Global incidences of out-of-hospital cardiac arrest and survival rates: Systematic review of 67 prospective studies

Aim

The aim of this investigation was to estimate and contrast the global incidence and outcome of out-of-hospital cardiac arrest (OHCA) to provide a better understanding of the variability in risk and survival of OHCA.

Methods

We conducted a review of published English-language articles about incidence of OHCA, available through MEDLINE and EmBase. For studies including adult patients and both adult and paediatric patients, we used Utstein data reporting guidelines to calculate, summarize and compare incidences per 100,000 person-years of attended OHCAs, treated OHCAs, treated OHCAs with a cardiac cause, treated OHCA with ventricular fibrillation (VF), and survival-to-hospital discharge rates following OHCA.

Results

Sixty-seven studies from Europe, North America, Asia or Australia met inclusion criteria. The weighted incidence estimate was significantly higher in studies including adults than in those including adults and paediatrics for treated OHCAs (62.3 vs 34.7; P < 0.001); and for treated OHCAs with a cardiac cause (54.6 vs 40.8; P = 0.004). Neither survival to discharge rates nor VF survival to discharge rates differed statistically significant among studies. The incidence of treated OHCAs was higher in North America (54.6) than in Europe (35.0), Asia (28.3), and Australia (44.0) (P < 0.001). In Asia, the percentage of VF and survival to discharge rates were lower (11% and 2%, respectively) than those in Europe (35% and 9%, respectively), North America (28% and 6%, respectively), or Australia (40% and 11%, respectively) (P < 0.001, P < 0.001).

Conclusions

OHCA incidence and outcome varies greatly around the globe. A better understanding of the variability is fundamental to improving OHCA prevention and resuscitation.     

Out-of-hospital cardiac arrest frequency and survival: Evidence for temporal variability

Aim

Some cardiac phenomena demonstrate temporal variability. We evaluated temporal variability in out-of-hospital cardiac arrest (OHCA) frequency and outcome.

Methods

Prospective cohort study (the Resuscitation Outcomes Consortium) of all OHCA of presumed cardiac cause who were treated by emergency medical services within 9 US and Canadian sites between 12/1/2005 and 02/28/2007. In each site, Emergency Medical System records were collected and analyzed. Outcomes were individually verified by trained data abstractors.

Results

There were 9667 included patients. Median age was 68 (IQR 24) years, 66.7% were male and 8.3% survived to hospital discharge. The frequency of cardiac arrest varied significantly across time blocks (p < 0.001). Compared to the 0001-0600 hourly time block, the odds ratios and 95% CIs for the occurrence of OHCA were 2.02 (1.90, 2.15) in the 0601-1200 block, 2.01 (1.89, 2.15) in the 1201-1800 block, and 1.73 (1.62, 1.85) in the 1801-2400 block. The frequency of all OHCA varied significantly by day of week (p = 0.03) and month of year (p < 0.001) with the highest frequencies on Saturday and during December. Survival to hospital discharge was lowest when the OHCA occurred during the 0001-0600 time block (7.3%) and highest during the 1201-1800 time block (9.6%). Survival was highest for OHCAs occurring on Mondays (10.0%) and lowest for those on Wednesdays (6.8%) (p = 0.02).

Conclusion

There is temporal variability in OHCA frequency and outcome. Underlying patient, EMS system and environmental factors need to be explored to offer further insight into these observed patterns.     

Changing EMS dispatcher CPR instructions to 400 compressions before mouth-to-mouth improved bystander CPR rates

Background

To examine the impact of changing dispatcher CPR instructions (400 compressions: 2 breaths, followed by 100:2 ratio) on rates of bystander CPR and survival in adults with presumed cardiac out-of-hospital arrest (OHCA) in Melbourne, Australia.

Methods

The Victorian Ambulance Cardiac Arrest Registry (VACAR) was searched for OHCA where Emergency Medical Services (EMS) attempted CPR between August 2006 and August 2009. OHCA included were: (1) patients aged ≥18 years old; (2) presumed cardiac etiology; and (3) not witnessed by EMS.

