Outcomes following out-of-hospital cardiac arrest with an initial cardiac rhythm of asystole or pulseless electrical activity in Victoria,Australia

Background

While internationally reported survival from out-of-hospital cardiac arrest (OHCA) is improving, much of the increase is being observed in patients presenting to emergency medical services (EMS) in shockable rhythms. The purpose of this study was to assess survival and 12-month functional recovery in patients presenting to EMS in asystole or pulseless electrical activity (PEA).

Methods

The Victorian Ambulance Cardiac Arrest Registry was searched for adult OHCA patients presenting in non-shockable rhythms in Victoria, Australia between 1st July 2003 and 30th June 2013. We excluded patients defibrillated prior to EMS arrival and arrests witnessed by EMS. Twelve-month quality-of-life interviews were conducted on survivors who arrested between 1st January 2010 and 31st December 2012. The main outcome measures were survival to hospital discharge and 12-month functional recovery measured by the Extended Glasgow Outcome Scale (GOSE).

Results

A total of 38,378 non-shockable OHCA attended by EMS were included, of which 88.0% were asystole and 11.6% were PEA. Of the patients receiving resuscitation, survival to hospital discharge was 1.1% for asystole and 5.9% for PEA (p < 0.001), with no significant improvement observed over the 10 year study period. In survivors with 12-month follow-up data, the combined rate of death, vegetative state or lower severe disability was 66.7% (95% CI 41.0–80.0%) for asystole and 44.7% (95% CI 30.2–59.9%) for PEA.

Conclusion

Survival outcomes following OHCA with initial rhythms of asystole or PEA did not improve over the 10-year study period. Our findings indicate high rates of death within 12 months, and unfavourable functional recovery for survivors.     

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.

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.     

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.     

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.     

Exploring gender differences and the “oestrogen effect” in an Australian out-of-hospital cardiac arrest population

Background

Recent studies have suggested gender differences in out-of-hospital cardiac arrests (OHCA) including outcomes favouring young women. We aimed to investigate these findings in an Australian OHCA population using the Victorian Ambulance Cardiac Arrest Registry (VACAR).

Methods and results

The VACAR was searched for adult presumed cardiac OHCAs between 2003 and 2010 where Emergency Medical Services (EMS) attempted resuscitation. Gender and age differences in survival to hospital arrival and to hospital discharge were examined using logistic regression adjusting for known predictors of survival. There were 10,453 OHCA meeting inclusion criteria (863 aged between 18 and 44 years). Women were less likely to be younger, have a witnessed arrest, receive bystander CPR, arrest in a public place, have an initial shockable rhythm or receive transport to 24-h cardiac interventional hospital. After adjusting for differences in pre-hospital factors, women were more likely to survive to hospital arrival than men (aOR 3.47, 95% CI: 2.19–5.50), but no gender differences were seen in survival to hospital discharge either overall or specifically in women aged between 18 and 44 years. Both younger men and younger women were more likely to survive to hospital discharge compared to older men and women.

Conclusion

Women were more likely to survive to hospital arrival despite less favourable baseline variables. However, this initial improvement in survival did not translate to better survival to hospital discharge either overall, or in women of a reproductive age. Further study is required to determine gender differences in the underlying causes of OHCA and in EMS transportation practices.     

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.     

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.     

The effect of time to defibrillation and targeted temperature management on functional survival after out-of-hospital cardiac arrest

Background

Cardiac arrest physiology has been proposed to occur in three distinct phases: electrical, circulatory and metabolic. There is limited research evaluating the relationship of the 3-phase model of cardiac arrest to functional survival at hospital discharge. Furthermore, the effect of post-cardiac arrest targeted temperature management (TTM) on functional survival during each phase is unknown.

Objective

To determine the effect of TTM on the relationship between the time of initial defibrillation during each phase of cardiac arrest and functional survival at hospital discharge.

Methods

This was a retrospective observational study of consecutive adult (≥18 years) out-of-hospital cardiac arrest (OHCA) patients with initial shockable rhythms. Included patients obtained a return of spontaneous circulation (ROSC) and were eligible for TTM. Multivariable logistic regression was used to determine predictors of functional survival at hospital discharge.

