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.     

Outcome analysis of cardiac arrest due to hanging injury

Objective

The aim of this study was to review patient characteristics and analyze the outcomes in patients who have had cardiac arrest from hanging injuries.

Methods

A retrospective review was performed that examined the victims of out-of-hospital cardiac arrest (OHCA) due to hanging who presented to a tertiary general hospital from January 2000 to December 2009. Utstein style variables were evaluated, and patient outcomes were assessed at the time of hospital discharge using the cerebral performance category (CPC) scale.

Results

Fifty-two patients with OHCA due to hanging were enrolled in this study from the aforementioned 10-year inclusion period. Resuscitation attempts were performed in 31 patients (60%), and 21 patients were pronounced dead. In all cases, the first monitored cardiac rhythms were either asystole or pulseless electrical activity (PEA) and were therefore nonshockable rhythms. Of the patients for whom resuscitation was attempted, 13 (42%) experienced a return of spontaneous circulation and 1 revealed cervical spine fracture. Of the 13 return-of-spontaneous-circulation patients, 5 survived to be discharged. The mean age of these 5 surviving patients was 36 years. All 5 patients were graded as cerebral performance category 4 at discharge.

Conclusion

The first monitored cardiac rhythms of patients presenting with OHCA due to hanging were nonshockable rhythms wherein the survival rate of these patients was 9.6%. All of the survivors were relatively young and demonstrated poor neurologic outcomes at discharge. Physicians must consider cervical spine fracture in patients who had cardiac arrest from hanging.     

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.     

Outcome of out-of-hospital cardiac arrests in Beijing,China

Aim

The purpose of this study was to assess the outcome of out-of-hospital cardiac arrests (OHCAs) in Beijing, China.

Methods

In this prospective study, data were collected according to the Utstein style on all cases of OHCA that occurred between January and December 2012 in urban areas covered by Beijing Emergency Medical Services (EMS). The cases were followed-up for 1 year.

Results

Out of the 9897 OHCAs recorded, cardiopulmonary resuscitation (CPR) was initiated in 2421 patients (24.4%). Among the CPR-receivers (n = 2421), 1804 patients (74.5%) had collapsed at home, while 375 patients (15.5%) at a public place. The average time interval from call to EMS arrival at the collapse location was 16 min (range, 4–43 min). Of the 1693 OHCA cases with cardiac aetiology, 1246 cases (73.6%) were witnessed, and basic CPR was performed by bystanders before arrival of the EMS personnel in 193 patients (11.4%). Of the OHCAs with cardiac aetiology, 1054 patients (62.3%) had asystole, 131 patients (7.7%) had shockable rhythms, restoration of spontaneous circulation was achieved in 85 patients (5.0%), 71 patients (4.2%) were admitted to the hospital alive, and of the 22 patients (1.3%) who were discharged alive, 17 patients (1%) had good neurological outcomes. At 1 year post-OHCA, 17 patients were alive.

Conclusion

In the urban areas of Beijing with EMS services, survival rate after OHCA was unsatisfactory. Improvements are required in every link of the ‘chain of survival’.     

Traumatic out-of-hospital cardiac arrests in Melbourne, Australia

Introduction

Many consider attempted resuscitation for traumatic out-of-hospital cardiac arrest (OHCA) futile. This study aims to describe the characteristics and profile of adult traumatic OHCA.

Methods

The Victorian Ambulance Cardiac Arrest Registry (VACAR) was used to identify all trauma related cases of OHCA in patients aged ≥16 years.

