Review articleIn out-of-hospital cardiac arrest patients, does the description of any specific symptoms to the emergency medical dispatcher improve the accuracy of the diagnosis of cardiac arrest: A systematic review of the literature☆
Introduction
Bystander cardiopulmonary resuscitation (CPR) can significantly improve the likelihood of survival for out-of-hospital cardiac arrest victims (OHCA).1 Unfortunately, bystander CPR rates remain low and vary significantly from one region to another.2,3 Sixty-five percent of all cardiac arrests occur outside the hospital setting,4 where the overall rate of survival to hospital discharge rarely exceeds 8%.2,5 Various attempts have been made to improve bystander CPR rates on a large scale, including the organization of large group CPR training events, promotional CPR videos, and CPR training of high school students.5 Unfortunately, none of these initiatives have succeeded in significantly improving bystander CPR or survival rates for cardiac arrest thus far. Other experts have proposed targeting CPR training for family members of patients suffering from heart disease, but more than 40% of all deaths from heart disease occur suddenly and often constitute the victim's first manifestation of heart disease.6
Emergency medical dispatcher-assisted CPR instructions have been shown to significantly improve community bystander CPR rates.7, 8, 9, 10, 11 This intervention combines the benefits of training a large number of citizens with the highly targeted approach of providing CPR teaching or reminders to callers reporting a victim in cardiac arrest. In order to recognize cardiac arrest over the phone, most emergency medical dispatchers (EMDs) ask a number of standardized questions including information on the victims’ consciousness, absence of breathing, or presence of abnormal breathing. Using this strategy, their ability to recognize cardiac arrest over the telephone ranges from 70% to 90%.12,13 Agonal or abnormal breathing is often seen in the initial minutes of cardiac arrest, and may be misinterpreted as a sign of life.7 In addition to abnormal breathing, other factors may be involved and limit the ability of EMDs to make a diagnosis of cardiac arrest.14, 15, 16, 17, 18, 19 The correct identification of cardiac arrest has been associated with increased survival.19,20
For adult and pediatric patients with OHCA, we sought to determine if the description of any specific symptoms to the EMD by the caller (compared with the absence of any specific description) improves the accuracy of the diagnosis of cardiac arrest.
Section snippets
Methods
This systematic review was completed as part of the C2010 Consensus on Science and Treatment Recommendations process, managed by the International Liaison Committee on Resuscitation (ILCOR).21
Literature search results
Our systematic review of the literature identified 714 potentially relevant citations. After manually removing duplicates, there remained 494 unique citations to review. Using standardized pre-determined selection criteria, we excluded 420 citations based on manuscript title and abstract (kappa = 0.70; 95% confidence interval 0.59–0.80). We used the same criteria to review full-text copies of the remaining 74 manuscripts. Characteristics of the 51 papers rejected at this stage are presented in
Discussion
Findings from this systematic review of the literature can be summarized in the following manner: (1) dispatchers should assume that cardiac arrest is present when a caller describes the victim as unconscious, not breathing, or not breathing normally; (2) additional instructions on the significance of abnormal breathing should be provided to EMDs in order to improve their ability to recognize cardiac arrest over the phone; (3) in addition, dispatch protocols could be modified to include tools
Conclusions
Emergency medical dispatchers should assume that cardiac arrest is present when a caller describes the victim as unconscious, not breathing, or not breathing normally. They should be educated about the significance of abnormal breathing in the context of cardiac arrest, and they should consider the introduction of focused questions when victims present with seizure activity. The quality of most studies included in this systematic review was classified as “Fair”.
Conflicts of interest
Dr. Christian Vaillancourt received funding from the Canadian Institutes of Health Research (CIHR) and the Heart and Stroke Foundation of Ontario (HSFO) to study dispatch-assisted CPR instructions.
Manya Charette has no conflicts of interest to declare.
Katarina Bohm has no conflicts of interest to declare.
Dr. James Dunford has no conflicts of interest to declare.
Dr. Maaret Castrén received funding from the Laerdal Foundation to study dispatch-assisted CPR instructions.
Funding sources
Academic practice plan of the Department of Emergency Medicine, University of Ottawa.
Acknowledgements
Disclaimer: This review includes information on resuscitation questions developed through the C2010 Consensus on Science and Treatment Recommendations process, managed by the International Liaison Committee on Resuscitation (http://www.americanheart.org/ILCOR). The questions were developed by ILCOR Task Forces, using strict conflict of interest guidelines. In general, each question was assigned to two experts to complete a detailed structured review of the literature, and complete a detailed
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Cited by (49)
A mixed methods analysis of caller-emergency medical dispatcher communication during 9–1–1 calls for out-of-hospital cardiac arrest
2022, Patient Education and CounselingCitation Excerpt :Although the EMD’s role in OHCA survival is important, little research has focused on the characteristics of communication between callers and EMDs during 9–1–1 calls. Prior studies indicate that only 11.3% of OHCA victims receive dispatcher-assisted CPR, and one study has previously assessed terms used by 9–1–1 callers to describe the characteristics of OHCA victims [11,12]. However, it is unknown if other communication elements during 9–1–1 calls are associated with OHCA or how a caller’s or EMD’s communication may relate to successful CPR initiation.
Responding to Cardiac Arrest in the Community in the Digital Age
2022, Canadian Journal of CardiologyCitation Excerpt :and “Is the patient breathing normally or abnormally?”24 This evidence stems from 23 observational studies in > 17,000 patients and has been reported to have a sensitivity ranging from 38% to 97% and a specificity exceeding 97%.25 Recent efforts to improve EMS dispatcher recognition of SCA over the phone have involved the use of ML.
Unrecognized cardiac arrests: A one-year review of audio from emergency medical dispatch calls
2022, American Journal of Emergency MedicineCitation Excerpt :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 unrecognized 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.
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A Spanish translated version of the abstract of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2011.05.020.