After switching to a simplified communication strategy, Los Angeles emergency dispatchers got more 9-1-1 callers to initiate early CPR on people with out-of-hospital cardiac arrest (OHCA), especially callers speaking limited English.
In a retrospective cohort study, the rate of callers with limited English proficiency engaging in telecommunicator CPR increased significantly from 28% to 69% after the City of Los Angeles 9-1-1 Dispatch Center transitioned from using the standard Medical Priority Dispatch System (MPDS) to using the Los Angeles Tiered Dispatch System (LA-TDS).
Callers with English proficiency also had telecommunicator CPR rates improve significantly, albeit more modestly, from 55% to 67% after implementation of LA-TDS, according to Stephen Sanko, MD, of the Keck School of Medicine of the University of Southern California in Los Angeles, and colleagues.
The jump in CPR was achieved using the same 9-1-1 dispatch personnel, minimal retraining, and only a 1-month run-in period, Sanko and colleagues noted in JAMA Network Open. Their study had previously been presented at the 2017 Society of Academic Emergency Medicine meeting.
Under the LA-TDS system, Los Angeles dispatchers were retrained to ask fewer questions and treat vague answers regarding life status as suggestive of agonal breathing before sending help to OHCA calls.
Sanko’s group found the new protocol to be associated with less time to recognition of cardiac arrest and dispatch of resources for OHCA calls from people with limited English proficiency.
However, the study was too small to show an improvement in rates of sustained return of spontaneous circulation (31% vs 31%, respectively) or the number of survivors to hospital discharge (12% vs 11%, P>0.99 for both) among OHCA calls.
“Any innovations to 9-1-1 operator procedures that allow for improved and expedited recognition of cardiac arrest, and result in increased bystander CPR rates, will lead to improved outcomes for OHCA,” commented Brian Grunau, MD, MHSc, of St. Paul’s Hospital and the University of British Columbia, Vancouver, who was not involved with the study.
Grunau told MedPage Today that an improvement in bystander CPR alone is already a positive result.
Thus, greater expansion of the local LA-TDS system would represent a “powerful public health opportunity,” according to Thomas Rea, MD, MPH, of the University of Washington, Seattle, and colleagues in an accompanying editorial.
“[Telecommunicator CPR] relies on rapid and efficient communication, a reality that can be challenging especially when the caller has limited English proficiency. Previous investigation has demonstrated that limited English proficiency inhibits cardiac arrest recognition and bystander CPR and, in turn, may be associated with worse survival outcome, highlighting a mechanism that is associated with outcome disparity after cardiac arrest,” the editorialists noted.
Sanko and colleagues had performed a secondary analysis of a study analyzing field-confirmed, nontraumatic OHCA calls before (from Jan. 1, 2014-March 31, 2014) and after LA-TDS implementation (from Jan. 1, 2015-March 31, 2015) at the Los Angeles dispatch center.
The dispatch center, otherwise unchanged during the study, is staffed by sworn firefighters with a minimum of basic life support training and 2 years of field EMS experience. Callers interact with a single telecommunicator who uses scripted and semi-scripted questions.
For the study, trained data abstractors evaluated 9-1-1 audio recordings for the initiation of telecommunicator-assisted CPR and judged the English proficiency of each caller.
Out of 1,027 EMS-treated OHCA cases during the study period, there were 597 meeting the inclusion criteria of the study, split between 289 older calls on MPDS and 308 newer ones on LA-TDS. Callers with limited English proficiency included 26 and 35 people, respectively, in the two groups.
That means roughly 10% of emergency calls came from people with limited English proficiency when 19% of people in Los Angeles are thought to be at this language level.
“This finding suggests the possibility that populations with limited English proficiency are less likely to activate 9-1-1 for incidence of cardiac arrest. If true, this finding would compound the health disparity observed among those with limited English proficiency,” Rea and colleagues said.
“Close examination of the results also revealed that, even with the improvement associated with the local algorithm, the group with limited English proficiency still appeared to lag behind the group with English proficiency with regard to timely CPR delivery,” they noted.
OHCA calls on MPDS and LA-TDS were similar in age, sex, known comorbidities, arrest location, and witnessed status. Use of interpreter services was unchanged between cohorts, according to study authors.
Results of the study may not be generalizable to other settings and communities, Sanko’s group cautioned.
Other limitations include the potential for a Hawthorne effect and a small sample that precluded investigators from detecting any between-group differences in clinical outcomes.
“Further studies are needed to characterize underrepresented 9-1-1 callers with diverse cultural linguistic backgrounds to improve access, promote activation of the chain of survival, and reduce disparities in cardiac arrest care. The precise elements of LA-TDS that are associated with increased telecommunicator-assisted CPR performance must also be examined,” study authors urged.
“Yet we should appreciate that real progress in cardiac arrest resuscitation is being made,” Rea and colleagues argued. “As we advance a public health strategy for community-based resuscitation care, the approaches that adapt the initial links between early recognition, early activation of emergency response, early CPR and early defibrillation offer the most accessible, cost-effective, and hence impactful opportunities to improve care and outcome.”
The study was supported by an NIH grant.
Neither study authors nor editorialists had any disclosures.