Dispatch Center Research Articles

Impact of the first response unit on prehospital on-scene time among paramedic-suspected stroke patients: a retrospective before–after cohort study in Finland

BackgroundRevascularization of an occluded artery by either thrombolysis or mechanical thrombectomy is a time-critical intervention in ischaemic stroke. Each link in the stroke chain of survival should minimize the delay to definitive treatment in every possible way. In this study, we investigated the effect of routine dispatch of a first response unit (FRU) on prehospital on-scene time (OST) on stroke missions.MethodsMedical dispatch of FRU together with an emergency medical service (EMS) ambulance was a routine strategy in the Tampere University Hospital area before 3 October 2018, after which the FRU has only been dispatched to medical emergencies on the decision of an EMS field commander. This study presents a retrospective before–after analysis of 2,228 paramedic-suspected strokes transported by EMSs to Tampere University Hospital. We collected data from EMS medical records from April 2016 to March 2021, and used statistical tests and binary logistic regression to detect the associations between the variables and the shorter and longer half of OSTs.ResultsThe median OST of stroke missions was 19 min, IQR [14–25] min. The OST decreased when the routine use of the FRU was discontinued (19 [14–26] min vs. 18 [13–24] min, p < 0.001). The median OST with the FRU being the first at the scene (n = 256, 11%) was shorter than in cases where the FRU arrived after the ambulance (16 [12–22] min vs. 19 [15–25] min, p < 0.001). The OST with a stroke dispatch code was shorter than with non-stroke dispatches (18 [13–23] min vs. 22 [15–30] min, p < 0.001). The OST for thrombectomy candidates was shorter than that for thrombolysis candidates (18 [13–23] min vs. 19 [14–25], p = 0.01). The shorter half of OSTs were associated with the FRU arriving first at the scene, stroke dispatch code, thrombectomy transportation and urban location.ConclusionThe routine dispatch of the FRU to stroke missions did not decrease the OST unless the FRU was first to arrive at the scene. In addition, a correct stroke identification in the dispatch centre and thrombectomy candidate status decreased the OST.

Update tele-emergency medicine : Status quo and perspectives

Increasing numbers of rescue missions in recent years have led to agrowing staff shortage of paramedics as well as physicians in the emergency medical system (EMS) with an urgent need for optimized usage of resources. One option is the implementation of atele-EMS physician system, which has been established in the EMS of the City of Aachen since 2014. In addition to pilot projects, political decisions lead to the introduction of tele-emergency medicine. The expansion is currently progressing in various federal states, and acomprehensive introduction has been decided for North Rhine-Westphalia and Bavaria. The adaptation of the EMS physician catalog of indications is essential for the integration of atele-EMS physician. The tele-EMS physician offers the possibility of along-term and comprehensive EMS physician expertise in the EMS regardless of location and, therefore, to partially compensate for alack of EMS physicians. Tele-EMS physicians can also support the dispatch center in an advisory capacity and, for example, clarify secondary transport. Auniform qualification curriculum for tele-EMS physicians was introduced by the North Rhine and Westphalia-Lippe Medical Associations. In addition to consultations from emergency missions, tele-emergency medicine can also be used for innovative educational applications, for example, in the supervision of young physicians or recertification of EMS staff. Alack of ambulances could be compensated for by acommunity emergency paramedic, who could also be connected to the tele-EMS physician.

