3.1%) at intensive care unit discharge, in 108 (8.3%) vs 100 (7.8%) (risk difference, 0.55%; 95% CI, –1.5% to 2.6%) at hospital discharge, in 105 (8.1%) vs 94 (7.3%) (risk difference, 0.78%; 95% CI, –1.3% to 2.8%) at 1 month, and in 110 (8.5%) vs 98 (7.6%) (risk difference, 0.86%; 95% CI, –1.2% to 3.0%) at 6 months with mechanical CPR and manual CPR, respectively. Among patients surviving at 6 months, 99% in the mechanical CPR group and 94% in the manual CPR group had CPC scores of 1 or 2.
Conclusions and Relevance Among adults with out-of-hospital cardiac arrest, there was no significant difference in 4-hour survival between patients treated with the mechanical CPR algorithm or those treated with guideline-adherent manual CPR. The vast majority of survivors in both groups had good neurological outcomes by 6 months. In clinical practice, mechanical CPR using the presented algorithm did not result in improved effectiveness compared with manual CPR.
Trial Registration clinicaltrials.gov Identifier: NCT00609778 Many factors affect the chances of survival after cardiac arrest, including early recognition of arrest, effective cardiopulmonary resuscitation (CPR) and defibrillation, and postresuscitation care. One important link is the delivery of high-quality chest compressions to achieve restoration of spontaneous circulation (ROSC).1- 4 The effectiveness of manual chest compressions depends on the endurance and skills of rescuers, and manual compressions provide only approximately 30% of normal cardiac output.5,6 Manual CPR is also limited by prolonged hands-off time, and its quality is particularly poor when it is administered during patient transport.7,8 Mechanical chest compression devices have therefore been developed to improve CPR.
Experimental studies with the mechanical chest compression device used in this study have shown improved organ perfusion pressures, enhanced cerebral blood flow, and higher end-tidal CO2 compared with manual CPR, with the latter also supported by clinical data.9- 11 This device sustains adequate circulation during percutaneous coronary intervention and has been used in cases of hypothermia/drowning.12,13 Two randomized pilot studies (N = 328 and N = 149) of out-of-hospital cardiac arrest compared manual and mechanical chest compressions using this device and did not find any outcome differences.14,15 To date, there has been no evidence from large randomized trials about the effectiveness and safety of this mechanical device compared with manual CPR.
The LINC (LUCAS in Cardiac Arrest) study was designed to evaluate the effectiveness and safety of an algorithm using mechanical chest compressions combined with defibrillation during ongoing compressions (mechanical CPR) compared with manual CPR according to guidelines.16,17 The rationale for this design of the algorithm with mechanical chest compressions was based on studies suggesting the importance of compressions before defibrillation and a minimal hands-off interval.4,18,19 The primary objective was to assess whether treatment with mechanical CPR would result in superior 4-hour survival in patients with out-of-hospital cardiac arrest compared with treatment with manual CPR.
The LINC study was initiated by Uppsala University and sponsored by Physio-Control/Jolife AB. The study was approved by the regional ethical review board in Uppsala, Sweden, the research ethics committee in the United Kingdom, and the United Human Subjects Research Committees in the Netherlands. It was conducted in accordance with regulatory requirements, Good Clinical Practices, and the ethical principles of the Declaration of Helsinki. All survivors with sufficient mental capacity were given information about the study. If further participation was agreed on, written consent was obtained. If survivors did not have sufficient mental capacity, information was presented to family, who provided written consent if they decided to further participate. Consent was waived for included nonsurvivors by the ethical committees.
