Cardiac resuscitation in the community. Importance of rapid provision and implications for program planning

Characteristics of out-of-hospital cardiac arrest patients in Riyadh province, Saudi Arabia: a cross-sectional study

Introduction

Little work has been done on out-of-hospital cardiac arrest (OHCA) in Saudi Arabia. Our goal is to report the characteristics of OHCA patients and predictors of bystander cardiopulmonary resuscitation (CPR).

Materials and methods

This cross-sectional study utilized data from the Saudi Red Crescent Authority (SRCA), a governmental emergency medical service (EMS). A standardized data collection form based on the "Utstein-style" guidelines was developed. Data were retrieved from the electronic patient care reports that SRCA providers fill out for every case. OHCA cases that were attended by SRCA in Riyadh province between June 1st, 2020 and May 31st, 2021 were included. Multivariate regression analysis was performed to assess independent predictors of bystander CPR.

Results

A total of 1,023 OHCA cases were included. The mean age was 57.2 (±22.6). 95.7% (979/1,023) of cases were adults and 65.2% (667/1,023) were males. Home was the most common location of OHCA [784/1,011 (77.5%)]. The initial recorded rhythm was shockable in 131/742 (17.7%). The EMS mean response time was 15.9 min (±11.1). Bystander CPR was performed in 130/1,023 (12.7%) and was more commonly performed in children as compared to adults [12/44 (27.3%) vs. 118/979 (12.1%), p = 0.003]. Independent predictors of bystander CPR were being a child (OR = 3.26, 95% CI [1.21-8.82], p = 0.02) and having OHCA in a healthcare institution (OR = 6.35, 95% CI [2.15-18.72], p = 0.001).

Conclusion

Our study reported the characteristics of OHCA cases in Saudi Arabia using EMS data. We observed young age at presentation, low rates of bystander CPR, and long response time. These characteristics are distinctly different from other countries and call for urgent attention to OHCA care in Saudi Arabia. Lastly, being a child and having OHCA in a healthcare institution were found to be independent predictors of bystander CPR.

Spatial Accessibility Assessment of Prehospital EMS with a Focus on the Elderly Population: A Case Study in Ningbo, China

The spatial accessibility of prehospital EMS is particularly important for the elderly population’s physiological functions. Due to the recent expansion of aging populations all over the globe, elderly people’s spatial accessibility to prehospital EMS presents a serious challenge. An efficient strategy to address this issue involves using geographic information systems (GIS)-based tools to evaluate the spatial accessibility in conjunction with the spatial distribution of aging people, available road networks, and prehospital EMS facilities. This study employed gravity model and empirical Bayesian Kriging (EBK) interpolation analysis to evaluate the elderly’s spatial access to prehospital EMS in Ningbo, China. In our study, we aimed to solve the following specific research questions: In the study area, “what are the characteristics of the prehospital EMS demand of the elderly?” “Do the elderly have equal and convenient spatial access to prehospital EMS?” and “How can we satisfy the prehospital EMS demand of an aging population, improve their spatial access to prehospital EMS, and then ensure their quality of life?” The results showed that 37.44% of patients admitted to prehospital EMS in 2020 were 65 years and older. The rate of utilization of ambulance services by the elderly was 27.39 per 1000 elderly residents. Ambulance use by the elderly was the highest in the winter months and the lowest in the spring months (25.90% vs. 22.38%). As for the disease spectrum, the main disease was found to be trauma and intoxication (23.70%). The mean accessibility score was only 1.43 and nearly 70% of demand points had scored lower than 1. The elderly’s spatial accessibility to prehospital EMS had a central-outward gradient decreasing trend from the central region to the southeast and southwest of the study area. Our proposed methodology and its spatial equilibrium results could be taken as a benchmark of prehospital care capacity and help inform authorities’ efforts to develop efficient, aging-focused spatial accessibility plans.

Incidence and Outcomes of Out-of-Hospital Cardiac Arrest in Singapore and Victoria: A Collaborative Study

Background

Incidence and outcomes of out‐of‐hospital cardiac arrest (OHCA) vary between communities. We aimed to examine differences in patient characteristics, prehospital care, and outcomes in Singapore and Victoria.

Methods and Results

Using the prospective Singapore Pan‐Asian Resuscitation Outcomes Study and Victorian Ambulance Cardiac Arrest Registry, we identified 11 061 and 32 003 emergency medical services‐attended adult OHCAs between 2011 and 2016 respectively. Incidence and survival rates were directly age adjusted using the World Health Organization population. Survival was analyzed with logistic regression, with model selection via backward elimination. Of the 11 061 and 14 834 emergency medical services‐treated OHCAs (overall mean age±SD 65.5±17.2; 67.4% males) in Singapore and Victoria respectively, 11 054 (99.9%) and 5595 (37.7%) were transported, and 440 (4.0%) and 2009 (13.6%) survived. Compared with Victoria, people with OHCA in Singapore were older (66.7±16.5 versus 64.6±17.7), had less shockable rhythms (17.7% versus 30.3%), and received less bystander cardiopulmonary resuscitation (45.7% versus 58.5%) and defibrillation (1.3% versus 2.5%) (all P<0.001). Age‐adjusted OHCA incidence and survival rates increased in Singapore between 2011 and 2016 (P<0.01 for trend), but remained stable, though higher, in Victoria. Likelihood of survival increased significantly (P<0.001) with arrest in public locations (adjusted odds ratio [aOR] 1.81), witnessed arrest (aOR 2.14), bystander cardiopulmonary resuscitation (aOR 1.72), initial shockable rhythm (aOR 9.82), and bystander defibrillation (aOR 2.04) but decreased with increasing age (aOR 0.98) and emergency medical services response time (aOR 0.91).

Conclusions

Singapore reported increasing OHCA incidence and survival rates between 2011 and 2016, compared with stable, albeit higher, rates in Victoria. Survival differences might be related to different emergency medical services practices including patient selection for resuscitation and transport.

Factors Impacting Patient Outcomes Associated with Use of Emergency Medical Services Operating in Urban Versus Rural Areas: A Systematic Review

The goal of this systematic review was to examine the existing literature base regarding the factors impacting patient outcomes associated with use of emergency medical services (EMS) operating in urban versus rural areas. A specific subfocus on low and lower-middle-income countries was planned but acknowledged in advance as being potentially limited by a lack of available data. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed during the preparation of this systematic review. A comprehensive literature search of PubMed, EBSCO (Elton B. Stephens Company) host, Web of Science, ProQuest, Embase, and Scopus was conducted through May 2018. To appraise the quality of the included papers, the Critical Appraisal Skills Programme Checklists (CASP) were used. Thirty-one relevant and appropriate studies were identified; however, only one study from a low or lower-middle-income country was located. The research indicated that EMS in urban areas are more likely to have shorter prehospital times, response times, on-scene times, and transport times when compared to EMS operating in rural areas. Additionally, urban patients with out-of-hospital cardiac arrest or trauma were found to have higher survival rates than rural patients. EMS in urban areas were generally associated with improved performance measures in key areas and associated higher survival rates than those in rural areas. These findings indicate that reducing key differences between rural and urban settings is a key factor in improving trauma patient survival rates. More research in rural areas is required to better understand the factors which can predict these differences and underpin improvements. The lack of research in this area is particularly evident in low- and lower-middle-income countries.

A US National Study of the Association Between Income and Ambulance Response Time in Cardiac Arrest

IMPORTANCE

Emergency medical services (EMS) provide critical prehospital care, and disparities in response times to time-sensitive conditions, such as cardiac arrest, may contribute to disparities in patient outcomes.

OBJECTIVES

To investigate whether ambulance 9-1-1 times were longer in low-income vs high-income areas and to compare response times with national benchmarks of 4, 8, or 15 minutes across income quartiles.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cross-sectional study was performed of the 2014 National Emergency Medical Services Information System data in June 2017 using negative binomial and logistic regressions to examine the association between zip code-level income and EMS response times. The study used ambulance 9-1-1 response data for out-of-hospital cardiac arrest from 46 of 50 state repositories (92.0%) in the United States. The sample included 63 600 cardiac arrest encounters of patients who did not die on scene and were transported to the hospital.

