Cardiac arrest predictability in seizure patients based on emergency medical dispatcher identification of previous seizure or epilepsy history

A mixed methods analysis of caller-emergency medical dispatcher communication during 9-1-1 calls for out-of-hospital cardiac arrest

OBJECTIVE

Recognition of out-of-hospital cardiac arrest (OHCA) during 9-1-1 calls is critically important, but little is known about how laypersons and emergency medical dispatchers (EMDs) communicate. We sought to describe 9-1-1 calls for OHCA.

METHODS

We performed a mixed-methods, retrospective analysis of 9-1-1 calls for OHCA victims in a large urban emergency medical services (EMS) system using a random sampling of cases containing the term "cardiopulmonary resuscitation" (CPR) in the EMS electronic report. A constant comparison qualitative approach with four independent reviewers continued until thematic saturation was achieved. Quantitative analysis employed computational linguistics. Callers' emotional states were rated using the emotional content and cooperation score (ECCS).

RESULTS

Thematic saturation was achieved after 46 calls. Three "OHCA recognition" themes emerged [ 1) disparate OHCA terms used, 2) OHCA mimics create challenges, 3) EMD questions influence recognition]. Three "CPR facilitation" themes emerged [ 1) directive language may facilitate CPR, 2) specific instructions assist CPR, 3) caller's emotions affect CPR initiation]. Callers were generally "anxious but cooperative." Callers saying "pulse" was associated with OHCA recognition.

CONCLUSION

Communication characteristics appear to influence OHCA recognition and CPR facilitation.

PRACTICE IMPLICATIONS

Dispatch protocols that acknowledge characteristics of callers' communication may improve OHCA recognition and CPR facilitation.

Seizure-like activity at the onset of emergency medical service-witnessed out-of-hospital cardiac arrest: An observational study

Aims

Emergency medical service (EMS) may detect seizure-like activity in addition to agonal breathing in out-of-hospital cardiac arrest (OHCA). This study investigates the incidence and predictors of seizure-like activity in nontraumatic, EMS-witnessed OHCA and their association with clinical outcomes.

Methods

This prospective study explored EMS-recorded concomitant signs/symptoms that lead to the requirement of advanced life support in patients with nontraumatic, EMS-witnessed OHCA. Seizure-like activity includes abnormal/tonic movements and eyeball deviation. Sudden OHCA was defined by the absence of signs/symptoms of impending cardiac arrest at EMS contact or progressive circulatory/respiratory depressions after the EMS contact. Neurologically favorable outcomes were defined as the cerebral performance category score of 1 or 2 at discharge.

Results

From April 2012 to March 2020, 465 patients were studied. The incidence of seizure-like activity at cardiac arrest onset was 12.7% (59/465) in all patients with nontraumatic, EMS-witnessed OHCA. Seizure-like activity was common during shockable initial rhythm; in patients with “sudden” OHCA; and in patients who were younger, male, or had a presumed cardiac etiology. In a boosting tree, shockable initial rhythm, “sudden” OHCA, and presumed cardiac etiology were major factors that predicted the incidence of seizure-like activity. Multivariate logistic regression models including and excluding OHCA characteristics revealed that both seizure-like activity and agonal breathing recorded during EMS-witnessed OHCA were associated with favorable outcomes.

Conclusions

Seizure-like activity is a major sign/symptom of the onset of “sudden” cardiac arrest of presumed cardiac etiology, particularly in patients with shockable initial rhythms. Such activity were significantly associated with neurologically favorable outcomes.

A data linkage study of suspected seizures in the urgent and emergency care system in the UK

INTRODUCTION

The urgent and emergency care (UEC) system is struggling with increased demand, some of which is clinically unnecessary. Patients suffering suspected seizures commonly present to EDs, but most seizures are self-limiting and have low risk of short-term adverse outcomes. We aimed to investigate the flow of suspected seizure patients through the UEC system using data linkage to facilitate the development of new models of care.

METHODS

We used a two-stage process of deterministic linking to perform a cross-sectional analysis of data from adults in a large region in England (population 5.4 million) during 2014. The core dataset comprised a total of 739 436 ambulance emergency incidents, 1 033 778 ED attendances and 362 358 admissions.

RESULTS

A high proportion of cases were successfully linked (86.9% ED-inpatient, 77.7% ED-ambulance). Suspected seizures represented 2.8% of all ambulance service incidents. 61.7% of these incidents led to dispatch of a rapid-response ambulance (8 min) and 72.1% were conveyed to hospital. 37 patients died before being conveyed to hospital and 24 died in the ED (total 61; 0.3%). The inpatient death rate was 0.4%. Suspected seizures represented 0.71% of ED attendances, 89.8% of these arrived by emergency ambulance, 45.4% were admitted and 44.5% of these admissions lasted under 48 hours.

CONCLUSIONS

This study confirms previously published data from smaller unlinked datasets, validating the linkage method, and provides new data for suspected seizures. There are significant barriers to realising the full potential of data linkage. Collaborative action is needed to create facilitative governance frameworks and improve data quality and analytical capacity.