Results

For the pre- and post-study periods, 1021 and 2101 OHCAs met inclusion criteria, respectively. Rates of bystander CPR increased overall (45-55%, p < 0.001) and by initial rhythm (shockable 55-70%, p < 0.001 and non-shockable 40-46%, p = 0.01). In VF/VT OHCA, there were improvements in the number of patients arriving at hospital with a return of spontaneous circulation (ROSC) (48-56%, p = 0.02) and in survival to hospital discharge (21-29%, p = 0.002), with improved outcomes restricted to patients receiving bystander CPR. After adjusting for factors associated with survival, the period of time following the change in CPR instructions was a significant predictor of survival to hospital discharge in VF/VT patients (OR 1.57, 95% CI: 1.15-2.20, p = 0.005).

Conclusion

Following changes to dispatcher CPR instructions, significant increases were seen in rates of bystander CPR and improvements were seen in survival in VF/VT patients who received bystander CPR, after adjusting for factors associated with survival.     

Cardiac arrest outcomes before and after the 2005 resuscitation guidelines implementation: evidence of improvement?

Background

Previous studies have reported improvements in out-of-hospital cardiac arrest (OHCA) outcomes with the introduction of the 2005 cardiopulmonary resuscitation guidelines however they have not adjusted for underlying trends in OHCA survival. We compare outcomes before and after the 2005 guideline changes adjusting for underlying trends in OHCA survival.

Methods

The Victorian Ambulance Cardiac Arrest Registry (VACAR) was searched for adult (≥16 years) OHCA of presumed cardiac aetiology, unwitnessed by paramedics with attempted resuscitation. Outcomes for OHCA occurring between 2003 and 2005 were compared with 2007-2009. Segmented regression analysis of interrupted time series data was performed, adjusting for known predictors, to examine changes in survival to hospital and survival to hospital discharge.

Results

For the pre- and post- guideline periods there were 3115 and 3248 OHCAs, respectively. Asystole increased as presenting rhythm (33-43%, p < 0.001) as did median EMS response times (7.1-7.8 min, p < 0.001) over the two periods. VF/VT arrests decreased (40-35.5%, p = 0.001) as did bystander witnessed arrests (63-59%, p = 0.002). On univariate analysis survival to hospital discharge improved between the two periods (9.4-11.8%, p = 0.002) due to improved outcomes in VF/VT (19-28%, p < 0.001). Segmented regression analysis of interrupted time series data showed improvement in the rate of survival to get to hospital for shockable and non-shockable rhythms [OR (95% CI) = 1.54 (1.10-2.15, p = 0.01) and 1.45 (1.10-2.00, p = 0.02), respectively] following implementation of the guidelines however survival to hospital discharge did not improve [OR = 1.07 (0.70-1.62, p = 0.70) and 1.40 (0.69-2.85, p = 0.40), respectively].

Conclusions

OHCA outcomes have improved since introduction of the 2005 CPR guidelines, but multivariable segmented regression analysis adjusting for pre-existing trends in survival suggests that this improvement may not be due to implementation of the 2005 resuscitation guidelines.     

Assessment of outcomes and differences between in- and out-of-hospital cardiac arrest patients treated with cardiopulmonary resuscitation using extracorporeal life support

Aim

Cardiopulmonary resuscitation (CPR) using extracorporeal life support (ECLS) for in-hospital cardiac arrest (IHCA) patients has been assigned a low-grade recommendation in current resuscitation guidelines. This study compared the outcomes of IHCA and out-of-hospital cardiac arrest (OHCA) patients treated with ECLS.

Methods

A total of 77 patients were treated with ECLS. Baselines characteristics and outcomes were compared for 38 IHCA and 39 OCHA patients.

