Interventional strategies associated with improvements in survival for out-of-hospital cardiac arrests in Singapore over 10 years

AimWe aim to study if there has been an improvement in survival for Out-of-Hospital Cardiac Arrest (OHCA) in Singapore, the effects of various interventional strategies over the past 10 years, and identify strategies that contributed to improved survival.MethodsRates of OHCA survival were compared between 2001–2004 and 2010–2012, using nationwide data for all OHCA presenting to EMS and public hospitals. A multivariate logistic regression model for survival to discharge was constructed to identify strategies with significant impact.ResultsA total of 5453 cases were included, 2428 cases from 2001 to 2004 and 3025 cases from 2010 to 2012. There was significant improvement in Utstein (witnessed, shockable) survival to discharge from 2001–2004 (2.5%) to 2010–2012 (11.0%), adjusted odds ratio (OR) 9.6 [95% CI: 2.2–41.9]). Overall survival to discharge increased from 1.6% to 3.2% (adjusted OR 2.2 [1.5–3.3]). Bystander CPR rates increased from 19.7% to 22.4% (p = 0.02). The multivariate regression model (adjusted for important non-modifiable risk factors) showed that response time <8 min (OR 1.5 [1.0–2.3]), bystander AED (OR 5.8 [2.0–16.2]), and post-resuscitation hypothermia (OR 30.0 [11.5–78.0]) were significantly associated with survival to hospital discharge. Conversely, pre-hospital epinephrine (OR 0.6 [0.4–0.9]) was associated negatively with survival.ConclusionsOHCA survival has improved in Singapore over the past 10 years. Improvement in response time, public AEDs and post-resuscitation hypothermia appear to have contributed to the increase in survival. Singapore's experience might suggest that developing EMS systems should focus on reducing times to basic life support, including bystander defibrillation and post-resuscitation care.     

Out-of-hospital cardiac arrest survival improving over time: Results from the Resuscitation Outcomes Consortium (ROC)

BackgroundOut-of-hospital cardiac arrest (OHCA) remains a leading cause of death and a 2010 meta-analysis concluded that outcomes have not improved over several decades. However, guidelines have changed to emphasize CPR quality, minimization of interruptions, and standardized post-resuscitation care. We sought to evaluate whether OHCA outcomes have improved over time among agencies participating in the Resuscitation Outcomes Consortium (ROC) cardiac arrest registry (Epistry) and randomized clinical trials (RCTs).MethodsObservational cohort study of 47,148 EMS-treated OHCA cases in Epistry from 139 EMS agencies at 10 ROC sites that participated in at least one RCT between 1/1/2006 and 12/31/2010. We reviewed patient, scene, event characteristics, and outcomes of EMS-treated OHCA over time, including subgroups with initial rhythm of pulseless ventricular tachycardia or ventricular fibrillation (VT/VF).ResultsMean response interval, median age and male proportion remained similar over time. Unadjusted survival to discharge increased between 2006 and 2010 for treated OHCA (from 8.2% to 10.4%), as well as for subgroups of VT/VF (21.4% to 29.3%) and bystander witnessed VT/VF (23.5% to 30.3%). Compared with 2006, adjusted survival to discharge was significantly higher in 2010 for treated cases (OR = 1.72; 95% CI 1.53, 1.94), VT/VF cases (OR = 1.69; 95% CI 1.45, 1.98) and bystander witnessed VT/VF cases (OR = 1.65; 95% CI 1.36, 2.00). Tests for trend in each subgroup were significant (p < 0.001).ConclusionsROC-wide survival increased significantly between 2006 and 2010. Additional research efforts are warranted to identify specific factors associated with this improvement.     

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

AimWe 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.MethodsNon-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.ResultsAmong 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.ConclusionsSurvival 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.     