Results

Between 2000 and 2009, EMS attended 33,178 OHCAs of which 2187 (6.6%) had a traumatic aetiology. The median age (IQR) of traumatic OHCA cases was 36 (25–55) years and 1612 were male (77.5%). Bystander CPR was performed in 201 cases (10.2%) with median (IQR) EMS response time 8 (6–11) min. The first recorded rhythm by EMS was asystole seen in 1650 (75.4%), PEA in 294 (13.4%) cases and VF in 35 cases (1.6%). Cardiac output was present in 208 (9.5%) cases who subsequently had an EMS witnessed OHCA. EMS attempted resuscitation in 545 (24.9%) patients of whom 84 (15.4%) achieved ROSC and were transported, and 27 (5.1%) survived to hospital discharge; 107 were transported with CPR of whom 8 (7.4%) survived to hospital discharge. Where EMS attempted resuscitation in traumatic OHCAs, survival for VF was 11.8% (n = 4), PEA 5.1% (n = 10) and asystole 2.4% (n = 3). In EMS witnessed traumatic OHCA, resuscitation was attempted in 175 cases (84.1%), 35 (16.8%) patients achieved sustained ROSC before transport of whom 5 (14%) survived to leave hospital and 60 (28.8%) were transported with CPR of whom 6 (10%) survived to leave hospital. Compared to OHCA cases with ‘presumed cardiac’ aetiology traumatic OHCAs were younger [median years (IQR): 36 (25–55) vs 74 (61–82)], had resuscitation attempted less (25% vs 48%), were less likely to have a shockable rhythm (1.6% vs 17.1%), were more likely to be witnessed (62.8% vs 38.1%) and were less likely to receive bystander CPR (10.2% vs 25.5%) (p < 0.001, respectively). Multivariate logistic regression identified factors associated with EMS decision to attempt resuscitation. The odds ratio [OR (95% CI)] for ‘presence of bystander CPR’ was 5.94 (4.11–8.58) and for ‘witnessed arrest’ was 2.60 (1.86–3.63).

Conclusion

In this paramedic delivered EMS attempted resuscitation was not always futile in traumatic OHCA with a survival of 5.1%. The quality of survival needs further study.     

Comparison of Helsinki and European Resuscitation Council “do not attempt to resuscitate” guidelines, and a termination of resuscitation clinical prediction rule for out-of-hospital cardiac arrest patients found in asystole or pulseless electrical activity

Background

The outcome of out-of-hospital cardiac arrest (OHCA) with a non-shockable rhythm is poor.For patients found in asystole or pulseless electrical activity (PEA), recent guidelines or rules that may be used include “do not attempt to resuscitate” (DNAR) guidelines from Helsinki, discontinuing resuscitation in the guidelines of the European Resuscitation Council and a clinical prediction rule from Canada. We compared these guidelines and the rule using a large Scandinavian dataset.

Materials and methods

The Swedish Cardiac Arrest Registry includes prospectively collected data on 44 121 OHCA patients. We identified patients with asystole or PEA as the initial rhythm and excluded cases caused by trauma or drowning. The specificities and positive predictive values (PPVs) were calculated for the guidelines, and the clinical prediction rule for comparison.

Results

A total of 20 484 patients with non-shockable rhythms were identified; 85% had asystole and 15% PEA. The overall survival to hospital admission was 9% (n = 1.861) and 1% (n = 231) were alive at 1 month from the arrest. The specificity of the Helsinki guidelines in identifying non-survivors was 71% (95% confidence interval (CI): 65-77%) and the PPV was 99.4% (95% CI: 99.3-99.5), while the corresponding values for the European Resuscitation Council (ERC) was 95% (95% CI: 91.3-97.5) and 99.9% (95% CI: 99.9-99.9) and, for the prediction rule, 99.1% (95% CI: 96.7-99.9) and 99.9% (95% CI: 99.9-100.00), respectively.

Conclusion

In this comparison study, the Helsinki DNAR guidelines did not perform well enough in a general OHCA material to be widely adopted. The main reason for this was the unpredicted survival of patients with unwitnessed asystole. The clinical prediction rule and the recommendations of the ERC Guidelines worked well.     

Survival rates in out-of-hospital cardiac arrest patients transported without prehospital return of spontaneous circulation: An observational cohort study

Background

Some Emergency Medical Services currently use just one component of the Universal Termination of Resuscitation (TOR) Guideline, the absence of prehospital return of spontaneous circulation (ROSC), as the single criteria to terminate resuscitation, which may deny transport to potential survivors.

Objective

This study aimed to report the survival to hospital discharge rate in non-traumatic, adult out-of-hospital cardiac arrest (OHCA) patients transported to hospital without a prehospital ROSC.

Methods

An observational study of OHCA patients without a prehospital ROSC who met the Universal TOR Guideline for transport to hospital with ongoing resuscitation. Multivariable logistic regression was used to determine the association of each variable with survival to hospital discharge.

Results

Of 20,207 OHCA treated by EMS, 3374 (16.4%) did not have a prehospital ROSC but met the Universal TOR guideline for transport to hospital with ongoing resuscitation. Of these patients, 122 (3.6%) survived to hospital discharge. Survival to discharge was associated with initial shockable VF/VT rhythms (OR 5.07; 95% CI 2.77–9.30), EMS-witnessed arrests (OR 3.51; 95% CI 1.73–7.15), bystander-witnessed arrests (OR 2.11; 95% CI 1.18–3.77), and public locations (OR 1.57; 95% CI 1.02–2.40).

