Effect of out-of-hospital defibrillation by basic life support providers on cardiac arrest mortality: a metaanalysis

Advancements in automated external and wearable cardiac defibrillators

PURPOSE OF REVIEW

Survival statistics for out-of-hospital cardiac arrests remain unsatisfactory. Prompt defibrillation of shockable rhythms, such as ventricular fibrillation and pulseless ventricular tachycardia, is crucial for improving survival. Automated external defibrillators (AEDs) and wearable cardiac defibrillators (WCDs) seek to improve the survival rates following out-of-hospital cardiac arrests. We aim to review the indications, utility, advancements, and limitations of AEDs and WCDs, as well as their role in contemporary and future clinical practice.

RECENT FINDINGS

Recent advancements in these technologies, such as smartphone applications and drone delivery of AEDs and less inappropriate shocks and decreased size of WCDs, have increased their ubiquity and efficacy. However, implementation of this technology remains limited due to lack of resources and suboptimal patient adherence.

SUMMARY

Out of hospital cardiac arrests continue to pose a significant public health challenge. Advancements in AEDs and WCDs aim to facilitate prompt defibrillation of shockable rhythms with the goal of improving survival rates. However, they remain underutilized due to limited resources and suboptimal patient adherence. As these technologies continue to evolve to become smaller, lighter and more affordable, their utilization and accessibility are expected to improve.

Defibrillator charging before rhythm analysis causes peri-shock pauses exceeding guideline recommended maximum 5 s : A randomized simulation trial

INTRODUCTION

Charging defibrillators prior to analyzing heart rhythms may decrease the no-flow time during rhythm check pauses while resuscitating in cardiac arrest. Although this anticipatory method is already used in some centers little is known about its safety. This study was carried out to confirm the safety and feasibility of the anticipatory method. It was hypothesized that this anticipatory method results in shorter total no-flow times, while other parameters of defibrillation efficacy including defibrillator safety and minimization of peri-shock pauses are unchanged.

METHODS

This manikin study assigned 243 medical students randomly to study groups, 121 to the anticipatory method and 122 to the recommended European Resuscitation Council (ERC) algorithm. Of these 237 students ultimately underwent training (112 anticipatory method vs. 125 ERC algorithm). Participants were assessed and video recorded during a simulated cardiac arrest scenario which included three different heart rhythms (ventricular fibrillation [VF], pulseless ventricular tachycardia [pVT], asystole) in randomized order. Video and software analyses were performed. Defibrillation safety was assessed using a 17-item checklist defined beforehand.

RESULTS

A total of 203 simulated cardiac arrests (75 anticipatory method and 128 ERC 2010 algorithm) were analyzed. The anticipatory method did not significantly reduce no-flow time (25.8 s, standard deviation, SD 7.4 s vs. 27.4 s SD 8.4 s, p = 0.19); however, peri-shock pauses were significantly longer in the anticipatory group compared to the ERC 2010 group (9.5 s SD 2.8 s vs. 3.3 s SD 1.9 s, p < 0.001). No significant difference concerning defibrillation safety between the groups was observed according to the 17-item checklist (14.6 SD 1.6 vs. 15.0 SD 1.4, p = 0.07).

CONCLUSION

Charging defibrillators before rhythm analysis did not decrease total no-flow time in simulated cardiac arrests but resulted in significantly longer peri-shock pauses exceeding 5 s. No significant differences in defibrillation safety were observed between the groups.

Out-of-Hospital Cardiac Arrest in a Teaching Hospital in Hong Kong: Descriptive Study Using the Utstein Style

Objective

To describe, using the Utstein template, the characteristics of patients presenting with out-of-hospital cardiac arrest to a university teaching hospital in the New Territories of Hong Kong, and to evaluate survival.

Design

Prospective study.

Setting

The emergency department of a teaching hospital in the New Territories, Hong Kong.

Participants

Patients older than 12 years with non-traumatic out-of-hospital cardiac arrest who were transported to the hospital between 1 July 2002 and 31 December 2002.

Main outcome measures

Demographic data, characteristics of cardiac arrest and response time intervals of the emergency medical service presented according to the Utstein style, and also survival to hospital discharge rate.

Results

A total of 124 patients were included (49.2% male; mean age 71.9 years). The majority of cardiac arrests occurred in patients' home. The overall bystander cardiopulmonary resuscitation (CPR) rate was 15.3% (19/124). The most common electrocardiographic rhythm at scene was asystole, whilst pulseless ventricular tachycardia (VT)/ventricular fibrillation (VF) was found in 18.0%. The overall survival was 0.8% (1/124), and survival to hospital discharge was significantly higher for patients with VF or pulseless VT than those patients with other rhythms of cardiac arrest (11.1% versus 0%). The median witnessed/recognised collapse to defibrillation time was 14 minutes. The median prehospital time interval from collapse/recognition to arrival at hospital was 33 minutes.

Conclusion

The prognosis of out-of-hospital cardiac arrest in Hong Kong was poor. Major improvements in every component of the chain of survival are necessary.

Bystander automated external defibrillator use and clinical outcomes after out-of-hospital cardiac arrest: A systematic review and meta-analysis

AIM

To systematically review studies comparing bystander automated external defibrillator (AED) use to no AED use in regard to clinical outcomes in out-of-hospital cardiac arrest (OHCA), and to provide a descriptive summary of studies on the cost-effectiveness of bystander AED use.