Results

The time interval between collapse and starting ECLS was significantly shorter after IHCA than after OHCA (25 (21-43) min versus 59 (45-65) min, p < 0.001). The weaning rate from ECLS (61% versus 36%, p = 0.03) and 30-day survival (34% versus 13%, p = 0.03) were higher for IHCA compared with OHCA patients. IHCA patients had a higher rate of favourable neurological outcome compared to OHCA patients, but the difference was not statistically significant (26% versus 10%, p = 0.07). Kaplan-Meier analysis showed improved 30-day and 1-year survival for IHCA patients treated with ECLS compared to OHCA patients who had ECLS. However, multivariate stepwise Cox regression model analysis indicated no difference in 30-day (odds ratio 0.94 (95% confidence interval 0.68-1.27), p = 0.67) and 1-year survival (0.99 (0.73-1.33), p = 0.95).

Conclusion

CPR with ECLS led to more favourable patient outcomes after IHCA compared with OHCA in our patient group. The difference in outcomes for ECLS after IHCA and OHCA disappeared after adjusting for patient factors and the time delay in starting ECLS.     

Association of out-of-hospital cardiac arrest with prior activity and ambient temperature

Objective

Little is known about triggers of sudden cardiac arrest. This study aimed to analyze the association of the occurrence of out-of-hospital cardiac arrest (OHCA) with patient activities just before the arrest and ambient temperature as one of the major environmental factors.

Methods

This prospective, population-based cohort study enrolled all person aged 18 years or older with OHCA of presumed cardiac origin in Osaka Prefecture, Japan, from 2005 through 2007. Patient activities before arrest were divided into six categories: sleeping, bathing, working, exercising, non-specific activities, and unknown. Age-adjusted annual incidence rate of OHCA according to their prior activity and an hourly event rate in each activity by temperature were calculated.

Results

Among 19,303 OHCAs, 10,723 were presumed to be of cardiac etiology. The event rate of OHCA was 6.22, 54.49, 1.15, and 10.11 per 10,000,000 population per hour for sleeping, bathing, working, and exercising, respectively. Among patients who suffered OHCA during bathing, the event rate of OHCA per 10,000,000 per hour increased with decreasing temperature from 18.27 (≥25.1 °C) to 111.42 (≤5.0 °C) (odds ratio [OR] for 1 °C increase in temperature, 0.915; 95% confidence interval [CI], 0.907-0.923), while it was almost constant among those who were working (OR for 1 °C increase, 0.994; 95% CI, 0.981-1.007) or exercising (OR for 1 °C increase, 1.004; 95% CI, 0.971-1.038) before arrest.

Conclusion

Both activities before cardiac arrest and ambient temperature were associated with the occurrence of OHCA. Preventive measures against OHCA should be enveloped considering these behavioral and environmental factors.     

Impact of transport to critical care medical centers on outcomes after out-of-hospital cardiac arrest

Background

Post-resuscitation care has emerged as an important predictor of survival from out-of-hospital cardiac arrest (OHCA). In Japan, selected hospitals are certified as Critical Care Medical Centers (CCMCs) based on their ability and expertise.

Hypothesis

Outcome after OHCA is better in patients transported to a CCMC compared a non-critical care hospital (NCCH).

Materials and methods

Adults with OHCA of presumed cardiac etiology, treated by emergency medical services systems, and transported in Osaka from January 1, 2005 to December 31, 2007 were registered using a prospective Utstein style population cohort database. Primary outcome measure was 1 month neurologically favorable survival (CPC ≤ 2). Outcomes of patients transported to CCMC were compared with patients transported to NCCH using multiple logistic regressions and stratified on the basis of stratified field ROSC.

Results

10,383 cases were transported. Of these, 2881 were transported to CCMC and 7502 to NCCH. Neurologically favorable 1-month survival was greater in the CCMC group [6.7% versus 2.8%, P < 0.001]. Among patients who were transported to hospital without field ROSC, neurologically favorable outcome was greater in the CCMC group than the NCCH group [1.7% versus 0.5%; adjusted odds ratio (OR), 3.39; 95% confidence interval (CI), 2.17-5.29; P < 0.001]. In the presence of field ROSC, survival was similar between the groups [43% versus 41%; adjusted OR, 1.09; 95% CI, 0.82-1.45; P = 0.554].