Attacking IEC 61850 Substations by Targeting the PTP Protocol

Digital substations, also referred to as modern power grid substations, utilize the IEC 61850 station and process bus in conjunction with IP-based communication. This includes communication with switch yard equipment within the substation as well as the dispatch center. IEC 61850 is a global standard developed to standardize power grid communications, covering multiple communication needs related to modern power grid substations or digital substations. Unlike the legacy communication standards, IEC 60870-5-104 and DNP3, IEC 61850 is specifically designed for IP-based communication. It comprises several communication models and supports real-time communication by introducing the process bus to replace traditional peer-to-peer communication with standard network communication between substation equipment and the switch yard. The process bus, especially Sampled Measured Values (SMV) communication, in modern power grid substations relies on extremely accurate and synchronized time to prevent equipment damage, maintain power grid system balance, and ensure safety. In IEC 61850, time synchronization is provided by the Precision Time Protocol (PTP). This paper discusses the significance and challenges of time synchronization in IEC 61850 substations, particularly those associated with PTP. It presents the results of a controlled experiment that subjects time synchronization and PTP to cyber-attacks and discusses the potential consequences of such attacks. The paper also provides recommendations for potential mitigation strategies. The contribution of this paper is to provide insights and recommendations for enhancing the security of IEC 61850-based substations against cyber-attacks targeting time synchronization. The paper also explores the potential consequences of cyber-attacks and provides recommendations for potential mitigation strategies.

Regression Model-Based Short-Term Load Forecasting for Load Despatch Centre

Forecasting load is an integral part of the planning, operation, and control of power systems. This paper is part of a research effort aimed at developing better energy demand forecasting models for load dispatch centers (LDCs) in Indian states as part of an ambitious project utilizing artificial intelligence-based load forecasting models. In this paper, we present a half hourly load forecasting method for the energy management system of the project that will be used at 33 /11 kV and 0.415 kV substations with good accuracy. The paper uses the half-hourly load consumption dataset collected from MSEDCL for Maharashtra from July 1, 2020 through August 31, 2022. This paper evaluates 24 regression model-based half hourly based load forecasting algorithms for ALE PHATA load based on the load consumption dataset and the collected meteorological dataset. The 24 models in MATLAB Regression belong to five types of regression models: Linear Regression, Regression Trees, Support Vector Machines (SVM), Gaussian Process Regression (GPR), Ensemble of Trees, and Neural Networks. As a consequence of their nonparametric kernel-based probabilistic nature, the GPR family of models demonstrates the best load forecasting performance. Least squares estimation was used to determine the regression coefficients. There is a direct correlation between load in an electrical power system and temperature, due point, and seasons, as well as a correlation between load and previous load consumption. Therefore, the input variables are Wet Bulb Temperature at 2 Meters (C), Dew/Frost Point at 2 Meters (C), Temperature at 2 Meters (C), Relative Humidity at 2 Meters (%), Specific Humidity at 2 Meters (g/kg) and Wind Speed at 10 Meters (m/s). The mean absolute percentage error and the R squared are used to validate or verify the accuracy of the model, which is shown in the results section. Based on this study, two GPR models are recommended for load forecasting, the Rational Quadratic GPR and the Exponential GPR and Exponential GPR as final model.

Strengthening Kampala's Urban Referral System for Maternal and Newborn Care Through Establishment of an Emergency Call and Dispatch Center.

Most pregnant women living in urban slum communities in Uganda deliver at public health centers that are not equipped to provide emergency obstetric and newborn care. When obstetric emergencies occur, pregnant women are referred to a higher-level facility and are responsible for arranging and paying for their own transport. The Kampala Slum Maternal Newborn (MaNe) project developed and tested an emergency call and ambulance dispatch center and a mobile application to request, deploy, and track ambulances. We describe the development of these 2 interventions and findings on the feasibility, acceptability, and sustainability of the interventions. MaNe conducted a mixed-method feasibility study that included an assessment of the acceptability and demand of the interventions. In-depth interviews (N=26) were conducted with facility proprietors, health providers, ambulance drivers, Kampala Capital City Authority officers, and community members to understand the successes and challenges of establishing the call center and developing the mobile application. Thematic content analysis was done. Quantitative data from the call center dispatch logs were analyzed descriptively to complement the qualitative findings. Between April 2020 and June 2021, 10,183 calls were made to the emergency call and dispatch center. Of these, 25% were related to maternal and newborn health emergencies and 14% were COVID-19 related. An ambulance was dispatched to transfer or evacuate a patient in 35% of the calls. Participants acknowledged that the call center and mobile application allowed for efficient communication, coordination, and information flow between health facilities. Supportive district leadership facilitated the establishment of the call center and has taken over the operating costs of the center. The call center and referral application improved the coordination of drivers and ambulances and allowed facilities to prepare for and treat cases more efficiently.

