Science of emergency medical dispatch

Video-assisted cardiopulmonary resuscitation: Does the camera perspective matter? A randomized, controlled simulation trial

BACKGROUND

Dispatcher assistance can help to save lives during layperson cardiopulmonary resuscitation during cardiac arrest. The aim of this study was to investigate the influence of different camera positions on the evaluation of cardiopulmonary resuscitation performance during video-assisted cardiopulmonary resuscitation.

METHODS

For this randomized, controlled simulation trial, seven video sequences of cardiopulmonary resuscitation performance were recorded from three different camera positions: side, foot and head position. Video sequences showed either correct cardiopulmonary resuscitation performance or one of the six typical errors: low and high compression rate, superficial and increased compression depth, wrong hand position or incomplete release. Video sequences with different cardiopulmonary resuscitation performances and camera positions were randomly combined such that each evaluator was presented seven individual combinations of cardiopulmonary resuscitation and camera position and evaluated each cardiopulmonary resuscitation performance once. A total of 46 paramedics and 47 emergency physicians evaluated seven video sequences of cardiopulmonary resuscitation performance from different camera positions. The primary hypothesis was that there are differences in accuracy of correct assessment/error recognition depending on camera perspective. Generalized linear multi-level analyses assuming a binomial distribution and a logit link were employed to account for the dependency between each evaluator's seven ratings.

RESULTS

Of 651 video sequences, cardiopulmonary resuscitation performance was evaluable in 96.8% and correctly evaluated in 74.5% over all camera positions. Cardiopulmonary resuscitation performance was classified correctly from a side perspective in 81.3%, from a foot perspective in 68.8% and from a head perspective in 73.6%, revealing a significant difference in error recognition depending on the camera perspective (p = .01). Correct cardiopulmonary resuscitation was mistakenly evaluated to be false in 46.2% over all perspectives.

CONCLUSIONS

Participants were able to recognize significantly more mistakes when the camera was located on the opposite side of the cardiopulmonary resuscitation provider. Foot position should be avoided in order to enable the dispatcher the best possible view to evaluating cardiopulmonary resuscitation quality.

A registry-based observational study comparing emergency calls assessed by emergency medical dispatchers with and without support by registered nurses

Background

The requirement concerning formal education for emergency medical dispatcher (EMD) is debated and varies, both nationally and internationally. There are few studies on the outcomes of emergency medical dispatching in relation to professional background. This study aimed to compare calls handled by an EMD with and without support by a registered nurse (RN), with respect to priority level, accuracy, and medical condition.

Methods

A retrospective observational study, performed on registry data from specific regions during 2015. The ambulance personnel’s first assessment of the priority level and medical condition was used as the reference standard. Outcomes were: the proportion of calls dispatched with a priority in concordance with the ambulance personnel’s assessment; over- and undertriage; the proportion of most adverse over- and undertriage; sensitivity, specificity and predictive values for each of the ambulance priorities; proportion of calls dispatched with a medical condition in concordance with the ambulance personnel’s assessment. Proportions were reported with 95% confidence intervals. χ²-test was used for comparisons. P-levels < 0.05 were regarded as significant.

Results

A total of 25,025 calls were included (EMD n = 23,723, EMD + RN n = 1302). Analyses relating to priority and medical condition were performed on 23,503 and 21,881 calls, respectively. A dispatched priority in concordance with the ambulance personnel’s assessment were: EMD n = 11,319 (50.7%) and EMD + RN n = 481 (41.5%) (p < 0.01). The proportion of overtriage was equal for both groups: EMD n = 5904, EMD + RN n = 306, (26.4%) p = 0.25). The proportion of undertriage for each group was: EMD n = 5122 (22.9%) and EMD + RN n = 371 (32.0%) (p < 0.01). Sensitivity for the most urgent priority was 54.6% for EMD, compared to 29.6% for EMD + RN (p < 0.01), and specificity was 67.3% and 84.8% (p < 0.01) respectively. A dispatched medical condition in concordance with the ambulance personnel’s assessment were: EMD n = 13,785 (66.4%) and EMD + RN n = 697 (62.2%) (p = 0.01).

Conclusions

A higher precision of emergency medical dispatching was not observed when the EMD was supported by an RN. How patient safety is affected by the observed divergence in dispatched priorities is an area for future research.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00987-y.

