LINC: Mechanical chest compressions equally as effective as manual compressions

Issue: October 2013

AMSTERDAM — Cardiac arrest patients who received mechanical chest compressions with defibrillation during ongoing compressions had similar outcomes as those who received manual compressions during cardiopulmonary resuscitation, according to data presented at ESC Congress 2013.

Perspective from Peter J. Kudenchuk, MD, FACP, FACC, FAHA, FHRS

For the LINC study, Sten Rubertsson, MD, PhD, and colleagues compared a mechanical compression device (LUCAS, Physio-Control Inc.) with manual compressions to determine survival rates after 4 hours and neurological outcomes among survivors up to 6 months.

The researchers studied 2,589 patients from four sites in Sweden, one in England and one in the Netherlands. In all cases, manual chest compressions were performed as soon as emergency personnel arrived. Then, patients were randomly assigned to continued manual compressions (n=1,289) or switched to the mechanical compression device with defibrillation during ongoing compressions (n=1,300).

Sten Rubertsson

Survival rates after 4 hours were similar: 23.6% for the group that received a mechanical compression device vs. 23.7% for the group that received continued manual compressions, Rubertsson, of Uppsala University in Sweden, said during a press conference.

At 6 months, 8.5% of survivors who were assigned a mechanical compression device had positive neurological outcomes, defined as a Cerebral Performance Category Score of 1 or 2, vs. 7.6% of survivors who were assigned manual compressions, Rubertsson said.

“There was no statistically significant difference here,” he said. “What was encouraging, though, was that we had only one patient … with poor neurological outcome in the mechanical device group and six in the manual group.”

Although the findings did not demonstrate superiority for the mechanical compression device, it creates opportunities for further research to explore “situations where it would be preferable to have mechanical assistance,” Rubertsson said. These situations could include CPR during transportation and CPR for extended time periods, he said. – by Katie Kalvaitis and Erik Swain

For more information:

Rubertsson S. Hot Line II: Late breaking trials on intervention and devices. Presented at: the European Society of Cardiology Congress; Aug. 31-Sept. 4, 2013; Amsterdam.

Disclosure: The study was initiated by Uppsala University and sponsored by Physio-Control/Jolife AB. Rubertsson has received consulting income from Physio-Control/Jolife AB. All of the other researchers’ institutions received compensation from Physio-Control/Jolife AB for their work.

Perspective

Peter J. Kudenchuk, MD, FACP, FACC, FAHA, FHRS

The recently completed LINC trial compared a piston-like mechanical CPR device against conventional CPR’s effect on survival and neurological outcome after out-of-hospital cardiac arrest. The LUCAS device offers a number of potential advantages over conventional CPR, including more consistent CPR metrics (rate and compression depth), active compression-decompression (ACD) CPR and administration of shock without interrupting chest compressions. These, coupled with high hopes for the device and the inability to blind care providers to treatment assignment would seemingly have favored it against conventional CPR — for which CPR metrics are operator dependent, does not provide ACD and requires interruption to administer shocks.

That none of the targeted clinical outcomes were improved by LUCAS is therefore surprising and disappointing. In part, the answer may lie in comparing the actual metrics achieved between the two forms of CPR. For now, the assertion that the trial demonstrated equivalence between mechanical and conventional CPR should be taken cautiously. LINC was designed as a superiority, not noninferiority trial, from which one cannot validly conclude that the two CPR modalities are necessarily equivalent. It would require a sizably larger trial to establish such a claim.

Some time ago, a commercial for a hamburger franchise featured this now iconic reaction by an elderly matron to a competitor’s product: ‘Where’s the beef?’ Considering the added cost in equipment and training, the routine use of a mechanical device in the resuscitation of cardiac arrest leaves one asking the same question.

Peter J. Kudenchuk, MD, FACP, FACC, FAHA, FHRS

Professor of Medicine, University of Washington

Associate Medical Director

King County Emergency Medical Services

Public Health – Seattle/King County

Disclosures: Kudenchuk reports no relevant financial disclosures.