Patient views on use of emergency and alternative care services for adult epilepsy: A qualitative study

PURPOSE

Emergency Department (ED) visits are costly to the health service and alternative care pathways may address this whilst improving outcomes. We aimed to describe decision-making and preferences of people with epilepsy (PWE) during emergency service use, and views of ED alternatives, including use of an Urgent Treatment Centre and telephone-based support from an epilepsy nurse specialist.

METHODS

We conducted a community-based interview study in South East England, informed by a qualitative framework approach. 25 adults with epilepsy and 5 of their carers took part.

RESULTS

Participants' choice to attend ED generally corresponded with guidelines, including continuing seizures and injury. Nevertheless, over half reported unwanted or unnecessary ED attendance, mainly due to lack of access to individual patient history, a carer, or seizures occurring in a public place. Participants used proactive strategies to communicate their care needs to others, including 24 -h alarm devices and care plans. Some suggested preventative strategies including referral after ED. Participants highlighted the importance of ambulance staff in providing fast and efficient care that gives reassurance.

CONCLUSION

Improving communication and access to preventative, proactive services may facilitate better outcomes within existing care pathways. PWE felt ED alternatives were helpful in some circumstances, but Urgent Treatment Centres or epilepsy nurse specialists were not viewed as an ED replacement.

How to Perform Prehospital Emergency Telephone Triage: A Systematic Review

Prehospital emergency telephone triages are mechanisms to verify the appropriate need for care in an emergency call by telephone. Considering the high rates of trauma and clinical cases that need prehospital care, the importance of knowing how the services that send rescue teams can guarantee improved care is highlighted. The objective of this study was to characterize the services that support effective telephone triage. Literature review was conducted in 6 phases to answer the following question: How can prehospital emergency telephone triage be performed? To search for primary studies, we used specific search strategies in the databases: LILaCs, PubMed, CINAHL, LISA, ISTA, and SCOPUS. The sample consisted of 23 studies whose information was extracted using a validated tool. Among the selected studies, 2 come from CINAHL, 2 from LISA, 4 from PubMed, 1 from ISTA, and 14 from SCOPUS, which were published between 2006 and 2016 in 17 different journals with varying types of scopes and originated from 13 countries on 3 distinct continents. The articles were nonexperimental and indicated the broad use of software constructed to support the telephone triage. The prehospital emergency telephone triages are frequently performed to identify the event, deduct the need for support, and prioritize those calls that require a rescue team. They should take place with the support of institutional protocols and technological support to guarantee dynamic data and constant training of the ambulance dispatchers.

Effectiveness of dispatcher training in increasing bystander chest compression for out-of-hospital cardiac arrest patients in Japan

Aim

The Japanese government has developed a standardized training program for emergency call dispatchers to improve their skills in providing oral guidance on chest compression to bystanders who have witnessed out‐of‐hospital cardiac arrests (OHCAs). This study evaluated the effects of such a training program for emergency call dispatchers in Japan.

Methods

The analysis included all consecutive non‐traumatic OHCA patients transported to hospital by eight emergency medical services, where the program was implemented as a pilot project. We compared the provision of oral guidance and the incidence of chest compression applications by bystanders in the 1‐month period before and after the program. Data collection was undertaken from October 2014 to March 2015.

Results

The 532 non‐traumatic OHCA cases were used for analysis: these included 249 cases before and 283 after the guidance intervention. Most patients were over 75 years old and were men. After the program, provision of oral guidance to callers slightly increased from 63% of cases to 69% (P = 0.13) and implementation of chest compression on patients by bystanders significantly increased from 40% to 52% (P = 0.01). Appropriate chest compression also increased from 34% to 47% (P = 0.01). In analysis stratified by the provision of oral guidance, increased chest compressions were observed only under oral guidance.

Conclusions

We found increased provision of oral guidance by dispatchers and increased appropriate chest compressions by bystanders after the training program for dispatchers had been rolled out. Long‐term observation and further data analysis, including patient outcomes, are needed.

Paramedics' views on their seizure management learning needs: a qualitative study in England

INTRODUCTION

The UK ambulance service often attends to suspected seizures. Most persons attended to will not require the facilities of a hospital emergency department (ED) and so should be managed at scene or by using alternative care pathways. Most though are transported to ED. One factor that helps explain this is paramedics can have low confidence in managing seizures.

OBJECTIVES

With a view to ultimately developing additional seizure management training for practicing paramedics, we explored their learning needs, delivery preferences and potential drivers and barriers to uptake and effectiveness.

DESIGN AND SETTING

Semistructured interviews were conducted with a purposive sample of paramedics from the English ambulance service. Interviews were transcribed and thematically analysed.

PARTICIPANTS

A diverse sample of 19 professionals was recruited from 5 different ambulance NHS trusts and the College of Paramedics.

RESULTS

Participants said seizure management was neglected within basic and postregistration paramedic training. Most welcomed additional learning opportunities and identified gaps in knowledge. This included how to differentiate between seizure types and patients that do and do not need ED. Practical, interactive e-learning was deemed the most preferable delivery format. To allow paramedics to fully implement any increase in skill resulting from training, organisational and structural changes were said to be needed. This includes not penalising paramedics for likely spending longer on scene.

