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).     

Survival in out-of-hospital cardiac arrests with initial asystole or pulseless electrical activity and subsequent shockable rhythms

Background

Non-shockable arrest rhythms (pulseless electrical activity and asystole) represent an increasing proportion of reported cases of out-of-hospital cardiac arrest (OHCA). The prognostic significance of conversion from non-shockable to shockable rhythms during the course of resuscitation remains unclear.

Objective

To evaluate whether out-of-hospital cardiac arrest survival with initially non-shockable arrest rhythms is improved with subsequent conversion to shockable rhythms.

Methods

Secondary analysis of data in Epistry – Cardiac Arrest, an epidemiologic registry maintained by the Resuscitation Outcomes Consortium (ROC). This analysis includes OHCA events from December 1, 2005 through May 31, 2007 contributed by six US and two Canadian sites. For all EMS-treated adult (18 and older) cardiac arrest patients who presented with non-shockable cardiac arrest, we compared survival to hospital discharge between patients who did develop a shockable rhythm and those who did not based on receipt of subsequent defibrillation. Missing data were handled using multiple imputation. Multivariable logistic regression was used to adjust for potentially confounding variables.

Results

A total of 6556 EMS treated adult cardiac arrest cases presented in non-shockable rhythms. Survival to discharge in patients who converted to a shockable rhythm was 2.77% while survival in those who did not was 2.72% (p = 0.92). After adjusting for confounders, conversion to a shockable rhythm was not associated with improved survival (OR 0.88, 95% CI: 0.60–1.30).

Conclusion

For OHCA patients presenting in PEA/asystole, survival to hospital discharge was not associated with conversion to a shockable rhythm during EMS resuscitation efforts.     

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.     

Double Sequential External Defibrillation and Survival from Out-of-Hospital Cardiac Arrest: A Case Report

Background: Patients who present in ventricular fibrillation are typically treated with cardiopulmonary resuscitation (CPR), epinephrine, antiarrhythmic medications, and defibrillation. Although these therapies have shown to be effective, some patients remain in a shockable rhythm. Double sequential external defibrillation has been described as a viable option for patients in refractory ventricular fibrillation. Objective: To describe the innovative use of two defibrillators used to deliver double sequential external defibrillation by paramedics in a case of refractory ventricular fibrillation resulting in prehospital return of spontaneous circulation and survival to hospital discharge with good neurologic function. Case: A 28-year-old female sustained a witnessed out-of-hospital cardiac arrest (OHCA). Bystander CPR was performed by her husband followed by paramedics providing high-quality CPR, antiarrhythmic medication, and 6 biphasic defibrillations using standard energy levels. Double sequential external defibrillation was applied and a return of spontaneous circulation was attained on scene and maintained through to arrival to the emergency department. Following admission to hospital the patient was diagnosed with long QT syndrome. An implantable cardioverter defibrillator was placed and the patient was discharged with a Cerebral Performance Category of 2 as well as a modified Rankin Scale of 2 after an 18-day hospital stay. The patient's functional status continued to improve post discharge. Conclusion: The addition of double sequential external defibrillation as part of a well-organized resuscitation effort may be a valid treatment option for OHCA patients who present in refractory ventricular fibrillation.     

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.     

Time to first defibrillation and survival outcomes of out-of-hospital cardiac arrest with refractory ventricular fibrillation