MAIN OUTCOMES AND MEASURES

Four time measures were examined, including response time, on-scene time, transport time, and total EMS time. The study compared response times with EMS response time benchmarks for responding to cardiac arrest calls within 4, 8, and 15 minutes.

RESULTS

The study sample included 63 600 cardiac arrest encounters of patients (mean [SD] age, 60.6 [19.0] years; 57.9% male), with 37 550 patients (59.0%) from high-income areas and 8192 patients (12.9%) from low-income areas. High-income areas had greater proportions of white patients (70.1% vs 62.2%), male patients (58.8% vs 54.1%), privately insured patients (29.4% vs 15.9%), and uninsured patients (15.3% vs 7.9%), while low-income areas had a greater proportion of Medicaid-insured patients (38.3% vs 15.8%). The mean (SD) total EMS time was 37.5 (13.6) minutes in the highest zip code income quartile and 43.0 (18.8) minutes in the lowest. After controlling for urban zip code, weekday, and time of day in regression analyses, total EMS time remained 10% longer (95% CI, 9%-11%; P < .001), translating to 3.8 minutes longer in the poorest zip codes. The EMS response time to patients in high-income zip codes was more likely to meet 8-minute and 15-minute cutoffs compared with low-income zip codes.

CONCLUSIONS AND RELEVANCE

Patients with cardiac arrest from the poorest neighborhoods had longer EMS times compared with those from the wealthiest, and response times were less likely to meet national benchmarks in low-income areas, which may lead to increased disparities in prehospital delivery of care over time.

Emergency response time and pre-hospital trauma survival rate of the national ambulance service, Greater Accra (January - December 2014)

BACKGROUND

Every year, about 1.2 million people die through road traffic crashes worldwide. Majority of these deaths occur in Africa where most of their emergency medical services are underdeveloped. In 2004, Ghana established the National Ambulance Council to provide timely and efficient pre-hospital emergency medical care to the sick and injured. Pre-hospital emergency medical service is essential for accident victims since it has the potential of saving lives. The study sought to determine the relationship between pre-hospital trauma survival rate and response time to emergencies and factors associated to pre-hospital trauma survival  in Accra, Ghana.

METHODS

The study was a cross sectional study which reviewed pre-hospital care forms of trauma patients from the fourteen ambulance stations in the Greater Accra region from January to December 2014. Data were extracted from these forms and the response time estimated. Conscious patients who were alert were categorized as responsive under the AVPU scale. The proportion of patients who survived pre-hospital trauma and  the time pre-hospital trauma cases were responded to was estimated. Multiple logistic regression analysis was conducted to determine which variables were associated with survival.

RESULTS

A total of 652 pre-hospital care forms were reviewed. About 87% survived pre-hospital trauma. The average response time to patients was (16.9 ± 0.7) minutes and the median transportation time of the patient was 82 min. Level of consciousness of a patient and response time of patients transported was found to be significantly associated with pre-hospital trauma survival.

CONCLUSION

There was a high trauma patient survival rate among victims attended to by an NAS. The average response time in Greater Accra region in the 14 ambulance stations is 16.9 min which is not different from the 17 min recorded in 2013 by NAS. Factors that were associated with pre-hospital survival were alertness in the level of consciousness and response time less than 17 min.

Disparities in telephone CPR access and timing during out-of-hospital cardiac arrest

AIM

Spanish-only speaking residents in the United States face barriers to receiving potentially life-saving 911 interventions such as Telephone -cardiopulmonary resuscitation (TCPR) instructions. Since 2015, 911 dispatchers have placed an increased emphasis on rapid identification of potential cardiac arrest. The purpose of this study was to describe the utilization and timing of the 911 system during suspected out-of-hospital cardiac arrest (OHCA) by Spanish-speaking callers in Metropolitan Phoenix, Arizona.

METHODS

The dataset consisted of suspected OHCA from 911 centers from October 10, 2010 through December 31, 2013. Review of audio TCPR process data included whether the need for CPR was recognized by telecommunicators, whether CPR instructions were provided, and the time elements from call receipt to initiation of compressions.

RESULTS

A total of 3398 calls were made to 911 for suspected OHCA where CPR was indicated. A total of 39 (1.2%) were determined to have a Spanish language barrier. This averages to 18 calls per year with a Spanish language barrier during the study period, compared with 286 OHCAs expected per year among this population. The average time until telecommunicators recognized CPR need was 87.4s for the no language barrier group compared to 160.6s for the Spanish-language barrier group (p<0.001).Time to CPR instructions started was significantly different between these groups (144.4s vs 231.3s, respectively) (p<0.001), as was time to first compression, (174.4s vs. 290.9s, respectively) (p<0.001).

CONCLUSIONS

Our study suggests that Hispanic callers under-utilize the 911 system, and when they do call 911, there are significant delays in initiating CPR.

Developing quality indicators for physician-staffed emergency medical services: a consensus process

Background

There is increasing interest for quality measurement in health care services; pre-hospital emergency medical services (EMS) included. However, attempts of measuring the quality of physician-staffed EMS (P-EMS) are scarce. The aim of this study was to develop a set of quality indicators for international P-EMS to allow quality improvement initiatives.

Methods

A four-step modified nominal group technique process (expert panel method) was used.

Results

The expert panel reached consensus on 26 quality indicators for P-EMS. Fifteen quality indicators measure quality of P-EMS responses (response-specific quality indicators), whereas eleven quality indicators measure quality of P-EMS system structures (system-specific quality indicators).

Discussion

When measuring quality, the six quality dimensions defined by The Institute of Medicine should be appraised. We argue that this multidimensional approach to quality measurement seems particularly reasonable for services with a highly heterogenic patient population and complex operational contexts, like P-EMS. The quality indicators in this study were developed to represent a broad and comprehensive approach to quality measurement of P-EMS.

Conclusions

The expert panel successfully developed a set of quality indicators for international P-EMS. The quality indicators should be prospectively tested for feasibility, validity and reliability in clinical datasets. The quality indicators should then allow for adjusted quality measurement across different P-EMS systems.

Electronic supplementary material

The online version of this article (doi:10.1186/s13049-017-0362-4) contains supplementary material, which is available to authorized users.

Exploratory analysis of real personal emergency response call conversations: considerations for personal emergency response spoken dialogue systems

BACKGROUND

The purpose of this study was to derive data from real, recorded, personal emergency response call conversations to help improve the artificial intelligence and decision making capability of a spoken dialogue system in a smart personal emergency response system. The main study objectives were to: develop a model of personal emergency response; determine categories for the model's features; identify and calculate measures from call conversations (verbal ability, conversational structure, timing); and examine conversational patterns and relationships between measures and model features applicable for improving the system's ability to automatically identify call model categories and predict a target response.

METHODS

This study was exploratory and used mixed methods. Personal emergency response calls were pre-classified according to call model categories identified qualitatively from response call transcripts. The relationships between six verbal ability measures, three conversational structure measures, two timing measures and three independent factors: caller type, risk level, and speaker type, were examined statistically.

RESULTS

Emergency medical response services were the preferred response for the majority of medium and high risk calls for both caller types. Older adult callers mainly requested non-emergency medical service responders during medium risk situations. By measuring the number of spoken words-per-minute and turn-length-in-words for the first spoken utterance of a call, older adult and care provider callers could be identified with moderate accuracy. Average call taker response time was calculated using the number-of-speaker-turns and time-in-seconds measures. Care providers and older adults used different conversational strategies when responding to call takers. The words 'ambulance' and 'paramedic' may hold different latent connotations for different callers.

