The location of collapse and its effect on survival from cardiac arrest

Underlying reasons for sex difference in survival following out-of-hospital cardiac arrest: a mediation analysis

AIMS

Previous studies have indicated a poorer survival among women following out-of-hospital cardiac arrest (OHCA), but the mechanisms explaining this difference remain largely uncertain.This study aimed to assess the survival after OHCA among women and men and explore the role of potential mediators, such as resuscitation characteristics, prior comorbidity, and socioeconomic factors.

METHODS AND RESULTS

This was a population-based cohort study including emergency medical service-treated OHCA reported to the Swedish Registry for Cardiopulmonary Resuscitation in 2010-2020, linked to nationwide Swedish healthcare registries. The relative risks (RR) of 30-day survival were compared among women and men, and a mediation analysis was performed to investigate the importance of potential mediators. Total of 43 226 OHCAs were included, of which 14 249 (33.0%) were women. Women were older and had a lower proportion of shockable initial rhythm. The crude 30-day survival among women was 6.2% compared to 10.7% for men [RR 0.58, 95% confidence interval (CI) = 0.54-0.62]. Stepwise adjustment for shockable initial rhythm attenuated the association to RR 0.85 (95% CI = 0.79-0.91). Further adjustments for age and resuscitation factors attenuated the survival difference to null (RR 0.98; 95% CI = 0.92-1.05). Mediation analysis showed that shockable initial rhythm explained ∼50% of the negative association of female sex on survival. Older age and lower disposable income were the second and third most important variables, respectively.

CONCLUSION

Women have a lower crude 30-day survival following OHCA compared to men. The poor prognosis is largely explained by a lower proportion of shockable initial rhythm, older age at presentation, and lower income.

Prehospital Predictors of Survival in Patients with Out-of-Hospital Cardiac Arrest

Background and Objectives: Despite advances in the treatment of heart diseases, the outcome of patients experiencing sudden cardiac arrest remains poor. The aim of our study was to determine the prehospital variables as predictors of survival outcomes in out-of-hospital cardiac arrest (OHCA) victims. Materials and Methods: This was a retrospective observational cohort study of OHCA cases. EMS protocols created in accordance with the Utstein style reporting for OHCA, first responder intervention reports, medical dispatch center dispatch protocols and hospital medical reports were all reviewed. Multivariate logistic regression was performed with the following variables: age, gender, witnessed status, location, bystander CPR, first rhythm, and etiology. Results: A total of 381 interventions with resuscitation attempts were analyzed. In more than half (55%) of them, bystander CPR was performed. Thirty percent of all patients achieved return of spontaneous circulation (ROSC), 22% of those achieved 30-day survival (7% of all OHCA victims), and 73% of those survived with Cerebral Performance Score 1 or 2. The logistic regression model of adjustment confirms that shockable initial rhythm was a predictor of ROSC [OR: 4.5 (95% CI: 2.5-8.1)] and 30-day survival [OR: 9.3 (95% CI: 2.9-29.2)]. Age was also associated (≤67 years) [OR: 3.9 (95% CI: 1.3-11.9)] with better survival. Conclusions: Elderly patients have a lower survival rate. The occurrence of bystander CPR in cardiac arrest remains alarmingly low. Shockable initial rhythm is associated with a better survival rate and neurological outcome compared with non-shockable rhythm.

Impact of dispatcher-assisted cardiopulmonary resuscitation on neurologically intact survival in out-of-hospital cardiac arrest: a systematic review

Background

Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) increases neurologically intact survival in out-of-hospital cardiac arrest (OHCA) according to several studies. This systematic review summarizes neurologically intact survival outcomes of DA-CPR in comparison with bystander-initiated CPR and no bystander CPR in OHCA.

Methods

The systematic review was conducted according to the PRISMA guidelines. All studies including adult and/or pediatric OHCAs that compared DA-CPR with bystander-initiated CPR or no bystander CPR were included. Primary outcome was neurologically intact survival at discharge, one-month or longer. Studies were searched for in PubMed (MEDLINE), EMBASE, and the Cochrane Library databases. The risk of bias was evaluated using the Newcastle-Ottawa Scale.

Results

The search string generated 4742 citations of which 33 studies were eligible for inclusion. Due to overlapping study populations, the review included 14 studies. All studies were observational. The study populations were heterogeneous and included adult, pediatric and mixed populations. Some studies reported only witnessed cardiac arrests, arrests of cardiac ethiology, and/or shockable rhythm. The individual studies scored between six and nine on the Newcastle-Ottawa Scale of risk of bias. The median neurologically intact survival at hospital discharge with DA-CPR was 7.0% (interquartile range (IQR): 5.1–10.8%), with bystander-initiated CPR 7.5% (IQR: 6.6–10.2%), and with no bystander CPR 4.4% (IQR: 2.0–9.0%) (four studies). At one-month neurologically intact survival with DA-CPR was 3.1% (IQR: 1.6–3.4%), with bystander-initiated CPR 5.7% (IQR: 5.0–6.0%), and with no bystander CPR 2.5% (IQR: 2.1–2.6%) (three studies).

Conclusion

Both DA-CPR and bystander-initiated CPR increase neurologically intact survival compared with no bystander CPR. However, DA-CPR demonstrates inferior outcomes compared with bystander-initiated CPR. Early CPR is crucial, thus in cases where bystanders have not initiated CPR, DA-CPR provides an opportunity to improve neurologically intact survival following OHCA. Variability in OHCA outcomes across studies and multiple confounding factors were identified.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00875-5.

Effects of vibration-guided cardiopulmonary resuscitation with a smartwatch versus metronome guidance cardiopulmonary resuscitation during adult cardiac arrest: a randomized controlled simulation study

BACKGROUND

Smartwatches could be used as a cardiopulmonary resuscitation (CPR) guidance system through its vibration function. This study was conducted to determine whether vibration guidance by a smartwatch application influences CPR performance compared to metronome guided CPR in a simulated noisy setting.