METHODS

We searched Medline, Embase, the Web of Science, and the Cochrane Library for randomized trials and observational studies published before June 1, 2017. Meta-analyses were performed for patients with all rhythms, shockable rhythms, and non-shockable rhythms.

RESULTS

Forty-four observational studies, 3 randomized trials, and 13 cost-effectiveness studies were included. Meta-analysis of 6 observational studies without critical risk of bias showed that bystander AED use was associated with survival to hospital discharge (all rhythms OR: 1.73 [95%CI: 1.36, 2.18], shockable rhythms OR: 1.66 [95%CI: 1.54, 1.79]) and favorable neurological outcome (all rhythms OR: 2.12 [95%CI: 1.36, 3.29], shockable rhythms OR: 2.37 [95%CI: 1.58, 3.57]). There was no association between bystander AED use and neurological outcome for non-shockable rhythms (OR: 0.76 [95%CI: 0.10, 5.87]). The Public-Access Defibrillation trial found higher survival rates when volunteers were equipped with AEDs. The other trials found no survival difference, although their study settings differed. The quality of evidence was low for randomized trials and very low for observational studies. AEDs were cost-effective in settings with high cardiac arrest incidence, with most studies reporting ratios < $100,000 per quality-adjusted life years.

CONCLUSIONS

The evidence supports the association between bystander AED use and improved clinical outcomes, although the quality of evidence was low to very low.

Prehospital critical care for out-of-hospital cardiac arrest: An observational study examining survival and a stakeholder-focused cost analysis

Background

Survival rates from out-of-hospital cardiac arrest (OHCA) remain low, despite remarkable efforts to improve care. A number of ambulance services in the United Kingdom (UK) have developed prehospital critical care teams (CCTs) which attend critically ill patients, including OHCA. However, current scientific evidence describing CCTs attending OHCA is sparse and research to date has not demonstrated clear benefits from this model of care.

Methods

This prospective, observational study will describe the effect of CCTs on survival from OHCA, when compared to advanced-life-support (ALS), the current standard of prehospital care in the UK. In addition, we will describe the association between individual critical care interventions and survival, and also the costs of CCTs for OHCA.

To examine the effect of CCTs on survival from OHCA, we will use routine Utstein variables data already collected in a number of UK ambulance trusts. We will use propensity score matching to adjust for imbalances between the CCT and ALS groups. The primary outcome will be survival to hospital discharge, with the secondary outcome of survival to hospital admission.

We will record the critical care interventions delivered during CCT attendance at OHCA. We will describe frequencies and aim to use multiple logistic regression to examine possible associations with survival.

Finally, we will undertake a stakeholder-focused cost analysis of CCTs for OHCA. This will utilise a previously published Emergency Medical Services (EMS) cost analysis toolkit and will take into account the costs incurred from use of a helicopter and the proportion of these costs currently covered by charities in the UK.

Discussion

Prehospital critical care for OHCA is not universally available in many EMS. In the UK, it is variable and largely funded through public donations to charities. If this study demonstrates benefit from CCTs at an acceptable cost to the public or EMS commissioners, it will provide a rationale to increase funding and service provision. If no clinical benefit is found, the public and charities providing these services can consider concentrating their efforts on other areas of prehospital care.

Trial registration

ISRCTN registry ID ISRCTN18375201.

The impact of a pre-hospital critical care team on survival from out-of-hospital cardiac arrest

AIM

To assess the impact of a pre-hospital critical care team (CCT) on survival from out-of-hospital cardiac arrest (OHCA).

METHODS

We undertook a retrospective observational study, comparing OHCA patients attended by advanced life support (ALS) paramedics with OHCA patients attended by ALS paramedics and a CCT between April 2011 and April 2013 in a single ambulance service in Southwest England. We used multiple logistic regression to control for an anticipated imbalance of prognostic factors between the groups. The primary outcome was survival to hospital discharge. All data were collected independently of the research.

RESULTS

1851 cases of OHCA were included in the analysis, of which 1686 received ALS paramedic treatment and 165 were attended by both ALS paramedics and a CCT. Unadjusted rates of survival to hospital discharge were significantly higher in the CCT group, compared to the ALS paramedic group (15.8% and 6.5%, respectively, p<0.001). After adjustment using multiple logistic regression, the effect of CCT treatment was no longer statistically significant (OR 1.54, 95% CI 0.89-2.67, p=0.13). Subgroup analysis of OHCA with first monitored rhythm of ventricular fibrillation or pulseless ventricular tachycardia showed similar results.

CONCLUSION

Pre-hospital critical care for OHCA was not associated with significantly improved rates of survival to hospital discharge. These results are in keeping with previously published studies. Further research with a larger sample size is required to determine whether CCTs can improve outcome in OHCA.

Intraarrest rhythms and rhythm conversion in asphyxial cardiac arrest

OBJECTIVES

The objective was to analyze the cardiac arrest rhythms presenting during asphyxial cardiac arrest (ACA).

METHODS

Asphyxial cardiac arrest was induced in 30 Landrace large white piglets, aged 12 to 15 weeks and with a mean (±SD) weight of 20 (±2) kg. After the onset of cardiac arrest, the animals were left untreated for 4 minutes, after which cardiopulmonary resuscitation was commenced. Heart rhythms were monitored from the onset of asphyxia until return of spontaneous circulation or death.

