Emergency Medicine

Unrecognized cardiac arrests: A one-year review of audio from emergency medical dispatch calls

a b s t r a c t

Objectives: Immediate recognition of out-of-hospital cardiac arrest (OHCA) by Emergency Medical Dispatch (EMD) operators is crucial to facilitate timely initiation of telephone cardiopulmonary resuscitation (T-CPR) and to enable the appropriate level of Emergency Medical Services (EMS) response. The goal of this study was to identify patterns that can increase EMD-level recognition of cardiac arrests prior to EMS arrival.

Methods: The Combined Communications Center in Alachua County, Florida provided audio recordings of all emergency calls from January 1, 2018 to November 16, 2018 dispatched as a chief complaint other than OHCA, but later identified as cardiac arrest. A multi-disciplinary medical team transcribed and analyzed the calls to determine common themes and trends.

Results: Out of an initial 81 calls meeting inclusion criteria, 69 were immediately recognized as OHCA by EMDs, leaving 12 calls of unrecognized OHCA. In 11 of 12 calls respiratory issues were described to EMD. In 10 of 12 calls the subject was described as unconscious, and in the other 2 calls, the subject lost consciousness during the call.

Conclusions: Lack of recognition of OHCA by EMD occurred in most calls due to difficulty communicating the sub- ject’s Respiratory status. Further emphasis should be placed on identifying non-viable respirations in Unconscious patients in EMD training and algorithms to increase recognition of OHCA and initiation of T-CPR. A multi-year re- view of a comparable dataset from geographically and socioeconomically diverse regions in the United States can validate and expand these preliminary trends.

(C) 2022

  1. Introduction

Out-of-hospital cardiac arrest (OHCA) remains a common Public health problem with over 356,000 OHCAs each year in the United States [1]. Rapid recognition of OHCA by Emergency Medical Dispatch (EMD) operators is essential to initiating early cardiopulmonary resuscitation (CPR) and allocating the correct response by Emergency Medical Services (EMS). EMD operators who recognize the onset of OHCA quickly can pro- vide potentially lifesaving telephone cardiopulmonary resuscitation

Abbreviations: OHCA, out-of-hospital cardiac arrest; EMD, Emergency Medical Dispatch; T-CPR, telephone cardiopulmonary resuscitation; CPR, cardiopulmonary resuscitation; EMS, Emergency Medical Services; ROSC, return of spontaneous circulation.

* Corresponding author.

E-mail addresses: [email protected] (D.B. Crabb), [email protected] (Z.C. Gibson), [email protected] (D.C. Ralston), [email protected] (C. Harrell), [email protected] (S.A. Cohen), [email protected] (D.E. Fitzpatrick), [email protected] (T.K. Becker).

1 Drs. Crabb and Elmelige contributed equally to the manuscript.

2 Present address for this author: Department of Emergency Medicine, Summa Health, Akron, OH

(T-CPR) instructions prior to the arrival of EMS. Recognition of OHCA by EMD operators during calls is associated with increased bystander CPR, return of spontaneous circulation (ROSC), and 30-day survival [2]. The benefits of this are seen downstream in the “Chain of survival” as im- provements in T-CPR timeliness are associated with improvements in survival to hospital discharge and survival with favorable outcomes [3].

Lack of EMD recognition of OHCA during a call is associated with de- creased patient survival [4]. Therefore, it is crucial to identify and ad- dress challenges facing EMD operators as they attempt to rapidly collect the required information from callers. Differences in callers’ de- scriptions of the patient status can hinder the EMD operator’s ability to recognize OHCA. Previous studies have identified the breathing as- sessment as a major source of missed OHCAs [5,6]. Multiple studies have seen increases in OHCA detection when EMD-level training and protocols are specifically modified to address recognition of agonal breathing [7,8,9].

Given the importance of recognizing OHCA at the EMD-level, we aimed to identify common descriptions of cardiac arrest during emer- gency calls in a moderate-sized city in the southeastern United States

https://doi.org/10.1016/j.ajem.2022.01.068

0735-6757/(C) 2022

that, if recognized early, may accelerate EMD recognition of OHCA, thereby increasing early T-CPR and improving OHCA outcomes.

