Mobile-Phone Dispatch of Trained Volunteers May Increase Rate of "Bystander" CPR

Deborah Brauser

June 16, 2015

STOCKHOLM, SWEDEN — A newly created mobile-phone positioning system may provide needed help sooner to individuals experiencing an out-of-hospital cardiac arrest, suggests new research from Sweden[1]. The process dispatches volunteers trained in cardiopulmonary resuscitation (CPR) to the vicinity of a cardiac arrest; a randomized trial of the strategy showed that the intervention significantly increased rates of "bystander" CPR initiation compared with not activating it.

A second, observational cohort study from the same investigators examined records for more than 30,000 patients who had a witnessed out-of-hospital cardiac arrest[2]. It showed a more-than-twofold-higher 30-day survival rate for those who received CPR before the arrival of emergency medical services (EMS) compared with those who did not.

"Both our studies clearly show that CPR is an effective, lifesaving treatment and that further encouragement must be given to respond swiftly on suspected cardiac arrest," coinvestigator on both studies, Dr Jacob Hollenberg (Karolinska Institutet, Stockholm, Sweden), told heartwire from Medscape by email.

"The new mobile-phone text-message alert system shows convincingly that new technology can be used to ensure that more people receive lifesaving treatment as they wait for an ambulance," added Hollenberg.

In an accompanying editorial[3], Drs Comilla Sasson and David J Magid (Colorado School of Public Health, Aurora) write that "bystander-initiated CPR generally happens more by chance than by design," but if trained volunteers can be integrated into the EMS system, "we may finally improve rates of survival after out-of-hospital cardiac arrest."

The studies and editorials were published in the June 11, 2015 issue of the New England Journal of Medicine.

Take That Call

The investigators created the mobile-phone positioning system specifically for their study and then recruited 5989 volunteers who had already undergone CPR training. The process was activated by dispatchers in Stockholm County from April 2012 to December 2013.

After a possible cardiac arrest had been reported, dispatchers sent out ambulances and either fire or police vehicles (first responders), as well as notifying study volunteers. The study included 667 incidents that called for activation. Of these, 306 were considered to be part of the intervention group and 361 were part of the control group.

If a patient with a suspected cardiac arrest was randomly assigned to the intervention group, volunteers within 500 m from the incident received an automatic phone call and text message relaying the location, along with a link to the location on a map. If a patient was in the control group, the volunteers were located but did not receive any information.

The primary outcome measure of bystander-initiated CPR rates prior to the arrival of EMS was significantly higher in the intervention group than in the control group (61.6% vs 47.8%, respectively; P<0.001).

Bystander-initiated CPR, "including CPR performed with telephone instructions," was also significantly higher in the intervention vs control groups (P=0.01). Although there were no between-group differences in 30-day survival rates or return of spontaneous circulation, the researchers note that that could be because of the low number of overall incidents.

In Sweden, "first responders arrive at the scene before an ambulance in about 40% of all out-of-hospital cardiac arrests," write the investigators. "Thus, we speculate the mobile phone-based alerting system might have a greater effect in areas that lack first responders and that have low baseline rates of bystander-initiated CPR."

Increased Survival

In the second study, the investigators examined 30,381 records of out-of-hospital cardiac arrests that occurred in Sweden from January 1990 through December 2011. In 51.1% of these incidents, CPR was given before EMS arrived.

In the group where CPR was performed before the arrival of EMS, the 30-day survival rate was 10.5%, vs 4% in the group without prearrival CPR (P <0.001). After propensity-score adjustment for variables such as age, sex, cause, and EMS response time, the odds ratio for 30-day survival was 2.15 (95% CI 1.88–2.45) for the prearrival CPR-given vs not-given groups. Not surprisingly, the survival rate decreased as the time to initiate CPR increased.

Hollenberg reported that the investigators launched a new app last week that not only dispatches volunteers for CPR help but tells them where to "fetch the nearest available public automated external defibrillator (AED)." Created for both the iPhone and Android, the new app will match the location of the available AEDs with available volunteers in Stockholm and the location of the cardiac arrest.

"I believe this new method is a way forward that will increase not only the proportion of bystander CPR but also early defibrillation and survival," said Hollenberg.

Generalizable to the US?

In their editorial, Sasson and Magid called both studies "well-designed" and note that the records review, while among the largest to examine this issue, is consistent with past research.

"The findings . . . reinforce the conclusion that there is a critical need for interventions to increase the use of bystander-initiated CPR," write the editorialists. They note that although interventions such as public-education campaigns, especially those that target black and Latino neighborhoods, have been somewhat successful, "there is plenty of room for improvement."

"New approaches to sending people who are trained in CPR to the right place at the right time—so they can perform what they have been trained to do—are needed," they write, noting that the mobile-phone study showcases just such an approach.

"Could a system involving mobile phones be used similarly in the United States?" ask Sasson and Magid. They note that although this type of technology "is ubiquitous," there are several barriers to implementing such a system in the US.

This includes most 911 centers' inability to identify cell-phone-call locations or to send text messages, no current database for the volunteers' phone numbers, and concerns regarding dispatchers having access to a volunteer's location—or a volunteer possibly being sued if they do not respond quickly enough or at all.

"Clarification of local Good Samaritan laws would address these concerns," they write, noting that the number of potential responders could be huge if even a fraction of the individuals who learn CPR each year opted in to such a program.

The mobile-phone study was supported by the Swedish Heart-Lung Foundation and Stockholm County. The meta-analysis was supported by grants from the Swedish Heart-Lung Foundation, the Laerdal Foundation for Acute Medicine in Norway, and the Swedish Association of Local Authorities and Regions. Hollenberg and the coauthors report they have no relevant financial relationships, as do the editorialists.


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