CONCLUSIONS

This study provides the first evidence on the learning needs and preferences of paramedics regarding seizures. It can be used to inform the development of a bespoke training programme for paramedics. Future research should develop and then assess the benefit such training has on paramedic confidence and on the quality of care they offer to seizure patients.

Association between ambulance dispatch priority and patient condition

OBJECTIVE

To compare chief complaints of the Medical Priority Dispatch System in terms of the match between dispatch priority and patient condition.

METHODS

This was a retrospective whole-of-population study of emergency ambulance dispatch in Perth, Western Australia, 1 January 2014 to 30 June 2015. Dispatch priority was categorised as either Priority 1 (high priority), or Priority 2 or 3. Patient condition was categorised as time-critical for patient(s) transported as Priority 1 to hospital or who died (and resuscitation was attempted by paramedics); else, patient condition was categorised as less time-critical. The χ² statistic was used to compare chief complaints by false omission rate (percentage of Priority 2 or 3 dispatches that were time-critical) and positive predictive value (percentage of Priority 1 dispatches that were time-critical). We also reported sensitivity and specificity.

RESULTS

There were 211 473 cases of dispatch. Of 99 988 cases with Priority 2 or 3 dispatch, 467 (0.5%) were time-critical. Convulsions/seizures and breathing problems were highlighted as having more false negatives (time-critical despite Priority 2 or 3 dispatch) than expected from the overall false omission rate. Of 111 485 cases with Priority 1 dispatch, 6520 (5.8%) were time-critical. Our analysis highlighted chest pain, heart problems/automatic implanted cardiac defibrillator, unknown problem/collapse, and headache as having fewer true positives (time-critical and Priority 1 dispatch) than expected from the overall positive predictive value.

CONCLUSION

Scope for reducing under-triage and over-triage of ambulance dispatch varies between chief complaints of the Medical Priority Dispatch System. The highlighted chief complaints should be considered for future research into improving ambulance dispatch system performance.

Cross-sectional study of the prehospital management of adult patients with a suspected seizure (EPIC1)

OBJECTIVES

Suspected seizures are a common reason for emergency calls to ambulance services. Prehospital management of these patients is an important element of good quality care. The aim of this study, conducted in a regional ambulance service in the UK, was to quantify the number of emergency telephone calls for suspected seizures in adults, the associated costs, and to describe the patients' characteristics, their prehospital management and their immediate outcomes.

DESIGN

Quantitative cross-sectional study using routinely collected data and a detailed review of the clinical records of a consecutive series of adult patients (≥ 16 years).

SETTING

A regional ambulance service within the National Health Service in England.

PARTICIPANTS

Cross-sectional data from all 605,481 adult emergency incidents managed by the ambulance service from 1 April 2012 to 31 March 2013. We selected a consecutive series of 178 individual incidents from May 2012 for more detailed analysis (132 after exclusions and removal of non-seizure cases).

RESULTS

Suspected seizures made up 3.3% of all emergency incidents. True medical emergencies were uncommon but 3.3% had partially occluded airways, 6.8% had ongoing seizure activity and 59.1% had clinical problems in addition to the seizure (29.1% involving injury). Emergency vehicles were dispatched for 97.2% of suspected seizures, the seizure had terminated on arrival in 93.2% of incidents, 75% of these patients were transported to hospital. The estimated emergency management cost per annum of suspected seizures in the English ambulance services is £45.2 million (€64.0 million, $68.6 million).

CONCLUSIONS

Many patients with suspected seizures could potentially be treated more effectively and at lower cost by modifying ambulance call handling protocols. The development of innovative care pathways could give call handlers and paramedics alternatives to hospital transportation. Increased adoption of care plans could reduce 999 calls and could increase the rates of successful home or community treatment.

A 1.83 μJ/Classification, 8-Channel, Patient-Specific Epileptic Seizure Classification SoC Using a Non-Linear Support Vector Machine

A non-linear support vector machine (NLSVM) seizure classification SoC with 8-channel EEG data acquisition and storage for epileptic patients is presented. The proposed SoC is the first work in literature that integrates a feature extraction (FE) engine, patient specific hardware-efficient NLSVM classification engine, 96 KB SRAM for EEG data storage and low-noise, high dynamic range readout circuits. To achieve on-chip integration of the NLSVM classification engine with minimum area and energy consumption, the FE engine utilizes time division multiplexing (TDM)-BPF architecture. The implemented log-linear Gaussian basis function (LL-GBF) NLSVM classifier exploits the linearization to achieve energy consumption of 0.39 μ J/operation and reduces the area by 28.2% compared to conventional GBF implementation. The readout circuits incorporate a chopper-stabilized DC servo loop to minimize the noise level elevation and achieve noise RTI of 0.81 μ Vrms for 0.5-100 Hz bandwidth with an NEF of 4.0. The 5 × 5 mm (2) SoC is implemented in a 0.18 μm 1P6M CMOS process consuming 1.83 μ J/classification for 8-channel operation. SoC verification has been done with the Children's Hospital Boston-MIT EEG database, as well as with a specific rapid eye-blink pattern detection test, which results in an average detection rate, average false alarm rate and latency of 95.1%, 0.94% (0.27 false alarms/hour) and 2 s, respectively.