CONCLUSIONS

The data derived from the real personal emergency response recordings may help a spoken dialogue system classify incoming calls by caller type with moderate probability shortly after the initial caller utterance. Knowing the caller type, the target response for the call may be predicted with some degree of probability and the output dialogue could be tailored to this caller type. The average call taker response time measured from real calls may be used to limit the conversation length in a spoken dialogue system before defaulting to a live call taker.

Population-level Spatial Access to Prehospital Care by the National Ambulance Service in Ghana

BACKGROUND

Conditions requiring emergency treatment disproportionately affect low- and middle-income countries (LMICs), where there is often insufficient prehospital care capacity. To inform targeted prehospital care development in Ghana, we aimed to describe spatial access to formal prehospital care services and identify ambulance stations for capacity expansion.

METHODS

Cost distance methods were used to evaluate areal and population-level access to prehospital care within 30 and 60 minutes of each of the 128 ambulance stations in Ghana. With network analysis methods, a two-step floating catchment area model was created to identify district-level variability in access. Districts without NAS stations within their catchment areas were identified as candidates for an additional NAS station. Additionally, five candidate stations for capacity expansion (e.g., addition of an ambulance) were then identified through iterative simulations that were designed to identify the stations that had the greatest influence on the access scores of the ten lowest access districts.

RESULTS

Following NAS inception, the proportion of Ghana's landmass serviceable within 60 minutes of a station increased from 8.7 to 59.4% from 2004 to 2014, respectively. Over the same time period, the proportion of the population with access to the NAS within 60-minutes increased from 48% to 79%. The two-step floating catchment area model identified considerable variation in district-level access scores, which ranged from 0.05 to 2.43 ambulances per 100,000 persons (median 0.45; interquartile range 0.23-0.63). Seven candidate districts for NAS station addition and five candidate NAS stations for capacity expansion were identified. The addition of one ambulance to each of the five candidate stations improved access scores in the ten lowest access districts by a total 0.22 ambulances per 100,000 persons.

CONCLUSIONS

The NAS in Ghana has expanded its population-level spatial access to the majority of the population; however, access inequality exists in both rural and urban areas that can be improved by increasing station capacity or adding additional stations. Geospatial methods to identify access inequities and inform service expansion might serve as a model for other LMICs attempting to understand and improve formal prehospital care services.

The CPR outcomes of online medical video instruction versus on-scene medical instruction using simulated cardiac arrest stations

BACKGROUND

Non-traumatic cardiac arrest is a fatal emergency condition. Its survival rate and outcomes may be better with quick and effective cardiopulmonary resuscitation (CPR). Telemedicine such as telephone or real time video has been shown to improve chest compression procedures. There are limited data on the effects of telemedicine in cardiac arrest situations in the literature particularly in Asian settings.

METHODS

This study was conducted by using two simulated cardiac arrest stations during the 2014 annual Thai national conference in emergency medicine. These two stations, nos. 5 and 11, were a part of the conference activity called "EMS rally" which was comprised of 14 stations. Both stations were shockable and out-of-hospital cardiac arrest situations; station 5 was online instructed, while station 11 was on-scene instructed. There were 14 representative teams from each province from all over Thailand who participated in the rally. Each team had one physician, one nurse, and two emergency medicine technicians. Eight CPR outcomes were evaluated and compared between the online versus on-scene situations.

RESULTS

There were 14 representative teams that participated in the study; a total of 14 physicians, 14 nurses, and 28 emergency medicine technicians. The average ages of participants in all three occupations were between the second and third decade of life. The percentages of participants with more than 3 years in ambulance experience was 7.1, 64.3, and 53.6 % in the physicians, nurses, and EMTs groups. The median times of all outcomes were significantly longer in the online group than the on-scene group including times from start to chest compression (total 102 vs 36 s), total times from the start to VT/VF detection (187 vs 99 s); times from VT/VF detection to the first defibrillation (57 vs 28 s); and times from the start of adrenaline injection (282 vs 165 s). The percentages of using amiodarone (21.43 % vs 57.14 %; p value < 0.001), establishment of a definitive airway (35.71 % vs 100 %; p value 0.003), and correct detections of pulseless electrical activity (PEA) (28.57 % vs 100 %; p value < 0.001) were significantly lower in the online group than the on-scene group. The high quality CPR outcomes between the online group and on-scene group were comparable.

CONCLUSIONS

The online medical instruction may have worse CPR outcomes compared with on-scene medical instruction in shockable, simulated CPR scenarios. Further studies are needed to confirm these results.

Prehospital triage accuracy in a criteria based dispatch centre

BACKGROUND

Priority dispatch accuracy is a key issue in optimizing the match between patients' medical needs and pre-hospital resources. This study measures the accuracy of a Criteria Based Dispatch (CBD) system, by evaluating discrepancies between dispatch priorities and ambulance crews' severity evaluations.

METHODS

This is a retrospective study conducted from January 2011 to December 2011. We ruled that a National Advisory Committee for Aeronautics (NACA) score > 3 (injuries/diseases which can possibly lead to deterioration of vital signs) to 7 (lethal injuries/ diseases) should require a priority dispatch with lights and siren (L&S), while NACA scores < 4 should require a priority dispatch without L&S. Over triage was defined as the proportion of L&S dispatches with a NACA score < 4, and under triage as the proportion of dispatches without L&S with a NACA score > 3.

RESULTS

There were 29,008 primary missions in 2011, 1122 were excluded. Of the 15,749 L&S missions, 12,333 patients had a NACA score < 4, leading to an over triage rate of 78 %; 561 missions out of 12,137 missions without L&S had a NACA score > 3, leading to an under triage rate of 4.6 %. Sensitivity was 86 % (95 % confidence interval: 85.6-86.4 %), specificity 48 % (47.4-48.6 %), positive predictive value 21.7 % (21.2-22.2 %), and negative predictive value 95.4 % (95.2-95.6 %).

CONCLUSION

The rates of over triage and under triage in our CBD are 78 and 4.6 % respectively. The lack of consistent or universal metrics is perhaps the most important limitation in dispatch accuracy research. This is mainly due to the large heterogeneity of dispatch systems and prehospital emergency system.

Time on the scene and interventions are associated with improved survival in pediatric out-of-hospital cardiac arrest

BACKGROUND

Survival is less than 10% for pediatric patients following out-of-hospital cardiac arrest. It is not known if more time on the scene of the cardiac arrest and advanced life support interventions by emergency services personnel are associated with improved survival.

AIM

This study was performed to determine which times on the scene and which prehospital interventions were associated with improved survival.

METHODS

We studied patients aged 3 days to 19 years old with out-of-hospital cardiac arrest, using the Resuscitation Outcomes Consortium cardiac arrest database from 11 North American regions, from 2005 to 2012. We evaluated survival to hospital discharge according to on-scene times (<10, 10 to 35 and >35 min).

RESULTS

Data were available for 2244 patients (1017 infants, 594 children and 633 adolescents). Infants had the lowest rate of survival (3.7%) compared to children (9.8%) and adolescents (16.3%). Survival improved over the 7 year study period especially among adolescents. Survival was highest in the 10 to 35 min on-scene time group (10.2%) compared to the >35 min. group (6.9%) and the <10 min. group (5.3%, p=0.01). Intravenous or intra-osseous access attempts and fluid administration were associated with improved survival, whereas advanced airway attempts were not associated with survival and resuscitation drugs were associated with worse survival.

CONCLUSIONS

In this observational study, a scene time of 10 to 35 min was associated with the highest survival, especially among adolescents. Access for fluid resuscitation was associated with increased survival but advanced airway and resuscitation drugs were not.

Revisiting the "Golden Hour": An Evaluation of Out-of-Hospital Time in Shock and Traumatic Brain Injury

STUDY OBJECTIVE

We evaluate patients with shock and traumatic brain injury who were previously enrolled in an out-of-hospital clinical trial to test the association between out-of-hospital time and outcome.