Symptom-Based Dispatching in an Emergency Medical Communication Centre: Sensitivity, Specificity, and the Area under the ROC Curve

Measuring the performance of emergency medical dispatch tools used in paramedic-staffed emergency medical communication centres (EMCCs) is rarely performed. The objectives of our study were, therefore, to measure the performance and accuracy of Geneva's dispatch system based on symptom assessment, in particular, the performance of ambulance dispatching with lights and sirens (L&S) and to measure the effect of adding specific protocols for each symptom. Methods: We performed a prospective observational study including all emergency calls received at Geneva's EMCC (Switzerland) from 1 January 2014 to 1 July 2019. The risk levels selected during the emergency calls were compared to a reference standard, based on the National Advisory Committee for Aeronautics (NACA) scale, dichotomized to severe patient condition (NACA ≥ 4) or stable patient condition (NACA < 4) in the field. The symptom-based dispatch performance was assessed using a receiver operating characteristic (ROC) curve. Contingency tables and a Fagan nomogram were used to measure the performance of the dispatch with or without L&S. Measurements were carried out by symptom, and a group of symptoms with specific protocols was compared to a group without specific protocols. Results: We found an acceptable area under the ROC curve of 0.7474, 95%CI (0.7448-0.7503) for the 148,979 assessments included in the study. Where the severity prevalence was 21%, 95%CI (20.8-21.2). The sensitivity of the L&S dispatch was 87.5%, 95%CI (87.1-87.8); and the specificity was 47.3%, 95%CI (47.0-47.6). When symptom-specific assessment protocols were used, the accuracy of the assessments was slightly improved. Conclusions: Performance measurement of Geneva's symptom-based dispatch system using standard diagnostic test performance measurement tools was possible. The performance was found to be comparable to other emergency medical dispatch systems using the same reference standard. However, the implementation of specific assessment protocols for each symptom may improve the accuracy of symptom-based dispatch systems.

Key performance indicators' assessment to develop best practices in an Emergency Medical Communication Centre

INTRODUCTION

Emergency Medical Communication Centre (EMCC) represents a pivotal link in the chain of survival for those requiring rapid response for out-of-hospital medical emergencies. Assessing and grading the performance of EMCCs are warranted as it can affect the health and safety of the served population.

OBJECTIVE

The aim of our work was to describe the activity on an EMCC and to explore the associations between different key performance indicators.

METHODS

We carried out our prospective observational study in the EMCC of Nantes, France, from 6 June 2011 to 6 June 2015. The EMCC performance was assessed with the following key performance indicators: answered calls, Quality of Service 20 s (QS20), occupation rate and average call duration.

RESULTS

A total of 35 073 h of dispatch activity were analysed. 1 488 998 emergency calls were answered. The emergency call incidence varied slightly from 274 to 284 calls/1000 citizens/year between 2011 and 2015. The median occupation rate was 35% (25-44). QS20 was correlated negatively with the occupation rate (Spearman's ρ: -0.78). The structural equation model confirmed that the occupation rate was highly correlated with the QS20 (standardized coefficient: -0.89). For an occupation rate of 26%, the target value estimated by our polynomial model, the probability of achieving a QS20 superior or equal to 95% varied between 56 and 84%.

CONCLUSION

The occupation rate appeared to be the most important factor contributing towards the QS20. Our data will be useful to develop best practices and guidelines in the field of emergency medicine communication centres.

Does the prehospital National Early Warning Score predict the short-term mortality of unselected emergency patients?

OBJECTIVES

The prehospital research field has focused on studying patient survival in cardiac arrest, as well as acute coronary syndrome, stroke, and trauma. There is little known about the overall short-term mortality and its predictability in unselected prehospital patients. This study examines whether a prehospital National Early Warning Score (NEWS) predicts 1-day and 30-day mortalities.

METHODS

Data from all emergency medical service (EMS) situations were coupled to the mortality data obtained from the Causes of Death Registry during a six-month period in Northern Finland. NEWS values were calculated from first clinical parameters obtained on the scene and patients were categorized to the low, medium and high-risk groups accordingly. Sensitivities, specificities, positive predictive values (PPVs), negative predictive values (NPVs), and likelihood ratios (PLRs and NLRs) were calculated for 1-day and 30-day mortalities at the cut-off risks.