Dispatch-assisted cardiopulmonary resuscitation: the anchor link in the chain of survival

PURPOSE OF REVIEW

Early bystander cardiopulmonary resuscitation (CPR) provides a vital bridge after collapse from cardiac arrest until defibrillation can be performed. However, due to multiple barriers and despite large-scale public CPR training, this life-saving therapy is still not rendered in a majority of cardiac arrest events. As a result, cardiac arrest survival remains very low in most communities.

RECENT FINDINGS

Several large-scale studies have shown the benefits of dispatch-assisted CPR. These studies have confirmed that on-going dispatch-assisted CPR programs that use a simplified and abbreviated set of standardized questions can hasten the recognition of cardiac arrest. Dispatchers can also utilize strategies to help bystanders overcome the obstacles to beginning CPR. In some communities, dispatch-assisted CPR accounts for up to half of all bystander CPR. Dispatch-assisted CPR programs combined with large-scale public CPR training may be what is needed to elevate CPR rates and survival from out-of-hospital cardiac arrest nationally.

SUMMARY

This review focuses on the rationale and evolving science behind dispatch CPR instructions, as well as some best practices for implementing and measuring dispatch-assisted CPR with the goal of maximizing its potential to save lives from sudden cardiac arrest.

Pre-hospital care after a seizure: Evidence base and United Kingdom management guidelines

PURPOSE

Seizures are a common presentation to pre-hospital emergency services and they generate significant healthcare costs. This article summarises the United Kingdom (UK) Ambulance Service guidelines for the management of seizures and explores the extent to which these guidelines are evidence-based.

METHODS

Summary of the Clinical Practice Guidelines of the UK Joint Royal Colleges Ambulance Liaison Committee relating to the management of seizures. Review of the literature relating to pre-hospital management of seizure emergencies.

RESULTS

Much standard practice relating to the emergency out of hospital management of patients with seizures is drawn from generic Advanced Life Support (ALS) guidelines although many patients do not need ALS during or after a seizure and the benefit of many ALS interventions in seizure patients remains to be established. The majority of studies identified pertain to medical treatment of status epilepticus. These papers show that benzodiazepines are safe and effective but it is not possible to draw definitive conclusions about the best medication or the optimal route of administration.

CONCLUSION

The evidence base for current pre-hospital guidelines for seizure emergencies is incomplete. A large proportion of patients are transported to hospital after a seizure but many of these may be suitable for home management. However, there is very little research into alternative care pathways or criteria that could be used to help paramedics avoid transport to hospital. More research is needed to improve care for people after a seizure and to improve the cost-effectiveness of the healthcare systems within which they are treated.

Which emergency medical dispatch codes predict high prehospital nontransport rates in an urban community?

BACKGROUND

The Medical Priority Dispatch System (MPDS) is a commonly used computer-based emergency medical dispatch (EMD) system that is widely used to prioritize 9-1-1 calls and optimize resource allocation. There are five major priority classes used to dispatch 9-1-1 calls in the San Francisco System; Alpha codes are the lowest priority (lowest expected acuity) and Echo are the highest priority.

OBJECTIVE

We sought to determine which MPDS dispatch codes are associated with high prehospital nontransport rates (NTRs).

METHODS

All unique MPDS call categories from 2009 in a highly urbanized, two-tier advanced life support (ALS) system were sorted according to highest NTRs. There are many reasons for nontransport, such as "gone on arrival," and "patient denied transport." Those categories with greater than 100 annual calls were further evaluated. MPDS groups that included multiple categories with NTRs exceeding 25% were then identified and each category was analyzed. Results. EMS responded to a total of 81,437 calls in 2009, of which 18,851 were not transported by EMS. The majority of the NTRs were found among "cardiac/ respiratory arrest/death," "assault/sexual assaults," "unknown problem/man down," "traffic/transportation accidents," and "unconscious/fainting." "Cardiac or respiratory arrest/death -obvious death" (9B1) had the highest overall nontransport rate, 99.25% (1/134), most likely due to declaration of death. "Unknown problem -man down -medical alert notification" had the second highest NTR, 67.22% (138/421). However, Echo priority codes had the highest overall nontransport rates (45.45%) and Charlie had the lowest (13.84%).

CONCLUSIONS

The nontransport rates of individual MPDS categories vary considerably and should be considered in any system design. We identified 52 unique call categories to have a 25% or greater NTR, 18 of which exceeded 40%. The majority of NTRs occurred among the "cardiac/respiratory arrest/death," "assault/sexual assaults," "unknown problem/man down," "traffic/transportation accidents," and "unconscious/fainting" categories. The higher the priority code within each subset (AB vs. CDE), the less likely the patient was to be transported. Charlie priority codes had a lower NTR than Delta, and Delta was lower than Echo. Charlie codes were therefore the strongest predictors of hospital transport, while Echo codes (highest priority) were those with the highest nontransport rates and were the worst predictors of hospital transport in the emergent subset.

Emergency medical dispatch codes association with emergency department outcomes

BACKGROUND

Emergency medical dispatch systems are used to help categorize and prioritize emergency medical services (EMS) resources for requests for assistance.