RESULTS

After endotracheal tube clamping and prior to cardiac arrest, normal sinus rhythm was noted in 14 animals, atrial fibrillation in two animals, Mobitz II atrioventricular block in 10 animals, and third-degree atrioventricular block in four animals. At the onset of cardiac arrest, seven animals had ventricular fibrillation (VF), two had asystole, and 21 had pulseless electrical activity (PEA). During the 4-minute period of untreated arrest, however, significant changes in the monitored rhythm were noted; at the end of the fourth minute, 19 animals had VF, two animals had asystole, and nine animals had PEA.

CONCLUSIONS

The most common rhythm after 4 minutes of untreated ACA was VF, while in 57% of animals, PEA was spontaneously converted to VF during the cardiac arrest interval.

Comparison of different techniques for in microgravity-a simple mathematic estimation of cardiopulmonary resuscitation quality for space environment

BACKGROUND

Since astronauts are selected carefully, are usually young, and are intensively observed before and during training, relevant medical problems are rare. Nevertheless, there is a certain risk for a cardiac arrest in space requiring cardiopulmonary resuscitation (CPR). Up to now, there are 5 known techniques to perform CPR in microgravity. The aim of the present study was to analyze different techniques for CPR during microgravity about quality of CPR.

MATERIAL AND METHODS

To identify relevant publications on CPR quality in microgravity, a systematic analysis with defined searching criteria was performed in the PubMed database (http://www.pubmed.com). For analysis, the keywords ("reanimation" or "CPR" or "resuscitation") and ("space" or "microgravity" or "weightlessness") and the specific names of the techniques ("Standard-technique" or "Straddling-manoeuvre" or "Reverse-bear-hug-technique" or "Evetts-Russomano-technique" or "Hand-stand-technique") were used. To compare quality and effectiveness of different techniques, we used the compression product (CP), a mathematical estimation for cardiac output.

RESULTS

Using the predefined keywords for literature search, 4 different publications were identified (parabolic flight or under simulated conditions on earth) dealing with CPR efforts in microgravity and giving specific numbers. No study was performed under real-space conditions. Regarding compression depth, the handstand (HS) technique as well as the reverse bear hug (RBH) technique met parameters of the guidelines for CPR in 1G environments best (HS ratio, 0.91 ± 0.07; RBH ratio, 0.82 ± 0.13). Concerning compression rate, 4 of 5 techniques reached the required compression rate (ratio: HS, 1.08 ± 0.11; Evetts-Russomano [ER], 1.01 ± 0.06; standard side straddle, 1.00 ± 0.03; and straddling maneuver, 1.03 ± 0.12). The RBH method did not meet the required criteria (0.89 ± 0.09). The HS method showed the highest cardiac output (69.3% above the required CP), followed by the ER technique (33.0% above the required CP).

CONCLUSIONS

Concerning CPR quality, the HS seems to be most effective to treat a cardiac arrest. In some environmental conditions where this technique cannot be used, the ER technique is a good alternative because CPR quality is only slightly lower.

Basic life support knowledge of healthcare students and professionals in the Qassim University

OBJECTIVE

To evaluate the knowledge of basic life support (BLS) among students and health providers in Medicine, Pharmacy, Dentistry, and Allied Health Science Colleges at Qassim University.

METHODOLOGY

A cross sectional study was performed using an online BLS survey that was completed by 139 individuals.

RESULTS

Ninety-three responders were medical students, 7 were medical interns, 6 were dental students, 7 were pharmacy students, 11 were medical science students and 15 were clinical practitioners. No responder scored 100% on the BLS survey. Only two out of the 139 responders (1.4%) scored 90-99%. Both of these individuals were fifth year medical students. Six responders (4.3%) scored 80-89%. Of these, 5 were fifth year medical students, and one was fourth-year medical student. Eleven responders (7.9%) scored 70-79%. Of these, eight were fifth year medical students, two were medical interns and one was a pharmacist. Twenty-three responders (16.5%) scored 60-69%. Of these, 11 were fifth year medical students, 1 was a fourth-year medical student, 3 were medical interns, 2 were medical science students, 1 was a dentistry student, and 5 were pharmacists. Twenty-eight responders (20.1%) scored 50-59%. Of these, 11 were fifth year medical students, 3 were fourth-year medical students, 1 was a third-year medical student, 1 was a second-year medical student, 2 were first-year medical students, 1 was a pharmacy student, 3 were dental students, 1 was a allied health science student, 2 were doctors, and 3 were pharmacists. The remaining 69 responders (49.6%) scored less than 50%.

CONCLUSION

Knowledge of BLS among medicine, pharmacy, dentistry, and allied health science students and health providers at Qassim University is poor and needs to be improved. We suggest that inclusion of a BLS course in the undergraduate curriculum with regular reassessment would increase awareness and application of this valuable life-saving skill set.

Defibrillation in rural areas

AIM OF THE STUDY

Automated external defibrillation (AED) and public access defibrillation (PAD) have become cornerstones in the chain of survival in modern cardiopulmonary resuscitation. Most studies of AED and PAD have been performed in urban areas, and evidence is scarce for sparsely populated rural areas. The aim of this review was to review the literature and discuss treatment strategies for out-of-hospital cardiac arrest in rural areas.