Results

There were 20,165 OHCA treated by EMS and 871 patients were eligible for TTM. Of these patients, 622 (71.4%) survived to hospital discharge and 487 (55.9%) had good functional survival. Good functional survival was associated with younger age (OR 0.94; 95% CI 0.93–0.95), shorter times from collapse to initial defibrillation (OR 0.73; 95% CI 0.65–0.82), and use of post-cardiac arrest TTM (OR 1.49; 95% CI 1.07–2.30). Functional survival decreased during each phase of the model (65.3% vs. 61.7% vs. 50.2%, P < 0.001).

Conclusion

Functional survival at hospital discharge was associated with shorter times to initial defibrillation and was decreased during each successive phase of the 3-phase model. Post-cardiac arrest TTM was associated with improved functional survival.     

Factors associated with sustained return of spontaneous circulation in children after out-of-hospital cardiac arrest of noncardiac origin

Purpose

The study aimed to determine the factors predictive of sustained return of spontaneous circulation (ROSC) in children with out-of-hospital cardiac arrest (OHCA) of noncardiac origin.

Methods

Eighty children were included in this retrospective study. The variables that lead to sustained ROSC and those that do not lead to sustained ROSC were analyzed. Survival analyses, including chance of achieving sustained ROSC and sum duration of ROSC, were conducted according to the duration of in-hospital cardiopulmonary resuscitation (CPR).

Results

Etiologies of noncardiac OHCA differed significantly across different age groups (P < .001). Only 8.8% of children had initial arrest rhythms that were shockable. Predictors of sustained ROSC included the initial cardiac rhythm (P = .002), a shorter period between collapse and the first chest compression (P = .002), a shorter in-hospital CPR duration (P = .004), and prehospital CPR (P = .007). In children where ROSC was initially sustained, those with in-hospital CPR of more than 20 minutes, ROSC was sustained for less time (P < .001).

Conclusions

Few children with noncardiac OHCA present with shockable cardiac rhythms. Furthermore, long-term ROSC is difficult to maintain in children who receive in-hospital CPR for more than 20 minutes.     

Survival after out-of-hospital cardiac arrest in relation to sex: A nationwide registry-based study

Aim

Crude survival has increased following an out-of-hospital cardiac arrest (OHCA). We aimed to study sex-related differences in patient characteristics and survival during a 10-year study period.

Methods

Patients ≥12 years old with OHCA of a presumed cardiac cause, and in whom resuscitation was attempted, were identified through the Danish Cardiac Arrest Registry 2001–2010. A total of 19,372 patients were included.

Results

One-third were female, with a median age of 75 years (IQR 65–83). Compared to females, males were five years younger; and less likely to have severe comorbidities, e.g., chronic obstructive pulmonary disease (12.8% vs. 16.5%); but more likely to have arrest outside of the home (29.4% vs. 18.7%), receive bystander CPR (32.9% vs. 25.9%), and have a shockable rhythm (32.6% vs. 17.2%), all p < 0.001. Thirty-day crude survival increased in males (3.0% in 2001 to 12.9% in 2010); and in females (4.8% in 2001 to 6.7% in 2010), p < 0.001.Multivariable logistic regression analyses adjusted for patient characteristics including comorbidities, showed no survival difference between sexes in patients with a non-shockable rhythm (OR 1.00; CI 0.72–1.40), while female sex was positively associated with survival in patients with a shockable rhythm (OR 1.31; CI 1.07–1.59). Analyses were rhythm-stratified due to interaction between sex and heart rhythm; there was no interaction between sex and calendar-year.

Conclusions

Temporal increase in crude survival was more marked in males due to poorer prognostic characteristics in females with a lower proportion of shockable rhythm. In an adjusted model, female sex was positively associated with survival in patients with a shockable rhythm.     

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.     

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’.     

Exploring which patients without return of spontaneous circulation following ventricular fibrillation out-of-hospital cardiac arrest should be transported to hospital?

Background

Currently many emergency medical services (EMS) that provide advanced cardiac life support (ACLS) at scene do not routinely transport out-of-hospital cardiac arrest (OHCA) patients without sustained return of spontaneous circulation (ROSC). This is due to logistical difficulties and historical poor outcomes. However, new technology for mechanical chest compression has made transport to hospital safer and extracorporeal membrane oxygenation during cardiopulmonary resuscitation (ECPR) enabling further intervention, may result in ROSC. We aimed to explore the characteristics and outcomes of patients with OHCA who were transported to hospital with ongoing CPR in the absence of ROSC, who might benefit from this new technology.