  1. Methods
    1. Study design and population

This was a retrospective analysis of emergency call recordings from January 1, 2018 to November 16, 2018 collected from the Combined Communications Center (CCC) located in Alachua County, Florida. The county has over 270,000 residents, with more than 130,000 living in Gainesville, its largest city. The median age is 30.1 years old [10]. The CCC is an accredited Center of Excellence by the International Academy of Emergency Dispatch (IAED), and all dispatchers are at least EMD trained. The CCC utilizes the Medical Priority Dispatch System approved by the IAED. About 8 call-taking-capable dispatchers are available dur- ing any given shift, and the center averaged 114 calls per day in 2018. The CCC handled a total of 41,694 calls in 2018. There were a total of 129 cardiac arrest calls during the study period.

    1. IRB approval

The University of Florida Institutional Review Board approved this study with data use agreements with the Alachua County CCC and Alachua County Fire Rescue in Alachua County, Florida, USA. All emer- gency call records are public record. To maintain patient confidentiality, no patient names or unique identifiers were transcribed from emer- gency calls.

    1. Data collection

All emergency calls dispatched as a chief complaint other than car- diac arrest (MPDS protocol version 13.1.244 STD) during the study pe- riod were reviewed. Those that were not immediately recognized as cardiac arrest prior to dispatch but later documented as”nature of call on scene: cardiac arrest” by the responding crew were included. Trau- matic arrests were excluded in accordance with current recommenda- tions on withholding and terminating resuscitation in adult traumatic arrests [11]. Inter-facility transfers were also excluded. The CCC pro- vided the audio files of the included calls for review by our team. In ad- dition, an operational review was performed on all of the original calls by the CCC for their own improvement. Our study team was blinded to this operational review until after our team’s review of the included calls had been completed.

    1. Data analysis

The study team performing the analysis included individuals with wide-ranging backgrounds: an educated layperson, pre-hospital per- sonnel, and EMS-, Critical Care-, and Emergency Medicine-trained phy- sicians. This team offered an interdisciplinary approach to ensure a broad range of backgrounds in language, linguistics, Emergency medical care, and emergency dispatch. With at least 3 or more members present during each review session, our team reviewed and transcribed each call provided by the CCC verbatim. Emphasis was placed on identifying words and phrases that callers used to describe the patient and their condition. When an agreement on an exact word or phrase could not be reached, “[unintelligible]” was recorded. Other noises such as heavy breathing or knocks at a door were noted for completeness. Heightened emotion or clear emotional states were documented if all members agreed on a consensus description of the state when present. Next, the team gathered all recorded complaints, signs, symptoms, and descriptions of patients. The four most recurrent items were identified, and all words or phrases in each call related to these are summarized in the results. Each call’s specific characteristics, such as type of caller, call location, time of day, time interval from call start to EMS initial contact,

EMS response level, and any changes in EMS response level, were also recorded.

  1. Results

There were 129 total cardiac arrest calls during the study time pe- riod. The average age of the patient was 59 years old. We identified 81 calls that met the inclusion criteria – “nature of call on scene: cardiac ar- rest” after they were dispatched as a different chief complaint. Of these, 69 were recognized as OHCA by EMD after dispatching the initial prior- ity code. Therefore 12 calls remained as unrecognized OHCA calls.

Of the 69 recognized OHCA cases, 36 were initially reported as “un- conscious but breathing” and upgraded to cardiac arrests while EMS was en-route. According to the CCC review, additional barriers to recog- nition were primarily related to caller delay in assessment or coopera- tion issues.

Of the 12 total unrecognized cardiac arrest calls, all occurred be- tween the hours of 12:00 AM and 8:00 AM. Nine of 12 calls came from homes, 2 from businesses, and 1 from a Healthcare facility. Breathing as- sessments were attempted in 8 calls, with the breathing assessment car- ried to completion in 4 of those (Table 1).

We found 4 main descriptions callers used for patients (Table 2): re- spiratory distress, loss of responsiveness, falls, and the patient being cold or blue. In 11 calls, callers described respiratory issues to EMD. Cal- lers describe the patients as “barely breathing,” “struggling to breathe,” and “having a hard time breathing.” In 10 calls, the patient was de- scribed as unconscious, and in the remaining 2 the patient lost con- sciousness during the call, with callers describing the patient as “sleeping” or “not responding.” In 6 calls, the patient was described as having fallen to the floor. Five callers described the patient’s skin as cool to touch or blue Skin color.