IntroductionTimely defibrillation is associated with increased survival in out-of-hospital cardiac arrest (OHCA) cases. This study aimed to determine whether the time to first defibrillation was associated with good neurological outcomes in OHCA patients with refractory ventricular fibrillation.MethodsBystander-witnessed adult OHCA patients with presumed cardiac etiology who presented with ventricular fibrillation and received ≥2 successive prehospital defibrillations from emergency medical services between 2013 and 2018 were included. The times from collapse to first defibrillation were categorized into Group 1 (0–5 min), Group 2 (6–10 min), Group 3 (11–15 min), and Group 4 (16–60 min). The primary outcome was a good neurological recovery (cerebral performance category 1–2). Multivariable logistic regression analysis was performed to calculate the adjusted odd ratios (AORs) and 95% confidence intervals (CIs) for outcomes according to time group (Group 1 as the reference) and per 1-min delay.ResultsThe study included 5753 patients, with overall rates of 34.4% for survival to discharge and 27.2% for good neurological recovery. The median number of prehospital defibrillations was 3 (interquartile range 2–5). Relative to Group 1, the AORs for good neurological recovery were 0.58 in Group 2 (95% CI: 0.41–0.82), 0.42 in Group 3 (95% CI: 0.29–0.60), and 0.19 in Group 4 (95% CI: 0.13–0.29). When time from collapse to first EMS defibrillation was analyzed as a continuous variable, each 1-min delay was associated with a significant decrease in the likelihood of good neurological recovery (AOR: 0.93, 95% CI: 0.91–0.94).ConclusionsA short time from collapse to first defibrillation was associated with good neurological recovery among patients with OHCA and refractory ventricular fibrillation. This result suggests that a failed first shock still has a positive effect if it is delivered quickly.     

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.     

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.     

Drowning related out-of-hospital cardiac arrests: Characteristics and outcomes

Aim

There are few studies on drowning-related out-of-hospital cardiac arrest (OHCA) in which patients are followed from the scene through to hospital discharge. This study aims to describe this population and their outcomes in the state of Victoria (Australia).

Methods

The Victorian Ambulance Cardiac Arrest Registry was searched for all cases of OHCA with a precipitating event of drowning attended by emergency medical services (EMS) between October 1999 and December 2011.

Results

EMS attended 336 drowning-related OHCA during the study period. Cases frequently occurred in summer (45%) and the majority of patients were male (70%) and adult (77%). EMS resuscitation was attempted on 154 (46%) patients. Of these patients, 41 (27%) survived to hospital arrival and 12 (8%) survived to hospital discharge (5 adults [6%] and 7 [12%] children). Few patients were found in a shockable rhythm (6%), with the majority presenting in asystole (79%) or pulse-less electrical activity (13%). An initial shockable rhythm was found to positively predict survival (AOR 48.70, 95% CI: 3.80–624.86) while increased EMS response time (AOR 0.73, 95% CI: 0.54–0.98) and salt water drowning (AOR 0.69, 95% CI: 0.01–0.84) were found to negatively predict survival.

Conclusions

Rates of survival in OHCA caused by drowning are comparable to other OHCA causes. Patients were more likely to survive if they did not drown in salt water, had a quick EMS response and they were found in a shockable rhythm. Prevention efforts and reducing EMS response time are likely to improve survival of drowning patients.     

Cardiac arrest survival is rare without prehospital return of spontaneous circulation

Abstract Background. Emergency medical services (EMS) are crucial in the management of out-of-hospital cardiac arrest (OHCA). Despite accepted termination-of-resuscitation criteria, many patients are transported to the hospital without achieving field return of spontaneous circulation (ROSC). Objective. We examine field ROSC influence on OHCA survival to hospital discharge in two large urban EMS systems. Methods. A retrospective analysis of prospectively collected data was conducted. Data collection is a component of San Antonio Fire Department's comprehensive quality assurance/quality improvement program and Cincinnati Fire Department's participation in the Cardiac Arrest Registry to Enhance Survival (CARES) project. Attempted resuscitations of medical OHCA and cardiac OHCA for San Antonio and Cincinnati, respectively, from 2008 to 2010 were analyzed by city and in aggregate. Results. A total of 2,483 resuscitation attempts were evaluated. Age and gender distributions were similar between cities, but ethnic profiles differed. Cincinnati had 17% (p = 0.002) more patients with an initial shockable rhythm and was more likely to initiate transport before field ROSC. Overall survival to hospital discharge was 165 of 2,483 (6.6%). More than one-third (894 of 2,483, 36%) achieved field ROSC. Survival with field ROSC was 17.2% (154 of 894) and without field ROSC was 0.69% (11 of 1,589). Of the 11 survivors transported prior to field ROSC, nine received defibrillation by EMS. No asystolic patient survived to hospital discharge without field ROSC. Conclusion. Survival to hospital discharge after OHCA is rare without field ROSC. Resuscitation efforts should focus on achieving field ROSC. Transport should be reserved for patients with field ROSC or a shockable rhythm.     

