Finding the Sweet Spot

Many combat veterans who went to Vietnam found pain and trauma. Dr. Ahamed Idris went to Vietnam and found something else–a career path.

“Before I went into the Army, I had absolutely no interest in medicine. I was going to be a physicist,” says the professor of surgery and internal medicine and director of emergency research at the University of Texas Southwestern Medical Center. “But I ended up in the Army Medical Corps. Being a medic in Vietnam was one big emergency, and I discovered that I enjoyed taking care of emergencies.”

Idris knew that he was deeply interested in research, a passion that had been with him since adolescence, so that’s where he focused his medical education.

Finding a Path
It was the late 1970s and the field of emergency medicine was just opening up. While working as an attending physician in the emergency department of The John H. Stroger, Jr. Hospital of Cook County (formerly Cook County Hospital) in Chicago, Idris helped the hospital develop the first emergency medicine residency program. “I didn’t do an emergency medicine residency, but I helped develop one at Cook County Hospital,” he says.

With his experiences in Vietnam and his subsequent medical education, a love of emergency medicine and research coalesced into a professional pathway that has had significant implications for both Idris and emergency medical research. His research findings have had a dramatic impact on the saving of tens of thousands of lives, specifically in the area of cardiac arrest survival. And on metronome sales as well, but we’ll get to that.

Recognized during 2013 as the most prolific principal investigator (PI) for the National Institutes of Health (NIH) Resuscitation Outcome Consortium (ROC), Idris has made some of his most compelling research advancements as a lead researcher for the ROC. Started by the NIH in 2004, ROC is a consortium of 10 regions throughout the United States and Canada. These regions include Seattle and King County, Wash.; Portland, Ore.; Dallas and Fort Worth, Texas; and San Diego. Other sites include Birmingham, Ala., Milwaukee and Pittsburgh. Ottawa, Toronto, and Vancouver, British Columbia make up the Canadian sites.

Twenty-two cities in Northern Texas, including Dallas and Fort Worth, participate in Idris’ ROC site. “We were formed by the NIH to conduct prehospital research focused on cardiac arrest and severe traumatic injury,” he says. “We’re probably the largest consortium in the world conducting these prehospital studies. We have completed four clinical trials and are currently doing two more cardiac arrest trials. We also are about to start another clinical trial on traumatic injury.”

Idris’ Dallas-Fort Worth ROC site now maintains a cardiac arrest registry of more than 20,000 patients and is the highest enrolling U.S. site in the ROC, in terms of number of patients enrolled in cardiac arrest and trauma studies. The ROC as a whole has more than 150,000 patients, with a database that increases by 25,000 every year. “I believe it’s one of the largest registries in the world,” says Idris.

Chest Compression Rates
Such a distinction is important because, in this case, size really does matter. To do the kind of research that impacts lives across the world, statistical samplings must be great enough to encompass large groups of diverse people. Take, for example, research on chest compression rates. Because of his role on the National Emergency Cardiovascular Care Committee for the American Heart Association (AHA), Idris was given the assignment to review 2010 guidelines for chest compression rates. He conducted a comprehensive review of existing research and literature, and what he found surprised him. “Not one human study of chest compression rates and outcomes existed,” Idris says, “in particular the outcomes for rescuer resuscitation and survival.”

Ahamed IdrisBecause of the scant information available, chest compression rates for prehospital providers were set at 100 per minute. “The American Heart Association committee didn’t place an upper limit on rate because there wasn’t evidence to suggest that there should be an upper limit,” says Idris. “There were a number of people who didn’t agree with that, including myself, but we had no evidence to refute it.”

Fortunately, Idris was in a position to do something about the lack of information because he was part of the ROC, which had a large amount of data that could speak to the guideline. Idris proposed a study on chest compression rates, with a return of spontaneous circulation and survival as an outcome. The proposal tested hypotheses and proposed agreed upon analytical methods, all overseen by a statistician. “That’s the advantage of dealing with a consortium like this,” Idris says. “The studies are legitimate and have high quality. I did the study because it needed to be done; we needed to have some human evidence.”

Chest Compression Study
The study looked at 3,000 patients, and when completed and analyzed, the results surprised Idris and others because they showed that the return of spontaneous circulation (ROSC) peaks at 100 to 120 compressions per minute. Idris calls this narrowly defined band the “sweet spot.” Above 120 compressions, successful resuscitation starts to fall off, and at 150 compressions, success is less than half. “No one knew that,” he says. “Half the people on the American Heart Association committee thought that faster was better because animal data showed that faster is better. In fact, the American Heart Association’s mantra is “push hard and fast.” The reason they have that mantra is because they thought people pressed too slowly.”

Idris adds: “Before the study, we had no knowledge of chest compression rates. We didn’t know that chest compression rates affected survival at all. So when I saw the curve I was pretty surprised.”

According to Idris, the results of the study now open a new field of research. And he emphasizes that EMS providers need to pay attention to their rate of compression and keep from going too fast or too slow. “On my site in Dallas, the mean chest compression rate, measured for the first two years, was 135 per minute,” Idris says. “And 150 to 180 was not uncommon. About a third of the chest compression rates, a third of the resuscitations, were over 120 per minute.” The newly discovered data suggests a paradigm shift for emergency medicine.

Tracking Compressions
Idris investigated other ROC sites across North America and found that most were using chest compression rates above 120 per minute with one-third of patients. Now that the “sweet spot” has been established, Idris has become a big proponent of the metronome.

“We can solve this problem by putting a metronome onboard ambulances,” he says. “Fortunately, many of the defibrillators and AEDs that are being used today have a metronome built into them.” Idris has also partnered with a company to design a metronome that gives guidance regarding ventilation and chest compression, which he has placed on ambulances and fire trucks. “And I think more companies are building better metronomes in their equipment now,” he says.

To be clear, the success of this study hinged on having viable and detailed raw data, which Idris was able to collect off of the electronic files of monitor defibrillators that are used on patients in the field during CPR. Those files were difficult to obtain, but Idris was persistent. “I had to really focus my efforts on developing a structure to collect the files off the defibrillators,” he says. “Now we have the highest rate of collection in the ROC. We are collecting files on more than 95% of patients who receive CPR in the field.”

What makes these electronic files so valuable is the detail–and the measurement–they track. The files record all chest compressions administered to a patient by a paramedic. Many of the monitors also show depth, interruptions and shock administration. “It’s almost as good as being there–maybe better,” Idris says. “You can’t change anything without first measuring it. Now that we have the ability to measure what’s going on during resuscitation, we have the opportunity to make discoveries.”

Improving Lives
Idris says he sees the path he has traveled from Vietnam medic to full-blown medical researcher as a logical progression in his life. “The place I’m at today gives me the greatest opportunity that I could have in improving people’s lives,” he says. “I don’t know how many people found a career as a result of their service in Vietnam, but I really owe my career to the Army. If I hadn’t become a medic, I wouldn’t have had any interest in medicine whatsoever.”

And that would have been a loss to us all. That Idris pursued the path he did has been a tremendous benefit to so many.

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