The association between chest compression release velocity and outcomes from out-of-hospital cardiac arrest

BackgroundPrevious studies have demonstrated significant relationships between cardiopulmonary resuscitation (CPR) quality metrics and survival to hospital discharge from out-of-hospital cardiac arrest (OHCA). Recently, it has been suggested that a new metric, chest compression release velocity (CCRV), may be associated with improved survival from OHCA.Methods and resultsWe performed a retrospective review of all treated adult OHCA occurring over a two year period beginning January 1, 2012. CPR metrics were abstracted from accelerometer measurements during each resuscitation. Multivariable regression analysis was used to examine the impact of CCRV on survival to hospital discharge. Secondary outcome measures were the impact of CCRV on return of spontaneous circulation (ROSC) and neurologically intact survival (MRS ≤ 3). Among 1800 treated OHCA, 1137 met inclusion criteria. The median (IQR) age was 71.6 (60.6, 82.3) with 724 (64%) being male. The median (IQR) CCRV (mm/s) amongst 96 survivors was 334.5 (300.0, 383.2) compared to 304.0 (262.6, 354.1) in 1041 non survivors (p < 0.001). When adjusted for Utstein variables, the odds of survival to hospital discharge for each 10 mm/s increase in CCRV was 1.02 (95% CI: 0.98, 1.06). Similarly the odds of ROSC and neurologically intact survival were 1.01 (95% CI: 0.99, 1.03) and 1.02 (95% CI: 0.98, 1.06), respectively.ConclusionsWhen adjusted for Utstein variables, CCRV was not significantly associated with outcomes from OHCA. Further research in other EMS systems is required to clarify the potential impact of this variable on OHCA survival.     

The time dependent association of adrenaline administration and survival from out-of-hospital cardiac arrest

BackgroundRecommended for decades, the therapeutic value of adrenaline (epinephrine) in the resuscitation of patients with out-of-hospital cardiac arrest (OHCA) is controversial.PurposeTo investigate the possible time-dependent outcomes associated with adrenaline administration by Emergency Medical Services personnel (EMS).MethodsA retrospective analysis of prospectively collected data from a near statewide cardiac resuscitation database between 1 January 2005 and 30 November 2013. Multivariable logistic regression was used to analyze the effect of the time interval between EMS dispatch and the initial dose of adrenaline on survival. The primary endpoints were survival to hospital discharge and favourable neurologic outcome.ResultsData from 3469 patients with witnessed OHCA were analyzed. Their mean age was 66.3 years and 69% were male. An initially shockable rhythm was present in 41.8% of patients. Based on a multivariable logistic regression model with initial adrenaline administration time interval (AATI) from EMS dispatch as the covariate, survival was greatest when adrenaline was administered very early but decreased rapidly with increasing (AATI); odds ratio 0.94 (95% Confidence Interval (CI) 0.92–0.97). The AATI had no significant effect on good neurological outcome (OR = 0.96, 95% CI = 0.90–1.02).ConclusionsIn patients with OHCA, survival to hospital discharge was greater in those treated early with adrenaline by EMS especially in the subset of patients with a shockable rhythm. However survival rapidly decreased with increasing adrenaline administration time intervals (AATI).     

Volume versus outcome: More emergency medical services personnel on-scene and increased survival after out-of-hospital cardiac arrest

Background and aim: The large regional variation in survival after treatment of out-of-hospital cardiac arrest (OHCA) is incompletely explained. Communities respond to OHCA with differing number of emergency medical services (EMS) personnel who respond to the scene. The effect of different numbers of EMS personnel on-scene upon outcomes is unclear. We sought to evaluate the association between number of EMS personnel on-scene and survival after OHCA.MethodsWe performed a retrospective review of prospectively collected data on 16,122 EMS-treated OHCA events from December 1, 2005 to May 31, 2007 from a combined population over 21 million people residing in an area of over 33,000 square miles in Canada and the United States. Number of EMS personnel on-scene was defined as the number of EMS personnel who responded to the scene of OHCA within 15 min after 9-1-1 call receipt and prior to patient death or transport away from the scene. Associations with survival to hospital discharge were assessed by using generalized estimating equations to construct multivariable logistic regression models.ResultsCompared to a reference number of EMS personnel on-scene of 5 or 6, 7 or 8 EMS personnel on-scene was associated with a higher rate of survival to hospital discharge, adjusted odds ratio [OR], 1.35 (95% CI: 1.05, 1.73). There was no significant difference in survival between 5 or 6 personnel on-scene versus fewer.ConclusionMore EMS personnel on-scene within 15 min of 9-1-1 call was associated with improved survival of out-of-hospital cardiac arrest. It is unlikely that this finding was mediated solely by earlier CPR or earlier defibrillation.     