METHODS

This was a secondary analysis of patients with shock and traumatic brain injury who were aged 15 years or older and enrolled in a Resuscitation Outcomes Consortium out-of-hospital clinical trial by 81 emergency medical services agencies transporting to 46 Level I and II trauma centers in 11 sites (May 2006 through May 2009). Inclusion criteria were systolic blood pressure less than or equal to 70 mm Hg or systolic blood pressure 71 to 90 mm Hg with pulse rate greater than or equal to 108 beats/min (shock cohort) and Glasgow Coma Scale score less than or equal to 8 (traumatic brain injury cohort); patients meeting both criteria were placed in the shock cohort. Primary outcomes were 28-day mortality (shock cohort) and 6-month Glasgow Outcome Scale-Extended score less than or equal to 4 (traumatic brain injury cohort).

RESULTS

There were 778 patients in the shock cohort (26% 28-day mortality) and 1,239 patients in the traumatic brain injury cohort (53% 6-month Glasgow Outcome Scale-Extended score ≤4). Out-of-hospital time greater than 60 minutes was not associated with worse outcomes after accounting for important confounders in the shock cohort (adjusted odds ratio [aOR] 1.42; 95% confidence interval [CI] 0.77 to 2.62) or traumatic brain injury cohort (aOR 0.77; 95% CI 0.51 to 1.15). However, shock patients requiring early critical hospital resources and arriving after 60 minutes had higher 28-day mortality (aOR 2.37; 95% CI 1.05 to 5.37); this finding was not observed among a similar traumatic brain injury subgroup.

CONCLUSION

Among out-of-hospital trauma patients meeting physiologic criteria for shock and traumatic brain injury, there was no association between time and outcome. However, the subgroup of shock patients requiring early critical resources and arriving after 60 minutes had higher mortality.

Impact of vehicular networks on emergency medical services in urban areas

The speed with which emergency personnel can provide emergency treatment is crucial to reducing death and disability among acute and critically ill patients. Unfortunately, the rapid development of cities and increased numbers of vehicles are preventing emergency vehicles from easily reaching locations where they are needed. A significant number of researchers are experimenting with vehicular networks to address this issue, but in most studies the focus has been on communication technologies and protocols, with few efforts to assess how network applications actually support emergency medical care. Our motivation was to search the literature for suggested methods for assisting emergency vehicles, and to use simulations to evaluate them. Our results and evidence-based studies were cross-referenced to assess each method in terms of cumulative survival ratio (CSR) gains for acute and critically ill patients. Simulation results indicate that traffic light preemption resulted in significant CSR increases of between 32.4% and 90.2%. Route guidance was found to increase CSRs from 14.1% to 57.8%, while path clearing increased CSRs by 15.5% or less. It is our hope that this data will support the efforts of emergency medical technicians, traffic managers, and policy makers.

Active chest compression-decompression for cardiopulmonary resuscitation

BACKGROUND

Active compression-decompression cardiopulmonary resuscitation (ACDR CPR) uses a hand-held suction device, applied mid-sternum, to compress the chest then actively decompress the chest after each compression. Randomised controlled trials testing this device have shown discordant results.

OBJECTIVES

To determine the effect of active chest compression-decompression CPR compared to standard chest compression CPR on mortality and neurological function in adults with cardiac arrest treated either in-hospital or out-of-hospital.

SEARCH METHODS

We updated the searches of CENTRAL in The Cochrane Library (Issue 12 of 12, 2012), MEDLINE (OVID, 1946 to January week 1 2013), and EMBASE (OVID, 1980 to week 1 2013) on 14 January 2013. We checked the reference list of retrieved articles, contacted experts in the field, and searched ClinicalTrials.gov.

SELECTION CRITERIA

All randomised or quasi-randomised studies comparing active compression-decompression with standard manual chest compression in adults with a cardiac arrest who received cardiopulmonary resuscitation by a trained medical or paramedical team.

DATA COLLECTION AND ANALYSIS

We independently extracted data on an intention-to-treat basis. When needed, we contacted the authors of the primary studies. If appropriate, we cumulated studies and pooled relative risk (RR) estimates. We predefined subgroup analyses according to setting (out-of-hospital or in-hospital) and attending team composition (with physician or paramedic only).

MAIN RESULTS

In this update, 27 new related publications were found, but they did not all fulfil inclusion criteria or concerned participants already reported in previous publications. In the end, we included 10 trials in this review: Eight were in out-of-hospital settings; one was set in-hospital only; and one had both in-hospital and out-of-hospital components. Allocation concealment was adequate in four studies. The two in-hospital studies were different in quality and size (773 and 53 participants). Both found no differences between ACDR CPR and STR in any outcome.Out-of-hospital trials cumulated 4162 participants. There were no differences between ACDR CPR and STR for mortality either immediately (RR 0.98, 95% confidence interval (CI) 0.94 to 1.03) or at hospital discharge (RR 0.99, 95% CI 0.98 to 1.01). The pooled RR of neurological impairment of any severity was 1.71 (95% CI 0.90 to 3.25), with a non-significant trend to more frequent severe neurological damage in survivors of ACDR CPR (RR 3.11, 95% CI 0.98 to 9.83). However, assessment of neurological outcome was limited, and few participants had neurological damage.There was no difference between ACDR CPR and STR with regard to complications such as rib or sternal fractures, pneumothorax, or haemothorax (RR 1.09, 95% CI 0.86 to 1.38). Skin trauma and ecchymosis were more frequent with ACDR CPR.

AUTHORS' CONCLUSIONS

Active chest compression-decompression in people with cardiac arrest is not associated with any clear benefit.

Emergency medical services intervals and survival in trauma: assessment of the "golden hour" in a North American prospective cohort

STUDY OBJECTIVE

The first hour after the onset of out-of-hospital traumatic injury is referred to as the "golden hour," yet the relationship between time and outcome remains unclear. We evaluate the association between emergency medical services (EMS) intervals and mortality among trauma patients with field-based physiologic abnormality.

METHODS

This was a secondary analysis of an out-of-hospital, prospective cohort registry of adult (aged > or =15 years) trauma patients transported by 146 EMS agencies to 51 Level I and II trauma hospitals in 10 sites across North America from December 1, 2005, through March 31, 2007. Inclusion criteria were systolic blood pressure less than or equal to 90 mm Hg, respiratory rate less than 10 or greater than 29 breaths/min, Glasgow Coma Scale score less than or equal to 12, or advanced airway intervention. The outcome was in-hospital mortality. We evaluated EMS intervals (activation, response, on-scene, transport, and total time) with logistic regression and 2-step instrumental variable models, adjusted for field-based confounders.

RESULTS

There were 3,656 trauma patients available for analysis, of whom 806 (22.0%) died. In multivariable analyses, there was no significant association between time and mortality for any EMS interval: activation (odds ratio [OR] 1.00; 95% confidence interval [CI] 0.95 to 1.05), response (OR 1.00; 95% CI 9.97 to 1.04), on-scene (OR 1.00; 95% CI 0.99 to 1.01), transport (OR 1.00; 95% CI 0.98 to 1.01), or total EMS time (OR 1.00; 95% CI 0.99 to 1.01). Subgroup and instrumental variable analyses did not qualitatively change these findings.

CONCLUSION

In this North American sample, there was no association between EMS intervals and mortality among injured patients with physiologic abnormality in the field.

An evaluation of 9-1-1 calls to assess the effectiveness of dispatch-assisted cardiopulmonary resuscitation (CPR) instructions: design and methodology

Background

Cardiac arrest is the leading cause of mortality in Canada, and the overall survival rate for out-of-hospital cardiac arrest rarely exceeds 5%. Bystander cardiopulmonary resuscitation (CPR) has been shown to increase survival for cardiac arrest victims. However, bystander CPR rates remain low in Canada, rarely exceeding 15%, despite various attempts to improve them. Dispatch-assisted CPR instructions have the potential to improve rates of bystander CPR and many Canadian urban communities now offer instructions to callers reporting a victim in cardiac arrest. Dispatch-assisted CPR instructions are recommended by the International Guidelines on Emergency Cardiovascular Care, but their ability to improve cardiac arrest survival remains unclear.

