Out of hospital cardiac arrest outside home in Sweden, change in characteristics, outcome and availability for public access defibrillation

Effects of a volunteer responder system for out-of-hospital cardiac arrest in areas of different population density - A retrospective cohort study

BACKGROUND

Volunteer responder dispatch to nearby out-of-hospital cardiac arrests using a smartphone application can increase the proportion of patients receiving cardiopulmonary resuscitation. It is unknown how population density is related to the efficacy of a volunteer responder system. This study aimed to compare the response time of volunteer responders and EMS dispatched to suspected OHCAs in areas of different population density.

METHODS

A total of 2630 suspected OHCAs in Stockholm County during 2018-2020 where at least one dispatched volunteer responder reached the patient were identified through the HeartRunner™ application database. Study outcome was the proportion of cases where volunteer responders arrived at the scene before EMS, as well as the difference in time between the arrival of volunteer responders and EMS.

RESULTS

Volunteer responders arrived before EMS in 68% of examined cases (n = 1613). Higher population density was associated with a lower proportion of cases where volunteer responders arrived at the scene before EMS. Time on scene before arrival of EMS was highest in areas of low population density and averaged 4:07 (mm:ss). Response time was significantly shorter for volunteer responders compared to EMS across all population density groups at 4:47 vs 8:11 (mm:ss) (p < 0.001); the largest difference in response time was found in low population density areas.

CONCLUSION

Volunteer responders have significantly shorter response time than EMS regardless of population density, with the greatest difference in low population density areas. Although their impact on clinical outcome remains unknown, the benefits of dispatching volunteer responders to OHCAs may be greatest in rural areas.

Firefighters as first-responders in out-of-hospital cardiac arrest- a retrospective study of a time-gain selective dispatch system in the Skåne Region, Sweden

AIM

To analyze the impact of a time-gain selective, first-responder dispatch system on the presence of a shockable initial rhythm (SIR), return of spontaneous circulation (ROSC) and 30-day survival after out-of-hospital cardiac arrest (OHCA).

METHOD

A retrospective observational study comprising OHCA registry data and dispatch data in the Skåne Region, Sweden (2010-2018). Data were categorized according to dispatch procedures, two ambulances (AMB-only) versus two ambulances and firefighter first-responders (DUAL-dispatch), based on the dispatcher's estimation of a time-gain. Dual dispatch was sub-categorized by arrival of first vehicle (first-responder or ambulance). Logistic regressions were used, additionally with groups matched (1:1) for age, witnessed event, bystander cardiopulmonary resuscitation and ambulance response time. Adjusted and conditional odds-ratios (aOR, cOR) with 95% confidence intervals (CI) are presented.

RESULTS

Of 3,245 eligible cases, 43% were DUAL-dispatches with first-responders first on scene (FR-first) in 72%. Despite a five-minute median reduction in response time in the FR-first group, no association with SIR was found (aOR 0.83, 95%CI 0.64-1.07) nor improved 30-day survival (aOR 1.03, 95%CI 0.72-1.47). A positive association between ROSC and the FR-first group (aOR 1.25, 95%CI 1.02-1.54) disappeared in the matched analysis (cOR 1.12, 95%CI 0.87-1.43). Time to first monitored rhythm was 7:06 minutes in the FR-first group versus 3:01 in the combined AMB-only/AMB-first groups.

CONCLUSION

In this time-gain selective first-responder dispatch system, a shorter response time was not associated with increased SIR, improved ROSC rate or survival. Process measures differed between the study groups which could account for the observed findings and requires further investigation.

Research study on the efficiency of a defibrillating biphasic pulse of various durations based on mathematical modeling and simulation of a cardiomyocyte

The paper presents the results of our research study on the impact of different durations of a biphasic rectangular pulse on the efficiency of the defibrillating action based on modeling and simulation of a cardiomyocyte in the framework of Cell Electrophysiology Simulation Environment. We used Luo-Rudy Mammalian Ventricular Model II (dynamic) as the mathematical model of the biochemical processes, which occur both on the surface and inside a cardiomyocyte in a guinea pig. An analysis of the obtained results allowed us to determine the optimal time of the defibrillating pulse. It has been shown that a pulse of 4 ms duration has the highest efficiency. The research has been carried out directly based on the mathematical model and simulation of the cardiomyocyte that makes it possible to minimize errors which may occur in experiments on animals

Out-of-hospital cardiac arrest in the Pilsen Region in 2018

AIMS

To acquire epidemiological data on pre-hospital cardiac arrest incidents occurring in the Pilsen Region of the Czech Republic in 2018, and the results of subsequent cardiopulmonary resuscitation Methods. A prospective observational study of the survival rate of out-of-hospital cardiac arrest (OHCA) in patients undergoing CPR carried out by emergency medical service personnel. The observed time period was from January 1^st, 2018 until December 31^st, 2018. The data were acquired from patients' records in paper and electronic forms.