OBJECTIVE

We examined whether a subset of Medical Priority Dispatch System (MPDS) codes could predict patient outcomes (emergency department [ED] discharge versus hospital admission/ED death).

METHODS

This retrospective observational cohort study analyzed requests for EMS through a single public safety answering point (PSAP) serving a mixed urban, suburban, and rural community over one year. Probabilistic matching was used to link subjects. Descriptive statistics, 95% confidence intervals (CIs), and logistic regression were calculated for the 107 codes and code groupings (9E vs. 9E1, 9E2, etc.) that were used 50 or more times during the study period.

RESULTS

Ninety percent of PSAP records were matched to EMS records and 84% of EMS records were matched to ED data, resulting in 26,846 subjects with complete records. The average age of the cohort was 46.2 years (standard deviation [SD] 24.8); 54% were female. Of the transported patients, 70% were discharged from the ED, with nine dispatch codes demonstrating a 90% or greater predictive power. Three code groupings had more than 60% predictive power for admission/death. Subjects aged 65 years and older were found to be at increased risk for admission/death in 33 dispatch codes (odds ratio [OR] 2.0 [95% confidence interval 1.3-3.0] to 19.6 [5.3-72.6]).

CONCLUSIONS

A small subset (8% of codes; 7% by call volume) of MPDS codes were associated with greater than 90% predictive ability for ED discharge. Older adults are at increased risk for admission/death in a separate subset of MPDS codes, suggesting that age criteria may be useful to identify higher-acuity patients within the MPDS code. These findings could assist in prehospital/hospital resource management; however, future studies are needed to validate these findings for other EMS systems and to investigate possible strategies for improvements of emergency response systems.

Medical Priority Dispatch System breathing problems protocol key question combinations are associated with patient acuity

INTRODUCTION

The Breathing Problems Chief Complaint (CC) protocol in the Medical Priority Dispatch System (MPDS) was the system's most frequently used protocol. While "severe breathing problems" is a significant predictor of cardiac arrest (CA), previous data have demonstrated that the DELTA-level determinant codes in this CC contain patients across a wide spectrum of acuity.

HYPOTHESIS

The hypothesis in this study was that certain combinations of caller answers to the breathing problems protocol key questions (KQs) are correlated with different but specific patient acuities.

METHODS

This was a retrospective study conducted at one International Academies of Emergency Dispatch (IAED) Accredited Center of Excellence. Key Question combinations were generated and analyzed from 11 months of dispatch data, and extracted from MPDS software and the computer assisted dispatch system. Descriptive statistics were used to evaluate measures between study groups.

RESULTS

Forty-two thousand cases were recorded; 52% of patients were female and the median age was 61 years. Overall, based on the original MPDS Protocol (before generating KQ combinations), patients with abnormal breathing and clammy conditions were the youngest. The MPDS DELTA-level constituted the highest percentage of cases (74.0%) and the difficulty speaking between breaths (DSBB) condition was the most prevalent (50.3%). Ineffective breathing and not alert conditions had the highest cardiac arrest quotient (CAQ). Based on the KQ combinations, the CA patients who also had the not alert condition were significantly older than other patients. The percentage of CA outcomes in asthmatic patients was significantly higher in DSBB plus not alert; DSBB plus not alert plus changing color; and DSBB plus not alert plus clammy conditions cases, compared to asthmatic abnormal breathing cases.

CONCLUSIONS

The study findings demonstrated that MPDS KQ answer combinations relate to patient acuity. Cardiac arrest patients are significantly less likely to be asthmatic than those without CA, and vice versa. Using a prioritization scheme that accounts for the presence of either single or multiple signs and/or symptom combinations for the Breathing Problems CC protocol would be a more accurate method of assigning DELTA-level cases in the MPDS.

Association between Patient Unconscious or Not Alert Conditions and Cardiac Arrest or High-Acuity Outcomes within the Medical Priority Dispatch System “Falls” Protocol

Introduction:

Falls are one of the most common types of complaints received by 9-1-1 emergency medical dispatch centers. They can be accidental or may be caused by underlying medical problems. Though not alert” falls patients with severe outcomes mostly are “hot” transported to the hospital, some of these cases may be due to other acute medical events (cardiac, respiratory, circulatory, or neurological), which may not always be apparent to the emergency medical dispatcher (EMD) during call processing.

Objectives:

The objective of this study was to characterize the risk of cardiac arrest and “hot-transport” outcomes in patients with “not alert” condition, within the Medical Priority Dispatch System (MPDS®) Falls protocol descriptors.

Methods:

This retrospective study used 129 months of de-identified, aggregate, dispatch datasets from three US emergency communication centers. The communication centers used the Medical Priority Dispatch System version 11.3–OMEGA type (released in 2006) to interrogate Emergency Medical System callers, select dispatch codes assigned to various response configurations, and provide pre-arrival instructions. The distribution of cases and percentages of cardiac arrest and hot-transport outcomes, categorized by MPDS® code, was profiled. Assessment of the association between MPDS® Delta-level 3 (D-3) “not alert” condition and cardiac arrest and hot-transport outcomes then followed.