METHODS

A Medline search was performed with the keywords automated external defibrillation (617 hits), public access defibrillation (256), and automated external defibrillator public (542). Of these 1415 abstracts and additional articles found by manually searching references, 92 articles were included in this nonsystematic review.

RESULTS

Early defibrillation is crucial for survival with good neurological outcome after cardiac arrest. Rapid defibrillation can be a challenge in sparsely populated and remote areas, where the incidence of cardiac arrest is low and rescuer response times can be long. The few studies performed in rural areas showed that the introduction of AED programs based on a 2-tier emergency medical system, consisting of Basic Life Support and Advanced Life Support teams, resulted in a decrease in collapse-to-defibrillation times and better survival of patients with out-of-hospital cardiac arrest.

CONCLUSIONS

In rural areas, introducing AED programs and a 2-tier emergency medical system may increase survival of out-of-hospital cardiac arrest patients. More studies on AED and PAD in rural areas are required.

Out-of-Hospital Cardiac Arrest Locations in a Rural Community: Where Should We Place AEDs?

Early defibrillation improves survival for patients suffering cardiac arrest from ventricular fibrillation (VF) or ventricular tachycardia (VT). Automated external defibrillators (AEDs) should be placed in locations in which there is a high incidence of out-of-hospital cardiac arrest (OOHCA). The study objective was to identify high-risk, rural locations that might benefit from AED placement. A retrospective review of OOHCA in a rural community during the past 5.5 years was conducted. The OOHCAs that occurred in non-residential areas were categorized based on location. Nine hundred, forty OOHCAs occurred during the study period of which 265 (28.2%) happened in non-residential areas. Of these, 127 (47.9%) occurred in healthcare-related locations, including 104 (39.2%) in extended care facilities. No location used in this study had more than two OOHCAs. Most (52.1%) non-residential OOHCAs occurred as isolated events in 146 different locations. Almost half of the OOHCAs that occurred in non-residential areas took place in healthcare-related facilities suggesting that patients at these locations may benefit from AED placement. First responders with AEDs are likely to have the greatest impact in a rural community.

Basic life support skills of high school students before and after cardiopulmonary resuscitation training: a longitudinal investigation

BACKGROUND

Immediate bystander cardiopulmonary resuscitation (CPR) significantly improves survival after a sudden cardiopulmonary collapse. This study assessed the basic life support (BLS) knowledge and performance of high school students before and after CPR training.

METHODS

This study included 132 teenagers (mean age 14.6 ± 1.4 years). Students completed a two-hour training course that provided theoretical background on sudden cardiac death (SCD) and a hands-on CPR tutorial. They were asked to perform BLS on a manikin to simulate an SCD scenario before the training. Afterwards, participants encountered the same scenario and completed a questionnaire for self-assessment of their pre- and post-training confidence. Four months later, we assessed the knowledge retention rate of the participants with a BLS performance score.

RESULTS

Before the training, 29.5% of students performed chest compressions as compared to 99.2% post-training (P < 0.05). At the four-month follow-up, 99% of students still performed correct chest compressions. The overall improvement, assessed by the BLS performance score, was also statistically significant (median of 4 and 10 pre- and post-training, respectively, P < 0.05). After the training, 99.2% stated that they felt confident about performing CPR, as compared to 26.9% (P < 0.05) before the training.

CONCLUSIONS

BLS training in high school seems highly effective considering the minimal amount of previous knowledge the students possess. We observed significant improvement and a good retention rate four months after training. Increasing the number of trained students may minimize the reluctance to conduct bystander CPR and increase the number of positive outcomes after sudden cardiopulmonary collapse.

Impact of spirituality/religiosity on mortality: comparison with other health interventions

Scientists have been interested in the influence of religion on mortality for at least 130 years. Since this time, many debates have been held by researchers who believe or do not believe in this association. The objective of this study is to compare the impact of spirituality and religiosity (S/R) with other health interventions on mortality. The authors selected 25 well-known health interventions. Then, a search of online medical databases was performed. Meta-analyses between 1994 and 2009 involving mortality were chosen. The same was done for religiosity and spirituality. The combined hazard ratio was obtained directly by the systematic reviews and the mortality reductions by S/R and other health interventions were compared. Twenty-eight meta-analyses with mortality outcomes were selected (25 health interventions and three dealing with S/R). From these three meta-analyses, considering those with the most conservative results, persons with higher S/R had an 18% reduction in mortality. This result is stronger than 60.0% of the 25 systematic reviews analyzed (similar to consumption of fruits and vegetables for cardiovascular events and stronger than statin therapy). These results suggest that S/R plays a considerable role in mortality rate reductions, comparable to fruit and vegetable consumption and statin therapy.

Cardiac arrest in Greek primary health care and willingness of general practitioners to use automatic external defibrillator

AIM

The aim of this study was to calculate the incidence of out-of-hospital cardiac arrest (OHCA) in primary health care in Greece and assess general practitioners' (GPs) willingness towards the use of automatic external defibrillator (AED).