Glasgow Coma Scale score of more than four on admission predicts in-hospital survival in patients after out-of-hospital cardiac arrest

AimThe aim of the study was to assess the usefulness of the Glasgow Coma Scale (GCS) score assessed by EMS team in predicting survival to hospital discharge in patients after out-of-hospital cardiac arrest (OHCA).MethodsSilesian Registry of OHCA (SIL-OHCA) is a prospective, population-based regional registry of OHCAs. All cases of OHCAs between the 1st of January 2018 and the 31st of December 2018 were included. Data were collected by EMS using a paper-based, Utstein-style form. OHCA patients aged ≥18 years, with CPR attempted or continued by EMS, who survived to hospital admission, were included in the current analysis. Patients who did not achieve return of spontaneous circulation (ROSC) in the field, with missing data on GCS after ROSC or survival status at discharge were excluded from the study.ResultsTwo hundred eighteen patients with OHCA, who achieved ROSC, were included in the present analysis. ROC analysis revealed GCS = 4 as a cut-off value in predicting survival to discharge (AUC 0.735; 95%CI 0.655–0.816; p < 0.001). Variables significantly associated with in-hospital survival were young age, short response time, witnessed event, previous myocardial infarction, chest pain before OHCA, initial shockable rhythm, coronary angiography, and GCS > 4. On the other hand, epinephrine administration, intubation, the need for dispatching two ambulances, and/or a physician-staffed ambulance were associated with a worse prognosis. Multivariable logistic regression analysis revealed GCS > 4 as an independent predictor of in-hospital survival after OHCA (OR of 6.4; 95% CI 2.0–20.3; p < 0.0001). Other independent predictors of survival were the lack of epinephrine administration, previous myocardial infarction, coronary angiography, and the patient's age.ConclusionThe survival to hospital discharge after OHCA could be predicted by the GCS score on hospital admission.     

Transthoracic impedance does not affect defibrillation, resuscitation or survival in patients with out-of-hospital cardiac arrest treated with a non-escalating biphasic waveform defibrillator

OBJECTIVE: This is a study of the influence of transthoracic impedance (TTI) on defibrillation, resuscitation and survival in patients with out-of-hospital cardiac arrest (OHCA), treated with a non-escalating impedance-compensating 150 J biphasic waveform defibrillator. METHODS: Cardiac arrest data from two EMS systems were analyzed retrospectively. All witnessed arrests from patients who presented with a shockable rhythm and were treated initially by BLS personnel were included (n = 102). For each defibrillation and resuscitation outcome variable, we tested differences in mean TTI for successful versus unsuccessful outcome. The effect of call-to-shock time on overall outcome was also examined. RESULTS: Initial shocks defibrillated 90% [83-95%] (95% confidence interval) of patients. Cumulative success with two shocks was 98% [93-100%] and with three shocks was 99% [95-100%]. TTI averaged 90 +/- 23 Omega. First-shock success, cumulative success through two shocks and cumulative success through the first-shock series were unrelated to TTI, as were BLS ROSC, pre-hospital ROSC, hospital admission and discharge. In contrast and consistent with previous findings, call-to-shock time was highly predictive of survival. CONCLUSIONS: High impedance patients were defibrillated by the biphasic waveform used in this study at high rates with a fixed energy of 150 J and without energy escalation. Rapid defibrillation rather than differences in patient impedance accounts for resuscitation success.     

Cardiac arrest due to drowning—Changes over time and factors of importance for survival

Aim

To evaluate changes in characteristics and survival over time in out-of-hospital cardiac arrest (OHCA) due to drowning and describe factors of importance for survival.

Method

Retrospectively reported and treated drowning cases reported to the Swedish OHCA registry between 1990 and 2012, n = 529. The data were clustered into three seven-year intervals for comparisons of changes over time.