RESULTS

A total of 12,426 EMS calls were included in the study. The overall 1-day and 30-day mortalities were 1.5 and 4.3%, respectively. The 1-day mortality rate for NEWS values ≤12 was lower than 7% and for values ≥13 higher than 20%. The high-risk NEWS group had sensitivities for 1-day and 30-day mortalities 0.801 (CI 0.74-0.86) and 0.42 (CI 0.38-0.47), respectively.

CONCLUSION

In prehospital environment, the high risk NEWS category was associated with 1-day mortality well above that of the medium and low risk NEWS categories. This effect was not as noticeable for 30-day mortality. The prehospital NEWS may be useful tool for recognising patients at early risk of death, allowing earlier interventions and responds to these patients.

Witnessed out-of-hospital cardiac arrest- effects of emergency dispatch recognition

BACKGROUND

Survival from an out-of-hospital cardiac arrest (OHCA) depends on the sequence of interventions in "the chain of survival". If OHCA is recognized in the emergency medical communication centre (EMCC), the proper emergency medical service (EMS) should be dispatched and cardiopulmonary resuscitation (CPR) instructions should be given to a bystander. The study aimed to examine the impact of OHCA recognition in the EMCC on survival rates and the main elements of the chain of survival.

METHODS

Data from the Helsinki University Hospital's registry of OHCA patients between 1997 and 2013 were studied. Altogether, 2054 EMCC-handled and bystander-witnessed OHCA proven events of cardiac origin were analysed.

RESULTS

In 80.5% of the victims, two EMS units were correctly dispatched and the OHCA was classified as recognized. Achieved return of spontaneous circulation (ROSC) and survival to hospital discharge were 49% and 23%, respectively, if cardiac arrest was recognized by the EMCC and 40% and 16% when it was not (P = 0.003 and 0.002). Dispatchers gave CPR instructions in 60% of the recognized OHCA cases. Bystander-performed CPR increased over time and was given in 58% of the recognized OHCAs and also in 17% of the unrecognized events. EMS delays were shorter if OHCA was recognized as opposed to unrecognized (8 min with an IQR 6.5-10 min vs. 9 min with an IQR 6.5-11 min; P = 0.001).

CONCLUSIONS

Recognition of OHCA by the EMCC was significantly associated with an increased rate of bystander-performed CPR, reduced EMS response time, and increased OHCA patient ROSC and survival rates.

A high proportion of prehospital emergency patients are not transported by ambulance: a retrospective cohort study in Northern Finland

BACKGROUND

The number of missions in the emergency medical services (EMS) has increased considerably in recent years. People are requesting ambulance for even minor illnesses and non-medical problems, which is placing financial and resource burdens on the EMS. The aim of this study was to determine the rate of non-transportation missions in Northern Finland and the reasons for these missions.

METHODS

All ambulance missions in two hospital districts in Northern Finland during the 6-month period of January 1 through June 30, 2014, were retrospectively evaluated from the EMS charts to identify missions in which the patients were not transported by the EMS. The non-transportation rates and reasons were calculated and expressed as percentages.

RESULTS

In 41.7% of the 13,354 missions, the patient was not transported from the scene by an ambulance. After a medical assessment and care was provided by the EMS, 48.2% of these non-transport patients were evaluated as not needing further treatment in the emergency department and were directed to contact the municipal health care center during office hours. There was no need for any medical care in 39.9% of non-transportation missions.

CONCLUSION

This study showed a high rate of EMS missions resulting in non-transportation in two hospital districts in Northern Finland. In the majority of these missions there was no need for emergency admission to an emergency department or for any medical care at all. These findings indicate that an improvement in the dispatch process and primary care resources might be of benefit.

Recognition of out-of-hospital cardiac arrest during emergency calls - a systematic review of observational studies

Background

The medical dispatcher plays an essential role as part of the first link in the Chain of Survival, by recognising the out-of-hospital cardiac arrest (OHCA) during the emergency call, dispatching the appropriate first responder or emergency medical services response, performing dispatcher assisted cardiopulmonary resuscitation, and referring to the nearest automated external defibrillator. The objective of this systematic review was to evaluate and compare studies reporting recognition of OHCA patients during emergency calls.