Improvements in Out-of-Hospital Cardiac Arrest Survival from 1998 to 2013

Objectives: Out-of-hospital cardiac arrest (OHCA) remains a major public health burden. Aggregate OHCA survival to hospital discharge has reportedly remained unchanged at 7.6% for almost 30 years from 1970 to 2008. We examined the trends in adult OHCA survival over a 16-year period from 1998 to 2013 within a single EMS agency. Methods: Observational cohort study of adult OHCA patients treated by Tualatin Valley Fire & Rescue (TVF&R) from 1998 to 2013. This is an ALS first response fire agency that maintains an active Utstein style cardiac arrest registry and serves a population of approximately 450,000 in 9 incorporated cities in Oregon. Primary outcomes were survival to hospital discharge in all patients and in the subgroup with witnessed ventricular fibrillation/pulseless ventricular tachycardia (VF/VT). The impact of key covariates on survival was assessed using univariate logistic regression. These included patient factors (age and sex), event factors (location of arrest, witnessed status, and first recorded cardiac arrest rhythm), and EMS system factors (response time interval, bystander CPR, and non-EMS AED shock). We used multivariate logistic regression to examine the impact of year increment on survival after multiple imputation for missing data. Sensitivity analysis was performed with complete cases. Results: During the study period, 2,528 adult OHCA had attempted field resuscitation. The survival rate for treated cases increased from 6.7% to 18.2%, with witnessed VF/VT cases increasing from 14.3% to 31.4% from 1998 to 2013. Univariate analysis showed that younger age, male sex, public location of arrest, bystander or EMS witnessed event, initial rhythm of pulseless electrical activity (PEA) or VF/VT, bystander CPR, non-EMS AED shock, and a shorter EMS response time were independently associated with survival. After adjustment for covariates, the odds of survival increased by 9% (OR 1.09, 95%CI: 1.05–1.12) per year in all treated cases, and by 6% (OR 1.06, 95% 1.01–1.10) per year in witnessed VF/VT subgroups. Findings remained consistent on sensitivity analysis. Conclusions: Overall survival from treated OHCA has increased over the last 16 years in this community. These survival increases demonstrate that OHCA is a treatable condition that warrants further investigation and investment of resources.     

Outcome of avalanche victims with out-of-hospital cardiac arrest

Study backgroundPrevious studies focused on the outcome of avalanche victims with out-of-hospital cardiac arrest (OHCA) after long duration of burial (>35 min); the outcome of victims with short duration (≤35 min) remains obscure.Aim of the studyTo investigate outcome of avalanche victims with OHCA.MethodsRetrospective analysis of avalanche victims with OHCA between 2008 and 2013 in the Tyrolean Alps.Results55 avalanche victims were identified, 32 of whom were declared dead after extrication without cardiopulmonary resuscitation (CPR), all with long duration of burial. In the remaining 23 CPR was initiated at scene; three were partially and 20 completely buried, nine of whom suffered short and 11 long duration of burial. All nine victims with short duration of burial underwent restoration of spontaneous circulation (ROSC) at scene, four of them after bystander CPR, five after advanced life support by the emergency physician. Two patients with ROSC after short duration of burial and bystander CPR survived to hospital discharge with cerebral performance category 1. None of the 11 victims with long duration of burial survived to hospital discharge, although six were transported to hospital with ongoing CPR and three were supported with extracorporeal circulation.ConclusionsIn this case series survival with favourable neurological outcome was observed in avalanche victims with short duration of burial only if bystander CPR was immediately performed and ROSC achieved. Strategies for reducing avalanche mortality should focus on prompt extrication from the snow and immediate bystander CPR by uninjured companions.     

Increased survival after EMS witnessed cardiac arrest. Observations from the Resuscitation Outcomes Consortium (ROC) Epistry—Cardiac arrest

Background

Out of hospital cardiac arrest (OHCA) is common and lethal. It has been suggested that OHCA witnessed by EMS providers is a predictor of survival because advanced help is immediately available. We examined EMS witnessed OHCA from the Resuscitation Outcomes Consortium (ROC) to determine the effect of EMS witnessed vs. bystander witnessed and unwitnessed OHCA.