Results:

Overall, patients within the D-3 and D-2 “long fall” conditions had the highest proportions (compared to the other determinants in the “falls” protocol) of cardiac arrest and hot-transport outcomes, respectively. “Not alert” condition was associated significantly with cardiac arrest and hot-transport outcomes (p < 0.001).

Conclusions:

The “not alert” determinant within the MPDS® “fall” protocol was associated significantly with severe outcomes for short falls (<6 feet; 2 meters) and ground-level falls. As reported to 9-1-1, the complaint of a “fall” may include the presence of underlying conditions that go beyond the obvious traumatic injuries caused by the fall itself.

Does Emergency Medical Dispatch Priority Predict Delphi Process-Derived Levels of Prehospital Intervention?

Objective:

The Medical Priority Dispatch System (MPDS) is an emergency medical dispatch system widely used to prioritize 9-1-1 calls and optimize resource allocation. This study evaluates whether the assigned priority predicts a Delphi process-derived level of prehospital intervention in each emergency medical dispatch category.

Methods:

All patients given a MPDS priority in a suburban California county from 2004–2006 were included. A Delphi process of emergency medical services (EMS) professionals in another system developed the following categories of prehospital treatment representing increasing acuity, which were adapted for this study: advanced life support (ALS) intervention, ALS–Stat, and ALS–Critical. The sensitivities and specificities of MPDS priority for level of prehospital intervention were determined for each MPDS category.

Results:

A total of 65,268 patients met inclusion criteria, representing 61% of EMS calls during the study period. The overall sensitivities of high-priority dispatch codes for ALS, ALS-Stat, and ALS-Critical interventions were 83% (95% confidence interval 83–84%), 83% (82–84%), and 94% (92–96%). Overall specificities were: ALS, 32% (31–32%); ALS-Stat, 31% (30–31%); and ALS-Critical 28% (28–29%). Compared to calls assigned to a low priority, calls with high-priority dispatch codes were more likely to receive ALS interventions by 22%, ALS-Stat by 20%, and ALS-Critical by 32%. A low priority dispatch code decreased the likelihood of ALS interventions by 48%, ALS-Stat by 45%, and ALS-Critical by 80%. Among high-priority dispatch codes, the rates of interventions were: ALS 26%, ALS-Stat 22%, and ALS-Critical 1.5%, all of which were significantly greater than low-priority calls (p <0.05) [ALS 13%, ALS-Stat 11%, and ALS-Critical 0.2%]. Major MPDS were categories with high sensitivities (>95%) for ALS interventions included breathing problems, cardiac or respiratory arrest/death, chest pain, stroke, and unconscious/fainting; these categories had an average specificity of 3%. Medical Priority Dispatch System categories such as back pain, unknown problem, and traumatic injury had sensitivities for ALS interventions <15%.

Conclusions:

The MPDS is moderately sensitive for the Delphi process derived ALS, ALS-Stat, and ALS-Critical intervention levels, but non-specific. A low MPDS priority is predictive of no prehospital intervention. A high priority, however, is of little predictive value for ALS, ALS-Stat, or ALSCritical interventions.

Time to first compression using Medical Priority Dispatch System compression-first dispatcher-assisted cardiopulmonary resuscitation protocols

INTRODUCTION

Without bystander cardiopulmonary resuscitation (CPR), cardiac arrest survival decreases 7%-10% for every minute of delay until defibrillation. Dispatcher-assisted CPR (D-CPR) has been shown to increase the rates of bystander CPR and cardiac arrest survival. Other reports suggest that the most critical component of bystander CPR is chest compressions with minimal interruption. Beginning with version 11.2 of the Medical Priority Dispatch System (MPDS) protocols, instructions for mouth-to-mouth ventilation (MTMV) and pulse check were removed and a compression-first pathway was introduced to facilitate rapid delivery of compressions. Additionally, unconscious choking and third-trimester pregnancy decision-making criteria were added in versions 11.3 and 12.0, respectively. However, the effects of these changes on time to first compression (TTFC) have not been evaluated.

OBJECTIVE

We sought to quantify the TTFC of MPDS versions 11.2, 11.3, and 12.0 for all calls identified as cardiac arrest on call intake that did not require MTMV instruction.

METHODS

Audio recordings of all D-CPR events for October 2005 through May 2010 were analyzed for TTFC. Differences in TTFC across versions were compared using the Kruskal-Wallis test.

RESULTS

A total of 778 cases received D-CPR. Of these, 259 were excluded because they met criteria for MTMV (pediatric patients, allergic reaction, etc.), were missing data, or were not initially identified as cardiac arrest. Of the remaining 519 calls, the mean TTFC was 240 seconds, with no significant variation across the MPDS versions (p = 0.08).

CONCLUSIONS

Following the removal of instructions for pulse check and MTMV, as well as other minor changes in the MPDS protocols, we found the overall TTFC to be 240 seconds with little variation across the three versions evaluated. This represents an improvement in TTFC compared with reports of an earlier version of MPDS that included pulse checks and MTMV instructions (315 seconds). However, the MPDS TTFC does not compare favorably with reports of older, non-MPDS protocols that included pulse checks and MTMV. Efforts should continue to focus on improving this key, and modifiable, determinant of cardiac arrest survival.