Incidence of alpine skiing and snowboarding injuries

BackgroundThe incidence of injuries on alpine ski slopes have been assessed using various methods. A decline in injury rate has been observed throughout the literature; however, the actual incidence remains unclear. The purpose of this study was therefore to evaluate the incidence of skiing and snowboarding injuries using large-sample data from an entire geographic state. MethodsData on alpine injuries over the course of five winter seasons between 2017 and 2022 were prospectively collected from the emergency service dispatch center of Tyrol (Austria). The incidence of injuries was assessed in relation to the number of skier days, which was obtained from the chamber of commerce. ResultsA total of 43,283 cases were identified, and a total of 98.1 Mio skier days were registered during the inclusion period of our study, resulting in an overall incidence of 0.44 injuries per 1,000 skier days. This is significantly less than reported from previous studies. From 2017/18 to 2021/22 there was a slight increase in injuries per 1000 skier days with an exception only for the COVID-19 related season 2020/21. ConclusionOur study showed a significant reduction in the incidence of alpine skiing and snowboarding injuries in comparison with previous studies and should be considered a benchmark for future studies. Long-term studies on the efficacy of safety gear, as well as the influence of ski patrol and air-borne rescues on patient outcome are warranted.

Prevalence and Risk Factors for Workplace Violence in the Ambulance Service

Introduction:Workplace violence within the ambulance services is a serious problem. A prevalence of up to 8.5% of all ambulance missions has previously been reported. Prior research used a retrospective design and the knowledge of risk factors for workplace violence is weak. Therefore, the aim of the current study was to measure the prevalence of workplace violence within the ambulance service in a Swedish region.Method:This was a prospective cohort study using data from all ambulance missions in a region in Sweden during one year. The data was analyzed with descriptive and analytic statistics using SPSS.Results:Data was collected from 28,648 ambulance missions. A total of 209 unique workplace violence incidents were reported, corresponding to a prevalence of 0.7%. Seventy-three of all incidents reported physical violence and 161 verbal threats, where some of the incidents included both physical and verbal violence. The most common risk factors for workplace violence were: the perpetrator was under the influence of alcohol or drugs (70.5%), mental illness (60.5%) and communication problems (15.3%). The perpetrator was most often a man (n=68%) between 18 and 29 years of age. Co-variation between the risk factors was high. No significant differences in the occurrence of workplace violence could be seen in relation to time of the year, weekday, or time of day.Conclusion:The prevalence of workplace violence was one of the lowest reported. An understanding of risk factors could be used within the ambulance service and dispatch centers to identify situations with an increased risk of workplace violence and mitigate the risk of such incidents.

If We Open the Door–An Analysis of Prehospital Emergency Cases with the Need to Force the Door Open from Dresden, Germany

Introduction:Germany is a highly developed country. Nevertheless, there are reports that people have supply problems or die lonely and alone in their homes. Despite a differentiated social system, there seem to be significant gaps for individuals or old people. The rescue service is often involved in situations with unclear emergency calls or calls from third parties regarding social and supply problems. In some emergency cases the rescue service is alerted to someone's home but there is no response. Depending on the available information, a timely decision must be made to have the opportunity for life-saving. The door opening procedure is executed by the fire department. Afterward, the medical emergency teams take over. The goal of the study is to analyze findings discovered after opening the door.Method:Data of all emergencies from the dispatch center of Dresden operated by the fire and rescue department between January 2021 and December 2021 were recorded and transferred to a central database. All cases with the need to force the door open were extracted and analyzed.Results:There was a total number of 157.522 cases of emergency. In 847 cases the door was opened by the fire department. After door opening there was no emergency reported in 265 cases. 100 patients were found dead, six patients had cardiac arrest and received cardiopulmonary resuscitation, and 310 patients were transported to a hospital. The causes for emergencies were social problems, downfall and injuries, hypoglycemia, convulsion, stroke, psychiatric emergencies, dementia and suicide attempt. The mean age was 71 [18-103], 54,15% of patients were female.Conclusion:There is a high number of emergencies with the need to open the door. The number of patients transported to a hospital is also high and justified the procedure. Since numerous patients were found dead, this underlines a gap in the German social system.