Conclusions

Survival after OHCA of presumed cardiac etiology transported to CCMCs was better than those transported to NCCHs. For OHCA patients without field ROSC, transport to a CCMC was an independent predictor for a good neurological outcome.     

Esophageal temperature after out-of-hospital cardiac arrest: An observational study

Introduction

Out-of-hospital cardiac arrest (OHCA) is a significant cause of death and severe neurological disability. The only post-return of spontaneous circulation (ROSC) therapy shown to increase survival is mild therapeutic hypothermia (MTH). The relationship between esophageal temperature post OHCA and outcome is still poorly defined.

Methods

Prospective observational study of all OHCA patients admitted to a single centre for a 14-month period (1/08/2008 to 31/09/2009). Esophageal temperature was measured in the Emergency Department and Intensive Care Unit (ICU). Selected patients had pre-hospital temperature monitoring. Time taken to reach target temperature after ROSC was recorded, together with time to admission to the Emergency Department and ICU.

Results

164 OHCA patients were included in the study. 105 (64.0%) were pronounced dead in the Emergency Department. 59 (36.0%) were admitted to ICU for cooling; 40 (24.4%) died in ICU and 19 (11.6%) survived to hospital discharge. Patients who achieved ROSC and had esophageal temperature measured pre-hospital (n = 29) had a mean pre-hospital temperature of 33.9 °C (95% CI 33.2-34.5). All patients arriving in the ED post OHCA had a relatively low esophageal temperature (34.3 °C, 95% CI 34.1-34.6). Patients surviving to hospital discharge were warmer on admission to ICU than patients who died in hospital (35.7 °C vs 34.3 °C, p < 0.05). Patients surviving to hospital discharge also took longer to reach T_targ than non-survivors (2 h 48 min vs 1 h 32 min, p < 0.05).

Conclusions

Following OHCA all patients have esophageal temperatures below normal in the pre-hospital phase and on arrival in the Emergency Department. Patients who achieve ROSC following OHCA and survive to hospital discharge are warmer on arrival in ICU and take longer to reach target MTH temperatures compared to patients who die in hospital. The mechanisms of action underlying esophageal temperature and survival from OHCA remain unclear and further research is warranted to clarify this relationship.     

Epidemiology and outcomes from non-traumatic out-of-hospital cardiac arrest in Korea: A nationwide observational study

Objectives

We aimed to describe the epidemiological features and to determine the predictors for survival to discharge of non-traumatic out-of-hospital cardiac arrest (OHCA) in Korea.

Subjects and methods

A nationwide Utstein style OHCA database (2006-2007) was constructed from ambulance records and hospital medical record review. Cases were enrolled when they were non-traumatic OHCA with presumed cardiac aetiology. Using the population census (2005), we calculated age-gender standardized incidence rates (SIR) and mortality (SMR). We modelled a multivariate logistic regression analysis to determine the effect of risk factors on hospital outcomes.

Results

The total number of EMS-assessed non-traumatic OHCA patients was 19 045. The SIR was 20.9 (2006) and 22.2 (2007) per 100 000 and survival-to-discharge rate was 2.3% for EMS-assessed non-traumatic OHCA, and was 3.5% for the resuscitation-attempted group. From a multivariate logistic regression analysis, witnessed arrest, and shorter basic life support (BLS) and EMS intervals turned out to be significant predictors of good outcome in the resuscitation-attempted group.

Conclusion

From a nationwide OHCA cohort, the incidence of EMS-assessed non-traumatic OHCA was found to be low. Survival-to-discharge rate in the resuscitation-attempted group was 3.5%, which was significantly associated with witnessed arrest, and shorter BLS and EMS intervals.     

Chest compression-only cardiopulmonary resuscitation performed by lay rescuers for adult out-of-hospital cardiac arrest due to non-cardiac aetiologies

Objective

Bystander CPR improves survival in patients with out-of-hospital cardiac arrest (OHCA). For adult sudden collapse, bystander chest compression-only CPR (COCPR) is recommended in some circumstances by the American Heart Association and European Resuscitation Council. However, adults who arrest from non-cardiac causes may also receive COCPR. Because rescue breathing may be more important for individuals suffering OHCA secondary to non-cardiac causes, COCPR is not recommended for these cases. We evaluated the relationship of lay rescuer COCPR and survival after OHCA from non-cardiac causes.