METHODS

We conducted a survey in GPs working in both private and public sectors. The survey consisted of 32 questions and was distributed via email in 180 randomly selected GPs. To estimate OHCA incidence, data concerning the number of examined patients and the number of cardiac arrests were used.

RESULTS

Based on the population of our study, the incidence of OHCA in primary health care in Greece is 15.3/100,000 population per year. Most of the arrests occur in health centers, while ventricular fibrillation/ventricular tachycardia are the first monitored rhythms. Almost all GPs were willing to use an AED even though some of them did not know how to use it.

CONCLUSIONS

The incidence of OHCA in primary health care in Greece is 15.3/100,000 population per year. Greek GPs may have an important role in managing OHCA victims and are willing to use an AED. This is the first study estimating OHCA in primary health care in Greece.

Advances in cardiopulmonary resuscitation

This article focuses on important advances in the science of cardiopulmonary resuscitation in the last decade that have led to a significant improvement in understanding the complex physiology of cardiac arrest and critical interventions for the initial management of cardiac arrest and postresuscitation treatment. Special emphasis is given to the basic simple ways to improve circulation, vital organ perfusion pressures, and the grave prognosis of sudden cardiac death.

Advances in Cardiopulmonary Resuscitation

This article focuses on important advances in the science of cardiopulmonary resuscitation (CPR) in the last decade that have led to a significant improvement in understanding the complex physiology of cardiac arrest and critical interventions for the initial management of cardiac arrest and postresuscitation treatment. Special emphasis is given to the basic simple ways to improve circulation, vital organ perfusion pressures, and the grave prognosis of sudden cardiac death.

Predictors of survival from out-of-hospital cardiac arrest: a systematic review and meta-analysis

BACKGROUND

Prior studies have identified key predictors of out-of-hospital cardiac arrest (OHCA), but differences exist in the magnitude of these findings. In this meta-analysis, we evaluated the strength of associations between OHCA and key factors (event witnessed by a bystander or emergency medical services [EMS], provision of bystander cardiopulmonary resuscitation [CPR], initial cardiac rhythm, or the return of spontaneous circulation). We also examined trends in OHCA survival over time.

METHODS AND RESULTS

An electronic search of PubMed, EMBASE, Web of Science, CINAHL, Cochrane DSR, DARE, ACP Journal Club, and CCTR was conducted (January 1, 1950 to August 21, 2008) for studies reporting OHCA of presumed cardiac etiology in adults. Data were extracted from 79 studies involving 142 740 patients. The pooled survival rate to hospital admission was 23.8% (95% CI, 21.1 to 26.6) and to hospital discharge was 7.6% (95% CI, 6.7 to 8.4). Stratified by baseline rates, survival to hospital discharge was more likely among those: witnessed by a bystander (6.4% to 13.5%), witnessed by EMS (4.9% to 18.2%), who received bystander CPR (3.9% to 16.1%), were found in ventricular fibrillation/ventricular tachycardia (14.8% to 23.0%), or achieved return of spontaneous circulation (15.5% to 33.6%). Although 53% (95% CI, 45.0% to 59.9%) of events were witnessed by a bystander, only 32% (95% CI, 26.7% to 37.8%) received bystander CPR. The number needed to treat to save 1 life ranged from 16 to 23 for EMS-witnessed arrests, 17 to 71 for bystander-witnessed, and 24 to 36 for those receiving bystander CPR, depending on baseline survival rates. The aggregate survival rate of OHCA (7.6%) has not significantly changed in almost 3 decades.

CONCLUSIONS

Overall survival from OHCA has been stable for almost 30 years, as have the strong associations between key predictors and survival. Because most OHCA events are witnessed, efforts to improve survival should focus on prompt delivery of interventions of known effectiveness by those who witness the event.

Levosimendan improves the initial outcome of cardiopulmonary resuscitation in a swine model of cardiac arrest

BACKGROUND

Cardiac arrest remains the leading cause of death in Western societies. Advanced Life Support guidelines propose epinephrine (adrenaline) for its treatment. The aim of this study was to assess whether a calcium sensitizer agent, such as levosimendan, administered in combination with epinephrine during cardiopulmonary resuscitation, would improve the initial resuscitation success.

METHODS

Ventricular fibrillation was induced in 20 Landrace/Large-White piglets, and left untreated for 8 min. Resuscitation was then attempted with precordial compressions, mechanical ventilation and electrical defibrillation. The animals were randomized into two groups (10 animals each): animals in Group A received saline as placebo (10 ml dilution, bolus) + epinephrine (0.02 mg/kg), and animals in Group B received levosimendan (0.012 mg/kg/10 ml dilution, bolus) + epinephrine (0.02 mg/kg) during cardiopulmonary resuscitation. Electrical defibrillation was attempted after 10 min of ventricular fibrillation.

RESULTS

Four animals in Group A showed restoration of spontaneous circulation and 10 in Group B (P = 0.011). The coronary perfusion pressure, saturation of peripheral oxygenation and brain regional oxygen saturation were significantly higher during cardiopulmonary resuscitation in Group B.

CONCLUSIONS

A calcium sensitizer agent, when administered during cardiopulmonary resuscitation, significantly improves initial resuscitation success and increases coronary perfusion pressure during cardiopulmonary resuscitation.