In 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

AIM

We sought to determine if, in patients with out-of-hospital cardiac arrest (OHCA), the description of any specific symptoms to the emergency medical dispatcher (EMD) improved the accuracy of the diagnosis of cardiac arrest.

METHODS

For this systematic review, we searched MEDLINE, EMBASE and the Cochrane Library with no restrictions, and hand-searched the gray literature. Eligible studies included dispatcher interaction with callers reporting OHCA, and reported diagnosis of cardiac arrest. Two independent reviewers used standardized forms and procedures to review papers for inclusion, quality, and to extract data from eligible studies. Findings were peer-reviewed by the International Liaison Committee on Resuscitation.

RESULTS

We identified 494 citations; 74 were selected for full evaluation (kappa=0.70) and 23 were included (kappa=0.68), including six before-after, two case-control, and 15 descriptive studies. One before-after study and ten descriptive studies report that inquiring about consciousness and breathing status can help dispatchers recognize cardiac arrest with moderate sensitivity [ranging from 38% to 97%], and high specificity [ranging from 95% to 99%]. One case-control study, three before-after studies, and four observational studies report that abnormal breathing is a significant barrier to cardiac arrest recognition. One before-after study and two descriptive studies report that seizure activity can be a manifestation of cardiac arrest.

CONCLUSION

Dispatchers should recognize cardiac arrest when a victim is described as unconscious and not breathing or not breathing normally, and consider cardiac arrest when generalized seizure is described. They should receive specific instructions on how to best recognize the presence of abnormal breathing.

Comparing emergency medical service systems--a project of the European Emergency Data (EED) Project

AIM

The aim of this prospective study was the comparison of four emergency medical service (EMS) systems-emergency physician (EP) and paramedic (PM) based-and the impact of advanced live support (ALS) on patients status in preclinical care.

METHODS

The EMS systems of Bonn (GER, EP), Cantabria (ESP, EP), Coventry (UK, PM) and Richmond (US, PM) were analysed in relation to quality of structure, process and performance when first diagnosis on scene was cardiac arrest (OHCA), chest pain or dyspnoea. Data were collected prospectively between 01.01.2001 and 31.12.2004 for at least 12 month.

RESULTS

Over all 6277 patients were included in this study. The rate of drug therapy was highest in the EP-based systems Bonn and Cantabria. Pain relief was more effective in Bonn in patients with severe chest pain. In the group of patients with chest pain and tachycardia ≥ 120 beats/min, the heart rate was reduced most effective by the EP-systems. In patients with dyspnoea and S(p)O(2) <90% the improvement of oxygen saturation was most effective in Bonn and Richmond. After OHCA significant more patients reached the hospital alive in EMS systems with EPs than in the paramedic staffed (Bonn = 35.6%, Cantabria = 30.1%; Coventry = 11.9%, Richmond = 9.2%). The introduction of a Load Distributing Band chest compression device in Richmond improved admittance rate after OHCA (21.7%) but did not reach the survival rate of the Bonn EMS system.

CONCLUSIONS

Higher qualification and greater training and experience of ALS unit personnel increased survival after OHCA and improved patient's status with cardiac chest pain and respiratory failure.

How many emergency dispatches occurred per cardiac arrest?

BACKGROUND

The Medical Priority Dispatch System (MPDS) is an emergency medical dispatch (EMD) system that is widely used to prioritize 9-1-1 calls and optimize resource allocation. Calls are assigned an MPDS determinant, which includes a number (1-32) representing chief complaint and priority (Alpha through Echo) representing acuity.

OBJECTIVE

This study evaluates the number of emergency dispatches per cardiac arrest (NOD-CA) in cardiac arrest and non-cardiac arrest MPDS determinants.

METHODS

All patients assigned a determinant by MPDS from January 1, 2008 to June 30, 2009 in a large metropolitan area were included. Prehospital electronic patient care records were linked with dispatch data. For each MPDS determinant, the number of calls for which the paramedic impression was listed as "Cardiac Arrest - Non-Traumatic" was tabulated. The NOD-CA was calculated for each cardiac arrest and non-cardiac arrest MPDS determinant. Non-MPDS calls with cardiac arrests were analyzed separately.

RESULTS

A total of 101,642 patients were included. Among them, 555 had "Cardiac Arrest - Non-Traumatic" listed as the paramedic impression. The Cardiac/Respiratory Arrest/Death protocol had the highest number of cardiac arrests (285), followed by Breathing Problems (99) and Unconscious/Fainting (76). Overall, 183 dispatched occurred for each cardiac arrest, 131 of which resulted in a lights and sirens response. The NOD-CA was 7 in the Cardiac Arrest/Death protocol, 122 in Breathing Problems, and 104 in Unconscious/Fainting. 31 Cardiac arrests occurred in non-MPDS dispatch categories (N=62,989), most of which were calls for medical assistance from police or fire units.

CONCLUSIONS

MPDS was designed to detect cardiac arrest with high sensitivity, leading to a significant degree of mistriage. The number of dispatches for each cardiac arrest may be a useful way to quantify the degree of mistriage and optimize EMS dispatch. This large descriptive study revealed a low NOD-CA in most cardiac arrest MPDS determinants. We demonstrated significant variability in the NOD-CA among non-cardiac arrest MPDS determinants, and few cardiac arrests in non-MPDS dispatch categories.