Methods

Analysis of a statewide Utstein-style registry of adult OHCA, during a large scale campaign endorsing COCPR for OHCA from presumed cardiac cause. The relationship between lay rescuer CPR (both conventional CPR and COCPR) and survival to hospital discharge was evaluated.

Results

Presumed non-cardiac aetiologies of OHCA accounted for 15% of all cases, and lay rescuer CPR was provided in 29% of these cases. Survival to hospital discharge occurred in 3.8% after conventional CPR, 2.7% after COCPR, and 4.0% after no CPR (p = 0.85). The proportion of patients receiving COCPR was much lower in the cohort of OHCA from respiratory causes (8.3%) than for those with presumed cardiac OHCA (18.0%; p < 0.001).

Conclusions

In the setting of a campaign endorsing lay rescuer COCPR for cardiac OHCA, bystanders were less likely to perform COCPR on OHCA victims who might benefit from rescue breathing.     

Good outcome in every fourth resuscitation attempt is achievable--an Utstein template report from the Stavanger region

Aim of the study

Out-of-hospital cardiac arrest (OHCA) is a major cause of death in the western world. We wanted to study changes in survival over time and factors linked to this in a region which have already reported high survival rates.

Methods

We used a prospectively collected Utstein template database to identify all resuscitation attempts in adult patients with OHCA of presumed cardiac origin. We included 846 resuscitation attempts and compared survival to discharge with good outcome in two time periods (2001-2005 vs. 2006-2008).

Results

We found no significant differences between the two time periods for mean age (71 and 70 years (p = 0.309)), sex distribution (males 70% and 71% (p = 0.708)), location of the OHCA (home 64% and 63% (p = 0.732)), proportion of shockable rhythms (44% and 47% (p = 0.261)) and rate of return of spontaneous circulation (38% and 43% (p = 0.136)), respectively. Bystander cardiopulmonary resuscitation (CPR), however, increased significantly from 60% to 73% (p < 0.0001), as did the overall rate of survival to discharge from 18% to 25% (p = 0.018). In patients with a shockable first rhythm, rate of survival to discharge increased significantly from 37% to 48% (p = 0.036). In witnessed arrest with shockable rhythm survival to discharge increased from 37% to 52% (p = 0.0105).

Conclusion

Overall, good outcome is now achievable in every fourth resuscitation attempt and in every second resuscitation attempt when patients have a shockable rhythm. The reason for the better outcomes is most likely multi-factorial and linked to improvements in the local chain of survival.     

Resuscitation feedback and targeted education improves quality of pre-hospital resuscitation in Scotland

Background

Out-of-hospital cardiac arrest (OHCA) is a leading cause of mortality and serious neurological morbidity in Europe. Recent studies have demonstrated the adverse physiological consequences of poor resuscitation technique and have shown that quality of cardiopulmonary resuscitation (CPR) is a critical determinant of outcome from OHCA. Telemetry of the defibrillator transthoracic impedance (TTI) trace can objectively measure quality of pre-hospital resuscitation. This study aims to analyse the impact of targeted resuscitation feedback and training on quality of pre-hospital resuscitation.

Methods

Prospective, single centre, cohort study over 13 months (1st December 2009-31st December 2010). Baseline pre-hospital resuscitation data was gathered over a 3-month period. Modems (n = 40) were fitted to defibrillators on ambulance vehicles. Following a resuscitation attempt, the event was sent via telemetry and the TTI trace analysed. Outcome measures were time spent performing chest compressions, compression rate, the interval required to deliver a defibrillator shock and use of automatic or manual cardiac rhythm analysis. Targeted resuscitation classes were introduced and all ambulance crews received feedback following a resuscitation attempt. Pre-hospital resuscitation quality pre and post intervention were compared.