  1. Discussion

Obtaining a rapid and accurate history from mostly layperson callers represents a significant challenge. Dispatchers must ask questions of an emotionally distracted caller in order to obtain critical time sensitive in- formation. Dispatchers must navigate through all of this for the timely identification of OHCA with the ultimate goal of initiating early T-CPR prior to EMS arrival, especially given the favorable outcomes associated with T-CPR [3]. In addition, they are able to accurately prepare EMS responding to the scene for an ongoing cardiac arrest. In the majority – 69 of 81 calls – not dispatched as OHCA, EMDs were able to quickly navigate the challenge, and correct or update the report to EMS crews. In the remaining 12 cases with unrecognized OHCA, the time interval until EMS arrival on-scene was 4-9 min, compared to the median re- sponse time of 5 min 23 s for all cardiac arrest calls in 2018 in the county. It is difficult to predict if these Response times would have changed with earlier recognition, but every second is crucial in cardiac arrest resuscitation. Therefore, earlier recognition will at least prepare EMS crews for the quickest, most appropriate response.

Similar to previous studies [5-9], a decreased level of consciousness

and an abnormal respiratory status was described in almost every un- recognized cardiac arrest call included in our study. This remains true despite many studies taking place on different continents, in different cultures, and in different languages. Objective breathing assessments were attempted in 8 of the calls but can be difficult to complete depend- ing on caller cooperation. Potential barriers to the appropriate initiation and completion of a breathing assessment in these calls include family or caller emotions hindering their ability to follow instructions as well as lack of EMD ability to recognize that a breathing assessment was warranted. Non-viable respirations described as “hardly” or “barely” breathing and abnormally long pauses in respirations should be high- lighted in EMD-training as possible descriptions of agonal breathing. Objective descriptions of cyanosis, cool skin temperature, and diaphore- sis are also key to identifying ineffective breathing or impending

Table 1 Characteristics of the calls included in the study. For comparison, in this county, the median dispatch time for EMS to arrive in 2018 to a cardiac arrest call was 5 min 23 s. The median time for EMS to arrive in 2018 to all calls was 6 min 37 s.

Call No.

Caller relation to patient

Caller proximity to patient

Initial Chief Complaint

Location

Breathing Assessment

Abnormal Breathing

Response level upgraded during call

EMS arrival time (mins into call)

Time of Day

1

Self

N/A

law enforcement medical request

Home

Not attempted

Yes

No

8:46 (police)

Overnight

2

Self

N/A

Breathing problems

Home

Not attempted

No

No

5:07

Overnight

3

Grandchild

With patient

Unconscious/fainting

Home

Completed

Yes

No

4:51

Overnight

4

Neighbor

With patient

Overdose/poisoning

Home

Completed

Yes

Yes

4:07

Morning

5

Bystander

With patient

Unconscious/fainting

Business

Attempted

Yes

No

7:0 l

Overnight

6

Bystander

With patient

Unconscious/fainting

Home

Attempted

Yes

Yes

6:07

Overnight

7

Healthcare

With patient

Lifeline alarm

Home

Completed

Yes

No

9:54

Overnight

8

assistant

Nurse

With patient

Breathing problems

Healthcare

Not attempted

No

No

4:47

Morning

9

Bystander

With patient

Unconscious/fainting

facility

Business

Attempted

Yes

No

3:59

Overnight

10

Neighbor

Near patient

Unconscious/fainting

Home

Attempted

Yes

Yes

3:57

Overnight

11

Wife

With patient

Breathing problems

Home

Completed

Yes

Yes

6:35

Overnight

12

Son-in-law

With patient

Breathing problems

Home

Not attempted

Yes

No

8:42

Overnight

respiratory collapse. The EMD must be able to recognize these descrip- tors and, combined with a description of unresponsiveness, immedi- ately direct the caller in T-CPR.

By reviewing audio from OHCA calls, an EMS agency can learn how their local population describes many of their cases. Recognizing and addressing region-specific descriptions of OHCA may improve EMD-level recognition. These communication barriers can signifi- cantly affect the “quality of communication,” which can directly in- fluence patient health outcomes as observed in physician-patient communication [12]. Identified region-specific words and phrases may become cues to increase the suspicion for OHCA by the dis- patcher. These can assist the dispatcher even when the caller has heightened emotions and cannot provide a clear history. limited English proficiency increases a patient’s risk of an adverse event in US hospitals [13]; however, these barriers are likely underreported and under-addressed at an EMD level. Callers with limited English proficiency may also benefit from focused interventions with EMD protocols to increase awareness of descriptions of OHCA [14]. No cal- lers in this study spoke in a language other than English during the call, but review of calls from non-native English speakers would be very beneficial in identifying other terms that suggest OHCA.