METHODS

This study was randomised controlled trial. A total of 130 university students were enrolled. The experiment was conducted using a cardiac arrest model with hands-only CPR. Participants were randomly divided into two groups 1:1 ratio and performed 2-min metronome guidance or vibration guidance compression at the rate of 110/min. Basic life support quality data were compared in simulated noisy environments.

RESULTS

There were significant differences between the audio and vibration guidance groups in the mean compression rate (MCR). However, there were no significant differences in correct or mean compression depth, correct hand position, and correctly released compression. The vibration guidance group resulted in 109 MCR (Interquartile range [IQR] 108-110), whereas the metronome guidance group resulted in 115 MCR (IQR 112-117) (p < 0.001).

CONCLUSION

In a simulated noisy environment, vibration guided CPR showed to be particularly advantageous in maintaining a desired MCR during hands-only CPR compared to metronome guided CPR.

The influence of past experiences on future willingness to perform bystander cardiopulmonary resuscitation

Background

The influence of past familial experiences of receiving cardiopulmonary resuscitation (CPR) and medical help in various cardiac arrest and nonfatal cardiac events toward willingness to “pay it forward” by helping the next cardiac arrest victim was explored.

Methods

Using a validated questionnaire, 6248 participants were asked to rate their willingness to perform bystander chest compression with mouth-to-mouth ventilation and chest compression-only CPR. Their past familial experiences of receiving cardiopulmonary resuscitation (CPR) and medical help in various cardiac arrest and nonfatal cardiac events were also recorded.

Results

Kruskal-Wallis test with post hoc Dunn’s pairwise comparisons showed that the following were significantly more willing to perform CPR with mouth-to-mouth ventilation: familial experience of “nonfatal cardiac events” (mean rank = 447) vs “out-of-hospital cardiac arrest with no CPR” (mean rank = 177), U = 35442.5, z = −2.055, p = 0.04; “in-hospital cardiac arrest and successful CPR” (mean rank = 2955.79) vs “none of these experiences” (mean rank = 2468.38), U = 111903, z = −2.60, p = 0.01; and “in-hospital cardiac arrest with successful CPR” (mean rank = 133.45) vs “out-of-hospital arrest with no CPR” (mean rank = 112.36), U = 4135.5, z = −2.06, p = 0.04. For compression-only CPR, Kruskal-Wallis test with multiple runs of Mann-Whitney U tests showed that “nonfatal cardiac events” group was statistically higher than the group with “none of these experiences” (mean rank = 3061.43 vs 2859.91), U = 1194658, z = −2.588, p = 0.01. The groups of “in-hospital cardiac arrest with successful CPR” and “in-hospital cardiac arrest with transient return of spontaneous circulation” were the most willing groups to perform compression-only CPR.

Conclusion

Prior familial experiences of receiving CPR and medical help, particularly among those with successful outcomes in a hospital setting, seem to increase the willingness to perform bystander CPR.

Effectiveness of a community based out-of-hospital cardiac arrest (OHCA) interventional bundle: Results of a pilot study

BACKGROUND

70% of Out-of-hospital cardiac arrests (OHCA) in Singapore occur in residential areas, and are associated with poorer outcomes. We hypothesized that an interventional bundle consisting of Save-A-life (SAL) initiative (cardiopulmonary resuscitation (CPR)/automated external defibrillator (AED) training and public-housing AED installation), dispatcher-assisted CPR (DA-CPR) program and myResponder (mobile application) will improve OHCA survival.

METHODS

This is pilot data from initial implementation of a stepped-wedge, before-after, real-world interventional bundle in six selected regions. Under the SAL initiative, 30,000 individuals were CPR/AED trained, with 360 AEDs installed. Data was obtained from Singapore's national OHCA Registry. We included all adult patients who experienced OHCA in Singapore from 2011 to 2016 within study regions, excluding EMS-witnessed cases and cases due to trauma/drowning/ electrocution. Cases occurring before and after intervention were allocated as control and intervention groups respectively. Survival was assessed via multivariable logistic regression.

RESULTS

1241 patients were included for analysis (Intervention: 361; Control: 880). The intervention group had higher mean age (70 vs 67 years), survival (3.3% [12/361] vs. 2.2% [19/880]), pre-hospital return of spontaneous circulation (ROSC) (9.1% [33/361] vs 5.1% [45/880]), bystander CPR (63.7% [230/361] vs 44.8% [394/880]) and bystander AED application (2.8% [10/361] vs 1.1% [10/880]). After adjusting for age, gender, race and significant covariates, the intervention was associated with increased odds ratio (OR) for survival (OR 2.39 [1.02-5.62]), pre-hospital ROSC (OR 1.94 [1.15-3.25]) and bystander CPR (OR 2.29 [1.77-2.96]).

CONCLUSION

The OHCA interventional bundle (SAL initiative, DA-CPR, myResponder) significantly improved survival and is being scaled up as a national program.

A local neighborhood volunteer network improves response times for simulated cardiac arrest

AIM

Each minute is crucial in the treatment of out-of-hospital cardiac arrest (CA). Immediate chest compressions and early defibrillation are keys to good outcomes. We hypothesized that a coordinated effort of alerting trained local neighborhood volunteers (vols) simultaneously with 911 activation of professional EMS providers would result in substantial decreases in call-to-arrival times, leading to earlier CPR and defibrillation.

METHODS

We developed a program of simultaneously alerting CPR- and AED-trained neighborhood vols and the local EMS system for CA events in a retirement residential neighborhood in Southern Arizona, encompassing approximately 440 homes. The closest EMS station is 3.3 miles from this neighborhood. Within this neighborhood, 15 vols and the closest EMS station were involved in multiple days of mock CA notifications and responses.

RESULTS

The two groups differed significantly in distance to the mock CA event and in response times. The volunteers averaged 0.3 ± 0.2 miles from the mock CA incidences while the closest EMS station averaged 3.4 ± 0.1 miles away (p < 0.0001). Response times (time from call to arrival) also differed. Two volunteers, one bringing an AED, averaged 1 min 38 s ± 53 s in Phase 1, while it took the EMS service an average of 7 min 20 s ± 1 min 13 s to arrive on scene; p < 0.0001.