Results

111 resuscitation traces were analysed. Mean hands-on-chest time improved significantly following feedback and targeted resuscitation training (73.0% vs 79.3%, p = 0.007). There was no significant change in compression rate during the study period. There was a significant reduction in median time-to-shock interval from 20.25 s (IQR 15.50-25.50 s) to 13.45 s (IQR 2.25-22.00 s) (p = 0.006). Automatic rhythm recognition fell from 50% to 28.6% (p = 0.03) following intervention.

Conclusion

Telemetry and analysis of the TTI trace following OHCA allows objective evaluation of the quality of pre-hospital resuscitation. Targeted resuscitation training and ambulance feedback improves the quality of pre-hospital resuscitation. Further studies are required to establish possible survival benefit from this technique.     

Bystander CPR in south east Scotland increases over 16 years

Background

Out-of-hospital cardiac arrest (OHCA) remains a leading cause of mortality and serious neurological disability across Europe. Without immediate bystander cardiopulmonary resuscitation (CPR), chances of survival are minimal. Despite community initiatives to increase the number of trained CPR providers, the effectiveness of these measures remains unknown and the proportion of OHCA patients receiving bystander CPR in the United Kingdom yet to be established. We sought to identify the change in the rate of bystander CPR in south east Scotland over a 16-year period.

Methods

Retrospective cohort study of all adult non-traumatic OHCA in south east Scotland from 1 January 1992 to 31 December 2007 using the Heartstart Scotland database.

Results

7928 OHCA were included. The proportion of patients receiving bystander CPR increased from 34% in 1992 to 52% in 2007 (p for trend <0.0001). The rate of CPR from bystanders, spouses and from relatives increased significantly over the study period. Patients arresting at home received significantly less bystander CPR than those arresting away from home (39% vs 52%, p < 0.0001) regardless of age or sex.

Conclusion

There has been a significant increase in bystander CPR in south east Scotland during the 16-year period. Bystander CPR is associated with an increased rate of survival and targeted CPR training for relatives of patients at risk of sudden cardiac death may be beneficial.     

Examining the contextual effects of neighborhood on out-of-hospital cardiac arrest and the provision of bystander cardiopulmonary resuscitation

Objective

To understand the association between neighborhood and individual characteristics in determining whether or not bystanders perform cardiopulmonary resuscitation (CPR) in cases of out-of-hospital cardiac arrest (OHCA).

Methods

Between October 1, 2005 to November 30, 2008, 1108 OHCA cases from Fulton County (Atlanta), GA, were eligible for bystander CPR. We conducted multi-level non-linear regression analysis and derived Empirical Bayes estimates for bystander CPR by census tract.

Results

279 (25%) cardiac arrest victims received bystander CPR. Provision of bystander CPR was significantly more common in witnessed events (odds ratio [OR] 1.64; 95% confidence interval [CI] 1.21-2.22, p < 0.001) and those that occurred in public locations (OR 1.67; 95% CI 1.16-2.40, p < 0.001). Other individual-level characteristics were not significantly associated with bystander CPR. Cardiac arrests in the census tracts that rank in the highest income quintile, as compared to the lowest income quintile were much more likely (OR 4.98; 95% CI 1.65-15.04) to receive bystander CPR.

Conclusion

Cardiac arrest victims in the highest income census tracts were much more likely to receive bystander CPR than in the lowest income census tracts, even after controlling for individual and arrest characteristics. Low-income neighborhoods may be particularly appropriate targets for community-based CPR training and awareness efforts.     

Are trained individuals more likely to perform bystander CPR? An observational study

Background

This study aimed to evaluate the association of cardiopulmonary resuscitation (CPR) training with bystander resuscitation performance and patient outcomes after out-of-hospital cardiac arrest (OHCA).