Methods and results

The Victorian Ambulance Cardiac Arrest Registry (VACAR) was searched for adult OHCA with an initial shockable rhythm between 2003 and 2012. There were 5593 OHCA meeting inclusion criteria. Analysis was performed on 3095 (55%) of patients who did not achieve sustained ROSC in the field. Of these only 589 (20%) had ongoing CPR to hospital. There was a significant decline in rates of transport over the study period. Predictors of transport with ongoing CPR included younger patients, decreased time to first shock and intermittent ROSC prior to transport. Survival to hospital discharge occurred in 52 (9%) of patients who had ongoing CPR to hospital.

Conclusion

In an EMS that provides ACLS at scene, patients without ROSC in the field who receive CPR to hospital have poor outcomes. Developing a system which provides safe transport with ongoing CPR to a hospital that provides ECPR, should be considered.     

Long-term prognosis following resuscitation from out-of-hospital cardiac arrest: role of aetiology and presenting arrest rhythm

ObjectiveLittle is known about long-term prognosis following resuscitation from out-of-hospital cardiac arrest, especially as it relates to the presenting rhythm or arrest aetiology. We investigated long-term survival among those discharged alive following resuscitation according to presenting rhythm and arrest aetiology.MethodsWe conducted a cohort investigation of all non-traumatic adult out-of-hospital cardiac arrest patients resuscitated and discharged alive from hospital between January 1, 2001 and December 31, 2009 in a large metropolitan emergency medical service system. Information about demographics, circumstances, presenting arrest rhythm and aetiology was collected using the dispatch, EMS, and hospital records. Long-term vital status was ascertained using state death records and the Social Security Death Index through 31st December 2010. We used Kaplan Meier to evaluate survival.ResultsDuring the study period, a total of 1001/5958 (17%) persons were resuscitated and discharged alive, of whom 313/1001 (31%) presented with a non-shockable rhythm and 210/1001 (21%) had a non-cardiac aetiology. Overall median survival was 9.8 years with 64% surviving >5 years. Five-year survival was 43% for non-shockable rhythms compared to 73% for shockable rhythms, and 45% for non-cardiac aetiology compared to 69% for cardiac aetiology (p < 0.001 respectively).ConclusionCardiac arrest due to non-shockable rhythm or non-cardiac aetiology comprises a substantial proportion of those who survive to hospital discharge. Although long-term survival in these groups is less than their shockable or cardiac aetiology counterparts, nearly half are alive 5 years following discharge. The findings support efforts to improve resuscitation care for those with non-shockable rhythms or non-cardiac cause.     

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.     

Therapeutic hypothermia after out-of-hospital cardiac arrest in Finnish intensive care units: the FINNRESUSCI study

Purpose

We aimed to evaluate post-resuscitation care, implementation of therapeutic hypothermia (TH) and outcomes of intensive care unit (ICU)-treated out-of-hospital cardiac arrest (OHCA) patients in Finland.

Methods

We included all adult OHCA patients admitted to 21 ICUs in Finland from March 1, 2010 to February 28, 2011 in this prospective observational study. Patients were followed (mortality and neurological outcome evaluated by Cerebral Performance Categories, CPC) within 1 year after cardiac arrest.

Results

This study included 548 patients treated after OHCA. Of those, 311 patients (56.8 %) had a shockable initial rhythm (incidence of 7.4/100,000/year) and 237 patients (43.2 %) had a non-shockable rhythm (incidence of 5.6/100,000/year). At ICU admission, 504 (92 %) patients were unconscious. TH was given to 241/281 (85.8 %) unconscious patients resuscitated from shockable rhythms, with unfavourable 1-year neurological outcome (CPC 3–4–5) in 42.0 % with TH versus 77.5 % without TH (p < 0.001). TH was given to 70/223 (31.4 %) unconscious patients resuscitated from non-shockable rhythms, with 1-year CPC of 3–4–5 in 80.6 % (54/70) with TH versus 84.0 % (126/153) without TH (p = 0.56). This lack of difference remained after adjustment for propensity to receive TH in patients with non-shockable rhythms.

Conclusions

One-year unfavourable neurological outcome of patients with shockable rhythms after TH was lower than in previous randomized controlled trials. However, our results do not support use of TH in patients with non-shockable rhythms.     