CONCLUSION

Local neighborhood volunteers were geographically closer and arrived significantly sooner at the mock CA scene than did the EMS service. The approximate time savings from call to arrival with the volunteers was 4-6 min.

Dispatcher-Assisted Cardiopulmonary Resuscitation Program and Outcomes After Pediatric Out-of-Hospital Cardiac Arrest

OBJECTIVES

A dispatcher-assisted bystander cardiopulmonary resuscitation (DA-BCPR) is expected to influence the outcomes of pediatric out-of-hospital cardiac arrest (OHCA). Our objective was to measure the effect size of a DA-BCPR on survival outcomes according to location of the event.

METHODS

All emergency medical service treated OHCA patients younger than 19 years in Korea from January 2012 through December 2013 were analyzed. Patients with OHCA witnessed by emergency medical service providers and those with missing outcome information were excluded. Patients were categorized into the following categories: No-BCPR, BCPR without dispatcher assistance (BCPR-NDA), and BCPR-DA. The primary outcome was survival to hospital discharge. Multivariable logistic regression analysis was performed to calculate the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for outcomes by exposure group (reference, No-BCPR group) with and without an interaction term between exposure and location of arrest.

RESULTS

A total of 1013 eligible patients were analyzed. Among these patients, 16.6% received BCPR-NDA, 23.2% received BCPR-DA, and 60.2% received no BCPR. After adjusting for potential confounders, compared with N0-BCPR group, AORs for survival were 1.79 (95% CI, 1.03-3.12) in BCPR group, 1.71 (95% CI, 0.85-3.46) in BCPR-NDA group, and 1.39 (95% CI, 0.72-2.69) in BCPR-DA group. The AORs for survival of BCPR-NDA and BCPR-DA in public location were 3.30 (95% CI, 1.12-9.72) and 2.95 (95% CI, 1.00-8.67), whereas BCPR-NDA and BCPR-DA in private locations were 1.62 (95% CI, 0.68-3.88) and 1.15 (95% CI, 0.53-2.51).

CONCLUSION

The DA-CPR was associated with better outcomes in pediatric OHCA patients whose arrest occurred in public locations, but no improvement in outcomes was identified in patients whose arrest occurred at private locations.

Out-of-hospital cardiac arrest at place of residence is associated with worse outcomes in patients admitted to intensive care. A post-hoc analysis of the targeted temperature management trial

BACKGROUND

The majority of out-of-hospital cardiac arrests (OHCAs) occur at place of residence, which is associated with worse outcomes in unselected prehospital populations. Our aim was to investigate whether location of arrest was associated with outcome in a selected group of initial survivors admitted to intensive care.

METHODS

This is a post-hoc analysis of the Targeted Temperature Management After Cardiac Arrest (TTM) trial, a multicenter controlled trial, randomizing 950 OHCA patients to an intervention of 33 °C or 36 °C. The location of cardiac arrest was defined as place of residence versus public place or other. The outcome measures were mortality and neurological outcome, as defined by the Cerebral Performance Category Scale, at 180 days.

RESULTS

Approximately half of 938 included patients arrested at place of residence (53%). Location groups did not differ with respect to age (P=0.11) or witnessed arrests (P=0.48) but bystander CPR was less common (P=0.02) at place of residence. OHCA at place of residence was associated with higher 180-day mortality (55% vs. 38%, P<0.001) and worse neurological outcome (61% vs. 43%, P<0.001) compared with a public place or other. After adjusting for known confounders, OHCA at place of residence remained an independent predictor of mortality (P=0.007).

CONCLUSIONS

Half of all initial survivors after OHCA admitted to intensive care had an arrest at place of residence which was independently associated with poor outcomes. Actions to improve outcomes after OHCA at place of residence should be addressed in future trials.

Skills among young and elderly laypersons during simulated dispatcher assisted CPR and after CPR training

BACKGROUND

Dispatcher assisted cardiopulmonary resuscitation (DA-CPR) increase the rate of bystander CPR. The aim of the study was to compare the performance of DA-CPR and attainable skills following CPR training between young and elderly laypersons.

METHODS

Volunteer laypersons (young: 18-40 years; elderly: > 65 years) participated. Single rescuer CPR was performed in a simulated DA-CPR cardiac arrest scenario and after CPR training. Data were obtained from a manikin and from video recordings. The primary endpoint was chest compression depth.

RESULTS

Overall, 56 young (median age: 26, years since last CPR training: 6) and 58 elderly (median age: 72, years since last CPR training: 26.5) participated. Young laypersons performed deeper (mean (SD): 56 (14) mm vs. 39 (19) mm, P < 0.001) and faster (median (25th-75th percentile): 107 (97-112) per min vs. 84 (74-107) per min, P < 0.001) chest compressions compared to elderly. Young laypersons had shorter time to first compression (mean (SD): 71 (11) seconds vs. 104 (38) seconds, P < 0.001) and less hands-off time (median (25th-75th percentile): 0 (0-1) seconds vs. 5 (2-10) seconds, P < 0.001) than elderly. After CPR training chest compressions were performed with a depth (mean (SD): 64 (8) mm vs. 50 (14) mm, P < 0.001) and rate (mean (SD): 111 (11) per min vs. 93 (18) per min, P < 0.001) for young and elderly laypersons respectively.

CONCLUSION

Despite long CPR retention time for both groups, elderly laypersons had longer retention time, and performed inadequate DA-CPR compared to young laypersons. Following CPR training the attainable CPR level was of acceptable quality for both young and elderly laypersons.

A Six-Year Prospective Study of Out-of-Hospital Cardiac Arrest Managed by a Voluntary Ambulance Organisation

Objective

To obtain a database on the epidemiology of prehospital cardiac arrest and its management by a voluntary ambulance service, with the view for developing future strategies and service improvement.

Design

A 6-year prospective study from December 1998 to November 2004, using the Utstein-style template.

Setting

A voluntary ambulance service in Hong Kong.

Subjects and methods

Ambulance members had to complete and submit a specially designed data form after managing a cardiac arrest case, together with the ambulance run record and the automated external defibrillator (AED) computer printout, if appropriate.