Conclusion

In OHCA patients without a prehospital ROSC who met the Universal TOR Guideline for transport with ongoing resuscitation survival rates were above the 1% futility rate. Employing only the lack of ROSC as criteria for termination of resuscitation may miss survivors after OHCA.     

Paediatric traumatic out-of-hospital cardiac arrests in Melbourne, Australia

Introduction

Many consider attempted resuscitation for traumatic out-of-hospital cardiac arrest (OHCA) futile. This study aims to describe the characteristics and profile of paediatric traumatic OHCA.

Methods

The Victorian Ambulance Cardiac Arrest Registry (VACAR) was used to identify all trauma related cases of OHCA in patients aged less than 16 years of age. Cases were linked with their coronial findings.

Results

Between 2000 and 2009, EMS attended 33,722 OHCAs including 2187 adult traumatic OHCAs. There were 538 (1.6%) OHCAs in children less than 16 years of age of which n = 64 were due to trauma. The median age (IQR) of paediatric traumatic OHCA was 7 (4.5–13) years and 44 were male (69%). Bystander CPR was performed in 22 cases (34.4%). The first recorded rhythm by EMS was asystole seen in 42 (66%), PEA in 14 (22%) cases and VF in 2 cases (3%). Cardiac output was present in 7 (11%) cases who subsequently had an EMS witnessed OHCA. EMS attempted resuscitation in 35 (55%) patients of whom 7 (20%) achieved ROSC and were transported, and 1 (3%) survived to hospital discharge with severe neurological sequelae; 14(40%) were transported with CPR of whom none survived. Coronial cause of death was multiple injuries in 35%, head injury in 33%, head and neck injury in 10%, chest injuries in 10% and other causes (12%).

Conclusions

Traumatic aetiology of OHCA when compared to the incidence of adult traumatic OHCAs is uncommon. Resuscitation efforts are seldom effective and associated with poor neurological outcome.     

Conversion to shockable rhythms during resuscitation and survival for out-of hospital cardiac arrest

Background

In out of hospital cardiac arrest (OHCA), the prognostic influence of conversion to shockable rhythms during resuscitation for initially non-shockable rhythms remains unknown. This study aimed to assess the relationship between initial and subsequent shockable rhythm and post-arrest survival and neurological outcomes after OHCA.

Use and benefits of public access defibrillation in a nation-wide network

Background

Automated External Defibrillators (AEDs) are known to increase survival after out-of-hospital cardiac arrest (OHCA). The aim of this study was to examine the use and benefit of public-access defibrillation (PAD) in a nation-wide network. We primarily sought to assess survival at 1 month but information about the circumstances of each OHCA is provided as well.

Methods

In this 28-month study, we assessed the use of 807 AEDs in Denmark. When an AED was deployed information about the circumstances of OHCA, the bystander, the AED and the victim's condition was obtained.

Results

An AED was connected to an OHCA victim prior to the arrival of Emergency Medical Services (EMS) in 48 instances. Ten percent of bystanders were off-duty healthcare professionals. Shockable arrests (N = 31, 70%) were significantly more likely to be witnessed (94% vs. 54%) to occur at sports facilities (74% vs. 31%), in relation to exercise (42% vs. 0%), and with improved 30-day survival (69% vs. 15%, p = 0.001). Among those presenting with a shockable rhythm, 20 (65%) had Return of Spontaneous Circulation upon arrival of EMS and 8 (26%) were conscious, which emphasizes the diagnostic value of ECG downloads from AEDs. Survival could be determined in 42 of 44 patients with OHCA of cardiac origin, and was 52% (n = 22, 95% CI [38–67]) and the Cerebral Performance Category was 1 (Good Cerebral Performance) in all survivors.

Conclusion

With a 30-day neurologically intact survival of 69% for patients with shockable rhythms, this study provides further evidence of the lifesaving potential of PAD.     

The incidence and significance of bacteremia in out of hospital cardiac arrest

Background

The most common etiology of cardiac arrest is presumed of myocardial origin. Recent retrospective studies indicate that preexisting pneumonia, a form of sepsis, is frequent in patients who decompensate with abrupt cardiac arrest without preceding signs of septic shock, respiratory failure or severe metabolic disorders shortly after hospitalization. The contribution of pre-existing infection on pre and post cardiac arrest events remains unknown and has not been studied in a prospective fashion. We sought to examine the incidence of pre-existing infection in out-of hospital cardiac arrest (OHCA) and assess characteristics associated with bacteremia, the goal standard for presence of infection.