Methods

This systematic review was reported in compliance with the PRISMA guidelines. We systematically searched MEDLINE, Embase and the Cochrane Library on 4 November 2015. Observational studies, reporting the proportion of clinically confirmed OHCAs that was recognised during the emergency call, were included. Two authors independently screened abstracts and full-text articles for inclusion. Data were extracted and the risk of bias within studies was assessed using the QUADAS-2 tool for quality assessment of diagnostic accuracy studies.

Results

A total of 3,180 abstracts were screened for eligibility and 53 publications were assessed in full-text. We identified 16 studies including 6,955 patients that fulfilled the criteria for inclusion in the systematic review. The studies reported recognition of OHCA with a median sensitivity of 73.9% (range: 14.1–96.9%). The selection of study population and the definition of “recognised OHCA” (threshold for positive test) varied greatly between the studies, resulting in high risk of bias. Heterogeneity in the studies precluded meta-analysis.

Conclusion

Among the 16 included studies, we found a median sensitivity for OHCA recognition of 73.9% (range: 14.1–96.9%). However, great heterogeneity between study populations and in the definition of “recognised OHCA”, lead to insufficient comparability of results. Uniform and transparent reporting is required to ensure comparability and development towards best practice.

Medical priority dispatch codes-comparison with National Early Warning Score

Background

In Finland, calls for emergency medical services are prioritized by educated non-medical personnel into four categories—from A (highest risk) to D (lowest risk)—following a criteria-based national dispatch protocol. Discrepancies in triage may result in risk overestimation, leading to inappropriate use of emergency medical services units and to risk underestimation that can negatively impact patient outcome. To evaluate dispatch protocol accuracy, we assessed association between priority assigned at dispatch and the patient’s condition assessed by emergency medical services on the scene using an early warning risk assessment tool.

Methods

Using medical charts, clinical variables were prospectively recorded and evaluated for all emergency medical services missions in two hospital districts in Northern Finland during 1.1.2014–30.6.2014. Risk assessment was then re-categorized as low, medium, or high by calculating the National Early Warning Score (NEWS) based on the patients’ clinical variables measured at the scene.

Results

A total of 12,729 emergency medical services missions were evaluated, of which 616 (4.8%) were prioritized as A, 3193 (25.1%) as B, 5637 (44.3%) as C, and 3283 (25.8%) as D. Overall, 67.5% of the dispatch missions were correctly estimated according to NEWS. Of the highest dispatch priority missions A and B, 76.9 and 78.3%, respectively, were overestimated. Of the low urgency missions (C and D), 10.7% were underestimated; 32.0% of the patients who were assigned NEWS indicating high risk had initially been classified as low urgency C or D priorities at the dispatch.

Discussion and conclusion

The present results show that the current Finnish medical dispatch protocol is suboptimal and needs to be further developed. A substantial proportion of EMS missions assessed as highest priority were categorized as lower risk according to the NEWS determined at the scene, indicating over-triage with the protocol. On the other hand, only a quarter of the high risk NEWS patients were classified as the highest priority at dispatch, indicating considerable under-triage with the protocol.

Electronic supplementary material

The online version of this article (doi:10.1186/s13049-016-0336-y) contains supplementary material, which is available to authorized users.

Medical dispatchers recognise substantial amount of acute stroke during emergency calls

Background

Immediate recognition of stroke symptoms is crucial to ensure timely access to revascularisation therapy. Medical dispatchers ensure fast admission to stroke facilities by prioritising the appropriate medical response. Data on medical dispatchers’ ability to recognise symptoms of acute stroke are therefore critical in organising emergency stroke care.

We aimed to describe the sensitivity and positive predictive value of medical dispatchers’ ability to recognise acute stroke during emergency calls, and to identify factors associated with recognition.

Methods

This was an observational study of 2653 consecutive unselected patients with a final diagnosis of stroke or transient ischemic attack (TIA). All admitted through the Emergency Medical Services Copenhagen, during a 2-year study period (2012–2014). Final diagnoses were matched with dispatch codes from the Emergency Medical Dispatch Centre. Sensitivity and positive predictive value were calculated. The effect of age, gender, and time-of-day was analysed using multivariable logistic regression.

Results

The sensitivity was 66.2 % (95 % CI: 64.4 %–68.0 %), and the positive predictive value was 30.2 % (95 % CI: 29.1 %–31.4 %). The multivariable logistic regression analyses showed that emergency calls during daytime and a final diagnosis of TIA vs. intracerebral haemorrhage (ICH), was positively associated with recognition of stroke (OR 2.70, 95 % CI: 2.04–3.57).