Methods

Data were analyzed from a prospective, population-based cohort study in 10 U.S. and Canadian ROC sites. Individuals with non-traumatic OHCA treated 04/01/06-03/31/07 by EMS providers with defibrillation or chest compressions were included. Cases were grouped into EMS-witnessed, bystander witnessed, and unwitnessed and further stratified for bystander CPR. Multiple logistic regressions evaluated the odds ratio (OR) for survival to discharge relative to the EMS-witnessed group after adjusting for age, sex, public/private location of collapse, ROC site, and initial ECG rhythm. Of 9991 OHCA, 1022 (10.2%) of EMS-witnessed, 3369 (33.7%) bystander witnessed, and 5600 (56.1%) unwitnessed.

Results

The most common initial rhythm in the EMS-witnessed group was PEA which was higher than in the bystander- and unwitnessed groups (p < 0.001). The adjusted OR (95% CI) of survival compared to the EMS-witnessed group was 0.41, (0.36, 0.46) in bystander witnessed with bystander CPR, 0.37 (0.33, 0.43) in bystander witnessed without bystander CPR, 0.17 (0.14, 0.20) in unwitnessed with bystander CPR and 0.21 (0.18, 0.24) in unwitnessed cases without bystander CPR.

Conclusions

Immediate application of prehospital care for OHCA may improve survival. Efforts should be made to educate patients to access 9-1-1 for prodromal symptoms.     

Urban and rural differences in out-of-hospital cardiac arrest in Ireland

BackgroundMore than a third of Ireland's population lives in a rural area, defined as the population residing in all areas outside clusters of 1500 or more inhabitants. This presents a challenge for the provision of effective pre-hospital resuscitation services. In 2012, Ireland became one of three European countries with nationwide Out-of-Hospital Cardiac Arrest (OHCA) register coverage. An OHCA register provides an ability to monitor quality and equity of access to life-saving services in Irish communities.AimTo use the first year of national OHCAR data to assess differences in the occurrence, incidence and outcomes of OHCA where resuscitation is attempted and the incident is attended by statutory Emergency Medical Services between rural and urban settings.MethodsThe geographical coordinates of incident locations were identified and co-ordinates were then classified as ‘urban’ or ‘rural’ according to the Irish Central Statistics Office (CSO) definition.Results1798 OHCA incidents were recorded which were attended by statutory Emergency Medical Services (EMS) and where resuscitation was attempted. There was a higher percentage of male patients in rural settings (71% vs. 65%; p = 0.009) but the incidence of male patients did not differ significantly between urban and rural settings (26 vs. 25 males/100,000 population/year p = 0.353). A higher proportion of rural patients received bystander cardiopulmonary resuscitation (B-CPR) 70% vs. 55% (p ≤ 0.001), and had defibrillation attempted before statutory EMS arrival (7% vs. 4% (p = 0.019), respectively). Urban patients were more likely to receive a statutory EMS response in 8 min or less (33% vs. 9%; p ≤ 0.001). Urban patients were also more likely to be discharged alive from hospital (6% vs. 3%; p = 0.006) (incidence 2.5 vs. 1.1/100,000 population/year; p ≤ 0.001).Multivariable analysis of survival showed that the main variable of interest i.e. urban vs. rural setting was also independently associated with discharge from hospital alive (OR 3.23 (95% CI 1.43–7.31)).ConclusionThere are significant disparities in the incidence of resuscitation attempts in urban and rural areas. There are challenges in the provision of services and subsequent outcomes from OHCA that occur outside of urban areas requiring novel and innovative solutions. An integrated community response system is necessary to improve metrics around OHCA response and outcomes in rural areas.     

Direction of first bystander call for help is associated with outcome from out-of-hospital cardiac arrest

Background

Preventable bystander delays following out-of-hospital cardiac arrest (OHCA) are common, and include bystanders inappropriately directing their calls for help.

Methods

We retrospectively extracted Utstein-style data from the Victorian Ambulance Cardiac Arrest Registry (VACAR) for adult OHCA occurring in Victoria, Australia, between July 2002 and June 2012. Emergency medical service (EMS) witnessed events were excluded. Cases were assigned into two groups on the basis of the first bystander call for help being directed to EMS. Study outcomes were: likelihood of receiving EMS treatment; survival to hospital, and; survival to hospital discharge.