Main outcome measures

Survival to hospital discharge and return of spontaneous circulation after resuscitation.

Results

A total of 72 cardiac arrests occurred during the period, with patients' age ranging from 29 to 106 years (mean 73.4). Most cardiac arrests occurred at home (46 or 63.9%). There were 58 witnessed cardiac arrests (80.5%), but bystander cardiopulmonary resuscitation (CPR) was started in only nine cases (15.5%) before the arrival of the ambulance crew. Six patients had evidence of rigor mortis or dependent lividity on ambulance arrival. For the 61 patients with electrocardiogram strips, the initial presenting rhythm on the AED was asystole in 45 (73.8%), pulseless electrical activity in 5 (8.2%), and ventricular fibrillation (VF) in 11 (18.0%). The median call-to-arrival time for VF cases (4.0 minutes) was significantly shorter than that of non-VF rhythms (8.5 minutes) [Mann-Whitney U test p=0.008]. Five patients had return of spontaneous circulation after resuscitation, but only one survived to hospital discharge.

Conclusions

Bystander CPR and ambulance response time are two areas requiring urgent improvement in our locality. As the majority of cardiac arrests occurred at home, the cost-effectiveness of public access defibrillation for Hong Kong is unclear. However, strategic placement of AED at high incidence' locations should be seriously considered.

Ethnic differences in sudden cardiac arrest resuscitation

OBJECTIVE

Ethnic differences in sudden cardiac arrest resuscitation have not been fully explored and studies have yielded inconsistent results. We examined the association of ethnicity with factors affecting sudden cardiac arrest outcomes.

METHODS

Retrospective cohort study of 3551 white, 440 black and 297 Asian sudden cardiac arrest cases in Seattle and King County, Washington, USA.

RESULTS

Compared with whites, blacks and Asians were younger, had lower socioeconomic status and were more likely to have diabetes, hypertension and end-stage renal disease (all p<0.001). Blacks and Asians were less likely to have a witnessed arrest (whites 57.6%, blacks 52.1%, Asians 46.1%, p<0.001) or receive bystander cardiopulmonary resuscitation (whites 50.9%, blacks 41.4%, Asians 47.1%, p=0.001), but had shorter average emergency medical services response time (mean in minutes: whites 5.18, blacks 4.75, Asians 4.85, p<0.001). Compared with whites, blacks were more likely to be found in pulseless electrical activity (blacks 20.9% vs whites 16.6%, p<0.001), and Asians were more likely to be found in asystole (Asians 41.1% vs whites 30.0%, p<0.001). One of the strongest predictors of resuscitation outcomes was initial cardiac rhythm with 25% of ventricular fibrillation, 4% of patients with pulseless electrical activity and 1% of patients with asystole surviving to hospital discharge (adjusted OR of resuscitation in pulseless electrical activity compared with ventricular fibrillation: 0.30, 95% CI 0.24 to 0.34, p<0.001, adjusted OR of resuscitation in asystole relative to ventricular fibrillation 0.21, 95% CI 0.17 to 0.26, p<0.001). Survival to hospital discharge was similar across all three ethnicities.

CONCLUSIONS

While there were differences in some prognostic characteristics between blacks, whites and Asians, we did not detect a significant difference in survival following sudden cardiac arrest between the three ethnic groups. There was, however, an ethnic difference in presenting rhythm, with pulseless electrical activity more prevalent in blacks and asystole more prevalent in Asians.

Treatment and outcome of out-of-hospital cardiac arrest in outpatient health care facilities

AIM

We evaluated the frequency and effectiveness of basic and advanced life support (ALS) interventions by medical professionals when out-of-hospital cardiac arrest (OHCA) occurred in ambulatory healthcare clinics before emergency medical services (EMS) arrival.

METHODS

Non-traumatic OHCAs in adults were systematically characterized over a 15 year period by their occurrence in clinics, at home, or in non-medical public locations, and outcomes compared between matched cohorts from each group.

RESULTS

Among 7784 patients, 6098 OHCA occurred at home, 1612 in non-medical public locations and 74 in clinics. Compared to non-medical public locations, clinic patients with OHCA were older, more often women and more frequently shocked; clinic arrests were more often witnessed, less likely to be of cardiac cause and to occur before EMS arrival. Compared to home, more clinic arrests were witnessed, occurred after EMS arrival, had bystander CPR, shockable rhythms and were defibrillated. When OHCA occurred before EMS arrival, 51 of 56 clinic patients (91%) received CPR, a defibrillator applied to 23 (41%), 17 (30%) were shocked, 4 (7%) intubated, and 7 (13%) received intravenous medications from facility personnel. Of these, only pre-EMS defibrillator use was associated with improved outcome. Among matched patients, OHCA survival was higher in clinics than at home (42% vs 26%, p=0.029), but comparable to other public locations.

CONCLUSIONS

Survival from OHCA in clinics was comparable to non-medical public locations, and higher than at home. Alongside CPR, use of defibrillators was associated with improved survival and worth prioritizing over other interventions before EMS arrival regardless of OHCA location.

Therapeutic Hypothermia and Out-of-Hospital Cardiac Arrest in a Child with Hypertrophic Obstructive Cardiomyopathy

Neurologic outcomes following pediatric cardiac arrest are consistently poor. Early initiation of cardiopulmonary resuscitation has been shown to have positive effects on both survival to hospital discharge, and improved neurological outcomes after cardiac arrest. Additionally, the use of therapeutic hypothermia may improve survival in pediatric cardiac arrest patients admitted to the intensive care unit. We report a child with congenital hypertrophic obstructive cardiomyopathy and an out-of-hospital cardiac arrest, in whom the early initiation of effective prolonged cardiopulmonary resuscitation and subsequent administration of therapeutic hypothermia contributed to a positive outcome with no gross neurologic sequelae. Continuing efforts should be made to promote and employ high-quality cardiopulmonary resuscitation, which likely contributed to the positive outcome of this case. Further research will be necessary to develop and solidify national guidelines for the implementation of therapeutic hypothermia in selected subpopulations of children with OHCA.