Methods/Design

The overall goal of this study is to better understand the factors leading to successful dispatch-assisted CPR instructions and to ultimately save the lives of more cardiac arrest patients. The study will utilize a before-after, prospective cohort design to specifically: 1) Determine the ability of 9-1-1 dispatchers to correctly diagnose cardiac arrest; 2) Quantify the frequency and impact of perceived agonal breathing on cardiac arrest diagnosis; 3) Measure the frequency with which dispatch-assisted CPR instructions can be successfully completed; and 4) Measure the impact of dispatch-assisted CPR instructions on bystander CPR and survival rates.

The study will be conducted in 19 urban communities in Ontario, Canada. All 9-1-1 calls occurring in the study communities reporting out-of-hospital cardiac arrest in victims 16 years of age or older for which resuscitation was attempted will be eligible. Information will be obtained from 9-1-1 call recordings, paramedic patient care reports, base hospital records, fire medical records and hospital medical records. Victim, caller and system characteristics will be measured in the study communities before the introduction of dispatch-assisted CPR instructions (before group), during the introduction (run-in phase), and following the introduction (after group).

Discussion

The study will obtain information essential to the development of clinical trials that will test a variety of educational approaches and delivery methods for telephone cardiopulmonary resuscitation instructions. This will be the first study in the world to clearly quantify the impact of dispatch-assisted CPR instructions on survival to hospital discharge for out-of-hospital cardiac arrest victims.

Trial Registration

ClinicalTrials.gov NCT00664443

A survey of attitudes and factors associated with successful cardiopulmonary resuscitation (CPR) knowledge transfer in an older population most likely to witness cardiac arrest: design and methodology

BACKGROUND

Overall survival rates for out-of-hospital cardiac arrest rarely exceed 5%. While bystander cardiopulmonary resuscitation (CPR) can increase survival for cardiac arrest victims by up to four times, bystander CPR rates remain low in Canada (15%). Most cardiac arrest victims are men in their sixties, they usually collapse in their own home (85%) and the event is witnessed 50% of the time. These statistics would appear to support a strategy of targeted CPR training for an older population that is most likely to witness a cardiac arrest event. However, interest in CPR training appears to decrease with advancing age. Behaviour surrounding CPR training and performance has never been studied using well validated behavioural theories.

METHODS/DESIGN

The overall goal of this study is to conduct a survey to better understand the behavioural factors influencing CPR training and performance in men and women 55 years of age and older. The study will proceed in three phases. In phase one, semi-structured qualitative interviews will be conducted and recorded to identify common categories and themes regarding seeking CPR training and providing CPR to a cardiac arrest victim. The themes identified in the first phase will be used in phase two to develop, pilot-test, and refine a survey instrument based upon the Theory of Planned Behaviour. In the third phase of the project, the final survey will be administered to a sample of the study population over the telephone. Analyses will include measures of sampling bias, reliability of the measures, construct validity, as well as multiple regression analyses to identify constructs and beliefs most salient to seniors' decisions about whether to attend CPR classes or perform CPR on a cardiac arrest victim.

DISCUSSION

The results of this survey will provide valuable insight into factors influencing the interest in CPR training and performance among a targeted group of individuals most susceptible to witnessing a victim in cardiac arrest. The findings can then be applied to the design of trials of various interventions designed to promote attendance at CPR classes and improve CPR performance.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00665288.

Characteristics and outcome among patients suffering from out-of-hospital cardiac arrest with the emphasis on availability for intervention trials

AIM

To describe all patients treated for out-of-hospital cardiac arrest (OHCA) according to the Utstein criteria and their characteristics and outcome with emphasis on whether they were available for early intervention trials.

DESIGN

Retrospective analysis of a study where data were collected prospectively.

SETTING

The Municipality of Göteborg/Mölndal in Sweden.

PATIENTS

All patients suffering from out-of-hospital cardiac arrest in the Municipality of Göteborg/Mölndal in whom cardiopulmonary resuscitation (CPR) was attempted between May 2003 and May 2005.

INTERVENTIONS

Part of the study cohort, i.e. patients with a witnessed, non-traumatic, out-of-hospital cardiac arrest were distributed (cluster) to mechanical (LUCAS) or manual chest compression.

RESULTS

The overall survival to discharge from hospital among the 508 patients was 8.5%. The corresponding value for non-cardiac cases was 5.1% and for cardiac cases if crew witnessed 16.1%, bystander witnessed 12.7% and non-witnessed 1.4%. Fifty-nine percent of the patients fulfilled the inclusion criteria for the trial and had no exclusion criteria and 9.7% of these survived to discharge. Ten percent of patients fulfilled the inclusion criteria but were excluded and 20.4% survived to discharge. Thirty-one percent of patients did not fulfil the inclusion criteria and 2.5% survived. Among patients included in the LUCAS group, many of the survivors, 10/13 (77%), experienced a rapid return of spontaneous circulation (ROSC) before the application of the device.

CONCLUSION

Among patients with OHCA in whom CPR was started 8.5% survived to hospital discharge and 59% were theoretically available for an early intervention trial. These patients have a different outcome compared with patients not available. However, among those available, the majority of survivors had a rapid ROSC before the application of the intervention (LUCAS). This raises concerns about the potential for early intervention trials to improve outcome after OHCA.

The formation of the emergency medical services system

The evolution of the emergency medical services system in the United States accelerated rapidly between 1960 and 1973 as a result of a number of medical, historical, and social forces. Current emergency medical services researchers, policy advocates, and administrators must acknowledge these forces and their limitations and work to modify the system into one that provides uniformly high-quality acute care to all patients, improves the overall public health through injury control and disease prevention programs, participates as a full partner in disease surveillance, and is prepared to address new community needs of all types.

Effect of automatic external defibrillator audio prompts on cardiopulmonary resuscitation performance

OBJECTIVES

To determine the effectiveness of the cardiopulmonary resuscitation (CPR) audio prompts in an automatic external defibrillator in 24 lay subjects, before and after CPR training.

METHODS

Untrained subjects were asked to perform CPR on a manikin with and without the assistance of audio prompts. All subjects were then trained in CPR, and retested them eight weeks later.

RESULTS

Untrained subjects who performed CPR first without audio prompts performed poorly, with only (mean (SD)) 24.5% (32%) of compressions at the correct site and depth, a mean compression rate of 52 (31) per minute, and with 15% (32%) of ventilatory attempts adequate. Repeat performance by this group with audio prompts resulted in significant improvements in compression rate (91(12), p = 0.0002, paired t test), and percentage of correct ventilations (47% (40%), p = 0.01 paired t test), but not in the percentage correct compressions (23% (29%)). Those who performed CPR first with audio prompts performed significantly better in compression rate (87 (19), p = 003, unpaired t test), and the percentage of correct ventilations (51 (34), p = 0.003 unpaired t test), but not in the percentage of correct compressions (18 (27)) than those without audio prompts. After training, CPR performance was significantly better than before training, but there was no difference in performance with or without audio prompts, although 73% of subjects commented that they felt more comfortable performing CPR with audio prompts.

CONCLUSIONS

For untrained subjects, the quality of CPR may be improved by using this device, while for trained subjects the willingness to perform CPR may be increased.

The ABC of resuscitation and the Dutch (re)treat

In 1982 the Netherlands made a unilateral decision to change the established airway-breathing-circulation (ABC) training sequence to a different approach that stressed efficiency in diagnosis and treatment. This Dutch approach became known as the CAB (circulation-airway-breathing) sequence. Twenty years later, being confronted with the new international guidelines (published 2000) that still use the ABC approach, the Netherlands Resuscitation Council (NRR) questioned again the validity of our persistence in using the "Dutch variant" of resuscitation. This resulted in revised national guidelines that conform again with the international guidelines. This article restates the main rationale and arguments behind the original decision to change to a Dutch (CAB) version of resuscitation over 20 years ago. The national decision to adopt the ABC approach once again was mainly to prevent resuscitation in the Netherlands from being isolated from the rest of the world and was not based on present knowledge of physiology and resuscitation. The authors hope that this article will open the discussion once again.