Results

A total of 44 499 adult OHCA cases attended by EMS were identified, of which first bystander calls for help were not directed to EMS in 2842 (6.4%) cases. Calls to a relative, friend or neighbour accounted for almost 60% of the total emergency call delays. Patient characteristics and survival outcomes were consistently less favourable when calls were directed to others. First bystander call to others was independently associated with older age, male gender, arrest in private location, and arrest in a rural region. The risk-adjusted odds of treatment by EMS (OR 1.33, 95% CI 1.20–1.48), survival to hospital (OR 1.64, 95% CI 1.37–1.96) and survival to hospital discharge (OR 1.64, 95% CI 1.13–2.36) were significantly improved if bystanders called EMS first.

Conclusion

The frequency of inappropriate bystander calls following OHCA was low, but associated with a reduced likelihood of treatment by EMS and poorer survival outcomes.     

Outcome of out-of-hospital cardiac arrest over a period of 15 years in comparison to the RACA score in a physician staffed urban emergency medical service in Germany

BackgroundPatient outcome after out of hospital cardiac arrest (OHCA) depends on the cardiopulmonary resuscitation (CPR) performance and might also be influenced by organisation of the emergency medical service (EMS) and implementation of guidelines.AimTo assess the rate of return of spontaneous circulation (ROSC) after cardiac arrest to the predicted rate by the ROSC after cardiac arrest (RACA) score over a 15-year period reflecting three different implemented ALS-guidelines in a physician-staffed EMS.MethodsAll adult patients with non-traumatic OHCA in the EMS of Bonn from 1996 to 2011 were included. Utstein data from three 5-years time periods (1996–2001, 2001–2006, 2006–2011) representing different ALS-guideline implementations were collected. Group comparisons were made in terms of incidence, epidemiology and short-term outcome of CPR with emphasis on changes over time and factors of importance. In each group observed ROSC rate were compared to the predicted ROSC rates (the RACA score).ResultsCPR by the ALS unit was attempted in a total of 1989 patients (735, 666, and 588 patients in the first, second and third period, respectively). Average crude incidence of CPR per 100,000 person-years decreased over time (61.3; 55.5; 49.0/100,000/years) while patients treated were significantly older (65.5 ± 16.5; 67.9 ± 15; 68.9 ± 15.7 (p < 0.001)). Observed ROSC rates were higher than predicted by the RACA score in all time periods, however, admittance to ICU decreased significantly from 50% in the first five-year period to 38% last five-year period (p < 0.001). From first to third period the proportion of arrests with first observed rhythm of VT/VF arrests did not change (29% vs. 27%, p = 0.323) nor there were changes in bystander CPR rates (17% vs. 17%, p = 0.520).ConclusionsIn a 15-years period and in the setting of a physician-staffed EMS the ROSC rates remain higher than predicted by the RACA score but the admittance to the ICU after OHCA declined significantly. This finding was accompanied by a decrease in CPR incidence and an increase in age of patients.     

Dispatcher instruction of chest compression-only CPR increases actual provision of bystander CPR

BackgroundA preceding randomized controlled trial demonstrated that chest compression-only cardiopulmonary resuscitation (CPR) instruction by dispatcher was more effective to increase bystander CPR than conventional CPR instruction. However, the actual condition of implementation of each type of dispatcher instruction (chest compression-only CPR [CCCPR] or conventional CPR with rescue breathing) and provision of bystander CPR in real prehospital settings has not been sufficiently investigated.MethodsThis registry prospectively enrolled patients aged =>18 years suffering an out-of-hospital cardiac arrest (OHCA) of non-traumatic causes before emergency-medical-service (EMS) arrival, who were considered as target subjects of dispatcher instruction, resuscitated by EMS personnel, and transported to medical institutions in Osaka, Japan from January 2005 through December 2012. The primary outcome measure was provision of CPR by a bystander. Multiple logistic regression analysis was used to assess factors that were potentially associated with provision of bystander CPR.ResultsAmong 37,283 target subjects of dispatcher instruction, 5743 received CCCPR instruction and 13,926 received conventional CPR instruction. The proportion of CCCPR instruction increased from 5.7% in 2005 to 25.6% in 2012 (p for trend <0.001). The CCCPR instruction group received bystander CPR more frequently than conventional CPR instruction group (70.0% versus 62.1%, p < 0.001). In the multivariable analysis, CCCPR dispatcher instruction was significantly associated with provision of bystander CPR compared with conventional CPR instruction (adjusted odds ratio 1.44, 95% CI 1.34–1.55).ConclusionsCCCPR dispatcher instruction among adult OHCA patients significantly increased the actual provision of bystander CPR.     