Results

There were no changes in age, gender, witnessed status, shockable rhythm or place of OHCA during the time periods. Bystander CPR increased over time, 59% in interval 1992–1998, versus 74% in interval 2006–2012 (p = 0.005). There was a decrease in delay between OHCA and calling for the Emergency Medical Service (EMS) over the years, while calling for the EMS to arrival increased in terms of time. Survival to hospital admission appears to have increased over the years (p = 0.009), whereas survival to one month did not change significantly over time. In a multivariate analysis, witnessed status, female gender, bystander CPR, place–home and EMS response time were associated with survival to hospital admission. For survival to one month, place, age, shockable rhythm and logarithmised delay from calling for an ambulance to arrival were of significance for survival.

Conclusion

In OHCA due to drowning, over a period of 20 years, bystanders have called for help at an earlier stage and administered CPR more frequently in the past few years. Survival to hospital admission has increased, while shockable rhythm and early arrival of the EMS appear to be the most important factors for survival to one month.     

Effectiveness of Prehospital Dual Sequential Defibrillation for Refractory Ventricular Fibrillation and Ventricular Tachycardia Cardiac Arrest

Objective: Dual sequential defibrillation (DSD) — successive defibrillations with two defibrillators — offers a novel approach to refractory ventricular fibrillation (RVF) and tachycardia (VF/VT). While associated with rescue shock success, the effect of DSD upon out-of-hospital cardiac arrest (OHCA) is unknown. We evaluated the association of DSD with survival after refractory VF/VT OHCA. Methods: We used data from a large metropolitan fire-based EMS service. We included all adult OHCA during 2013–2016 with ≥3 standard defibrillations. Physicians authorized subsequent DSD use by two separate defibrillators (PhysioControl LIFEPAK® 12/15) with pads placed anterior-lateral and anterior-posterior. Evaluated outcomes included return of spontaneous circulation (ROSC), survival to hospital admission, survival to 72?hours, and survival to hospital discharge. Using multivariable logistic regression, we evaluated the association between defibrillation type and OHCA outcomes, adjusting for patient demographics and event characteristics. Results: We included 310 patients in the analysis, 71 patients receiving DSD and 239 receiving conventional defibrillation. Patient demographics and event characteristics were similar between both groups. ROSC was lower for DSD than standard defibrillation: 39.4% vs. 60.3%, adjusted OR 0.46 (95% CI: 0.25–0.87). There were no differences in survival to hospital admission (35.2% vs. 49.2%, adjusted OR 0.57 [95% CI: 0.30–1.08]), survival to 72?hours (21.4% vs. 32.3%, adjusted OR 0.52 [95% CI: 0.26–1.10]), or survival to hospital discharge (14.3% vs. 20.9%, adjusted OR 0.63 [95% CI: 0.27–1.45]). Conclusions: Compared with conventional defibrillation, DSD was associated with lower odds of prehospital ROSC. Defibrillation type was not associated with other OHCA endpoints. DSD may not be beneficial in refractory VF/VT OHCA.     

Temporal Trends in Outcomes after Out-of-Hospital Cardiac Arrests Witnessed by Emergency Medical Services in Japan: A Population-Based Study

Objective: Survival after out-of-hospital cardiac arrests (OHCA) witnessed by emergency medical service (EMS) personnel has been insufficiently understood. The aim of this study was to evaluate temporal trends in survival after EMS-witnessed OHCAs in Japan. Methods: A nationwide, population-based, observational cohort study of consecutive adult OHCA patients with emergency responder resuscitation attempts from January 2005 to December 2012 in Japan. We assessed the trends in annual incidence, characteristics, and outcomes of OHCA patients witnessed by EMS personnel. Multiple logistic regression analysis was used to assess factors that were potentially associated with neurologically favorable outcome defined as cerebral performance category scale 1or 2. Results: During the study period, a total of 66,760 EMS-witnessed OHCAs were documented. The annual incidence rates per 100,000 persons of EMS-witnessed OHCA patients increased from 4.6 (n = 7219) in 2005 to 4.9 (n = 9256) in 2012 (p for trend = 0.035). The proportion of one-month survival with neurologically favorable outcome improved from 5.9% in 2005 to 8.6% in 2012 (p for trend < 0.001), and the proportion increased from 22.1% in 2005 to 30.2% in 2012 in cases with shockable rhythm (p for trend < 0.001). In a multivariate analysis, adults, male gender, shockable rhythm, presumed cardiac origin, and year were associated with a better neurological outcome. Conclusions: In this population, the proportion of one-month survival with neurologically favorable outcome among OHCA patients witnessed by EMS personnel significantly improved during the study period.     