Long-term prognosis after out-of-hospital cardiac arrest and primary percutaneous coronary intervention

AIMS

To study the long-term survival after out-of-hospital cardiac arrest and successful cardiopulmonary resuscitation (CPR) in patients with acute ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI).

MATERIAL AND METHODS

In-hospital and 2-year survival of 40 patients treated with primary PCI after out-of-hospital cardiac arrest and STEMI was compared with that of a reference group of 325 STEMI patients, without cardiac arrest, also treated with primary PCI in the same period.

RESULTS

In the group with out-of-hospital cardiac arrest, both in-hospital and 2-year mortality was 27.5%. In the reference group, in-hospital and 2-year mortality was 4.9 and 7.1%, respectively. After discharge from hospital there was no significant difference in mortality between the groups.

CONCLUSION

Long-term prognosis is good in selected patients after successful out-of-hospital CPR and STEMI treated with primary PCI.

Advanced cardiac life support in out-of-hospital cardiac arrest

BACKGROUND

The Ontario Prehospital Advanced Life Support (OPALS) Study tested the incremental effect on the rate of survival after out-of-hospital cardiac arrest of adding a program of advanced life support to a program of rapid defibrillation.

METHODS

This multicenter, controlled clinical trial was conducted in 17 cities before and after advanced-life-support programs were instituted and enrolled 5638 patients who had had cardiac arrest outside the hospital. Of those patients, 1391 were enrolled during the rapid-defibrillation phase and 4247 during the subsequent advanced-life-support phase. Paramedics were trained in standard advanced life support, which includes endotracheal intubation and the administration of intravenous drugs.

RESULTS

From the rapid-defibrillation phase to the advanced-life-support phase, the rate of admission to a hospital increased significantly (10.9 percent vs. 14.6 percent, P<0.001), but the rate of survival to hospital discharge did not (5.0 percent vs. 5.1 percent, P=0.83). The multivariate odds ratio for survival after advanced life support was 1.1 (95 percent confidence interval, 0.8 to 1.5); after an arrest witnessed by a bystander, 4.4 (95 percent confidence interval, 3.1 to 6.4); after cardiopulmonary resuscitation administered by a bystander, 3.7 (95 percent confidence interval, 2.5 to 5.4); and after rapid defibrillation, 3.4 (95 percent confidence interval, 1.4 to 8.4). There was no improvement in the rate of survival with the use of advanced life support in any subgroup.

CONCLUSIONS

The addition of advanced-life-support interventions did not improve the rate of survival after out-of-hospital cardiac arrest in a previously optimized emergency-medical-services system of rapid defibrillation. In order to save lives, health care planners should make cardiopulmonary resuscitation by citizens and rapid-defibrillation responses a priority for the resources of emergency-medical-services systems.

Optimal dosing of dobutamine for treating post-resuscitation left ventricular dysfunction

OBJECTIVES

This study was designed to determine the optimal dose of dobutamine in the treatment of post-resuscitation left ventricular dysfunction.

BACKGROUND

Global left ventricular dysfunction following successful resuscitation from prolonged, ventricular fibrillation cardiac arrest, negatively impacts long-term survival. Dobutamine can overcome this global myocardial stunning. Previous data indicate a dose of 10 mcg/kgmin improves systolic and diastolic function, but markedly increases the heart rate.

METHODS

Twenty swine (24 +/- 0.4 kg) were randomized to one of four doses (0, 2, 5, and 7.5 mcg/kgmin) of dobutamine for the treatment of post-resuscitation myocardial dysfunction following 12.5 min of untreated ventricular fibrillation cardiac arrest. Cardiac function was measured at pre-arrest baseline and serially for 6 h post-resuscitation. Left ventricular function was evaluated by contrast ventriculograms, left ventricular pressures, +dP/dt, Tau, -dP/dt, and cardiac output. Myocardial oxygen consumption and myocardial blood flow were measured to assess the functional significance of any dobutamine-mediated heart rate responses.

RESULTS

Left ventricular dysfunction was evident at 25 min and peaked 4 h post-resuscitation. Significant (P < 0.05) improvements in ventricular systolic (EF, CO) and diastolic (LVEDP, Tau) function were evident within minutes of dobutamine initiation and persisted at 6h for the 5 and 7.5 mcg/kgmin groups. Tachycardia manifested with all dobutamine doses, but only affected myocardial oxygen consumption significantly (P < 0.05) at the highest dose (7.5 mcg/kgmin).

CONCLUSIONS

Dobutamine at 5 mcg/kgmin appears optimal for restoring systolic and diastolic function post-resuscitation without adversely affecting myocardial oxygen consumption.

Modeling an emergency medical services system using computer simulation

STUDY OBJECTIVES

In the emergency medical services (EMS) system, appropriate prehospital care can substantially decrease casualty mortality and morbidity. This study designed a simulation model, evaluated the existing EMS system, and suggested improvements.

METHODS

The study focused on 23 networked EMS hospitals affiliated with 36 emergency response units (subgroups) to perform two-tier rescues (advanced life support [ALS] in addition to basic life support [BLS] services) in Taipei, Taiwan. Using the existing EMS model as a base, this research constructed a computer simulation model and explored several model alternatives to achieve the study's objectives. The virtual models varied with staffing level, number of assigned emergency network hospitals, and various two-tier rescue probabilities.

RESULTS

Increasing the staffing to two teams for Hospital 22 lessened the call waiting probability (delay between rescue call and ambulance dispatch) by 50%, even if the dispatch rate of the two-tier rescue increased from the empirical 2% to a simulated 10 and 20%. Changing the two-tier rescue pattern so each EMS subgroup cooperated with two specific, preassigned network hospitals lowered the probability of patients having to wait for rescue dispatch to under 1%.

CONCLUSION

The following alternatives provided the greatest combination of effectiveness, quality patient care, and cost-efficiency: (1) because of its unique location, increase Hospital 22's staffing level to two ALS teams. (2) Establish a specific rescue protocol for the two-tier system that preassigns two network hospitals to each of the 36 EMS subgroups along with a prearranged calling sequence. If implemented, this will improve EMS performance, streamline the system, reduce randomness, and enhance efficiency.

Sudden death in the community

About one fifth of all deaths occur suddenly and unexpectedly, often as the first manifestation of heart disease. Several tests have been developed during the past 2 decades for risk stratification of such an event, but only a minority of victims can be identified as being at high risk before sudden death occurs. Improving the results of out-of-hospital resuscitation attempts is of crucial importance. Use of the automated external defibrillator is rapidly increasing worldwide. However, the defibrillator must be used within minutes after the onset of cardiac arrest, and rapid recognition and localization of the victim are essential. The development of a device that constantly monitors vital signs and can diagnose cardiac arrest, generate an alarm, and transmit the location of the victim could be an important step in improving the results of cardiac resuscitation.

The automated external defibrillator: critical link in the chain of survival

Sudden death due to ventricular fibrillation (VF) is the leading cause of death in the United States. Early defibrillation is the most important determinant of survival and is the key element in cardiopulmonary resuscitation. Obstacles to rapid defibrillation by trained emergency personnel persist, but the development of the automated external defibrillator (AED) promises to realize the goal of widespread early defibrillation and translate to an improved chance for survival for the cardiac arrest victim. Technological advancements have made the AED safe, easy to use, accurate, and effective in terminating VF. Use of the AED by trained nontraditional first responders (e.g., firefighters, police officers, flight crews) has improved survival rates in a variety of settings and forms the basis for public-access defibrillation.