Allergic emergencies in the prehospital setting: a 5 year retrospective study.

Background. Patients with severe allergic conditions often request support from the prehospital emergency services given the rapid, unexpected and potentially life-threatening nature of the reactions, such as anaphylaxis. Studies regarding prehospital incidents for allergic conditions are scarce. This study aimed to characterize prehospitalar medical requesting assistance due to suspected hypersensitivity reactions (HSR). Methods. Retrospective study of allergic-related requesting assistances between 2017-2022 of a Portuguese emergency dispatch centre - Emergency and Resuscitation Medical Vehicle (VMER), in Coimbra University Hospital. Demographic and clinical variables were analysed, including clinical manifestations, anaphylaxis severity grading, therapeutic interventions, and post-incident allergic work-up. Regarding anaphylactic events, three diagnosis timings were compared: on-site, hospital emergency department and Investigator-diagnosis based on data reviewed. Results. Out of 12689 VMER requesting assistances, 210 (1.7%) were classified as suspected HSR reactions. After on-site medical evaluation, 127 (60.5%) cases maintained the HSR classification (median age 53 years; 56% males) and the main diagnoses included HSR to Hymenoptera venom (29.9%), food allergy (29.1%), and pharmaceutical drugs (25.5%). Anaphylaxis was assumed on-site in 44 (34.7%) cases, in the hospital emergency department in 53 cases (41.7%) and by investigators in 76 (59.8%) cases. Regarding management, epinephrine was administered on-site in 50 cases (39.4%). Conclusions. The main reason for prehospital requesting assistance was HSR to Hymenoptera venom. A high proportion of incidents met the criteria for anaphylaxis and despite the inherent difficulties of the prehospital setting, many of the on-site diagnoses agreed with the criteria. Regarding management, epinephrine was underused in this setting. Referral to specialized consultation is crucial for the management of prehospital incidents.

Voice Based App for Police PCR Van

Abstract: The police Public Call Response (PCR) van is a crucial component of law enforcement agencies, providing rapid response and assistance to emergency situations. However, traditional communication methods between PCR vans and dispatch centres, such as radio or phone calls, can be inefficient and prone to miscommunication. In recent years, voice-based applications have gained popularity due to their ease of use and accessibility. Therefore, this abstract proposes the development of a voice-based app for police PCR vans to enhance communication, coordination, and efficiency in emergency response situations. The voice-based app will be designed as a mobile application that can be installed on smartphones or tablets used by police officers in PCR vans. The app will leverage voice recognition technology to enable officers to communicate with the dispatch centre using voice commands, eliminating the need for typing or manual input. The app will also have a text-to-speech feature that can convert dispatch centre responses into audible messages for the officers to hear. The app will include features such as real-time location tracking of PCR vans, allowing dispatch centres to accurately locate and assign tasks to the nearest available van. It will also support voice-based status updates from officers, allowing them to quickly report their current situation or request backup. To ensure secure communication, the app will have robust authentication and encryption measures to protect sensitive information. Additionally, the app will be designed to work offline in areas with poor network connectivity, with data synchronisation capabilities once network connection is restored. The proposed voice-based app for police PCR vans has the potential to significantly improve communication and coordination in emergency response situations. By leveraging voice recognition technology, officers can communicate quickly and efficiently, allowing them to focus on their primary responsibilities of ensuring public safety

