Mechanical CPR and the LINC trial
The first time I saw the Thumper performing CPR on a patient I thought “well, that makes sense.” Since then we have seen other devices, most notably the Zoll AutoPulse and the Physio-Control LUCAS. It was disappointing to many in 2005 when the AutoPulse trial was halted early due to harm. 1 Although four-hour survival was similar between groups, the hospital discharge survival rate in the manual CPR group was 9.9% compared to 5.8% in the mechanical CPR group. Many hypotheses were proposed to explain the results, which included Hawthorne effect, prolonged device deployment time, and enrollment bias. Last month, the results of the LUCAS in Cardiac Arrest (LINC) trial were published in JAMA, breathing new life into the mechanical vs manual CPR debate. 2