RESULTS

In the monitored period 707 patients with signs of cardiac arrest were recorded in the Pilsen Region with an incidence rate of 128.9 per 100,000 inhabitants. Emergency medical units performed CPR in 484 cases. The incidence rate of pre-hospital CPR was 88.2 cases per 100,000 inhabitants. Spontaneous blood circulation was temporarily or permanently restored in 276 patients (57.0%), 203 (41.9%) patients were transferred to a hospital, and there were 61 (12.6%) cases of survival with Cerebral Performance Category (CPC) score of 1 or 2. The first monitored rhythm was a shockable in 134 (27.7%) cases. In this sub-group ROSC was achieved in 94 (70.1%) cases and 58 (43.3%) of those were subsequently transferred to a hospital. A good CPC result was achieved in 41 (30.6%) patients of this sub group.

CONCLUSION

The study has provided valuable epidemiological data on OHCA and prehospital CPR in the area of the Pilsen Region in 2018. The collected data, compared to international results, show a higher survival rate with good neurological score in 12.6% of cases.

Apples to apples: can differences in out-of-hospital cardiac arrest incidence and outcomes between Sweden and Ireland be explained by core Utstein variables?

BACKGROUND

Variation in reported incidence and outcome based on aggregated data is a persistent feature of out-of-hospital cardiac arrest (OHCA) epidemiology.

OBJECTIVE

To investigate the extent to which patient-level analysis using core 'Utstein' variables explains inter-country variation between Sweden and the Republic of Ireland.

METHODS

A retrospective cross-sectional comparative study was performed, including all Swedish and Irish OHCA cases attended by Emergency Medical Services (EMS-attended OHCA) where resuscitation was attempted from 1st January 2012 to 31st December 2014. Incidence rates per 100,000 population were adjusted for age and gender. Two subgroups were extracted: (1) Utstein - adult patients, bystander-witnessed collapse, presumed medical aetiology, initial shockable rhythm and (2) Emergency Medical Service (EMS)-witnessed events. Multivariable logistic regression analysis was used to identify predictors of survival following multiple imputations of data.

RESULTS

Five thousand eight hundred eighty six Irish and 15,303 Swedish patients were included. Swedish patients were older than Irish patients (median age 71 vs. 66 years respectively). Adjusted incidence was significantly higher in Sweden compared to the Republic of Ireland (52.9 vs. 43.1 per 100,000 population per year). Proportionate survival in Sweden was greater for both subgroups and all age categories. Regression analysis of the Utstein subgroup predicted approximately 17% of variation in outcome, but there was a large unexplained 'country effect' for survival in favour of Sweden (OR 4.40 (95% CI 2.55-7.56)).

CONCLUSIONS

Using patient level data, a proportion of inter-country variation was explained, but substantial variation was not explained by the core Utstein variables. Researchers and policy makers should be aware of the potential for unmeasured differences when comparing OHCA incidence and outcomes between countries.

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.

Barriers and facilitators to public access defibrillation in out-of-hospital cardiac arrest: a systematic review

Public access defibrillation initiatives make automated external defibrillators available to the public. This facilitates earlier defibrillation of out-of-hospital cardiac arrest victims and could save many lives. It is currently only used for a minority of cases. The aim of this systematic review was to identify barriers and facilitators to public access defibrillation. A comprehensive literature review was undertaken defining formal search terms for a systematic review of the literature in March 2017. Studies were included if they considered reasons affecting the likelihood of public access defibrillation and presented original data. An electronic search strategy was devised searching MEDLINE and EMBASE, supplemented by bibliography and related-article searches. Given the low-quality and observational nature of the majority of articles, a narrative review was performed. Sixty-four articles were identified in the initial literature search. An additional four unique articles were identified from the electronic search strategies. The following themes were identified related to public access defibrillation: knowledge and awareness; willingness to use; acquisition and maintenance; availability and accessibility; training issues; registration and regulation; medicolegal issues; emergency medical services dispatch-assisted use of automated external defibrillators; automated external defibrillator-locator systems; demographic factors; other behavioural factors. In conclusion, several barriers and facilitators to public access defibrillation deployment were identified. However, the evidence is of very low quality and there is not enough information to inform changes in practice. This is an area in urgent need of further high-quality research if public access defibrillation is to be increased and more lives saved. PROSPERO registration number CRD42016035543.