Discussion

This study reports a high rate of stroke recognition compared to other studies ranging from 31% to 74%. The high sensitivity is likely the result of a profound reorganisation of the Emergency Medical ServicesCopenhagen, including the introduction of EMDs with a medical profession, and a criteria-based dispatch tool. A recognition rate of 100 % is not obtainable without an inappropriate amount of false positive cases.

Conclusions

We report an overall high recognition of stroke by medical dispatchers. A final diagnosis of TIA, compared to ICH, was positively associated with recognition of acute stroke. Emergency medical dispatchers serve as the essential first step in ensuring fast-track stroke treatment, which would promote timely acute therapy.

Trial registration

Unique identifier: NCT02191514.

Electronic supplementary material

The online version of this article (doi:10.1186/s13049-016-0277-5) contains supplementary material, which is available to authorized users.

Why and when citizens call for emergency help: an observational study of 211,193 medical emergency calls

BACKGROUND

A medical emergency call is citizens' access to pre-hospital emergency care and ambulance services. Emergency medical dispatchers are gatekeepers to provision of pre-hospital resources and possibly hospital admissions. We explored causes for access, emergency priority levels, and temporal variation within seasons, weekdays, and time of day for emergency calls to the emergency medical dispatch center in Copenhagen in a two-year study period (December 1(st), 2011 to November 30(th), 2013).

METHODS

Descriptive analysis was performed for causes for access and emergency priority levels. A Poisson regression model was used to calculate adjusted ratio estimates for the association between seasons, weekdays, and time of day overall and stratified by emergency priority levels.

RESULTS

We analyzed 211,193 emergency calls for temporal variation. Of those, 167,635 calls were eligible for analysis of causes and emergency priority level. "Unclear problem" was the most frequent category (19%). The five most common causes with known origin were categorized as "Wounds, fractures, minor injuries" (13%), "Chest pain/heart disease" (11%), "Accidents" (9%), "Intoxication, poisoning, drug overdose" (8%), and "Breathing difficulties" (7%). The highest emergency priority levels (Emergency priority level A and B) were assigned in 81% of calls. In the analysis of temporal variation, the total number of calls peaked at wintertime (26%), Saturdays (16%), and during daytime (39%).

CONCLUSION

The pattern of citizens' contact causes fell into four overall categories: unclear problems, medical problems, intoxication and accidents. The majority of calls were urgent. The magnitude of unclear problems represents a modifiable factor and highlights the potential for further improvement of supportive dispatch priority tools or educational interventions at dispatch centers. Temporal variation was identified within seasons, weekdays and time of day and reflects both system load and disease occurrence. Data on contact patterns could be utilized in a public health perspective, benchmarking of EMS systems, and ultimately development of best practice in the area of emergency medicine.

Survey of a Protocol to Increase Appropriate Implementation of Dispatcher-Assisted Cardiopulmonary Resuscitation for Out-of-Hospital Cardiac Arrest

Background—

Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) attempts to improve the management of out-of-hospital cardiac arrest by laypersons who are unable to recognize cardiac arrest and are unfamiliar with CPR. Therefore, we investigated the sensitivity and specificity of our new DA-CPR protocol for achieving implementation of bystander CPR in out-of-hospital cardiac arrest victims not already receiving bystander CPR.

Methods and Results—

Since 2007, we have applied a new DA-CPR protocol that uses supplementary key words. Fire departments prospectively collected baseline data on DA-CPR from January 2009 to December 2011. DA-CPR was attempted in 2747 patients; of these, 417 (15.2%) did not experience cardiac arrest. The sensitivity and specificity of the 2007 protocol versus estimated values of the previous standard protocol were 72.9% versus 50.3% and 99.6% versus 99.8%, respectively. We identified key words that may be useful for detecting out-of-hospital cardiac arrest. Multiple logistic regression analysis revealed that the occurrence of cardiac arrest after an emergency call (odds ratio, 16.85) and placing an emergency call away from the scene of the arrest (odds ratio, 11.04) were potentially associated with failure to provide DA-CPR. Furthermore, at-home cardiac arrest (odds ratio, 1.61) and family members as bystanders (odds ratio, 1.55) were associated with bystander noncompliance with DA-CPR. No complications were reported in the 417 patients who received DA-CPR but did not have cardiac arrest.