Systematic downloading and analysis of data from automated external defibrillators used in out-of-hospital cardiac arrest

Background

Valuable information can be retrieved from automated external defibrillators (AEDs) used in victims of out-of-hospital cardiac arrest (OHCA). We describe our experience with systematic downloading of data from deployed AEDs. The primary aim was to compare the proportion of shockable rhythm from AEDs used by laypersons with the corresponding proportion recorded by the Emergency Medical Services (EMS) on arrival.

Methods

In a 20-month study, we collected data on OHCAs in the Capital Region of Denmark where an AED was deployed prior to arrival of EMS. The AEDs were brought to the emergency medical dispatch centre for data downloading and rhythm analysis. Patient data were retrieved from the medical records from the admitting hospital, whereas data on EMS rhythm analyses were obtained from the Danish Cardiac Arrest Register between 2001 and 2010.

Results

A total of 121 AEDs were deployed, of which 91 cases were OHCAs with presumed cardiac origin. The prevalence of initial shockable rhythm was 55.0% (95% CI [44.7–64.8%]). This was significantly greater than the proportion recorded by the EMS (27.6%, 95% CI [27.0–28.3%], p < 0.0001). Shockable arrests were significantly more likely to be witnessed (92% vs. 34%, p < 0.0001) and the bystander CPR rate was higher (98% vs. 85%, p = 0.04). More patients with initial shockable rhythm achieved return of spontaneous circulation upon hospital arrival (88% vs. 7%, p < 0.0001) and had higher 30-day survival rate (72% vs. 5%, p < 0.0001).

Conclusion

AEDs used by laypersons revealed a higher proportion of shockable rhythms compared to the EMS rhythm analyses.     

Characteristics of cardiac arrest and resuscitation by age group: an analysis from the Swedish Cardiac Arrest Registry

Aim

The objective of this study was to describe patients who experienced an out-of-hospital cardiac arrest (OHCA) by age group.

Methods

All patients who suffered from an OHCA between 1990 and 2005 and are included in the Swedish Cardiac Arrest Registry (n = 40,503) were classified into the following age groups: neonates, younger than 1 year; young children, between 1 and 4 years; older children, between 5 and 12 years; adolescents, between 13 and 17 years; young adults, between 18 and 35 years; adults not retired, between 36 and 64 years; adults retired, between 65 and 79 years; and older adults, 80 years or older.

Results

Ventricular fibrillation was lowest in young children (3%) and highest in adults (35%). Survival to 1 month was lowest in neonates (2.6%) and highest in older children (7.8%). Children (<18 years), young adults (18-35 years), and adults (>35 years) survived to 1 month 24.5%, 21.2%, and 13.6% of cases, respectively (P = .0003 for trend) when found in a shockable rhythm. The corresponding figures for nonshockable rhythms were 3.8%, 3.2%, and 1.6%, respectively (P < .0001 for trend).

Conclusions

There is a large variability in characteristics and outcome among patients in various age groups who experienced an OHCA. Among the large age groups, there was a successive decline in survival with increasing age in shockable and nonshockable rhythms.     

Adult Out-of-Hospital Cardiac Arrest Based on Chain of Survival in Taoyuan County,Northern Taiwan

Background

Most out-of-hospital cardiac arrest (OHCA) studies have been conducted in developed countries or metropolitan areas, and few in developing countries or rural areas.

Objectives

The aims of this study were to determine the weak links in the chain of survival and to estimate the outcomes of OHCA patients in Taoyuan, a nonmetropolitan area in Taiwan.

Methods

A retrospective review and analysis of OHCA data was conducted. The three outcomes were whether a return of spontaneous circulation (ROSC) was achieved, whether the patient survived to admission, or whether the patient survived to hospital discharge.

Results

From April to December 2008, 1048 OHCA patients were resuscitated, and 712 (67.9%) adult cardiac patients were used in this study. Among these 712 patients, 17.8% achieved ROSC (95% confidence interval [CI] 15.2–20.8%), 16.3% survived to admission (95% CI 13.6–19.0%), and 1.4% survived to discharge (95% CI 0.5–2.3%). Factors significantly associated with the three outcomes were witness status, response time to emergency medical services, and whether the patient had a shockable rhythm. Bystander cardiopulmonary resuscitation (CPR) did not add a notable benefit to the outcomes of OHCA.

Conclusions

The survival rate of OHCA patients in nonmetropolitan Taiwan was very low (1.4%). Lower witnessed rate, lower bystander CPR rate, and longer response interval in remote areas are the main causes of inferior survival rate.