Over the course of Keith Lurie’s, MD, more than 25-year career, he’s devoted himself to the kinds of research innovations that have saved thousands of lives. He was the first to use intrathoracic pressure regulation (IPR) as a therapy to improve perfusion and lower intracranial pressure. He has invented the impedance threshold devices (ITD) called the ResQPOD and the ResQGARD, as well as the ResQPUMP/ResQPOD combination, which is pending Food and Drug Administration approval. In addition, much of his research has helped to identify the profound consequences poor-quality CPR has on survival.
Many of these game-changing ideas started with a man in cardiac arrest and a garden-variety toilet plunger.
In 1988, a 65-year-old Iranian, medically indigent and suffering from severe coronary artery disease, collapsed in front of his family after dinner. Although they didn’t know how to perform CPR, the man’s wife and son used the family’s bathroom plunger to plunge his chest and revive him. It was the third such episode over several months.
The man was rushed to San Francisco General Hospital where Lurie treated him. The son remarked to Lurie that all critical care unit beds should have a toilet plunger standing nearby because they worked. Everyone laughed. The patient underwent successful revascularization and was discharged from the hospital later that week.
Lurie wrote up the episode in a letter for the Journal of the American Medical Association entitled, “CPR: The P stands for plumber’s helper.”
“We wrote this up because we were intrigued by the possibility of using the downstroke of the plunger to push blood out of the heart and the upstroke to suck air into the lungs,” Lurie said.
Despite the humor, the outcome of saving the man’s life was serious, and Lurie, now a professor of internal and emergency medicine at the University of Minnesota, thought long and hard about what had happened. With a scientific background and clinical training in cardiology and cardiac electrophysiology, Lurie was keenly focused on treating cardiac rhythm disorders and conducting resuscitation research to try to improve outcomes after cardiac arrest. He has authored or coauthored more than 250 papers on cardiac arrest, resuscitation, hypotension and heart failure.
“Most of my research is in the area of new devices to treat cardiac arrest and, more recently, shock and head injury,” said Lurie, who’s also the director of a resuscitation laboratory at Hennepin County Medical Center, codirector of the Resuscitation Center, Central Minnesota Heart Center and a cardiac electrophysiologist at St. Cloud Hospital in St. Cloud, Minn.
Over time, and thinking about the toilet plunger incident, Lurie began to study the concept of turning the chest from a passive chamber into an active bellows.
“We made the discovery that if we impeded air from rushing into the lungs at just the time we were pulling up with a suction cup device, we would create a vacuum inside the chest,” he said. That would pull more blood from outside the thorax back to refill the heart and pull venous blood out of the brain back to the heart, as well.
“When you push down the next time, you have a lot more blood going to the heart and the brain and the rest of the body,” he said. “We turned CPR from a passive process to an active one.”
“When you use the ResQPUMP and the ResQPOD together, you get three or four more times as much blood to the brain as you do with just a pair of hands,” he said. The combination of active compression-decompression (ACD) CPR and an ITD also has been shown in a landmark study published in The Lancet to improve neurologically intact survival from cardiac arrest by more than 50%.
“We have tested that device combination in thousands of patients, so we now know definitively that we can increase survival rates for patients who have had a cardiac arrest by about 50% a year compared with conventional CPR,” Lurie said. The combination of the ResQPUMP and ResQPOD ITD is expected to receive pre-market approval from the FDA in 2015.
While Lurie and his team were researching active ACD-CPR with a plunger device, they discovered this also led to a greater preload and cardiac output, which lowered the intercranial pressure on the brain. With this information, Lurie developed the next-generation device called the ResQPOD ITD, which doubles blood flow to the heart with conventional or standard CPR, increases blood flow to the brain by 50% during CPR, and has been shown to increase survival from cardiac arrest by 25% or more.
The National Institute of Health studied the ResQPOD ITD in a large trial from 2006—2010. Part of the study investigated the quality of CPR using the device. The findings proved that when CPR quality is good, the use of the ResQPOD ITD results in a 10% increase in the survival with good brain function for patients with v fib.
“In 100,000 patients that have a shockable rhythm, 10,000 more patients can be living, if you do conventional CPR correctly and use the ResQPOD ITD,” Lurie said. “That possibility drives many of my colleagues to remain doggedly determined and optimistic despite a lot of challenges.”
Lurie and his team also discovered that the creation of a vacuum inside the thorax mimicked breathing. “When you create this vacuum inside the thorax, the vacuum is transmitted immediately to the brain during CPR and that lowers pressures in the brain in a good way,” he said. “Venous blood is pulled out of the brain back to the heart and that provides a way to provide blood flow to the brain the next time you push down.”
This discovery led Lurie to develop a device that impedes or restricts air from rushing into the lungs during the chest recoil phase, creating for the patient a sensation equivalent to breathing through a straw. The device is called the ResQGARD ITD-7.
Lurie worked with Victor Convertino, MD, (an EMS 10 2013 winner) to develop the ResQGARD. They tested the device on astronauts coming back from outer space. “When you’ve been in outer space for three months and you come back to Earth, the effects of gravity are profound. Astronauts often can’t stand up,” said Lurie. “Our device has been shown to help treat this kind of orthostatic hypotension: People can stand up longer and think more clearly.”
Now the ResQGARD is found in many resuscitation kits carried by the military and some EMS systems.
Lurie brought the initial ResQPOD ITD idea to the University of Minnesota, but they weren’t interested in developing the technology. Lurie knew it had tremendous potential and decided to proceed on his own. “We pursued it very actively in an animal lab and multiple clinical trials,” he said. “Ultimately we started a company to try to get this technology out there.”
Lurie launched Advanced Circulatory Systems (ACS) in 1997 to manufacture the ResQPOD ITD and became the company’s chief medical officer. ACS was successful from the start. In December 2014, ZOLL Medical Corporation, a manufacturer of medical devices and related software solutions, announced it bought ACS. ACS will continue to operate out of Minnesota as a part of ZOLL’s core products division. The acquisition pleases Lurie.
“I’m looking forward to having a larger company with expertise in resuscitation help us carry the ball forward to get this life-enhancing technology to become a standard of care,” he said.
Lurie is gratified to see the fruition of his decades of work result in thousands of lives saved. As a testament to his dedication, Minnesota now has one of the highest cardiac arrest resuscitation survival rates in the country. More recently, Lurie has helped to discover that elevation of the head during CPR, using the ITD, also improves cerebral perfusion. This simple maneuver is the focus of his next major research effort, which he believes may result in another significant step forward in the field.
“I went to medical school not sure where the path would take me,” Lurie said. “I got involved with research early on to help pay for medical school, and I’ve been fortunate to have mentors who’ve had successes in their own fields of medicine blaze the trail. It’s been inspiring.”