Methods

This was a prospective, population-based cohort study of all persons aged 18 years or older with OHCA of presumed intrinsic origin and their rescuers from January through December 2008 in Takatsuki, Osaka prefecture, Japan. Data on resuscitation of OHCA patients were obtained by emergency medical service (EMS) personnel in charge based on the Utstein style. Rescuers’ characteristics including experience of CPR training were obtained by EMS personnel interview on the scene. The primary outcome was the attempt of bystander CPR.

Results

Data were collected for 120 cases out of 170 OHCAs of intrinsic origin. Among the available cases, 60 (50.0%) had previous CPR training (trained rescuer group). The proportion of bystander CPR was significantly higher in the trained rescuer group than in the untrained rescuer group (75.0% and 43.3%; p = 0.001). Bystanders who had previous experience of CPR training were 3.40 times (95% confidence interval 1.31-8.85) more likely to perform CPR compared with those without previous CPR training. The number of patients with neurologically favorable one-month survival was too small to evaluate statistical difference between the groups (2 [3.3%] in the trained rescuer group versus 1 [1.7%] in the untrained rescuer group; p = 0.500).

Conclusions

People who had experienced CPR training had a greater tendency to perform bystander CPR than people without experience of CPR training. Further studies are needed to prove the effectiveness of CPR training on survival.     

Pediatric out-of-hospital cardiac arrest in Korea: A nationwide population-based study

Study objectives

Our objective was to describe the incidence and demographics of pediatric out-of-hospital cardiac arrest (OHCA) in Korea.

Methods

We identified non-traumatic OHCA patients aged less than 20 years from a Korean nationwide OHCA registry (2006-2007). Data from emergency medical service (EMS) run-sheets and hospital records were reviewed. We excluded cases with unknown hospital outcomes. Patient characteristics, treatment by EMS, and outcomes were compared by age groups: infant (<1 year), children (1-11 years), and adolescents (12-19 years).

Results

A total of 971 patients including infants (n = 299, 30.8%), children (n = 305, 31.4%), and adolescents (n = 367, 37.8%) met inclusion criteria. The incidence of pediatric OHCA was 4.2 per 100,000 person-years (67.1 in infants, 2.5 in children, and 3.5 in adolescents). The rate of cardiopulmonary resuscitation administered was 82.1% (infants 80.6%, children 82.0%, and adolescent 83.4%). The rate of applying automated external defibrillators and advanced airway management (endotracheal intubation or laryngeal mask airway), was only 4.1% and 2.5%, respectively. 7.4% showed ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) in the initial ECG. Survival to hospital discharge for all pediatric OHCA was 4.9% (2.9% for infants, 4.7% for children, and 7.2% of adolescents). For EMS-treated pediatric OHCA or patients with VF or pulseless VT, the rate was 5.0% and 31.6%, respectively.

Conclusion

Incidence and hospital outcomes in pediatric OHCA in Korea were comparable to other population-based nationwide reports.     

Predicting non-cardiac aetiology: a strategy to allocate rescue breathing during bystander CPR

Aims

Optimal care for out-of hospital cardiac arrest (OHCA) patients may depend on the underlying aetiology of OHCA. Specifically chest compression only bystander CPR may provide greater benefit among those with cardiac aetiology and chest compressions plus rescue breathing may provide greater benefit among those with non-cardiac aetiology. The aim of this study was to generate a simple predictor model to identify OHCA patients with non-cardiac aetiology in order to accurately allocate rescue breathing.

Methods

We used two independent cohorts of OHCA patients from a randomized pre-hospital trial and a prospective hospital registry (total n = 3086) to assess whether the characteristics of age, gender and arrest location (private versus public) could sufficiently discriminate non-cardiac aetiology. We used logistic regression models to generate a receiver operator curve and likelihood ratios.

Results

Overall, 965/3086 (31%) had a final diagnosis of a non-cardiac cause. Using 8 exclusive groups according to age, gender, and location, the frequency of non-cardiac aetiology varied from a low of 16% (55/351) among men >age 50 in a public location up to 58% (199/346) among women <60 in a private location. Although each characteristic was predictive in the logistic regression model, the area under the curve in the receiver operating curve was only 0.66. The associated positive likelihood ratios ranged from 1 to 3 and the negative likelihood ratios ranged from 1 to 0.4.