[Acute kidney injury and renal replacement therapy in victims from out-of-hospital cardiac arrest with administration of contrast agent]

BACKGROUND

Early coronary angiography and computed tomography are recommended in survivors of out-of-hospital cardiac arrest (OHCA). However, both techniques require iodinated contrast agent although the effects on incident acute kidney injury are unknown. The aim of this study was to explore the incidence of acute kidney injuries (AKI) and need for renal replacement therapy (RRT) in patients after nontraumatic OHCA with special regard to the administration of contrast agent during the early in-hospital diagnostic workup.

MATERIALS AND METHODS

Data from all survivors of OHCA admitted to our hospital between 1 January 2008 and 30 June 2015 were retrospectively collected. Incidence of AKI and RRT between the contrast and no contrast groups were compared.

RESULTS

Of 280 OHCA survivors, 133 (47.5 %) received contrast agent (227.0 ± 136.5 ml). Within 72 h after hospital admission, 47 of 129 survivors (36.4 %) developed AKI of any stage, but AKI was more common in patients without early contrast administration than in patients with early contrast administration (54.5 vs. 28.2 %; p = 0.011). Patients who survived until hospital discharge had higher serum creatinine levels at admission than at hospital discharge (1.17 ± 0.37 vs. 0.92 ± 0.35; p < 0.001).

CONCLUSION

AKI is common in survivors of OHCA, and RRT following OHCA is needed more frequently than in other cardiac disease. Despite elevated serum creatinine levels at admission, we could not show an association between early contrast administration in survivors of OHCA and AKI incidence.

Risky locations for out-of-hospital cardiopulmonary arrest in a typical urban city

Background:

The aim of this study is to clarify the circumstances including the locations where critical events resulting in out-of-hospital cardiopulmonary arrest (OHCPA) occur.

Materials and Methods:

Subjects of this population-based observational case series study were the clinical records of patients with nontraumatic and nonneck-hanging OHCPA.

Results:

Of all 1546 cases, 10.3% occurred in a public place (shop, restaurant, workplace, stations, public house, sports venue, and bus), 8.3% on the street, 73.4% in a private location (victim's home, the homes of the victims’ relatives or friends or cheap bedrooms, where poor homeless people live), and 4.1% in residential institutions. In OHCPA occurring in private locations, the frequency of asystole was higher and the outcome was poorer than in other locations. A total of 181 OHCPA cases (11.7%) took place in the lavatory and 166 (10.7%) in the bathroom; of these, only 7 (3.9% of OHCPA in the lavatory) and none in the bath room achieved good outcomes. The frequencies of shockable initial rhythm occurring in the lavatory and in bath room were 3.7% and 1.1% (lower than in other locations, P = 0.011 and 0.002), and cardiac etiology in OHCPA occurring in these locations were 46.7% and 78.4% (the latter higher than in other locations, P < 0.001).

Conclusions:

An unignorable population suffered from OHCPA in private locations, particularly in the lavatory and bathroom; their initial rhythm was usually asystole and their outcomes were poor, despite the high frequency of cardiac etiology in the bathroom. We should try to treat OHCPA victims and to prevent occurrence of OHCPA in these risky spaces by considering their specific conditions.

Incidence and outcome from adult cardiac arrest occurring in the intensive care unit: a systematic review of the literature

BACKGROUND

Significant amount of data on the incidence and outcome of out-of-hospital and in-hospital cardiac arrest have been published. Cardiac arrest occurring in the intensive care unit has received less attention.

AIMS

To evaluate and summarize current knowledge of intensive care unit cardiac arrest including quality of data, and results focusing on incidence and patient outcome.

SOURCES AND METHODS

We conducted a literature search of the PubMed, CINAHL and Cochrane databases with the following search terms (medical subheadings): heart arrest AND intensive care unit OR critical care OR critical care nursing OR monitored bed OR monitored ward OR monitored patient. We included articles published from the 1st of January 1990 till 31st of December 2012. After exclusion of all duplicates and irrelevant articles we evaluated quality of studies using a predefined quality assessment score and summarized outcome data.