Methods and results

We prospectively observed 250 OHCA adult patients who presented to the Emergency Department (ED) between 2007 and 2009 to an urban academic teaching institution. Bacteremia was defined as one positive blood culture with non-skin flora bacteria or two positive blood cultures with skin flora bacteria. 77 met pre-defined exclusion criteria. Of the 173 OHCA adults, 65 (38%) were found to be bacteremic with asystole and PEA as the most common presenting rhythms. Mortality in the ED was significantly higher in bacteremic OHCA (75.4%) compared to non-bacteremic OHCA (60.2%, p < 0.05). After adjustment for potential confounders, predictive factors associated with bacteremic OHCA were lower initial arterial pH, higher lactate, WBC, BUN and creatinine.

Conclusions

Over one-third of OHCA adults were bacteremic upon presentation. These patients have greater hemodynamic instability and significantly increased short-term mortality. Further studies are warranted to address the epidemiology of infection as possible cause of cardiac arrest.     

Out-of-hospital cardiac arrests in young adults in Melbourne, Australia

Background

Characteristics and outcomes of out-of-hospital cardiac arrest (OHCA) in young adults are not well described in Australia.

Methods

A 10-year retrospective case review of all OHCA in young adults (aged 16-39) and not witnessed by EMS, was performed using data from the Victorian Ambulance Cardiac Arrest Registry (VACAR).

Results

Between 2000 and 2009 there were 30,006 adult cardiac arrests of which 3912 (13%) were in this age group. The median (IQR) age was 30 (25-35) years for both sexes with a 3:1 male to female ratio. Overdose was the most common precipitant (33.5%) followed by presumed cardiac (20%). Bystander CPR occurred in 21.2%, EMS median response time was 7 min and resuscitation was attempted in 36% of OHCAs. The presenting rhythm was asystole in 84.6%, PEA in 8.8% and VF/VT in 6.6%. Survival to hospital discharge, for all cause OHCA where resuscitation was attempted, was similar for young adult and older adults (8.8% vs 8.4%, p = 0.2). However, for presumed cardiac aetiology OHCA, young adults had a greater proportion of survivors (14.8% vs 9.0%, p < 0.001). Cardiac arrest with shockable rhythm (VF/pulseless VT) had a survival rate of 31.2% for young adults compared to 18.5% for older adults (p < 0.001).

Conclusion

Survival to hospital discharge rates from OHCA due to a ‘presumed cardiac’ precipitant in young adults is much better than older adults, however, all cause OHCA survival is similar. Multi agency novel upstream preventive strategies aimed at tackling drug overdose may reduce this aetiology of OHCA and save lives.     

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.     

Therapeutic hypothermia is associated with improved neurologic outcome and survival in cardiac arrest survivors of non-shockable rhythms

Background

Therapeutic hypothermia improves neurologic outcomes in patients resuscitated from cardiac arrest due to ventricular fibrillation. However, its role in patients with cardiac arrest due to non-shockable rhythms (pulseless electrical activity (PEA) and asystole) is unclear. We hypothesized that therapeutic hypothermia favorably impacts neurologic outcome and survival in patients resuscitated from cardiac arrest due to non-shockable rhythms.

Methods

Retrospectively collected data on consecutive adult patients admitted to Hartford Hospital from 1/1/2004 to 11/1/2010 who survived a cardiac arrest due to PEA or asystole were analyzed. Patients who underwent therapeutic hypothermia (1/1/2007-11/1/2010) formed the hypothermia group while patients admitted prior to the institution of therapeutic hypothermia (1/1/2004-1/1/2007) at Hartford Hospital formed the control group. The primary end-point was measured using the Pittsburgh cerebral performance category (CPC) scale and patients were assessed for a good (CPC 1 and 2) or poor (CPC 3-5) neurological outcome prior to discharge from hospital. A secondary end-point was measured as survival at discharge from hospital.