Sudden cardiac death in Brazil: a community-based autopsy series (2006-2010)

Background

Sudden cardiac death (SCD) is a sudden unexpected event, from a cardiac cause, that occurs in less than one hour after the symptoms onset, in a person without any previous condition that would seem fatal or who was seen without any symptoms 24 hours before found dead. Although it is a relatively frequent event, there are only few reliable data in underdeveloped countries.

Objective

We aimed to describe the features of SCD in Ribeirão Preto, Brazil (600,000 residents) according to Coroners’ Office autopsy reports.

Methods

We retrospectively reviewed 4501 autopsy reports between 2006 and 2010, to identify cases of SCD. Specific cause of death as well as demographic information, date, location and time of the event, comorbidities and whether cardiopulmonary resuscitation (CPR) was attempted were collected.

Results

We identified 899 cases of SCD (20%); the rate was 30/100000 residents per year. The vast majority of cases of SCD involved a coronary artery disease (CAD) (64%) and occurred in men (67%), between the 6^th and the 7^th decades of life. Most events occurred during the morning in the home setting (53.3%) and CPR was attempted in almost half of victims (49.7%). The most prevalent comorbidity was systemic hypertension (57.3%). Chagas’ disease was present in 49 cases (5.5%).

Conclusion

The majority of victims of SCD were men, in their sixties and seventies and the main cause of death was CAD. Chagas’ disease, an important public health problem in Latin America, was found in about 5.5% of the cases.

The influence of female gender on cardiac arrest outcomes: a systematic review of the literature

BACKGROUND

Sudden cardiac arrest is an important cause of cardiovascular mortality. The impact of gender on the outcome of cardiac arrest is not clear and data about that is limited.

OBJECTIVE

Understanding the influence of gender on cardiac arrest through a systematic review of the published literature.

METHODS

A search of all published studies in English between January 1970 and May 2013 was performed using the electronic databases PubMed and MEDLINE, using the key words 'cardiac arrest', 'outcome', and 'gender'.

RESULTS

Eleven studies were included in this review, all of which were observational studies conducted using national-based database registries of cardiac arrest. A total of 548,440 patients were enrolled in these studies with 220,646 (40.3%) of them being female patients. In general, there was a lower percentage of women in the reported studies compared to men. Women were older in age and more likely to have non-shockable rhythms as the initial rhythm. Women also had a lower rate of witnessed arrest, a lower rate of bystander resuscitation, a higher rate of survival until hospital admission and a lower rate of in-hospital survival compared to men. Women also had a more favorable one month survival and neurological outcome.

CONCLUSION

In the reported literature female gender seems to offer survival and outcome advantages following out-of-hospital cardiac arrest over male gender. This is in contrast to most other aspects of heart disease in which women tend to have a worse prognosis.

Disseminating cardiopulmonary resuscitation training by distributing 9,200 personal manikins

OBJECTIVES

Community members should be trained so that witnesses of cardiac arrests are able to trigger the emergency system and perform adequate resuscitation. In this study, the authors evaluated the results of cardiopulmonary resuscitation (CPR) training of communities in four Brazilian cities, using personal resuscitation manikins.

METHODS

In total, 9,200 manikins were distributed in Apucarana, Itanhaém, Maringá, and São Carlos, which are cities where the populations range from 80,000 to 325,000 inhabitants. Elementary and secondary school teachers were trained on how to identify a cardiac arrest, trigger the emergency system, and perform chest compressions. The teachers were to transfer the training to their students, who would then train their families and friends.

RESULTS

In total, 49,131 individuals were trained (6.7% of the population), but the original strategy of using teachers and students as multipliers was responsible for only 27.9% of the training. A total of 508 teachers were trained, and only 88 (17.3%) transferred the training to the students. Furthermore, the students have trained only 45 individuals of the population. In Maringá and São Carlos, the strategy was changed and professionals in the primary health care system were prepared and used as multipliers. This strategy proved extremely effective, especially in Maringá, where 39,041 individuals were trained (79.5% of the total number of trainings). Community health care providers were more effective in passing the training to students than the teachers (odds ratio [OR] = 7.12; 95% confidence interval [CI] = 4.74 to 10.69; p < 0.0001).

CONCLUSIONS

Instruction of CPR using personal manikins by professionals in the primary health care system seems to be a more efficient strategy for training the community than creating a training network in the schools.

Effect of Location of Out-of-Hospital Cardiac Arrest on Survival Outcomes

Introduction: This study aims to study how the effect of the location of patient collapses from cardiac arrest, in the residential and non-residential areas within Singapore, relates to certain survival outcomes. Materials and Methods: A retrospective cohort study of data were done from the Cardiac Arrest and Resuscitation Epidemiology (CARE) project. Out-of-hospital cardiac arrest (OHCA) data from October 2001 to October 2004 (CARE) were used. All patients with OHCA as confirmed by the absence of a pulse, unresponsiveness and apnoea were included. All events had occurred in Singapore. Analysis was performed and expressed in terms of the odds ratio (OR) and the corresponding 95% confidence interval (CI). Results: A total of 2375 cases were used for this analysis. Outcomes for OHCA in residential areas were poorer than in non-residential areas—1638 (68.9%) patients collapsed in residential areas, and 14 (0.9%) survived to discharge. This was significantly less than the 2.7% of patients who survived after collapsing in a non-residential area (OR 0.31 [0.16 – 0.62]). Multivariate logistic regression analysis showed that location alone had no independent effect on survival (adjusted OR 1.13 [0.32 – 4.05]); instead, underlying factors such as bystander CPR (OR 3.67 [1.13 – 11.97]) and initial shockable rhythms (OR 6.78 [1.95 – 23.53]) gave rise to better outcomes. Conclusion: Efforts to improve survival from OHCA in residential areas should include increasing CPR by family members, and reducing ambulance response times. Key words: Emergency Medical Services, Non-residential, Prehospital, Residential

Analysis of Prehospital Scene Time and Survival from Out-of-Hospital, Non-Traumatic, Cardiac Arrest