Conclusions—

Our 2007 protocol is safe and highly specific and may be more sensitive than the standard protocol. Understanding the factors associated with failure of bystanders to provide DA-CPR and implementing public education are necessary to increase the benefit of DA-CPR.

The inaugural European emergency medical dispatch conference--a synopsis of proceedings

The inaugural European Emergency Medical Dispatch conference was held in Stockholm, Sweden, in May 2013. We provide a synopsis of the conference proceedings, highlight key topic areas of emergency medical dispatch and suggest future research priorities.

Implementing a nationwide criteria-based emergency medical dispatch system: a register-based follow-up study

BACKGROUND

A criteria-based nationwide Emergency Medical Dispatch (EMD) system was recently implemented in Denmark. We described the system and studied its ability to triage patients according to the severity of their condition by analysing hospital admission and case-fatality risks.

METHODS

This was a register-based follow-up study of all 1-1-2 calls in a 6-month period that were triaged according to the Danish Index - the new criteria-based dispatch protocol. Danish Index data were linked with hospital and vital status data from national registries. Confidence intervals (95%) for proportions with binomial data were computed using exact methods. To test for trend the Wald test was used.

RESULTS

Information on level of emergency according to the Danish Index rating was available for 67,135 patients who received ambulance service. Emergency level A (urgent cases) accounted for 51.4% (n = 34,489) of patients, emergency level B for 46.3% (n = 31,116), emergency level C for 2.1% (n = 1,391) and emergency level D for 0.2% (n = 139). For emergency level A, the median time from call receipt to ambulance dispatch was 2 min 1 s, and the median time to arrival was 6 min 11 s. Data concerning admission and case fatality was available for 55,270 patients. The hospital admission risk for emergency level A patients was 64.4% (95% CI = 63.8-64.9). There was a significant trend (p < 0.001) towards lower admission risks for patients with lower levels of emergency. The case fatality risk for emergency level A patients on the same day as the 1-1-2 call was 4.4% (95% CI = 4.1-4.6). The relative case-fatality risk among emergency level A patients compared to emergency level B-D patients was 14.3 (95% CI: 11.5-18.0).

CONCLUSION

The majority of patients were assessed as Danish Index emergency level A or B. Case fatality and hospital admission risks were substantially higher for emergency level A patients than for emergency level B-D patients. Thus, the newly implemented Danish criteria-based dispatch system seems to triage patients with high risk of admission and death to the highest level of emergency. Further studies are needed to determine the degree of over- and undertriage and prognostic factors.

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.

Emergency medical coordination using a web platform: a pilot study

OBJECTIVE

To describe a management system for emergency medical coordination based on the worldwide web of computers.

METHODS

The emergency coordination system was developed according to an evolving software model for prototype development. Communication between users and the system was implemented by means of web technologies. The system was developed on a personal homepage and the database was developed using MySQL. The prototype was based on the medical coordination process of the Thirteenth Regional Healthcare Division of the State of São Paulo (Southeastern Brazil) and was applied to 26 municipalities within this regional division, for four consecutive weeks in September 2009. The system made it possible to document requests in chronological order, without allowing editing of data already entered, and ensured hierarchical confidential access to the information for each participant in the system.

RESULTS

The system presented 100% availability, reliability and integrity of information. A total of 1,046 requests were made to the system, of which 703 (68%) were completed. The solicitants already presented 98% adherence to the system in the first week of application, while adherence among service providers gradually increased (37% in the fourth week). The municipalities closest to Ribeirão Preto that did not have high-complexity providers were the ones that most used the system.

CONCLUSIONS

Medical coordination of emergency requests through the worldwide web of computers was shown to be feasible and reliable, and it enabled transparency within the process and direct access to information for managers. It allowed indicators to be constructed in order to monitor and improve the process, from the perspective of creating semi-automated coordination and advances in system organization.

Dispatcher-assisted telephone cardiopulmonary resuscitation using a French-language compression-only protocol in volunteers with or without prior life support training: A randomized trial

OBJECTIVES

Due to the recent interest in hands-only protocols for dispatcher-assisted cardiopulmonary resuscitation (CPR) and the lack of any validated algorithms in French, our primary objective was to evaluate a new French-language protocol in terms of its efficacy to help previously untrained volunteers in performing basic life support efforts of appropriate quality, and secondarily to investigate its potential utility in subjects with previous training.