In cases where the caller becomes the patient, it is imperative that the EMD be able to recognize objective audio clues such as difficulty speaking between breaths, inability to speak full sentences, gasping for air, change in word speed, decreasing responsiveness, and thuds or other noises indicating that a caller might have fallen. Being cognizant of such subtle clues can allow EMDs to change the priority response level for the call and dispatch closer First responders such as those through smart phone-based applications [15], thus decreasing time to initiation of CPR. In addition, early recognition of a patient-caller in dis- tress could prompt the EMD to encourage the caller to notify someone close by in case their condition should change quickly.

    1. Limitations

This study is limited by the small Number of calls in a specific geo- graphic region over a Short period of time. A multi-year review of a com- parable dataset from geographically and socioeconomically diverse areas of the US could expand these preliminary trends identified in our study. Poor audio quality and connectivity issues from patient, cal- ler, and dispatcher lines could also limit recognition of OHCA in calls and complicate EMDs abilities to recognize irregular respirations over

Table 2

A summary of the main descriptive and identifying terms callers used for subjects in cardiac arrest.

Call No.

Respiratory Distress

Loss of Responsiveness

Fall

Cold/Blue

1

Heavy breathing; Wheezing; Agonal breath sounds

“Sir, can you hear me?” 8x

2

“I got up and couldn’t hardly breathe””

…I got…shortness of breath…”

3

“…she’s unresponsive.”

“…she has fallen onto the floor.”

“…she’s freezing.”

4

“…he is not breathing…”

“…I can’t get him to wake up.”

“…he fell out of the chair and he’s on the

“…his hands are really, really

“He’s breathin’, but he stopped for a long time there a

floor…”

cold…”

couple times.”

5

“…he’s barely breathing, he just took a deep raspy

“…he’s sleeping, he’s

“He just fell.”

“…he’s turning blue in the

breath.””

unconscious…”

face.”

…it doesn’t look like he is breathing.”

“His chest is not moving.”

6

“…it’s like a snoring sound.”

“…somebody has collapsed…”

“He fell in the shower.”

7

“…he’s struggling to breathe.””

“I’m afraid he’s gone.”

“…he just fell out in the bedroom floor.”

…he is still taking labored breaths.”

8

“…breathing is labored…”

“She is not as responsive as she

“…she’s on the floor…”

“She is cold.”

should be.”

9

“…a customer just passed out….”

“…he’s on the floor.”

“…he’s turning really blue.”

“…his eyes just kinda rolled back.”

“…he fell backwards.”

10

“…she’s not responding…”

11

“…he is not breathing well…”

“He’s not responding to me.”

12

“she’s having a hard time breathing.”

“…she’s not responding.”

“she just having a hard time breathing.”

the phone. Novel technologies in audio-video communication may sig- nificantly impact these limitations in future practices of EMD. Addition- ally, the EMDs only completed an in-depth breathing assessment during calls in which the patient’s respiratory activity was reported uncertain by the caller. Because the sample size of this study is not large enough to draw definitive conclusions, future studies should specifically con- sider how staffing, the experience and training level of EMDs, and fatigue may affect OHCA recognition.

  1. Conclusion

Lack of recognition of OHCA occurred in most calls due to difficulty communicating and establishing the subject’s respiratory status. A de- creased level of consciousness and abnormal respiratory status must heighten suspicion for OHCA. By providing EMD operators specific words and phrases callers commonly use in these scenarios as well as common auditory clues to listen for, improvements may be observed in the rapid identification of OHCA and subsequent administration of T-CPR. A multi-year review of a larger dataset from geographically and socioeconomically diverse regions in the United States could validate and expand significantly on these findings.

Funding

This research did not receive any specific grant from funding agen- cies in the public, commercial, or not-for-profit sectors.

Sources of funding

This research did not receive any specific grant from funding agen- cies in the public, commercial, or not-for-profit sectors.

Disclosures

David B. Crabb: None. Yasmeen O. Elmelige: None. Zoe C. Gibson: None.

Daniel C. Ralston: None. Caleb Harrell: None.

Scott A. Cohen: None. Desmond E. Fitzpatrick: None. Torben K. Becker: None.

Declaration of Competing Interest

None.

Acknowledgements

We thank the Alachua County Fire Rescue, Alachua County Sheriff’s Office, and the Alachua County Combined Communications Center Emergency medical dispatchers for their time and assistance with this study and their dedication to the health and safety of our community. A special thanks to James Clifford, Sadie Darnell, Jim Lanier, Jennifer Altenburger, and Danielle Brightmon for their support and invaluable contributions to this study.

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