Automated CPR and impedance threshold device work in concert
It’s increasingly clear that improved outcomes after an out-of-hospital cardiac arrest depend on having a host of protocols in place, rather than relying on one therapy or benchmark. The combined use of an automated CPR device and an impedance threshold device is proving to be beneficial in this patient population.

Keith G. Lurie, MD, a staff cardiologist at St. Cloud Hospital in Minneapolis and a professor of internal and emergency medicine at the University of Minnesota, published in 2002 the first paper detailing a natural mechanism within the body that increases circulation to the heart and brain.

By creating a vacuum in the thorax during chest recoil, more blood is pumped to the heart, which results in more blood subsequently being pumped to the brain. Intracranial pressure also is simultaneously lowered. Out of this discovery came the ResQPod, an impedance threshold device recommended by the American Heart Association that improves survival for patients experiencing sudden cardiac arrest and receiving CPR. 

Today, the ResQPod is widely used in combination with automated CPR. In many counties in Minnesota, for example, the EMS personnel use the impedance threshold device with the Lucas (Physio-Control) mechanical CPR device in all cardiac arrest patients, Lurie says. Other major cities such as Austin, San Francisco and New Orleans have followed suit. “Fundamentally, there is this growing momentum to adopt a new approach for cardiac arrest patients,” he says.

Lurie first used the combination in a 46-year-old woman who had had a second cardiac arrest in the rescue helicopter in 2007. St. Cloud Hospital had just deployed the Lucas device in its emergency department after years of using the impedance device with manual CPR. After 49 minutes of the combination treatment, the woman stabilized, had her LAD opened in the cath lab and was cooled down. When she awoke, her neurological functions were intact.

“In the past, we would never recommend transport to the cath lab of a patient with refractory cardiac arrest. But now we can do so in a very stable manner,” Lurie says.