Outcomes for out-of-hospital cardiac arrests across 7 countries in Asia: The Pan Asian Resuscitation Outcomes Study (PAROS)

BackgroundThe Pan Asian Resuscitation Outcomes Study (PAROS) Clinical Research Network (CRN) was established in collaboration with emergency medical services (EMS) agencies and academic centers in Japan, Singapore, South Korea, Malaysia, Taiwan, Thailand, and UAE-Dubai and aims to report out-of-hospital cardiac arrests (OHCA) and provide a better understanding of OHCA trends in Asia.Methods and resultsThis is a prospective, international, multi-center cohort study of OHCA across the Asia-Pacific. Each participating country provided between 1.5 and 2.5 years of data from January 2009 to December 2012. All OHCA cases conveyed by EMS or presenting at emergency departments were captured.66,780 OHCA cases were submitted to the PAROS CRN; 41,004 cases were presumed cardiac etiology. The mean age OHCA occurred varied from 49.7 to 71.7 years. The proportion of males ranged from 57.9% to 82.7%. Proportion of unwitnessed arrests ranged from 26.4% to 67.9%. Presenting shockable rhythm rates ranged from 4.1% to 19.8%. Bystander cardiopulmonary resuscitation (CPR) rates varied from 10.5% to 40.9%, however <1.0% of these arrests received bystander defibrillation. For arrests that were with cardiac etiology, witnessed arrest and VF, the survival rate to hospital discharge varied from no reported survivors to 31.2%. Overall survival to hospital discharge varied from 0.5% to 8.5%. Survival with good neurological function ranged from 1.6% to 3%.ConclusionsSurvival to hospital discharge for Asia varies widely and this may be related to patient and system differences. This implies that survival may be improved with interventions such as increasing bystander CPR, public access defibrillation and improving EMS.     

Interaction effects between hypothermia and diabetes mellitus on survival outcomes after out-of-hospital cardiac arrest

ObjectivesMild therapeutic hypothermia (MTH) is the core hospital intervention to enhance neurological outcome after out-of-hospital cardiac arrest (OHCA). Diabetes mellitus (DM) has been known to be a harmful risk factor on survival after OHCA. This study aimed to investigate whether the effect of MTH on brain recovery after OHCA differed between patients with or without DM.MethodsWe used a Korean national OHCA database composed of hospital and ambulance data. We included adult OHCA patients who survived to admission with presumed cardiac etiology during the study period from 2009 to 2013. We excluded cases without hospital outcome data. The primary exposure was MTH, which included all kinds of cooling methods that had been initiated within 6 h after return of spontaneous circulation. DM was coded positive when the patient had a clinical history diagnosed by a physician before an OHCA event. The endpoints were discharge with good neurological recovery (cerebral performance category 1 or 2) and survival to discharge. We compared outcomes between MTH vs. non-MTH groups using multivariable logistic regression with an interaction term between MTH and DM for calculating adjusted odds ratios (AORs) and 95% confidence intervals (CIs) after adjusting for potential confounders.ResultsAmong 9735 patients following OHCA survived to hospital admission with cardiac etiology, MTH was performed in 16.5%. History of DM was observed in 25.4% among MTH group and 27.4% in non-MTH group (p = 0.09). MTH group showed better outcomes than non-MTH group; 23.6% vs. 15.7% for good neurological recovery (p < 0.01). AOR (95% CI) of MTH for good neurological recovery for all study groups was 1.23 (1.03–1.47). In the interaction model, AOR (95% CI) of MTH for good neurological recovery was 1.40 (1.16–1.70) in patients without DM vs. 0.69 (0.46–1.04) in patients with DM. For survival to discharge, the effects of MTH were different in patients without DM (1.97 (1.70–2.29)) and patients with DM (1.23 (0.96–1.57)).ConclusionDM modified the effect of MTH on survival and neurological outcomes for OHCA survivors. MTH is significantly associated with good neurological recovery in patients without DM, but not in patients with DM.     