Increasing use of cardiopulmonary resuscitation during out-of-hospital ventricular fibrillation arrest: survival implications of guideline changes

BACKGROUND

The most recent resuscitation guidelines have sought to improve the interface between defibrillation and cardiopulmonary resuscitation; the survival impact of these changes is unknown, however. A year before issuance of the most recent guidelines, we implemented protocol changes that provided a single shock without rhythm reanalysis, stacked shocks, or postdefibrillation pulse check, and extended the period of cardiopulmonary resuscitation from 1 to 2 minutes. We hypothesized that survival would be better with the new protocol.

METHODS AND RESULTS

The present study took place in a community with a 2-tiered emergency medical services response and an established system of cardiac arrest surveillance, training, and review. The investigation was a cohort study of persons who had bystander-witnessed out-of-hospital ventricular fibrillation arrest because of heart disease, comparing a prospectively defined intervention group (January 1, 2005, to January 31, 2006) with a historical control group that was treated according to previous guidelines of rhythm reanalysis, stacked shocks, and postdefibrillation pulse checks (January 1, 2002, to December 31, 2004). The primary outcome was survival to hospital discharge. The proportion of treated arrests that met inclusion criteria was similar for intervention and control periods (15.4% [134/869] versus 16.6% [374/2255]). Survival to hospital discharge was significantly greater during the intervention period compared with the control period (46% [61/134] versus 33% [122/374], P=0.008) and corresponded to a decrease in the interval from shock to start of chest compressions (28 versus 7 seconds). Adjustment for covariates did not alter the survival association.

CONCLUSIONS

These results suggest the new resuscitation guidelines will alter the interface between defibrillation and cardiopulmonary resuscitation and in turn may improve outcomes.

Future shock: automatic external defibrillators

PURPOSE OF REVIEW

This review provides a practical overview of the performance capabilities of automatic external defibrillators (AEDs), and of advances in technology and dissemination programmes for these devices.

RECENT FINDINGS

Arrhythmia analysis by AEDs is extremely reliable in most settings (sensitivity 81-100%, specificity 99.9-97.6%). Accurate detection of arrhythmias has also been demonstrated in children, leading the US Food and Drug Administration to approve the use of several AEDs in children aged 8 years or younger. Factors that potentially may reduce the quality of arrhythmia detection are the presence of wide complex supraventricular tachycardia and location of an arrythmic event near to high-power lines. AED use by professional basic life support providers resulted in increased survival in the prehospital setting. However, provision of AEDs to nonmedical rescue services did not result in universal improvement in patient outcome. Public access defibrillation programmes have led to higher rates of survival from cardiac arrest. The role of AEDs in hospitals has yet to be elucidated, although in-hospital mortality from ventricular arrhythmias has been shown to decrease following AED deployment.

SUMMARY

Given the correct setting, AEDs can ensure that defibrillation is not limited by lack of medical knowledge or difficulties in decision making. However, event-related variables and operator-related factors, that are yet to be determined, can significantly affect the efficacy of automatic external defibrillation.

Lessons learnt from the autopsies of 445 cases of sudden cardiac death in adults

AIM

To determine the cause of sudden cardiac death in adults who underwent autopsy.

METHODS

Four hundred and forty-five sudden cardiac deaths occurred within 1 h of the symptoms onset, and all other cardiac and noncardiac causes having been excluded from autopsy and toxicology screening, were retrospectively identified from among 902 autopsies performed in a 2-year period on the island of Crete. The presence of acute coronary thrombi and myocardial infarction was documented macroscopically and by light microscopy and histology.

RESULTS

In all 445 cases, at least one coronary artery had evidence of moderate to advanced atherosclerosis. About two thirds were between 50 and 70 years. Men had a higher incidence than women, but with advancing age (>60 years) this difference was reduced. Myocardial infarction was found in 17 cases (11 acute; 6 acute and healed). Fifty-eight cases (13.0%) had coronary thrombi, mostly involving the left anterior descending and the right coronary arteries (81%); only six of these were associated with acute myocardial infarction.

CONCLUSION

In our population, arrhythmia was the most common cause of sudden cardiac death, while acute coronary thrombi and acute myocardial infarction were detected only in some cases. Because of the heterogeneity in the cause of sudden cardiac deaths in adults, a detailed forensic investigation may provide important information on the cause of death and help in the development of primary and secondary prevention.

Prospective assessment of integrating the existing emergency medical system with automated external defibrillators fully operated by volunteers and laypersons for out-of-hospital cardiac arrest: the Brescia Early Defibrillation Study (BEDS)

AIMS

There are few data on the outcomes of cardiac arrest (CA) victims when the defibrillation capability of broad rural and urban territories is fully operated by volunteers and laypersons.