Results

Of 100 post-cardiac arrest patients included in the study, 15/52 (29%) patients in the hypothermia group had a good neurologic outcome as compared to 5/43 (10%) patients in the control group (P = 0.021). On multivariate analysis, the odds ratio for good neurologic outcome and survival at discharge from the hospital with therapeutic hypothermia as compared to control were 4.35 (95% CI 1.10-17.24, P = 0.04) and 5.65 (CI 1.66-19.23, P = 0.006) respectively.

Conclusion

Therapeutic hypothermia is associated with favorable neurologic outcome and survival in patients resuscitated after cardiac arrest due to non-shockable rhythms.     

Out-of-hospital cardiac arrest outcomes stratified by rhythm analysis

Background

Survival data for out-of-hospital cardiac arrest (OHCA) victims initially in PEA or asystole who convert to a shockable rhythm during attempted resuscitation, relative to an initial shockable rhythm, have never been previously reported. This study was done to assess OHCA outcomes among a large cohort of adults in the CARES dataset stratified by three rhythm categories: initial shockable (IS), converted shockable (CS), and never shockable (NS).

Methods

The study was IRB approved. All adult index events at participating sites (2005–2010) were study eligible. All patient data elements were provided. Odds ratios of CS and NS status for survival to hospital discharge were calculated via multivariate logistic regression that adjusted for demographics, site, resuscitation initiators, AED use, and other covariates.

Results

There were 40,274 OHCA records submitted to the CARES registry during the study period. After exclusions, our final sample size was 30,939 (7404 IS [23.9%], 3225 CS [10.4%], 20,310 NS [65.7%]). Raw survival rates of CS and NS patients were similar (4.7% vs. 4.1%, respectively; p = 0.08) but significantly lower than IS patients (26.9%; p < 0.001). The adjusted OR of survival to hospital discharge for CS was 0.17 (95%CI: 0.14, 0.20) and for NS it was 0.17 (95%CI: 0.15, 0.18) with IS as the referent.

Conclusion

After OHCA, the survival rate for CS victims is significantly lower than for IS patients. These findings suggest that CS and IS are different entities and that alternatives to existing resuscitation algorithm tailored to patients with CS should be investigated.     

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.     

Rapid epinephrine administration improves early outcomes in out-of-hospital cardiac arrest

Introduction

Early administration of epinephrine (Epi) improves outcomes in animal models of cardiac arrest, but there is limited time-dependent clinical data regarding its benefit.

Objective

Our objective was to assess whether timing of Epi administration was associated with improved outcomes after out of hospital cardiac arrest (OHCA).

Methods

We performed a retrospective analysis of a cardiac arrest database from a suburban EMS system from November 2005 to April 2011. Data was abstracted from EMS run sheets, including drug treatment, route and timing of drug administration, and other Utstein variables. Our primary outcome was return of spontaneous circulation (ROSC). Secondary outcomes measured were survival to hospital admission and discharge. For analysis, data were dichotomized according to timing of Epi administration: early Epi group (defined as 911 call to Epi administration of ≤10 min) and late Epi group (>10 min). Further, exploratory analyses were conducted looking at subgroups sorted by initial rhythm and whether the arrest was witnessed. Wilcoxon rank sum tests, chi-square tests, 95% confidence intervals, and multi-variable regression were used for statistical analysis.

Results

We reviewed 809 patients from study communities: 123 patients were excluded, leaving a sample size of 686 for study analysis. The mean time from 911-Epi was 14.3 ± 5.5 min, with 155 (22.6%) receiving early Epi. Key arrest and treatment characteristics were similar between groups. Patients who received early Epi were more likely to have ROSC (32.9% vs. 23.4%, OR 1.59 (1.07, 2.38)), however, no significant increase in survival to admission or discharge was observed. Patients with an initial rhythm of PEA had an increased rate of ROSC (48.6% vs. 21.5%, OR 3.45 (1.56, 7.62)) but not survival to discharge (5.9% vs. 2.6%), OR 2.35 (0.38, 14.7) with early Epi. In a multivariable analysis of bystander witnessed arrests, early Epi was associated with a higher rate of ROSC (OR 3.20 (1.75, 5.88) but not survival to discharge (OR 1.48 (0.50, 4.36)). No improvement in ROSC or secondary outcomes was noted in patients with other arrest rhythms or un-witnessed arrest with Early Epi.

Conclusions

Within the limitations of our study, this data suggests improved rates of ROSC with early Epi administration during OHCA resuscitation, but this study lacks adequate sample size to demonstrate impact on survival to discharge. Large prospective trials are needed to further delineate the benefit of early Epi administration in OHCA.     