The purpose of this study was to determine whether shorter prehospital scene time (ST) is associated with an increased survival rate in non-traumatic, out-of-hospital, cardiac arrest (CA) in a medium-sized, metropolitan EMS system. Information was retrieved for all adult victims (age ≥18 years) of CA treated and transported by a metropolitan fire department over a 16month period (6/87–9/88). Data were retrieved from the fire department's database, hospital records, and death certificates. Statistical analysis of continuous variables was performed using the two-tailed, Student's t-test and non-parametric evaluations were performed by square analysis with p<0.05 considered significant. Two hundred ninety-eight cases were recorded of which 293 patients (98.3%) had documented ST (study group). Seventy-nine patients (27.0%) had ST <12 minutes, while 214 (73.0%) had ST≥12 minutes. Patients with ST <12 minutes were more likely to have return of spontaneous circulation in the field (26.6% vs. 15.9%, p<0.05) and also were more likely to survive than were patients with ST ≥12 minutes (13.9% vs. 6.5%, p<0.05). Mean ST for survivors was significantly less than for non-survivors (12.8 vs. 15.3 min., p<0.05).

We conclude that, in our system, adult victims of CA with ST <12 minutes are more likely to survive than are patients with longer ST. In addition, the mean ST for survivors is shorter than for non-survivors. It remains unclear whether shorter ST actually has an impact on survival or is merely a reflection of a sub-group with rapid resuscitation and consequently a higher likelihood of survival. Future investigations are needed to determine whether shorter ST actually impacts the likelihood of survival from CA.

The increased mortality from witnessed out-of-hospital cardiac arrest in the home

BACKGROUND

Research in 2008 demonstrated that the majority of out-of-hospital cardiac arrests (OHCAs) occur in the home, and many important characteristics differ between private and public locations. However, the influence of the location of collapse on survival from OHCA is not well understood. Furthermore, most of the reports have been from Western countries; there is little research from Asia that differentiates the conditions of OHCA.

OBJECTIVE

To investigate the influence of the location of collapse on being discharged alive from OHCA and whether the location of collapse is also an independent predictor of survival from OHCA in Japan.

METHODS

We analyzed 463 consecutive cases of witnessed OHCA with cardiac etiology that occurred between October 2004 and September 2008 in Japan. We investigated the characteristics of OHCA patients who collapsed in private and public locations, and assessed the influence of the location of collapse on survival from OHCA.

RESULTS

Patients who collapsed outside the home were younger, more likely to be male, more likely to receive bystander cardiopulmonary resuscitation (CPR), and more likely to have ventricular fibrillation (VF)/pulseless ventricular tachycardia (VT) and had a shorter time interval between collapse and 9-1-1 call than patients who collapsed in the home. Mortality was significantly higher in the group who collapsed in the home. The independent influence of the location of collapse was eliminated by additional adjustment for time interval from collapse to 9-1-1 call, age, bystander CPR, and initial cardiac rhythm. Finally, VF/pulseless VT as the initial rhythm and bystander CPR were independently associated with the patient's being discharged alive; the location of collapse was not an independently associated variable.

CONCLUSIONS

The present analysis demonstrated that there were significant differences in survival between groups of patients who suffered from cardiac arrest inside and outside the home in Japan. The outside-the-home group had a higher rate of survival from OHCA; however, the location of collapse was not an independent predictor of survival from OHCA. Education of the families of high-risk patients in placing a rapid emergency call and performing effective CPR might be needed to improve survival from cardiac arrest in the home.

Optimizing community resources to address sudden cardiac death

The "chain of survival" (early access, early cardiopulmonary resuscitation, early defibrillation, and early advanced care) defines the proven interventions necessary for successful resuscitation and survival of patients with cardiac arrest. Low survival rates from cardiac arrest are not due to lack of understanding of effective interventions, but instead are due to weak links in the chain of survival and the inability of communities to make sure these links function in an efficient, timely, and coordinated fashion. This article reviews how quality is defined for each link, how communities can strengthen each link, and how communities can forge a strong relationship between each link. By optimizing local leadership and stakeholder collaboration, communities have the potential to vastly improve outcomes from this devastating disease.

Psychologic effects of automated external defibrillator training: a randomized trial

OBJECTIVE

The objective of this study was to test whether an automated external defibrillator (AED) training program would positively affect the mental health of family members of high-risk patients.

METHODS

A total of 305 patients with ischemic heart disease and their family members were randomized to 1 of 4 AED training programs: 2 video-based training programs and 2 face-to-face training programs that emphasized self-efficacy and perceived control. Patients and family members were surveyed at baseline and 3 and 9 months postischemic event on demographic characteristics, measures of quality of life (Short Form-36), self-efficacy, and perceived control. For this study, family members were the focus rather than the patients.

RESULTS

Regression analyses showed that family members in the face-to-face training programs did not score better on any of the mental health status variables than family members who participated in the other training programs except for an increase in self-efficacy beliefs at 3 months after training.

CONCLUSION

The findings suggest that a specifically designed AED training program emphasizing self-efficacy and perceived control beliefs is not likely to enhance family member mental health.

The association between emergency medical services staffing patterns and out-of-hospital cardiac arrest survival

OBJECTIVE

To determine whether the number of advanced life support-trained personnel at the scene of an out-of-hospital cardiac arrest (OHCA) was associated with return of spontaneous circulation (ROSC) or survival to hospital discharge.

METHODS

A retrospective database review using Utstein-style reporting definitions was conducted in Milwaukee County. All adult (>or= 18 years of age) OHCA cases of presumed cardiac etiology from January 1993 through December 2005 were eligible for inclusion in the study. Cardiac arrests resulting from a drug overdose, suicide, drowning, hypoxia, exsanguination, stroke, or trauma were excluded from the study. Also excluded were cases in which no crew configuration or responding unit was available, cases in which no resuscitation effort was attempted, and cases in which no time data were available. Return of spontaneous circulation and survival to hospital discharge for OHCA patients treated by a crew with two paramedics were compared to those patients treated by crews with three or more paramedics. Multivariable logistic regression was used for the analysis and the results are reported as odds ratios (ORs).