METHODS AND RESULTS

In this study, we investigated whether a programme based on diffuse deployment of automated external defibrillators (AEDs) operated by 2186 trained volunteers and laypersons across the County of Brescia, Italy (area: 4826 km(2); population: 1 112 628), would safely and effectively impact the current survival among victims of out-of-hospital CA. Forty-nine AEDs were added to the former emergency medical system that uses manual EDs in the emergency department of 10 county hospitals and in five medically equipped ambulances. The primary endpoint was survival free of neurological impairment at 1-year follow-up. Data were analysed in 692 victims before and in 702 victims after the deployment of the AEDs. Survival increased from 0.9% (95% CI 0.4-1.8%) in the historical cohort to 3.0% (95% CI 1.7-4.3%) (P=0.0015), despite similar intervals from dispatch to arrival at the site of collapse [median (quartile range): 7 (4) min vs. 6 (6) min]. Increase of survival was noted both in the urban [from 1.4% (95% CI 0.4-3.4 %) to 4.0% (95% CI 2.0-6.9 %), P=0.024] and in the rural territory [from 0.5% (95% CI 0.1-1.6%) to 2.5% (95% CI 1.3-4.2%), P=0.013]. The additional costs per quality-adjusted life year saved amounted to euro39 388 (95% CI euro16 731-49 329) during the start-up phase of the study and to euro23 661 (95% CI euro10 327-35 528) at steady state.

CONCLUSION

Diffuse implementation of AEDs fully operated by trained volunteers and laypersons within a broad and unselected environment proved safe and was associated with a significantly higher long-term survival of CA victims.

Lack of integration of automated external defibrillators with EMS response may reduce lifesaving potential of public-access defibrillation

OBJECTIVES

Automated external defibrillators (AEDs) used for public-access defibrillation (PAD) allow for rapid defibrillation, particularly if the AEDs are incorporated into an organized response plan. This project was undertaken to determine how many PAD AEDs were in North Carolina, how many were properly registered, and how many were integrated into the emergency medical services (EMS) response.

METHODS

Data were collected for this prospective, descriptive study via phone survey, e-mail survey, and/or direct personal interview. Four sources were utilized: 1) state office of EMS AED registration database, 2) AED sales representatives, 3) county EMS agency representatives, and 4) American Heart Association (AHA) training center instructors and regional faculty. The primary endpoint was determining the proportion of AEDs placed in unregistered locations.

RESULTS

The state EMS office provided the state registry of AED locations. One-hundred percent of state-recognized AED vendors and county EMS agencies provided data. Twelve of 55 (22%) AHA personnel provided data. Eight hundred eighty-one unique locations were identified. Although AED sales are required by law to be registered, the office of EMS database contained only 99 of the 552 (18%) unique PAD locations identified by the study.

CONCLUSIONS

A large number of unregistered AEDs are being placed in communities. AEDs placed as part of an organized PAD program improve the rates of survival from sudden cardiac death. In the absence of registration, it is difficult to determine the extent to which these AEDs are part of an organized PAD program.

Family presence during cardiopulmonary resuscitation

A recent phenomenon in emergency and critical care settings is the presence of family members during resuscitation events. It remains controversial in most institutions, but evidence is increasing that the experience has positive benefits for family members. In this article, the origin of family presence is described and research evidence about the experience is presented. Three case studies are presented to illustrate typical events, including the potential role of the hospital chaplain. Recommendations for implementation are included.

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.

Preliminary in-hospital experience with a fully automatic external cardioverter-defibrillator

BACKGROUND

Ventricular fibrillation (VF) and ventricular tachycardia (VT) are frequently present as initial rhythms during in-hospital cardiac arrest. Although ample evidence exists to support the need for rapid defibrillation, the response to in-hospital cardiac arrest remains without major advances in recent years. The delay between the arrhythmic event and intervention is still a challenge for clinical practice.

OBJECTIVE

To analyze the performance and safety of in-hospital use of a programmable, fully automatic external cardioverter-defibrillator (AECD).

METHODS

We conducted a prospective study at the Emergency Department of a university hospital. A total of 55 patients considered to be at risk of sustained VT/VF were included. Patients underwent monitoring of their cardiac rhythm by the AECD. Upon detection of a ventricular tachyarrhythmia, the AECD was programmed to automatically deliver shock therapy.

RESULTS

We recorded 19 episodes of VT/VF in 3 patients. The median time between the beginning of the arrhythmia and the first defibrillation was 33.4 s (21-65 s). One episode of spontaneous reversion of VT was documented 20 s after its origin and shock therapy was aborted. The defibrillation success was 94.4% (17/18) for the first shock and 100% (1/1) for the second shock. No case of inappropriate shock discharge was registered during the study period.

CONCLUSION

The AECD has the feasibility to combine long-term monitoring with automatic defibrillation safely and effectively. It presents the possibility of providing rapid identification of, and response to, in-hospital ventricular tachyarrhythmias.

Temporal Trends in Coronary Heart Disease Mortality and Sudden Cardiac Death From 1950 to 1999

Background— Throughout the past 50 years, heart disease has been the leading cause of death in the United States. Although declines in coronary heart disease (CHD) mortality have been noted, there is still uncertainty about the magnitude of the decline and whether the trend is similar for sudden cardiac death (SCD).

Methods and Results— We examined temporal trends in SCD and nonsudden CHD death in the Framingham Heart Study original and offspring cohorts from 1950 to 1999. SCD was defined as a death attributed to CHD with preceding symptoms that lasted less than 1 hour; all deaths were adjudicated by a physician panel. Log-linear Poisson regression was used to estimate CHD mortality and SCD risk ratios (RRs); RRs were adjusted for age and gender. There were 811 CHD deaths: 453 nonsudden and 358 SCDs. Ninety-one (20%) of nonsudden CHD deaths and 173 (48%) of SCDs were in subjects free of antecedent CHD. From 1950–1969 to 1990–1999, overall CHD death rates decreased by 59% (95% CI 47% to 68%, P trend <0.001). Nonsudden CHD death decreased by 64% (95% CI 50% to 74%, P trend <0.001), and SCD rates decreased by 49% (95% CI 28% to 64%, P trend <0.001). These trends were seen in men and women, in subjects with and without a prior history of CHD, and in smokers and nonsmokers.