Estimation and Analysis of CO2 emission in Thermal power plants

Abstract: Global warming can be reduced and sustainability can be achieved by reducing greenhouse gases emission. Therefore, it is helpful to know the forecast of CO2 emission in the southern region states. Knowing the comparative analysis might help to change the source of power generation to renewable. The data source is taken from the southern region load dispatch center (SRLDC). Carbon dioxide emission values were estimated using the method proposed by Central Electricity Authority. The random forest regression method has been used to forecast the emission values. The data were divided into training and testing sets for better results. The results showed the increasing nature of CO2 emission from power stations. The model could be used to forecast the emission values either for next month or next week. The accuracy for the model was favorable in the range from 0.80 to 0.92. From comparing the results of the states, it could be noticed which state has used its renewable power stations wisely to reduce greenhouse gases emission.

Burden of suspected epileptic seizures on emergency services: A population-based study.

Patients with acute epileptic seizures form a large patient group in emergency neurology. This study aims to determine the burden caused by suspected epileptic seizures at different steps in emergency care. A retrospective, cross-sectional, population-based (>1,000,000 inhabitants), 4-year (2015-2018) study was conducted in an urban setting with a single dispatch centre, a university hospital-affiliated emergency medical service (EMS), and five emergency departments (EDs). The study covered all adult (≥16 years old) emergency neurology patients receiving medical attention due to suspected epileptic seizures from the EMS and EDs and during hospital admissions in the Helsinki metropolitan area. Epileptic seizures were suspected in 14,364 EMS calls, corresponding to 3.3% of all EMS calls during the study period. 9,112 (63.4%) cases were transported to hospital due to suspected epileptic seizures, and 3368 (23.4%) were discharged on the scene. 6969 individual patients had 11,493 seizure-related ED visits, accounting for 3.1% of neurology- and internal medicine-related ED visits and 4607 hospital admissions were needed with 3 days' median length of stay (IQR=4, Range 1-138). Male predominance was noticeable at all stages (EMS 64.7%, EDs 60.1%, hospital admissions 56.2%). The overall incidence was 333/100,000 inhabitants/year for seizure-related EMS calls, 266/100,000 inhabitants/year for ED visits and 107/100,000 inhabitants/year for hospital admissions. Total estimated costs were 6.8 million €/year, corresponding to 0.5% of all specialized healthcare costs in the study area. Patients with suspected epileptic seizures cause a significant burden on the health care system. Present-day epidemiological data are paramount when planning resource allocation in emergency services.

Potential to enhance telephone cardiopulmonary resuscitation with improved instructions - findings from a simulation-based manikin study with lay rescuers

BackgroundTelephone-Cardiopulmonary Resuscitation (T-CPR) significantly increases rate of bystander resuscitation and improves patient outcomes after out-of-hospital cardiac arrest (OHCA). Nevertheless, securing correct execution of instructions remains a difficulty. ERC Guidelines 2021 recommend standardised instructions with continuous evaluation. Yet, there are no explicit recommendations on a standardised wording of T-CPR in the German language. We investigated, whether a modified wording regarding check for breathing in a German T-CPR protocol improved performance of T-CPR. MethodsA simulation study with 48 OHCA scenarios was conducted. In a non-randomised trial study lay rescuers were instructed using the real-life-CPR protocol of the regional dispatch centre and as the intervention a modified T-CPR protocol, including specific check for breathing (head tilt-chin lift instructions). Resuscitation parameters were assessed with a manikin and video recordings.ResultsCheck for breathing was performed by 64.3% (n = 14) of the lay rescuers with original wording and by 92.6% (n = 27) in the group with modified wording (p = 0.035). In the original wording group the head tilt-chin manoeuvre was executed by 0.0% of the lay rescuers compared to 70.3% in the group with modified wording (p < 0.001). The average duration of check for breathing was 1 ± 1 s in the original wording group and 4 ± 2 s in the group with modified wording (p < 0.001). Other instructions (e.g. check for consciousness and removal of clothing) were well performed and did not differ significantly between groups. Quality of chest compression did not differ significantly between groups, with the exception of mean chest compression depth, which was slightly deeper in the modified wording group.ConclusionCorrect check for breathing seems to be a problem for lay rescuers, which can be decreased by describing the assessment in more detail. Hence, T-CPR protocols should provide standardised explicit instructions on how to perform airway assessment. Each protocol should be evaluated for practicability.