Conclusion

The results highlight the challenge of accurately identifying non-cardiac aetiology by characteristics that could be consistently used to allocate bystander rescue breathing.     

Cardiopulmonary resuscitation outcome of out-of-hospital cardiac arrest in low-volume versus high-volume emergency departments: An observational study and propensity score matching analysis

Objective

This study aimed to determine whether cardiopulmonary resuscitation (CPR) volume is associated with survival to discharge rate for out-of hospital cardiac arrest (OHCA) victims.

Methods

This study was performed in an emergency medical service (EMS) system with single-tiered basic to intermediate service level. A nationwide OHCA cohort database from January 2006 to December 2007 was used and composed of hospital chart review and ambulance run sheet data. We enrolled data from the 410 emergency departments and excluded cases without available hospital outcome data. From sensitivity analysis, we decided cut-off value for the high volume (HV) versus low volume (LV) EDs. A matching process based on propensity score was used to equalize potential prognostic factors in both groups. The adjusted odds ratio (OR) and its 95% confidence interval (95% CI) for survival to admission and to discharge were calculated.

Results

Of the 34,408 patients with OHCA, 20,457 (59.5%) were included except cases with unknown outcome (n = 1284), traumatic cause (n = 4894), no CPR attempt by EMS (n = 7779), and cases transferred to non-ED facilities (n = 3885). Overall survival to admission and to discharge was 10.9% and 3.4%, respectively. When we performed the sensitivity analysis for deciding the cut-off value for HV versus LV, the number was 68 per two years (sensitivity 67.0%, specificity 67.0%). Using propensity score matching, 3533 cases were randomly assigned to HV and LV group, respectively. The unadjusted and adjusted OR for survival to admission in HV was 1.35 (95% CI 1.19-1.54) and 1.44 (95% CI 1.24-1.66), respectively. The unadjusted and adjusted OR for survival to discharge was 1.71 (95% CI 1.36-2.14) and 1.81 (95% 1.43-2.30), respectively.

Conclusions

Emergency departments with high volumes of CPR cases showed significantly better outcomes for OHCA patients than those with low volumes in an EMS system with single-tiered basic to intermediate service level.     

Delaying a shock after takeover from the automated external defibrillator by paramedics is associated with decreased survival

Introduction

The purpose of this study was to investigate whether the takeover by Advanced Life Support [ALS] trained ambulance paramedics from rescuers using an automated external defibrillator [AED] delays shocks and if this delay is associated with decreased survival after out-of-hospital cardiac arrest [OHCA].

Methods

We analyzed continuous ECG recordings of LIFEPAK AEDs and associated manual defibrillator recordings of OHCA of presumed cardiac cause, prospectively collected from July 2005 to July 2009. The primary outcome measure was survival to discharge. Among 693 patients treated with AEDs, 110 had a shockable initial rhythm and a shockable rhythm during ALS takeover. We measured the time interval between the expected shock if the AED would remain attached to the patient and the first observed shock given by the manual defibrillator [shock timing].

Results

Survival was 62% (13/21) if the shock was given early (<−20 s), 52% (11/21; odds ratio [OR] = 0.68, ns) if given on time (−20 to 20 s), 29% (10/34; OR = 0.26, 95% confidence interval [CI] = 0.08-0.81; P = 0.02) if the shock was 20-150 s delayed and 21% (7/34; OR = 0.16, 95% CI = 0.05-0.54; P = 0.003) if the shock was delayed >150 s. The OR for trend was 0.41, 95% CI = 0.25-0.71; P = 0.001. The association between shock timing and survival was significant for patients with more than 150 s shock delay (OR = 0.19; 95% CI = 0.04-0.71; P = 0.02) or for trend in shock timing (0.42, 95% CI = 0.20-0.84; P = 0.02) after multivariable adjustment for prognostic factors age and slope of ventricular fibrillation.

Conclusions

ALS takeover delays the next shock delivery in almost two-third of cases. This delay is associated with decreased survival.