RESULTS

The initial search yielded 794 articles of which 780 were excluded. Three papers were added after a manual search of the eligible studies' references. One paper was identified manually from the literature published after our initial search was completed, thus the final sample consisted of 18 papers. Of the studies included thirteen were retrospective, two based on prospective registries and three were focused prospective studies. All except two studies were from a single institution. Six studies reported the incidence of intensive care unit cardiac arrest, which varied from 5.6 to 78.1 cardiac arrests per 1000 intensive care unit admissions. The most frequently reported initial cardiac arrest rhythms were non-shockable. Patient outcome was variable with survival to hospital discharge being in the range of 0-79% and long-term survival ranging from 1 to 69%. Nine studies reported neurological status of survivors, which was mostly favorable, either no neurological sequelae or cerebral performance score mostly of 1-2. Studies focusing on post cardiac surgery patients reported the best long-term survival rates of 45-69%.

CONCLUSIONS

At present data on intensive care unit cardiac arrest is quite limited and originates mostly from retrospective single center studies. The quality of data overall seems to be poor and thus focused prospective multi-center studies are needed.

Developing an analytical tool for evaluating EMS system design changes and their impact on cardiac arrest outcomes: combining geographic information systems with register data on survival rates

Background

Out-of-hospital cardiac arrest (OHCA) is a frequent and acute medical condition that requires immediate care. We estimate survival rates from OHCA in the area of Stockholm, through developing an analytical tool for evaluating Emergency Medical Services (EMS) system design changes. The study also is an attempt to validate the proposed model used to generate the outcome measures for the study.

Methods and results

This was done by combining a geographic information systems (GIS) simulation of driving times with register data on survival rates. The emergency resources comprised ambulance alone and ambulance plus fire services. The simulation model predicted a baseline survival rate of 3.9 per cent, and reducing the ambulance response time by one minute increased survival to 4.6 per cent. Adding the fire services as first responders (dual dispatch) increased survival to 6.2 per cent from the baseline level. The model predictions were validated using empirical data.

Conclusion

We have presented an analytical tool that easily can be generalized to other regions or countries. The model can be used to predict outcomes of cardiac arrest prior to investment in EMS design changes that affect the alarm process, e.g. (1) static changes such as trimming the emergency call handling time or (2) dynamic changes such as location of emergency resources or which resources should carry a defibrillator.

Good outcome in every fourth resuscitation attempt is achievable--an Utstein template report from the Stavanger region

AIM OF THE STUDY

Out-of-hospital cardiac arrest (OHCA) is a major cause of death in the western world. We wanted to study changes in survival over time and factors linked to this in a region which have already reported high survival rates.

METHODS

We used a prospectively collected Utstein template database to identify all resuscitation attempts in adult patients with OHCA of presumed cardiac origin. We included 846 resuscitation attempts and compared survival to discharge with good outcome in two time periods (2001-2005 vs. 2006-2008).

RESULTS

We found no significant differences between the two time periods for mean age (71 and 70 years (p=0.309)), sex distribution (males 70% and 71% (p=0.708)), location of the OHCA (home 64% and 63% (p=0.732)), proportion of shockable rhythms (44% and 47% (p=0.261)) and rate of return of spontaneous circulation (38% and 43% (p=0.136)), respectively. Bystander cardiopulmonary resuscitation (CPR), however, increased significantly from 60% to 73% (p<0.0001), as did the overall rate of survival to discharge from 18% to 25% (p=0.018). In patients with a shockable first rhythm, rate of survival to discharge increased significantly from 37% to 48% (p=0.036). In witnessed arrest with shockable rhythm survival to discharge increased from 37% to 52% (p=0.0105).

CONCLUSION

Overall, good outcome is now achievable in every fourth resuscitation attempt and in every second resuscitation attempt when patients have a shockable rhythm. The reason for the better outcomes is most likely multi-factorial and linked to improvements in the local chain of survival.

Realistic expectations for public access defibrillation programs

PURPOSE OF REVIEW

Public access defibrillation programs have increased dramatically over the past 15 years. This review will focus on their effectiveness and operational characteristics and discuss the characteristics of successful programs, which can improve outcomes.

RECENT FINDINGS

Automated external defibrillators increase survival from cardiac arrest when used by a bystander. Recent studies show that the best outcomes are achieved when devices are placed in areas with a high frequency of cardiac arrest and there is ongoing supervision with emergency plans and cardiopulmonary resuscitation training. Programs are cost-effective under these circumstances, but become very inefficient when placed in areas of low risk. There are few adverse events related to the public access defibrillation programs and volunteers are not harmed. Unguided placement results in devices not being used and a decline in organizational structure of the program. As most cardiac arrests occur in the home, the impact on overall survival remains low.

SUMMARY

Automated external defibrillators are highly effective at reducing death from ventricular fibrillation and easy access in public areas is most effective. Placement must be prioritized based on public health impact and characteristics of the community.