Conclusions— The risks of SCD and nonsudden CHD mortality have decreased by 49% to 64% over the past 50 years. These trends were evident in subjects with and without heart disease, which suggests important contributions of primary and secondary prevention to the decreasing risk of CHD death and SCD.

Cardiac arrest survival as a function of ambulance deployment strategy in a large urban emergency medical services system

INTRODUCTION

This study examines the effect of paramedic deployment strategy on witnessed ventricular fibrillation (VF) cardiac arrest outcomes. Our null hypothesis was that there is no difference in survival between an EMS system using targeted response (TR) and one using a uniform or all advanced life support (ALS) response (UR) model. We define targeted response as a system where paramedics are sent to critical incidents while ambulances staffed with basic EMTs are sent to less critical incidents. A secondary outcome measure was paramedic skill proficiency between the systems.

METHODS

We conducted a retrospective review of all 1997 VF arrests in a large urban EMS system. The majority of the city is a busy, urban area that uses TR. Outlying areas of the city are suburban and are served by a UR model. All areas have first responders equipped with automated external defibrillators. Outcomes are compared using Utstein criteria.

RESULTS

Patient populations were well matched. There were 181 patients in the TR group and 24 in the UR group. Units in the TR area were able to demonstrate shorter response and time to defibrillation intervals than in the UR area. Rates for return of spontaneous circulation (ROSC), admission to the ward/intensive care unit (ICU), survival to discharge and survival to 1 year were all better in the cohort of patients cared for in the TR area than those in the UR area. Rates for successful intubation and IV initiation were also better in the TR areas than in the UR areas.

CONCLUSION

This study shows improved outcomes for a subset of patients with cardiac arrest when they are cared for in an area that uses TR compared to an area that uses a UR EMS system.

Trauma care systems in the United States

The trauma system in the United States is in the process of evolution. Although it is recognised that a systems approach to trauma care is ideal, this concept has yet to be realised fully due to political, financial and geographic considerations. The pre-hospital controversies of in-the-field care, resuscitation, and transport are still debated. In-hospital care is governed by a trauma service using the guidelines of the American College of Surgeons (ACS). Speciality care is usually delivered as a consultative service at the request of the trauma service. Co-ordination by the trauma surgeon assures appropriate timing and amount of care by the specialities. Problems facing the delivery of trauma care are malpractice, reimbursement for speciality trauma care call and the need to extend the system to all trauma patients.

The potential role for automatic external defibrillators in palliative care units

Cardiopulmonary resuscitation (CPR) has received frequent attention by professionals and the public in recent times. Concerns regarding the potential harms for little chance of success have caused palliative care units (PCUs) doubts about initiating CPR. However, there appears to be a moral responsibility to offer CPR to some, carefully selected, patients. Automatic external defibrillators (AEDs) have been shown to significantly increase chances of survival following CPR and are simple to use, even for non-professionals. It is argued that AEDs may increase the moral imperative on PCUs to offer CPR to certain patients and provide the basis for a necessary debate on where the border between appropriate active treatment and a disturbance to the aim of a peaceful death rests.

Treatment of cardiac arrest with automatic external defibrillators: impact on outcome

Sudden cardiac death is the leading cause of death in the US and most developed nations. Ventricular fibrillation (VF) is the most common initial rhythm in survivors of cardiac arrest. The most important factor in determining survival from VF is the time from collapse to administration of the first defibrillation shock. Automatic external defibrillators (AEDs) have been developed and widely deployed in an attempt to reduce the time to defibrillation. Data on early defibrillation using AEDs has led to a number of public access defibrillator placements in the US and ongoing studies of public access AED use. The safety of lay person AED use is clear. Clearly some concentrated captive populations (e.g. airports, airplanes) may benefit from public access AEDs. Therefore, widespread AED education as a means of increasing public acceptance of lay person AED use must be a priority. As technology evolves costs will decline, however, the current economic reality requires careful consideration of the cost effectiveness of specific AED placement.

Public access defibrillation

Very early defibrillation, within the first few minutes of VF cardiac arrest, results in significantly improved survival rates [1,10-12,34]. Most EMS systems cannot consistently provide defibrillation within the first few minutes following cardiac arrest. Defibrillation within the first few minutes following collapse is potentially achievable through the use of AEDs and PAD [9-14,62]. The delivery of defibrillation with AEDs has been made more efficient through the use of impedance-compensated defibrillation, larger pad sizes, and biphasic waveforms [34]. The technology is simple and easy to use. Preliminary cost-effectiveness analysis indicates that PAD and first-responder defibrillation are economically as attractive as other interventions in cardiac arrest [44]. Effective PAD requires significant investment in time, energy, informed planning, and rigorous quality improvement; however, the benefits are enormous. Reported VF survival rates can approach 50% or higher [11,12,62]. PAD provides the potential opportunity to transform cardiac arrest into a survivable event for most victims by making the community the ultimate coronary care unit.