An indoor location-based hospital Porter management system and trace analysis.

Porters play an important role in supporting hospital operations. Their responsibilities include transporting patients and medical equipment between wards and departments. They also need to deliver specimens, drugs, and patients' notes to the correct place at the right time. Therefore, maintaining a trustworthy and reliable porter team is crucial for hospitals to ensure the quality of patient care and smooth the flow of daily operations. However, most existing porter systems lack detailed information about the porter movement process. For example, the location of porters is not transparent to the dispatch center. Thus, the dispatcher does not know if porters are spending all their time providing services. The invisibility makes it difficult for hospitals to assess and improve the efficiency of porter operations. In this work, we first developed an indoor location-based porter management system (LOPS) on top of the infrastructure of indoor positioning services in the hospital National Taiwan University Hospital YunLin Branch. The LOPS provides real-time location information of porters for the dispatcher to prioritize tasks and manage assignments. We then conducted a 5-month field trial to collect porters' traces. Finally, a series of quantitative analyses were performed to assess the efficiency of porter operations, such as the movement distribution of porters in different time periods and areas, workload distribution among porters, and possible bottlenecks of delivering services. Based on the analysis results, recommendations were given to improve the efficiency of the porter team.

An Improved Master-Slave Control Strategy for Automatic DC Voltage Control Under the Master Station Failure in MTDC System

The master-slave (MS) control is often used in multi-terminal direct current (MTDC) system due to its stable dc voltage control and precise power regulation. However, the MS switching, which aims to maintain dc voltage control under the master station failure, relies heavily on the high-speed communication between the power dispatch center and each station. Some methods in existing works are proposed to address the high communication dependence, at the cost of steady-state control performance. In this article, an improved MS control including five-state control process is proposed to realize the automatic MS switching without communication participation. Based on logic judgment, the multilayer dc voltage clamping mechanism is created to enhance the redundancy of the dc voltage control, and a reasonable dc voltage recovery process is included to eliminate the dc voltage deviation caused by the master station failure. Furthermore, the power and dc voltage hybrid controller are developed to improve the dynamic performance of each station during the MS switching. Simulation and experimental results demonstrate the effectiveness and advantages of proposed method.

DEVELOPMENT OF A MATHEMATICAL MODEL AND AN AUTOMATED ALGORITHM FOR CALCULATING THROUGHPUT

Background. The problem of this work is to develop a methodology for calculating cash throughput, which is based on the well-known formulas for calculating cash throughput, the main innovation of which is to take into account the time spent by trains on acceleration and deceleration en route. Currently, in the process of calculating the available capacity, a formal approach is used to determine the removal coefficients, and the site speed is also taken into account, calculated taking into account acceleration and deceleration, but representing only the ratio of the length of a certain section of the railway polygon to the time of the train following it.&#x0D; Materials and/or methods: simulation modeling, economic and mathematical modeling, AnyLogic software package, methods of general systems theory, logistics.&#x0D; Results. An analytical formula is proposed that allows calculating the available throughput with higher accuracy. The results of the study can be used in the dispatch centers of transportation management of JSC “Russian Railways” in order to more fully analyze the operation of the landfill of the road, railway lines or individual sections in order to more fully analyze the work performed on transportation.&#x0D; Conclusion. The article develops a methodology for calculating the available capacity on a railway line with full consideration of the effect of acceleration and braking of trains on their way to the resulting available capacity.