Engaging a whole community in resuscitation

BackgroundSurvival after out-of-hospital cardiac arrest (OHCA) is influenced by each link in the chain of survival. On the Danish island of Bornholm (population 42,000, area 588 km²) none survived an OHCA in 2001–2003. Therefore, we designed a multifaceted community-based approach aiming at strengthening each link in the chain of survival.The purpose of this study was to evaluate the effect of implementation of the intervention on bystander basic life support (BLS) rates and survival to hospital discharge after OHCA.MethodsLaypersons completed 24-min DVD-based-self-instruction BLS courses in schools and workplaces or 4-h BLS/automated external defibrillator (AED) courses. The local television station had broadcasts about resuscitation. The ambulance personnel were trained and the staff at the island hospital completed BLS courses or more advanced courses.ResultsDuring 2 years 9226 people (22% of the population) completed the short course and 2453 (6% of the population) completed the 4-h course. The number of AEDs increased from 3 to 147. The bystander BLS rate for OHCAs with a presumed cardiac aetiology (N = 96, incidence 114/100,000 person-years) was 47% [95% CI 30–50] and for witnessed OHCAs (N = 35) it increased significantly from 22% (2004) to 74% [95% CI 58–86]. The AEDs were deployed in 9 cases. Survival to discharge for all-rhythms OHCA was 5.4% [95% CI 2–12], and for witnessed ventricular fibrillation (N = 17) 18% [95% CI 5–42].ConclusionStrengthening all links in the chain of survival was associated with significant increases in bystander BLS rates and survival after OHCA on a rural island.     

Recurrent ventricular fibrillation: Experience with first responders prior to advanced life support interventions

AimFollowing defibrillation, ventricular fibrillation (VF) frequently recurs during out-of-hospital cardiac arrest (OHCA). Prior studies have reported conflicting results regarding its association with survival. The aim of this study was to examine the impact of recurrent VF in the presence of first responders before advanced life support (ALS) interventions.MethodsElectrocardiographic data from first responder automated external defibrillators (AEDs) were analyzed. A successful shock was defined as termination of VF for 5 s or longer. Recurrent VF was defined as any VF that occurred after a successful shock. The primary outcome was neurologically intact survival to hospital discharge (CPC 1–2).Results108 patients within our emergency system experienced a witnessed VF arrest. Of these, 73 (68%) had at least one recurrence of VF. Median time to recurrence of VF was 25 s [interquartile range (IQR) 11–66 s]. Median time in recurrent VF was 180 s (IQR 105–266 s). Survival was observed in 25 (71%) of patients with no recurrent VF and in 36 (49%) who had recurrence. Recurrent VF was associated with a lower odds of survival on univariate analysis (OR 0.39, 95% CI 0.16–0.92, p = 0.0325). After adjusting for bystander CPR, gender and age, recurrent VF had a similar direction of effect but was no longer significantly associated with neurologically intact survival (OR 0.44, 95% CI 0.17–1.11, p = 0.081).ConclusionsIn the presence of first responders, VF recurred in 68% of patients. Recurrent VF was associated with a lower odds of survival, though its prognostic significance appeared to be blunted when considered in light of confounding variables. Recurrent VF may have significant survival implications, and further studies to assess its prognostic significance should be performed.     

Causes for the declining proportion of ventricular fibrillation in out-of-hospital cardiac arrest