Effects of prehospital epinephrine during out-of-hospital cardiac arrest with initial non-shockable rhythm: an observational cohort study

Introduction

Few clinical trials have provided evidence that epinephrine administration after out-of-hospital cardiac arrest (OHCA) improves long-term survival. Here we determined whether prehospital epinephrine administration would improve 1-month survival in OHCA patients.

Methods

We analyzed the data of 209,577 OHCA patients; the data were prospectively collected in a nationwide Utstein-style Japanese database between 2009 and 2010. Patients were divided into the initial shockable rhythm (n = 15,492) and initial non-shockable rhythm (n = 194,085) cohorts. The endpoints were prehospital return of spontaneous circulation (ROSC), 1-month survival, and 1-month favorable neurological outcomes (cerebral performance category scale, category 1 or 2) after OHCA. We defined epinephrine administration time as the time from the start of cardiopulmonary resuscitation (CPR) by emergency medical services personnel to the first epinephrine administration.

Results

In the initial shockable rhythm cohort, the ratios of prehospital ROSC, 1-month survival, and 1-month favorable neurological outcomes in the non-epinephrine group were significantly higher than those in the epinephrine group (27.7% vs. 22.8%, 27.0% vs. 15.4%, and 18.6% vs. 7.0%, respectively; all P < 0.001). However, in the initial non-shockable rhythm cohort, the ratios of prehospital ROSC and 1-month survival in the epinephrine group were significantly higher than those in the non-epinephrine group (18.7% vs. 3.0% and 3.9% vs. 2.2%, respectively; all P < 0.001) and there was no significant difference between the epinephrine and non-epinephrine groups for 1-month favorable neurological outcomes (P = 0.62). Prehospital epinephrine administration for OHCA patients with initial non-shockable rhythms was independently associated with prehospital ROSC (adjusted odds ratio [aOR], 8.83, 6.18, 4.32; 95% confidence interval [CI], 8.01-9.73, 5.82-6.56, 3.98-4.69; for epinephrine administration times ≤9 min, 10-19 min, and ≥20 min, respectively), with improved 1-month survival when epinephrine administration time was <20 min (aOR, 1.78, 1.29; 95% CI, 1.50-2.10, 1.17-1.43; for epinephrine administration times ≤9 min and 10-19 min, respectively), and with deteriorated 1-month favorable neurological outcomes (aOR, 0.63, 0.49; 95% CI, 0.48-0.80, 0.32-0.71; for epinephrine administration times 10-19 min and ≥20 min, respectively).

Conclusions

Prehospital epinephrine administration for OHCA patients with initial nonshockable rhythms was independently associated with achievement of prehospital ROSC and had association with improved 1-month survival when epinephrine administration time was <20 min.     

Subsequent shock deliveries are associated with increased favorable neurological outcomes in cardiac arrest patients who had initially non-shockable rhythms

IntroductionPrevious studies evaluating whether subsequent conversion to shockable rhythms in patients who had initially non-shockable rhythms was associated with altered clinical outcome reported inconsistent results. Therefore, we hypothesized that subsequent shock delivery by emergency medical service (EMS) providers altered clinical outcomes in patients with initially non-shockable rhythms.MethodsWe tested for an association between subsequent shock delivery in EMS resuscitation and clinical outcomes in patients with initially non-shockable rhythms (n = 11,481) through a survey of patients after out-of-hospital cardiac arrest in the Kanto region (SOS-KANTO) 2012 study cohort, Japan. The primary investigated outcome was 1-month survival with favorable neurological functions. The secondary outcome variable was the presence of subsequent shock delivery. We further evaluated the association of interval from initiation of cardiopulmonary resuscitation to shock with clinical outcomes.ResultsIn the univariate analysis of initially non-shockable rhythms, patients who received subsequent shock delivery had significantly increased frequency of return of spontaneous circulation, 24-hour survival, 1-month survival, and favorable neurological outcomes compared to the subsequent not shocked group (P <0.0001). In the multivariate logistic regression analysis, subsequent shock was significantly associated with favorable neurological outcomes (vs. not shocked; adjusted P = 0.0020, odds ratio, 2.78; 95 % confidence interval, 1.45–5.30). Younger age, witnessed arrest, initial pulseless electrical activity rhythms, and cardiac etiology were significantly associated with the presence of subsequent shock in patients with initially non-shockable rhythms.ConclusionsIn this study of cardiac arrest patients with initially non-shockable rhythms, patients who received early defibrillation by EMS providers had increased 1-month favorable neurological outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-1028-0) contains supplementary material, which is available to authorized users.     

