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Ore. EMS responders to test cardiac arrest treatments

By Tom Vogt
The Columbian
Copyright 2008 The Columbian

CLARK COUNTY, Ore. — Emergency medical personnel in Clark County will participate in a study of methods for resuscitating people whose hearts have stopped.

The study is part of a national assessment of emergency-response methods, financed by the National Institutes of Health. The Portland-area study group overseen by Oregon Health & Science University also includes Multnomah, Clackamas and Washington counties.

The study will compare outcomes when emergency medical responders use different methods to resuscitate people who suffer cardiac arrests. Agencies across the country that are dispatched by 911 systems vary slightly in their approaches to treating patients.

“We’re hoping these studies put science behind what we do,” said Dr. Mohamud Daya, associate professor of emergency medicine at OHSU.

More than 350,000 people die every year from cardiac arrest in North America. About half of them showed no prior symptoms of heart disease; only about 5 percent of cardiac-arrest patients survive.

Personnel from all fire and rescue agencies in Clark County as well as American Medical Response will take part in the study, said Dr. Lynn Wittwer, medical program director for Clark County’s emergency medical services.

EMS personnel in Clark County were the first to be trained, and they will be the first to implement the procedures on cardiac-arrest patients when the study begins June 2.

“Cardiac arrest means the heart stops beating, for whatever reason,” Wittwer said. “Maybe less than 50 percent are related to a heart attack. Some have a congenital abnormality of the heart’s electrical system and some have valve damage or congestive heart failure or a viral infection.”

The study will look at two resuscitation strategies “that have shown considerable promise in smaller trials,” said OHSU’s Daya, the study’s lead investigator.

The first line of treatment will look at how long to do CPR before using a defibrillator to shock the heart. For many years, the standard treatment has been to immediately shock the heart; however, smaller studies have shown that a sustained amount of CPR before shocking the heart may lead to increased blood flow and improved outcomes. Subjects in the study will randomly receive either about 30 seconds of CPR or three minutes of CPR before having their heart rhythm checked to determine if an electrical shock is needed.

The other treatment in the study is a small plastic device that fits onto the face mask or breathing tube used during CPR. The fist-sized device may provide increased blood flow back to the heart during the decompression phase of CPR, allowing more blood to circulate during the compression phase. People in the study will be treated with the actual device or with something that looks identical but has no effect.

People eligible for this study will be unconscious and will be unable to provide consent to participate in a medical study. The Food and Drug Administration allows research in certain life-threatening situations without pretreatment authorization. People who wish to exclude themselves from the study can request an “opt out” bracelet by calling OHSU at 503-494-7014.

This is the second study conducted at 10 sites across the United States and Canada through the federally funded Resuscitation Outcomes Consortium. The first study, which is still going on, is evaluating different types of saline solutions used to treat trauma victims. Thirty-three people in Clark County have been treated as part of that study.

When the saline study was announced two years ago, about 500 people in the Portland-Vancouver area requested opt-out bracelets, Daya said.