The impact of partial resuscitation attempts on the reported outcomes of out-of-hospital cardiac arrest in Victoria,Australia: Implications for Utstein-style outcome reports

Background

Success rates from cardiopulmonary resuscitation (CPR) are often quantified by Utstein-style outcome reports in populations who receive an attempted resuscitation. In some cases, evidence of futility is ascertained after a partial resuscitation attempt has been administered, and these cases reduce the overall effectiveness of CPR. We examine the impact of partial resuscitation attempts on the reported outcomes of out-of-hospital cardiac arrest (OHCA) in Victoria, Australia.

Methods

Between 2002 and 2012, 34,849 adult OHCA cases of presumed cardiac aetiology were included from the Victorian Ambulance Cardiac Arrest Registry. Resuscitation attempts lasting ≤10 min in cases which died on scene were defined as a partial resuscitation. We used logistic regression to identify factors associated with a partial resuscitation attempt in the emergency medical service (EMS) treated population. Survival outcomes with and without partial resuscitations were compared across included years.

Results

The proportion of partial resuscitations in the overall EMS treated population increased significantly from 8.6% in 2002 to 18.8% in 2012 (p for trend < 0.001), and were largely supported by documented evidence of irreversible death. Partial resuscitations were independently associated with older age, female gender, initial non-shockable rhythm, prolonged downtime, and lower skill level of EMS personnel. Selectively excluding partial resuscitations increased event survival by 7.6% (95% CI 4.1–11.2%), and survival to hospital discharge increased by 3.1% (95% CI 0.5–5.7%) in 2012 (p < 0.001 for both).

Conclusion

In our EMS system, evidence of futility was often identified after the commencement of a partial resuscitation attempt. Excluding these events from OHCA outcome reports may better reflect the overall effectiveness of CPR.     

Is pulseless electrical activity a reason to refuse cardiopulmonary resuscitation with ECMO support?

Background

Cardiopulmonary resuscitation with ECMO support (ECPR) has shown to improve outcome in patients after cardiac arrest under resuscitation. Most current recommendations for ECPR do not include patients with a non-shockable rhythm such as PEA and asystole.

External validation of termination of resuscitation guidelines in the setting of intra-arrest cold saline,mechanical CPR,and comprehensive post resuscitation care

Background

The development of advanced life support (ALS) termination of resuscitation (TOR) guidelines for out-of-hospital cardiac arrest (OHCA) seeks to improve the efficiency of scarce pre-hospital resources. However, as pre-hospital treatment for OHCA evolves and survival improves, these TOR guidelines must be reevaluated in the contemporary context of emergency medical services (EMS) providing access to advanced resuscitation care.

Methods

Retrospective review of all adult (>18 years old), non-traumatic, OHCA patients (defined as patients with absence of pulse who received either CPR and/or defibrillation) treated by EMS in Richmond, VA, from January 1, 2009 to December 31, 2010. In addition to standard ALS, intra-arrest cold saline, mechanical CPR, and transportation to a comprehensive post-resuscitation center (CPRC) was provided. Patient treatment and outcomes were recorded via prehospital patient care reports and data were evaluated against previously established criteria for termination of resuscitation in an ALS EMS system. According to the aforementioned previously described criteria for TOR, patients meeting a single criterion for transport are recommended to be transported emergently to a comprehensive post-resuscitation care facility. Conversely, patients failing to meet any of the TOR criteria can be presumed to be expired without exception. Survival at 180 days was presumed when death could not be verified from publically reportable sources.

Results

Of the 322 OHCA patients enrolled, the majority were male (59%), unwitnessed (52%), received no bystander CPR (67%), and presented in a non-shockable initial rhythm (79%), with an average age of 62.5 years. Overall survival was 17%, 14%, 12%, and 11% at 7, 14, 30, and 180 days, respectively. Of the 75 patients for which TOR guidelines recommended termination, none survived yielding both 100% specificity (95% CI 100–92.8%) and positive predictive value (95% CI 100–94.1%). However, TOR guidelines recommended transport of 208 of the 283 patients who died within 30 days, resulting in a sensitivity of 26.5% (95% CI 34.5–23.4%).

Conclusion

The TOR guidelines continue to have a reliable positive predictive value for death even in the setting of advanced EMS resuscitation methods and access to a CPRC. However, as the potential for survival from OHCA improves, the efficiency gained from their use is impacted greatly.