METHODS

Untrained volunteers were recruited among adults in a public movie centre and previously trained volunteers among undergraduate nursing students. Participants were randomly assigned to 'phone CPR' versus 'no phone CPR' by drawing sets of envelopes. Primary outcome measures were the results of the Cardiff evaluation test; the secondary measures were global scoring of a complete 5min period of CPR, in a manikin model of cardiac arrest.

RESULTS

Out of 146 volunteers assessed for eligibility, 36 previously untrained candidates declined participation. 110 participants, distributed into four groups, completed the study: the previously untrained non-guided group (group A, n=30), the previously untrained guided group (group B, n=30), the previously trained non-guided group (group C, n=25) and the previously trained guided group (group D, n=25). Results of the Cardiff test and global evaluation of CPR performance revealed a significant improvement in group B as compared with group A, approaching the level of the group C. Previously trained guided bystanders had the best CPR scores, notably because of an improvement in the quality of airway management.

CONCLUSION

When used by dispatchers, this new French-language algorithm offers the opportunity to help previously untrained bystanders initiate CPR. The same protocol may serve to guide volunteers with prior basic life support training to reach their best CPR performance.

Breathing patterns during cardiac arrest

The absence of respiratory movements is a major criterion recommended for use by bystanders for recognizing an out-of-hospital cardiac arrest (CA), as the persistence of eupneic breathing is considered to be incompatible with CA. The basis for CA-related apnea is, however, uncertain, since brain stem Po2 is not expected to drop immediately to the critical level where anoxic apnea occurs. It is therefore essential on both clinical and physiological grounds to determine whether and when breathing stops after the onset of CA. In eight patients, we measured the ventilatory response at the onset of ventricular fibrillation (VF) for 12–15 s during the placement of an implantable cardioverter-defibrillator device. We found that regular eupneic breathing was maintained unchanged despite the cessation of systemic and pulmonary blood flow generated by the heart. We extended these findings in adult sheep and found that, as in humans, the normal ventilatory pattern persists unchanged for the first 15 s despite the drop in blood pressure, followed by a progressive increase in minute ventilation, which was sustained for up to 164 s. The ensuing apnea was disrupted by typical gasps occurring at a very slow frequency. These observations suggest a complete “decoupling” between the return of CO2 to the pulmonary circulation and continued effective respiratory activity, contrary to what we predicted. This delayed cessation of eupneic breathing during the absence of cardiac pump function is likely related to the time needed for brain stem anoxia to develop. These findings challenge the notions that 1) ventilation stops as pulmonary blood flow/cardiac output ceases and 2) the presence of eupneic breathing is a reliable sign of effective cardiac pumping activity.

Fusion of dispatching centres into one entity: effects on performance

BACKGROUND

Dispatching centres were fused into one of the 112 entity, which caused concerns regarding whether the medical calls could be processed effectively also in the new centre. We evaluated the effects of the reform on key performance criteria in medical calls.

METHODS

This observational study in the Helsinki Dispatching Centre consisted of two periods: Period I 2 years before the reform and Period II 2 years after. The main outcome measures were answering and call processing times, accuracy of risk assessment and appropriate use of ambulances.

RESULTS

In Period I (n=574,276), 92.2% of all incoming phone calls were answered within 10 s and in Period II (n=758,022) 82.8% (P<0.0001). Time to dispatch a first responding fire unit increased from 98 to 113 s (P<0.0001) and an advanced life support unit in category A calls increased from 73 to 84 s (P<0.0001). In Period I 47.7%, 34.8% and 17.5% of phone calls were completed in <3, 3-5 and >5 min and in Period II 29.8%, 36.1% and 34.1% (P<0.0001). The number of three studied non-transportation call types and unnecessary lights-and-siren responses increased significantly (P<0.0001 and 0.0001, respectively). Neither the accuracy of risk assessment in the three studied call types nor the rate of telephone-guided cardiopulmonary resuscitation changed.

CONCLUSIONS

The reform increased the total number of ambulance dispatches, prolonged answering and call processing times and had a negative effect on the appropriate use of ambulances. The accuracy of risk assessment was not affected. Evidence-based data should be the basis for the future as dispatching centre processes are shown to be vulnerable during organisational reforms.