RESULTS

During the study period, there were 10,298 OHCAs of cardiac etiology. Of those, 10,057 (98%) cases had sufficient data to be included in the analysis. There were 4,229 patients treated by two paramedics (9% survived to discharge), 4,459 patients treated by three paramedics (9% survived to discharge), and 1,369 patients treated by four or more paramedics (8% survived to discharge). In the multivariable analysis, when referenced against crews with two paramedics and controlled for factors that have a known correlation with cardiac arrest survival, patients treated by crews with three paramedics (0.83, 95% confidence interval [CI] 0.70 to 0.97, p = 0.02) and crews with four or more paramedics (0.66, 95% CI 0.52 to 0.83, p < 0.01) were associated with reduced survival to hospital discharge. Return of spontaneous circulation was not influenced by the number of paramedics present.

CONCLUSIONS

The presence of three or more paramedics at the scene of OHCA was not associated with improved survival to hospital discharge when compared to crews with two paramedics. Additional research is needed to determine the potential cause of this finding.

Optimizing Community Resources to Address Sudden Cardiac Death

The "chain of survival" (early access, early cardiopulmonary resuscitation, early defibrillation, and early advanced care) defines the proven interventions necessary for successful resuscitation and survival of patients with cardiac arrest. Low survival rates from cardiac arrest are not due to lack of understanding of effective interventions, but instead are due to weak links in the chain of survival and the inability of communities to make sure these links function in an efficient, timely, and coordinated fashion. This article reviews how quality is defined for each link, how communities can strengthen each link, and how communities can forge a strong relationship between each link. By optimizing local leadership and stakeholder collaboration, communities have the potential to vastly improve outcomes from this devastating disease.

High school students as ambassadors of CPR--a model for reaching the most appropriate target population?

BACKGROUND

There is mismatch in age between those usually trained in CPR and those witnessing out-of-hospital cardiac arrest with mean age reported at 30 and 65 years old, respectively. Two tier mass CPR self-training with manikin-DVD sets using school children has been reported. We have studied high school students as first tier and encouraged them to train older people.

METHODS

Four separate groups were tested: students before or after training and second tier adults before or after training with first tier students as facilitators. CPR performance was videotaped and electronically documented on a Skillmeter Anne manikin.

RESULTS

Each student reported to train mean 2.8 extra persons, and 43% were aged 50 or older. Pre-training results were poor, while first and second tier persons performed equally well after training, and within ERC guideline recommendations.

CONCLUSIONS

People trained at home with a manikin-DVD set and high school students as facilitators were able to perform CPR as recommended by ERC guidelines with a reasonable percentage aged 50 or older.

The C. J. Shanaberger Lecture: The Evolution of Prehospital Cardiac Care: 1966–2006 andBeyond

Prehospital cardiac care began 40 year ago. This lecture reviews the origins and evolution of prehospital emergency care for cardiac arrest. Several national and international guidelines have defined an evolving standard of care. The most recent guidelines, published in 2005, argue for a return to the basics and emphasize the importance of CPR and defibrillation. In 40 years we have learned much about the epidemiology of cardiac arrest and the factors associated with successful resuscitation. Timely CPR and defibrillation remain the cornerstones of successful therapy. A new role for EMS personnel may help identify at-risk patients and thus prevent future cardiac arrest. A pilot program, know as SPHERE (Supporting Public Health with Emergency Responders) is underway in King County, Washington. The goal is to identify patients with risk factors of high blood pressure or high blood glucose and motivate the patient to seek follow-up care. Several intervention strategies are being tested. Since EMS providers see up to 10% of the population in any given year the chance to identify at-risk patients provides a public health opportunity.

Location of Cardiac Arrests in the Public Access Defibrillation Trial

BACKGROUND

The Public Access Defibrillation (PAD) Trial found an overall doubling in the number of out-of-hospital cardiac arrest (CA) survivors when a lay responder team was equipped with an automated external defibrillator (AED), compared with cardiopulmonary resuscitation (CPR) alone.

OBJECTIVES

To describe the types of facilities that participated in the trial and to report the incidence of CA and survival in these different types of facilities.

METHODS

In this post-hoc analysis of PAD Trial data, the physical characteristics of the participating facilities and the numbers of presumed CAs, treatable CAs, and survivors are reported for each category of facilities.

RESULTS

There were 625 presumed CAs at 1,260 participating facilities. Just under half (n = 291) of the presumed CAs were classified as treatable CAs. Treatable CAs occurred at a rate of 2.9 per 1,000 person-years of exposure; rates were highest in fitness centers (5.1) and golf courses (4.8) and lowest in office complexes (0.7) and hotels (0.7). Survival from treatable CA was highest in recreational complexes (0.5), public transportation sites (0.4), and fitness centers (0.4) and lowest in office complexes (0.1) and residential facilities (0.0).

CONCLUSIONS

During the PAD Trial, the exposure-adjusted rate of treatable CA was highest in fitness centers and golf courses, but the incidence per facility was low to moderate. Survival from treatable cardiac arrest was highest in recreational complexes, public transportation facilities, and fitness centers.

Validation of 3 termination of resuscitation criteria for good neurologic survival after out-of-hospital cardiac arrest

STUDY OBJECTIVE

Several termination of resuscitation criteria have been proposed to identify patients who will not survive to hospital discharge after out-of-hospital cardiac arrest. However, only 1 set has been derived to specifically predict survival to hospital discharge with good neurologic function. The objectives of this study were to externally validate the basic life support (BLS) termination of resuscitation, advanced life support (ALS) termination of resuscitation, and neurologic termination of resuscitation criteria and compare their abilities to predict survival to hospital discharge with good neurologic function after out-of-hospital cardiac arrest.

METHODS

This was a secondary analysis of the Denver Cardiac Arrest Registry. Consecutive adult nontraumatic cardiac arrest patients in Denver County from January 1, 2003, through December 31, 2004, were included in the study. The BLS termination of resuscitation, ALS termination of resuscitation, and neurologic termination of resuscitation criteria were applied to the cohort, and their predictive proportions and 95% confidence intervals (CIs) were calculated for each set of criteria.

