NEW ORLEANS — Tweaking emergency dispatcher assessment protocols to incorporate a few simple questions regarding agonal breathing markedly increases 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 net result is a greater than 30% increased likelihood that CPR will be started by bystanders as a result of the 911 call, well before emergency medical services (EMS) personnel can arrive on the scene.
And that, in turn, substantially increases chances for patient survival, according to Dr. Idris, professor of emergency medicine at the University of Texas, Dallas.
In a separate presentation, investigators described another novel approach to improving the rate of prompt CPR by lay rescuers in out-of-hospital cardiac arrest, this time through the use of a new, brief, self-guided CPR video instruction method for the general public that takes only one-eighth the time of the traditional 4-hour CPR group class.
Dr. Idris noted that studies from Sweden, Seattle, and Dallas have independently 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, thinking it an indication that the individual is not actually in cardiac arrest.
In fact, agonal breathing—a distinctively slow breathing pattern in which the collapsed person appears to be gasping for air—is an extremely common occurrence 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,” according to Dr. Idris, a member of the AHA Emergency Cardiovascular Care Committee.
He and his coworkers in an AHA-sponsored trial developed a series of three simple questions designed to be incorporated into emergency dispatcher protocols.
This is intended to enable individual dispatchers to better identify cardiac arrest through the improved detection of agonal breathing over the phone. (See box.)
The investigators 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 new dispatcher protocol that includes questioning about agonal breathing.
They found that, prior to the change, 28% of all cardiac arrests were missed, as confirmed upon subsequent arrival of EMS personnel, compared with 18.8% after the protocol change.
That's a 32% reduction in missed cases—and in the months following completion of the formal study, as emergency dispatchers have grown more experienced in identifying agonal breathing, the percentage of missed cardiac arrests has dropped even further, Dr. Idris continued.
In a separate presentation, Bonnie C. Lynch, Ph.D., pointed out that middle-aged adults are the individuals who are most likely to witness a cardiac arrest, and yet they are seriously underrepresented as participants in the standard 4-hour CPR Heartsaver training classes, which have tended to attract a younger population.
The AHA has set an ambitious goal of training 20 million people per year and is now in the process of training 9 million. In order to train more members of the general public in CPR, the AHA commissioned the development of a 30-minute CPR self-training kit.
The kit, designed for home or work settings, includes a 20-minute video, an inflatable mannequin, and an electronic coaching device that provides feedback regarding the trainee's chest compression technique.
The short self-training kit was tested in a randomized controlled trial in 285 40- to 70-year-olds in the Portland, Ore., area. Three-fifths used the kit, one-fifth took the standard 4-hour CPR training course, and the remainder received no training.
Evaluators blinded to the study tested CPR skills immediately after the training sessions and demonstrated that the kit users were as skilled as those participants who had completed the standard Heartsaver class.
When skills retention was tested 2 months later, the two groups remained closely comparable, said Dr. Lynch of RMC Research Corp., Portland.
The self-training kit is scheduled to be commercially available by midyear.
Cardiac Arrest Questionnaire
▸ 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?