AimsThe reported proportion of ventricular fibrillation (VF) in out-of-hospital cardiac arrest (OHCA) has declined worldwide. VF decline may be caused by less VF at collapse and/or faster dissolution of VF into asystole. We aimed to determine the causes of VF decline by comparing VF proportions in relation to delay from emergency medical services (EMS) call to initial ECG (call-to-ECG delay), and VF dissolution rates between two study periods.MethodsData from the AmsteRdam REsuscitation STudies (ARREST), an ongoing OHCA registry in the Netherlands, were used. We studied cardiac OHCA in the study periods 1995–1997 (n = 917) and 2006–2012 (n = 5695). Cases with available ECG and information on call-to-ECG delay were included. We tested whether initial VF proportion and VF dissolution rates differed between both study periods using logistic regression.ResultsDespite a 15% VF decline between the periods, VF proportion around EMS call remained high in 2006–2012 (64%). The odds ratio (OR) for VF proportion in 2006–2012 vs. 1995–1997 was 0.52 (95%-CI 0.45–0.60, P < 0.001), with similar rates of VF dissolution in both periods (P = 0.83). VF decline was higher for unwitnessed collapse (OR 0.41, 95%-CI 0.28–0.58) and collapse at home (OR 0.50, 95%-CI 0.42–0.59), but not for categories of bystander CPR, age or sex.ConclusionVF proportion early after collapse remains high. VF decline is explained by the occurrence of less initial VF, rather than faster dissolving VF. An increase in unwitnessed OHCA and collapse at home contributes to the observed VF decline.     

The significance of pre-arrest factors in out-of-hospital cardiac arrests witnessed by emergency medical services: A report from the Victorian Ambulance Cardiac Arrest Registry

BackgroundThe significance of pre-arrest factors in out-of-hospital cardiac arrests (OHCA) witnessed by emergency medical services (EMS) is not well established. The purpose of this study was to assess the association between prodromal symptoms and pre-arrest clinical observations on the arresting rhythm and survival in EMS witnessed OHCA.MethodsBetween 1st January 2003 and 31st December 2011, 1056 adult EMS witnessed arrests of a presumed cardiac aetiology were identified from the Victorian Ambulance Cardiac Arrest Registry. Pre-arrest prodromal features and clinical characteristics were extracted from the patient care record. Backward elimination logistic regression was used to identify pre-arrest factors associated with an initial shockable rhythm and survival to hospital discharge.ResultsThe median age was 73.0 years, 690 (65.3%) were male, and the rhythm of arrest was shockable in 465 (44.0%) cases. The most commonly reported prodromal symptoms prior to arrest were chest pain (48.8%), dyspnoea (41.8%) and altered consciousness (37.8%). An unrecordable systolic blood pressure was observed in 34.4%, a respiratory rate <13 or >24 min⁻¹ was present in 43.1%, and 45.5% had a Glasgow coma score <15. In the multivariable analysis, the following pre-arrest factors were significantly associated with survival: age, public location, aged care facility, chest pain, arm or shoulder pain, dyspnoea, dizziness, vomiting, ventricular tachycardia, pulse rate, systolic blood pressure, respiratory rate, Glasgow coma score, aspirin and inotrope administration.ConclusionPre-arrest factors are strongly associated with the arresting rhythm and survival following EMS witnessed OHCA. Potential opportunities to improve outcomes exist by way of early recognition and management of patients at risk of OHCA.     

The duration of cardiopulmonary resuscitation in emergency departments after out-of-hospital cardiac arrest is associated with the outcome: A nationwide observational study

Aim of the studyThe appropriate duration of cardiopulmonary resuscitation (CPR) for patients who experience out-of-hospital cardiac arrest (OHCA) remains unknown. This study aimed to evaluate the duration of CPR in emergency departments (EDs) and to determine whether the institutions’ median duration of CPR was associated with survival-to-discharge rate.MethodsA cohort of adult patients from a nationwide OHCA registry was retrospectively evaluated. The main variable was the median duration of CPR for each ED (institutional duration), and the main outcome was survival to discharge. Multivariable logistic regression analysis was performed to adjust for individual and aggregated confounders.ResultsAmong the 107,736 patients who experienced OHCA between 2006 and 2010, 30,716 (28.5%) were selected for analysis. The median age was 65 years, and 67.1% were men. The median duration of CPR for all EDs was 28 min, ranging from 11 to 45 min. EDs were categorized into 3 groups according to their institutional duration of CPR: groups A (<20 min), B (20–29 min), C (≥30 min). The observed survival rates of the 3 groups were 2.11%, 5.20%, and 5.62%, respectively. Compared with group B, the adjusted difference (95% confidence interval) for survival to discharge was 3.01% (1.90–4.11, P < 0.001) for group A, and 0.33% (−0.64 to 1.30, P = 0.51) for group C.ConclusionThe duration of CPR varied widely among hospitals. The institutional duration of CPR less than 20 min was significantly associated with lower survival-to-discharge rate.