Prehospital resuscitation practices: a survey of prehospital providers

Numerous factors affect decision making in the prehospital provision of resuscitative care. This study was undertaken to determine current practices involved in the initiation, continuation and termination of resuscitative efforts, and the impact of advance directives, in the prehospital resuscitation setting. This cross-sectional mailed questionnaire surveyed 3807 members of the National Association of Emergency Medical Technicians. The study instrument included questions regarding the termination and withholding of resuscitative efforts in the prehospital setting, as well as survival rates, local protocols and compliance with advance directives. Of 1546 respondents (41% response rate), with a mean 9.0 years of experience, most (89%) indicated that they would withhold resuscitative efforts in the presence of an official state-approved advance directive. However, very few providers would withhold resuscitative efforts if only an unofficial document (4%) or verbal report of an advance directive (10%) were available. Providers with more than 10 years experience were more likely to withhold resuscitation attempts in the presence of only a verbal report of an advance directive (p = 0.02, Chi-square), and were more likely to withhold resuscitation attempts in situations they considered futile (p = 0.001, Chi-square). Most (77%) respondents have local EMS guidelines for termination of resuscitation in the prehospital setting, but 23% of those consider existing guidelines to be inadequate. The majority of prehospital providers stated that they honor official state-approved advance directives, but do not follow directives from unofficial documents or verbal reports of advance directives. More experienced providers stated that they withhold resuscitative efforts more often in futile situations, or in the presence of unofficial advance directives. Advance directives should be utilized more uniformly among patients who wish to forgo resuscitative efforts in the event of cardiac arrest. Because many local protocols are judged to be inadequate, we support the institution of improved clinical guidelines regarding the prehospital termination of resuscitative efforts.

Common faults in resuscitation equipment--guidelines for checking equipment and drugs used in adult cardiopulmonary resuscitation

Successful advanced life support relies, in part, upon the availability and correct functioning of resuscitation equipment. However, numerous publications report deficiencies and defects in key items of resuscitation equipment, particularly those relating to airway management and defibrillation. Some of these are generic and relate to basic device failure (e.g. intrinsic design faults, manufacturing errors, random component failure), external factors (e.g. power failure, gas supply failure, electromagnetic interference) and human error (notably, inadequate knowledge, lack of experience and training, inadequate checking, insufficient maintenance). However, others are device specific. This paper identifies the common, generic faults that lead to equipment malfunction and recommends the resuscitation equipment essential for successful cardiopulmonary resuscitation. It also describes examples of specific equipment malfunction and makes suggestions for the nature and frequency of resuscitation equipment and drug checks, using a structured, and easy-to-recall list.

Community competence in cardiopulmonary resuscitation

The aim of this study was to determine community application of cardiopulmonary resuscitation (CPR) skills in an emergency, and, thus, assess the value of training programmes in raising community competence. A cross-sectional telephone survey of the Western Australian population was chosen randomly (n = 803). An urban sub-sample (n = 100) performed a practical demonstration of CPR skills using a simulated collapse scenario using a recording manikin as the victim. Performance was assessed by two observers using pre-determined criteria. Of all respondents, 64% had been trained in CPR. Practical and theoretical assessment scores were significantly better in trained versus untrained participants. The number of times a person was trained in CPR was more effective for retention and competence than time since last trained. Degree of training and theoretical competence were less in those aged over 65 years or with heart disease in the household. Theoretical competence poorly reflected practical performance in many tasks. This study provides a comprehensive database of CPR training and performance, and highlights future directions to ensure appropriate and cost-effective training. Specific factors to be addressed include increasing frequency of training, targeting of high-risk groups, simplification in teaching, and emphasising early activation of the emergency medical system.

The ABCs of recording paediatric cardiac arrests

OBJECTIVE

To examine the quality and comprehensiveness of documentation in Paediatric 'cardiac arrests'.

DESIGN

Retrospective chart review.

SETTING

Tertiary care hospital wards, Paediatric Intensive Care and Accident and Emergency department.

SUBJECTS

41 children experiencing acute life-threatening events in hospital.

RESULTS

Overall documentation of details related to time, place and personnel was highly variable but generally present in over half of the cases reviewed. Data relating to specific drug-related and interventional therapies was insufficient, as was documentation of time intervals and consequent therapeutic decisions.

CONCLUSIONS

Documentation of critical resuscitation episodes in children is below recognised standards and this has potential quality of care and medicolegal implications. Current teaching needs to emphasise this essential aspect of clinical care from the earliest level of training.

A selective alpha(2)-adrenergic agonist for cardiac resuscitation

The effects of selective alpha(2)-adrenergic agonist alpha-methylnorepinephrine on the initial success of resuscitation and postresuscitation myocardial function were compared with nonselective alpha- and beta-adrenergic epinephrine in a swine model of cardiac arrest. Epinephrine, the primary pharmacological intervention in the treatment of cardiac arrest, improves immediate outcome. However, epinephrine increases the severity of myocardial dysfunction after cardiac resuscitation. Both inotropic and chronotropic actions provoke disproportionate increases in myocardial oxygen consumption by the ischemic heart, prompting this study, in which we hypothesized that a selective alpha(2)-adrenergic agonist, alpha-methylnorepinephrine (alpha-MNE), would moderate these adverse effects of epinephrine and minimize postresuscitation myocardial dysfunction. After 7 minutes of untreated ventricular fibrillation (VF) in 14 anesthetized male domestic pigs, precordial compression at a fixed rate of 80 compressions/min was begun, along with mechanical ventilation. Either alpha-MNE (100 microg/kg) or epinephrine (20 microg/kg) was administered as a bolus after 2 minutes of precordial compression. After an additional 4 minutes of precordial compression, defibrillation was attempted. Left ventricular systolic and diastolic function was quantitated with the use of transesophageal echo-Doppler imaging. Comparable increases in coronary perfusion pressure to 15 mm Hg were observed after the administration of both drugs. All animals were successfully resuscitated; epinephrine and alpha-MNE were equally quick in restoring spontaneous circulation after 7 minutes of untreated VF. Ejection fraction was reduced by 35% and 14% by epinephrine and alpha-MNE, respectively, after resuscitation. Epinephrine and alpha-MNE increased postresuscitation heart rate by 38% and 15%, respectively. Accordingly, significantly less postresuscitation impairment followed the administration of alpha-MNE. alpha-MNE, a selective alpha-adrenergic agonist, was as effective as epinephrine in restoring spontaneous circulation after 7 minutes of untreated VF in a porcine model for CPR and demonstrated lesser postresuscitation myocardial injury.

Teaching hand placement for chest compression--a simpler technique

BACKGROUND

Simplification of the techniques and teaching of resuscitation are advocated as ways of improving skill acquisition and retention. A simple method for teaching hand placement for chest compression has been described but not validated.

OBJECTIVE

The objective of this study was to determine if instructing trainees simply to place their hands in the centre of the chest results in better initial and retained accuracy of hand placement than the usual method of first identifying anatomical landmarks.

METHODS

Volunteers received instruction in basic CPR, being taught hand placement either by the standard method (33 subjects) or the simplified method (32 subjects). They were tested for accuracy of hand position before training, immediately afterwards and 6 weeks later.

RESULTS

After training both groups showed an improvement in accuracy of hand placement but there was no significant difference in the degree of improvement between the groups (P=0.345), nor in the level of accuracy achieved (P=0.178). Six weeks after training, the Standard Group demonstrated a statistically significant deterioration in accuracy (P=0.001), whereas the Simple Group did not (P=0.561). By this time, however, there was no longer any difference in accuracy of hand placement for either group compared with before training (Standard Group P=0.912; Simple Group P=0.140). On the positive side, the Simple Group took significantly less time (2.90 s) than the Standard Group (4.43 s) to change from ventilation to chest compression (P=0.000003).

CONCLUSIONS

Simplifying the teaching of correct hand placement for chest compression does not appear to lead to improvement in acquisition or retention of the skill. However, it does result in a significant reduction in the length of the pauses between ventilation and chest compression.

Defibrillation by general practitioners

OBJECTIVE

To investigate the mode of cardiac arrest in patients with acute myocardial infarction attended by general practitioners, and the effectiveness of early defibrillation.

