NEW ORLEANS — Tweaking emergency dispatcher assessment protocols to include simple questions about agonal breathing markedly boosts the rate of cardiac arrest detection over the phone, Ahamed H. Idris, M.D., reported at the annual scientific sessions of the American Heart Association.
The result is a greater than 30% increased likelihood that CPR will be started by bystanders after a 911 call, well before emergency medical services (EMS) personnel arrive. That increases the chances for survival, added Dr. Idris, professor of emergency medicine at the University of Texas, Dallas.
Studies from Sweden, Seattle, and Dallas have shown that CPR is withheld from up to 40% of people with out-of-hospital cardiac arrest because potential rescuers or 911 dispatchers misinterpret agonal breathing as an indication that the individual is not in cardiac arrest, Dr. Idris said.
Agonal breathing—a distinctively slow breathing pattern in which the collapsed person seems to gasp for air—is extremely common shortly after the respiratory center in the brainstem becomes deprived of oxygen-rich blood. “That's the time when people are most likely to actually be saved if they receive intervention,” said Dr. Idris, a member of the AHA Emergency Cardiovascular Care Committee.
He and his coworkers in an AHA-sponsored trial devised three simple questions to use in emergency dispatcher protocols to better identify cardiac arrest by phone. (See box at left.) They studied all 962 cases of dispatcher-assisted out-of-hospital cardiac arrest in the Dallas area during the 8 months before and 4 months after implementation of the protocol. Prior to the change, 28% of all cardiac arrests were missed, compared with 18.8% after the change.
In a separate presentation, researchers described a new approach to improving the rate of prompt CPR by lay rescuers in out-of-hospital cardiac arrest, using a brief, self-guided CPR video instruction method for the public that takes one-eighth the time of the usual 4-hour CPR group class.
Middle-aged adults are most likely to witness a cardiac arrest, but are underrepresented in the standard 4-hour CPR Heartsaver training classes, which tend to attract a younger crowd, said Bonnie C. Lynch, Ph.D.
The AHA commissioned the development of a 30-minute CPR self-training kit. Designed for home or work settings, the kit includes a 20-minute video, an inflatable mannequin, and an electronic coaching device that gives feedback about the trainee's chest compression technique.
In a randomized trial, three-fifths of a group of 285 Portland, Ore.-area 40- to 70-year-olds used the kit, one-fifth took the standard 4-hour CPR training course, and the others received no training.
CPR skills testing by blinded evaluators after the training showed that kit users were as skilled as those who completed the standard class. Two months later, the two groups remained closely comparable, said Dr. Lynch of RMC Research Corp., Portland.
The kit is slated to become commercially available by midyear.
The Questions Dispatchers Should Ask
▸ Is the person awake and conscious?
▸ Is the person breathing normally? Count the breaths and describe what they sound like. (An interval of 10 or more seconds between breaths is a marker for agonal breathing and an indication to start CPR.)
▸ Is the person moving?