Profile of emergency medical dispatch calls for breathing problems within the medical priority dispatch system protocol

INTRODUCTION

A common chief complaint to emergency dispatch communication centers worldwide is "breathing problems". The chief complaint of breathing problems represents a wide spectrum of underlying diseases, patient conditions, and onset types. The current debate is on the potential ability of a dispatch protocol to safely and with high specificity, differentiate patients with minor or non-critical conditions from those conditions that pose risk to the patient and require advanced life support evaluation and care. This issue also has extended into the paramedic prehospital evaluation realm.

OBJECTIVE

The objective of this study was to describe the distribution of Medical Priority Dispatch System (MPDS) codes representing the spectrum of clinical descriptions within the breathing problems chief complaint and their associated outcomes, at the scene and during transport, as determined by [UK] paramedics.

METHODS

A retrospective, one-year study (September 2005 to August 2006) of a de-identified aggregate dataset from the London Ambulance Service (LAS) Trust was evaluated. A profile of the distribution of calls, incidents, patients, and outcomes (cardiac arrest [CA] and blue-in [BI] high acuity i.e., patients transported with lights and siren based on paramedic protocol) for the breathing problems chief complaint was evaluated. Odds ratios and 95% confidence intervals (CI) were used to quantify associations between the MPDS priority level's concurrent asthmatic conditions and outcomes. Two-sided Fisher's exact p-values were obtained to determine statistically significant associations, at a level of0.05.

RESULTS

Sixteen percent (95,848/599,093) of all the patients were classified under the breathing problems chief complaint. Of these 95,848 patients, 367 (0.38%) were CA outcomes, and 7.82% (n = 7,493) were BI outcomes.The Cardiac Arrest Quotient (i.e., the number of CA cases as a percentage of the number of patients) for the ECHO priority level was 46 times higher than was that of non-ECHO priority levels: DELTA and CHARLIE (17.05% vs. 0.37%). Asthmatics were associated with CA outcome (OR(95%CI): 0.60(0.47,0.77), p <0.001), but not with BI outcome.

CONCLUSIONS

The MPDS coding yielded a richer mix of severe outcomes in the higher priority levels.The Severe Respiratory Distress coding had the greatest number of patients and severe outcomes. Future studies that help refine the Severe Respiratory Distress code in the MPDS by more specific subgroups of patients would be beneficial.

Ability of the medical priority dispatch system protocol to predict the acuity of "unknown problem" dispatch response levels

OBJECTIVE

To determine if Medical Priority Dispatch System's (MPDS's) Protocol 32-Unknown Problem interrogation-based differential dispatch coding distinguishes the acuity of patients as found at the scene by responders, when little (if any) clinical information is known.

METHODS

"Unknown problem" situations (i.e., all cases not fitting into any other chief complaint group) constitute 5-8% of all calls to dispatch centers. From the total patient encounters (n=599,107) in the aggregate data of one year (September 2005 to August 2006), we examined 3,947 (0.7%) encounters initially coded as "unknown problem" by the London Ambulance Service Communications Center for the scene presence of cardiac arrest (CA) and paramedic-determined high-acuity (blue-in [BI]/"lights and siren") findings. Odds ratios (ORs) with 95% confidence intervals (95% CIs) and p-values were used to assess the degree of associations between determinant codes and case outcomes (i.e., CA/BI).

RESULTS

Statistically significant association between clinical dispatch determinant codes and case outcomes was observed in the "life status questionable" (LSQ; DELTA-1 [D-1]) and the "standing, sitting, moving, or talking" (BRAVO-1 [B-1]) code pair for the CA outcome (OR [95% CI]: 0.11 [0, 0.63], p=0.005) and for the BI outcome (OR [95% CI]: 0.47 [0.28, 0.77], p=0.003). The LSQ and all three code pairs (i.e., B-1; "community alarm notifications" [B-2]; and "unknown status" [B-3]) also demonstrated significant associations both with the CA outcome (OR [95% CI]: 0.43 [0.23, 0.81], p=0.010) and with the BI outcome (OR [95% CI]: 0.74 [0.56, 0.97], p=0.033). All the determinant code levels yielded significant association between BI and CA cases.

CONCLUSION

This dispatch protocol for unknown problems successfully differentiates dispatch coding of low-acuity and non-CA patients only when specific situational information such as the patient's standing, sitting, moving, or talking can be determined during the interrogation process. Also, emergency medical dispatcher (EMD) reliance on caller-volunteered information to identify predefined critical situations does not appear to add to the protocol's ability to differentiate high-acuity and CA patients. LSQ proved to be a better predictor of both CA and BI outcomes, when compared with the BRAVO-level determinant codes within the "unknown problem" chief complaint. The B-3 (completely unknown) determinant code is a better predictor of severe outcomes than nearly all of the clinically similar BRAVO determinant codes in the entire MPDS protocol. Hence, the B-3 coding should be considered-in terms of its predictability for severe outcome-as falling somewhere between a typical DELTA and a typical BRAVO determinant code.