RESULTS

Of the 715 patients included in this study, the median age was 65 years (interquartile range 52 to 78 years), and 69% were male patients. In addition, 223 (31%) had return of spontaneous circulation, 175 (24%) survived to hospital admission, 58 (8%) survived to hospital discharge, and 42 (6%) survived to hospital discharge with good neurologic function. The proportion of patients with good neurologic survival to hospital discharge correctly identified for continued resuscitation was 100% (95% CI 92% to 100%) for all 3 termination of resuscitation criteria. The proportion of patients with poor neurologic survival to hospital discharge or no survival to hospital discharge correctly identified as eligible for termination of resuscitation was 36% (95% CI 32% to 40%) with the BLS termination of resuscitation criteria, 25% (95% CI 22% to 29%) with the ALS termination of resuscitation criteria, and 6% (95% CI 4% to 8%) with the neurologic termination of resuscitation criteria. Use of the BLS termination of resuscitation criteria would have reduced transport of the largest number of patients.

CONCLUSION

All 3 termination of resuscitation criteria had equally high abilities to identify patients requiring continued resuscitation. The BLS termination of resuscitation criteria, however, had the best combined ability to predict good neurologic survival and poor neurologic survival or death. These findings and the relative simplicity of the BLS termination of resuscitation criteria support their use.

Aspects on the increase in bystander CPR in Sweden and its association with outcome

AIM

To describe changes in the proportion of bystanders performing cardiopulmonary resuscitation (CPR) in out of hospital cardiac arrest (OHCA) in Sweden and to study the impact of bystander CPR on ventricular fibrillation and on survival during various times.

PATIENTS AND METHODS

All patients who suffered from OHCA in Sweden in whom CPR was attempted and who were included in the Swedish cardiac arrest register (SCAR) between 1992 and 2005. Crew witnessed cases were excluded.

RESULTS

In all 34,125 patients were included in the survey. Among witnessed OHCA the proportion of patients receiving bystander CPR increased from 40% in 1992 to 55% in 2005 (p<0.0001). In non-witnessed OHCA the corresponding proportion increased from 22% to 44% (p<0.0001). There was a significant increase in bystander CPR regardless of age, sex and place. The increase was only found when CPR was performed by lay persons (21% in 1992 to 40% in 2005; p<0.0001). Bystander CPR was associated with an increased proportion of patients found in a shockable rhythm and a lower number of shocks to receive return of spontaneous circulation. Bystander CPR was associated with a similar increase in survival early and late in the evaluation.

CONCLUSION

There was a marked increase in bystander CPR in OHCA, when performed by lay persons, during the last 14 years in Sweden. Bystander CPR was associated with positive effects both on ventricular fibrillation and survival.

The willingness of final year medical and dental students to perform bystander cardiopulmonary resuscitation in an Asian community

BACKGROUND

Despite the importance of early effective chest compressions to improve the chance of survival of an out-of-hospital cardiac arrest victim, it is still largely unknown how willing our Malaysian population is to perform bystander cardiopulmonary resuscitation (CPR).

AIMS

We conducted a voluntary, anonymous self-administered questionnaire survey of a group of 164 final year medical students and 60 final year dental students to unravel their attitudes towards performing bystander CPR.

METHODS

Using a 4-point Likert scale of "definitely yes," "probably yes," "probably no," and "definitely no," the students were asked to rate their willingness to perform bystander CPR under three categories: chest compressions with mouth-to-mouth ventilation (CC + MMV), chest compressions with mask-to-mouth ventilation (CC + PMV), and chest compressions only (CC). Under each category, the students were given ten hypothetical victim scenarios. Categorical data analysis was done using the McNemar test, chi-square test, and Fisher exact test where appropriate. For selected analysis, "definitely yes" and "probably yes" were recoded as a "positive response."

RESULTS

Generally, we found that only 51.4% of the medical and 45.5% of the dental students are willing to perform bystander CPR. When analyzed under different hypothetical scenarios, we found that, except for the scenario where the victim is their own family member, all other scenarios showed a dismally low rate of positive responses in the category of CC + MMV, but their willingness was significantly improved under the CC + PMV and CC categories.

CONCLUSION

This study shows that there are unique sociocultural factors that contribute to the reluctance of our students to perform CC + MMV.

Delay prior to calling 9-1-1 is associated with increased mortality after out-of-hospital cardiac arrest

OBJECTIVE

We sought to characterize the collapse-to-9-1-1 call interval, to evaluate the frequency of pre-9-1-1 delay, and to assess whether delay is associated with decreased survival after out-of-hospital cardiac arrest (OHCA).

METHODS

This was a five-year prospective survey of bystanders to adult OHCA cases in which the victims were transported to seven local teaching hospitals in Michigan. Bystander data were obtained by telephone interview beginning two weeks after the event, and through review of emergency medical services (EMS) documents. Criteria for pre-9-1-1 delay were prospectively developed. Two paramedic reviewers were trained on these criteria and reviewed bystander and EMS data for each cardiac arrest case. Multivariate regression analysis was used to assess the independent impact of delay on survival. We collected common bystander and EMS OHCA demographics, as well as bystander description of events prior to the 9-1-1 call. Outcome was survival to hospital discharge.

RESULTS

During the study period we identified 1,004 OHCAs, for which 779 bystanders completed interviews. Of these interviews, 688 had adequate data for analysis. Raters showed moderate to strong agreement for a 15% subsample of cases. Of all cases, 330 (48%) were identified as having had pre-9-1-1 delay. Delay was less commonly associated with witnessed arrest (odds ratio [OR] 2.7; 95% confidence interval [CI] 2.0-3.7%) and public location (OR 1.57; 95% CI 1.1-2.2%). In a multivariate model, only initial-rhythm ventricular tachycardia/ventricular fibrillation was associated with improved survival (OR 2.28; 95% CI 1.3-4.1), and pre-9-1-1 delay was associated with decreased survival (OR 0.46; 95% CI 0.3-0.9%).

CONCLUSION

This method demonstrated that prehospital delay is common in OHCA and is associated with increased mortality. Measurement of pre-9-1-1 delay may improve precision of predictive models for OHCA survival.