Exploring the Development Trend of Ports in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) Based on the Intermodal Transport Development of Guangzhou Port

Nowadays, multimodal transport is developing rapidly, but the individual ports in the Greater Bay Area (GBA) have been operating separately. In this paper, the development status of multimodal transport in Guangzhou port will be used as an example to discuss the development trend of GBA ports. The study found that the multimodal transport model of the Port of Guangzhou has taken shape. However, there are still many shortcomings with old facilities, difficulties in sharing data, and a lack of unified management, which are common to all ports in the GBA. This paper aims to provide ideas for the direction of port development in GBA, hoping to enhance intermodal transport to connect the ports, improve the efficiency of freight transport and promote the formation of a unified dispatch centre for GBA ports. As a result, it is hoped that the GBA Port Management Committee will be built to achieve more efficient management.

Совершенствование аналитического метода расчета наличной пропускной способности с применением имитационного моделирования

Purpose: To develop method for calculating actual capacity on railway line on the basis of the improvement of analytical formulas and the use of simulation tools. Correction of mathematical apparatus and calculation of simulation modeling coefficient. Methods: Analytical method, simulation and dynamic modeling, mathematical modeling, AnyLogic Software Package tools were applied. Research results: New calculation approach that allows to raise railway line throughput precision. In its turn, the new approach will allow to optimize operating costs for the maintenance and current repair of railway infrastructure and rolling stock. Practical significance: The results obtained can be used in the analytics, prediction and modeling of transportation processes in the dispatch centers of JSC "Russian Railways" transportation management.

Математическая модель и способ расчета пропускной способности

Purpose: To propose methodology for calculating actual throughput on railway line with full consideration of racing and drag effect of trains along their way on resulting actual throughput. Methods: Methods of analytical review, simulation and dynamic modeling, mathematical modeling were applied. Results: Analytical transformations of well-known formula for calculating throughput were performed. Analytical formula has been obtained that allows calculating actual throughput with higher accuracy. Practical significance: The results of the study can be used in the dispatch centers of JSC "Russian Railways" transportation management for more complete analysis of the operation of the polygon of a road, railway lines or individual sections in order of more detailed analysis of work, performed on transportation.

Barriers to the Initiation of Telecommunicator-CPR during 9-1-1 Out-of-Hospital Cardiac Arrest Calls: A Qualitative Study

Introduction Fewer than 10% of individuals who suffer out-of-hospital cardiac arrest (OHCA) survive with good neurologic function. Bystander CPR more than doubles the chance of survival, and telecommunicator-CPR (T-CPR) during a 9-1-1 call substantially improves the frequency of bystander CPR. Objective We examined the barriers to initiation of T-CPR. Methods We analyzed the 9-1-1 call audio from 65 EMS-treated OHCAs from a single US 9-1-1 dispatch center. We initially conducted a thematic analysis aimed at identifying barriers to the initiation of T-CPR. We then conducted a conversation analysis that examined the interactions between telecommunicators and bystanders during the recognition phase (i.e., consciousness and normal breathing). Results We identified six process themes related to barriers, including incomplete or delayed recognition assessment, delayed repositioning, communication gaps, caller emotional distress, nonessential questions and assessments, and caller refusal, hesitation, or inability to act. We identified three suboptimal outcomes related to arrest recognition and delivery of chest compressions, which are missed OHCA identification, delayed OHCA identification and treatment, and compression instructions not provided following OHCA identification. A primary theme observed during missed OHCA calls was incomplete or delayed recognition assessment and included failure to recognize descriptors indicative of agonal breathing (e.g., “snoring”, “slow”) or to confirm that breathing was effective in an unconscious victim. Conclusions We observed that modifiable barriers identified during 9-1-1 calls where OHCA was missed, or treatment was delayed, were often related to incomplete or delayed recognition assessment. Repositioning delays were a common barrier to the initiation of chest compressions.