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.     

Out-of-hospital cardiac arrests occurring in primary health care facilities in Singapore

OBJECTIVES: To study out-of-hospital cardiac arrests (OHCA) occurring in primary healthcare facilities (HCF) in Singapore and to compare these with arrests occurring in the community. METHODS: This prospective observational study was part of the Cardiac Arrest and Resuscitation Epidemiology (CARE) project. Included were all patients with OHCA occurring in HCF. Patient characteristics, cardiac arrest circumstances, EMS response and outcomes were recorded according to the Utstein style. RESULTS: From 1 October 2001 to 14 October 2004, the data from 2428 subjects were received of which 138 patients were OHCA occurring in HCF. This is an incidence of 1.12/100,000 population per year and constituted 6.0% of all OHCA. Arrest occurring in HCF were more likely to be witnessed (p<0.01), or have bystander CPR (p<0.01). The HCF group was also more likely to receive CPR with both compression and ventilation (p<0.01) and have a non-trauma cause of arrest (p=0.03). HCF arrests also had a shorter collapse to call (EMS number) than the non-HCF group (HCF 1.54min versus non-HCF 5.36min, p=0.01). However, no HCF patient received defibrillation prior to EMS arrival. HCF patients were more likely to have return of spontaneous circulation at any time (p=0.05), survival to hospital admission (p<0.01) and survival to discharge (p<0.01) compared to non-HCF patients. CONCLUSION: This study suggests that primary health care providers do have an important role locally in managing out-of-hospital cardiac arrest. We propose an initiative to encourage early defibrillation by primary health care providers.     

EMS defibrillation-first policy may not improve outcome in out-of-hospital cardiac arrest

OBJECTIVE: Early defibrillation using automated external defibrillators (AEDs) has been advocated to improve survival in witnessed out-of-hospital cardiac arrest (OHCA) due to pulseless ventricular tachycardia (VT) and ventricular fibrillation (VF). However, when VT/VF is untreated and prolonged for more than a few minutes, defibrillation using AEDs may fail. METHODS: This retrospective study reviewed the charts from local emergency medical service (EMS) between the years 1993 to 2001 to evaluate the value of the AED after its introduction into our EMS. All witnessed OHCA due to VT/VF were analysed; cases of collapse witnessed by EMS were excluded. The primary endpoint was defined as survival to hospital discharge and at 1-year follow-up, and the secondary endpoint as survival without major neurological deficit. A total of 76 patients were treated for witnessed VT/VF before the implementation of the AED and 92 patients after its implementation. RESULTS: Before the introduction of paramedic AED defibrillation, physician defibrillation was performed at 15.6 min (+/-5.5, S.D.). After the introduction of AED defibrillation, paramedic defibrillation was performed at 5.7 min (+/-2.4, S.D.); the mean response interval from the call to defibrillation was shortened significantly (P<0.001). At the same time, survival to hospital discharge decreased from 23.7% (18/76 patients) to 14.1% (13/92) (P=0.112) and at 1-year follow-up from 17.1% (13/76) to 9.8% (9/92) (P=0.161). Favourable neurological outcome at 1-year follow-up also decreased from 14.5% (11/76) to 8.7% (8/92) (P=0.239). CONCLUSION: Implementation of the AED did not improve survival or a favourable neurological outcome in patients with OHCA due to VF/VT. However, with 5.7 min time to defibrillation, our EMS did not meet the criteria for early defibrillation. For prolonged periods of VT/VF, initial basic life support (BLS) may be superior to immediate AED. If response times of <4 min cannot be attained by the emergency systems, reconsidering of resuscitation algorithms seems to be advisable.