DESIGN

Retrospective observational study.

SETTING

British general practice.

PARTICIPANTS

General practitioners equipped with defibrillators by the British Heart Foundation.

MAIN OUTCOME MEASURES

Cardiac rhythm when first monitored, response to defibrillation assessed by survival to reach hospital alive and survival to hospital discharge.

INTERVENTIONS

Defibrillation and standard cardiopulmonary resuscitation in patients with cardiac arrest complicating acute myocardial infarction attended by British general practitioners.

RESULTS

When a doctor equipped with a defibrillator witnessed an arrest or was able to initiate resuscitation within 4 min of the patient collapsing, 90% of patients were found to have developed a rhythm likely to respond to a defibrillatory shock. Defibrillation under these circumstances was very successful with more than 70% of patients subsequently admitted to hospital alive and approximately 60% surviving to be discharged alive. When the doctor commenced resuscitation later, fewer patients were found to have rhythms likely to be responsive to a DC shock. A greater proportion was in asystole and resuscitation was less frequently successful under these circumstances. When the arrest occurred in the doctor's surgery, 85% of patients were admitted to hospital alive and three quarters survived to hospital discharge.

CONCLUSIONS

All those who provide the initial care for this vulnerable group of patients should be equipped with defibrillators. The more widespread deployment of defibrillators in the community may be a successful strategy for reducing unnecessary deaths from coronary heart disease.

Factors associated with CPR certification within an elderly community

OBJECTIVE

To determine the frequency of CPR certification amongst residents living within a predominantly elderly community and examine the perceived barriers to learning basic CPR and factors associated with intent to become certified.

METHODS

A household survey was sent with a community newsletter to each home of a non-gated elderly community that requires one member of each household to be at least 55 years of age. The community consists of 2488 homes (approximately 4000 residents). Thirteen Yes/No questions were asked in a skip-pattern based upon the question: "Are you CPR certified?" Data analysis included univariate, bivariate, and logistic regression.

RESULTS

947 participants with a mean age of 69 completed and returned the survey. Forty-eight percent of the participants had received prior training in CPR. Eighty-four percent were not currently certified in CPR, and top reasons cited were: 'don't know why' (36%), 'lack of interest' (20%), 'concerned about health risks' (17%). Forty-six percent of those not certified desired certification. Increasing age was inversely associated with CPR certification status and the desire to be certified.

CONCLUSION

Almost half of the residents in this predominantly elderly community had received prior training in CPR, although most were not currently certified and cite significant specific and non-specific reasons and obstacles. Improved survival requires targeted interventions to achieve higher proportions of CPR-competent individuals in such high-risk communities.

Out of hospital cardiac arrests--the experience of one hospital in Singapore

In Singapore, all public emergency ambulances are equipped with semi-automatic external defibrillators and the crew is trained in their use. This is the first paper from Singapore reporting the survival rate in patients presenting to an urban public hospital with acute coronary syndrome (ACS) who developed out-of-hospital cardiac arrest (OHCA). All consecutive patients who presented to the ED of a public hospital with OHCA or ACS were surveyed from 1 April 1999 to 30 September 1999. There were 392 patients among whom 115 (28.5%) had OHCA. There was no significant difference in age and gender distribution between the OHCA and non-OHCA patients. More than 2/3 of the OHCA patients had no report of chest pain or breathlessness before they collapsed. Forty five (39.1%) of the 115 OHCA patients were noted to have initial rhythms of ventricular tachycardia (VT) or ventricular fibrillation (VF) and received pre-hospital defibrillation. The mean time from collapse to first DC shock was 12.07+/-7.2 min. Twenty (17.4%) of the OHCA patients had return of spontaneous circulation after resuscitation in the ED. Four patients (3.5%), all with an initial rhythm of VF were discharged alive from the hospital. Much remains to be done to reduce the time interval to first DC shock for the OHCA group.

Resuscitation research: future directions and ethical issues

Cardiopulmonary resuscitation research is a vital area of research that has made significant contributions to medical care over the last several decades. Abundant information currently exists in the medical literature, as a result of research in the areas of cardiac arrest and outcomes, physiology of cardiac arrest, pharmacologic treatments, mechanical interventions, and societal and ethical issues. Despite numerous clinical trials demonstrating physiologic benefit of various interventions, few interventions have had as much impact on outcomes of cardiac arrest as have improvements in out-of-hospital response times and rapid availability of medical treatment. Although abundant information exists regarding physiologic aspects of resuscitation, relatively little information exists about ethical, psychological, and social aspects of resuscitation. In addition to attempts to improve outcomes of cardiac arrest, researchers should also strive to improve the experiences of patients and families involved. These realities provide future strategies and directions for the best use of resuscitation research resources; although physiologic and pharmacologic research will always have significant roles in the improvement of medical care, the rapid delivery of out-of-hospital care and ethical issues will be indispensable areas of research focus in the future.

Neurological rehabilitation of severely disabled cardiac arrest survivors. Part I. Course of post-acute inpatient treatment

BACKGROUND

Some survivors of out-of-hospital cardiac arrest (CA) sustain anoxic brain injury. The aim of this study was to offer these patients a new treatment approach, to describe the course and outcome of rehabilitation, and to judge whether rehabilitation provided benefit.

METHODS

Twenty severely disabled patients (mean age 47.6 years, 17 M:3 F) were admitted for inpatient rehabilitation after sustaining anoxic brain damage secondary to CA. The multidisciplinary treatment approach aimed at orientation, communication, mobility, and self care. Function was assessed using Barthel index (BI) score. On discharge, placement and global outcome was noted. Medical charts of consecutive patients were reviewed retrospectively.

RESULTS

Inpatient rehabilitation lasted on for average 12 weeks. Improvement in function was slow with a median increase of 1.88 BI score per week. Patients achieved clinically significant functional improvement as measured by pre-post comparison of BI (P<0.001). On discharge, overall disability was mild in 2 (10%), moderate in 7 (35%), and severe in 11 (55%) patients.

CONCLUSION

Rehabilitation of selected CA survivors is appropriate, reducing the subsequent burden of care. Although in 55%, only minor dependence on care persisted, on a group level, the potential for rehabilitation was modest, and recovery curve was flat. Before admission, families should be given realistic information about the possible outcome, because independence was rarely achieved.

Circadian variation in witnessed out of hospital cardiac arrest

OBJECTIVES

To examine the effect on circadian variation of out of hospital cardiac arrest according to the underlying aetiology and presenting rhythm of arrest, and to explore strategies that might help to improve survival outcome using circadian variation.

DESIGN

Population based retrospective study.

SETTING

County of Nottinghamshire with a total population of 993 914 and an area of 2183 km(2).

SUBJECTS

Between 1 January 1991 and 3 December 1994, all witnessed cardiac arrests attended by the Nottinghamshire Ambulance Service, of which 1196 patients had a cardiac cause for their arrest (ICD, 9th revision, codes 390-414 and 420-429) and 339 had a non-cardiac cause.

RESULTS

The circadian variation of the cardiac cases was not significantly different from that of non-cardiac cases (p = 0.587), even when adjusted for age, sex, or presenting rhythm of arrest. For cardiac cases, the circadian variation of those who presented with ventricular fibrillation was significantly different from those presenting with a rhythm other than ventricular fibrillation (p = 0.005), but was similar to the circadian variation of bystander cardiopulmonary resuscitation (p = 0.306) and survivors (p = 0.542). Ambulance response time was also found to have a circadian variation.

CONCLUSIONS

There is a common circadian variation of out of hospital cardiac arrest, irrespective of underlying aetiology, where the presenting rhythm is other than ventricular fibrillation. This is different from the circadian variation of cases of cardiac aetiology presenting with ventricular fibrillation. The circadian variation of ventricular fibrillation, and consequently survival, may be affected by the availability of bystander cardiopulmonary resuscitation and the speed of ambulance response.