Dispatcher-assisted bystander cardiopulmonary resuscitation in a metropolitan city: A before–after population-based study

Background

The goal of this study was to determine the effects of dispatcher-assisted bystander cardiopulmonary resuscitation (DA-CPR) on outcomes of out-of-hospital cardiac arrest (OHCA).

Methods

All EMS in a metropolitan city with a population of 10 million are dispatched by a single, centralized, and physician-supervised center. Data on patients with adult OHCA with cardiac etiology were collected from the dispatch center registry and from EMS run sheets and hospital medical record review from 2009 to 2011. A standardized DA-CPR protocol (aligned with the 2010 AHA guidelines) we implemented as an intervention in January 2011. The end points were survival to discharge, good neurological outcome, and bystander CPR rate. Multivariate logistic analysis was used to compare between intervention group (2011) and historical control group (2009–2010).

Results

Of 8.144 eligible patients, bystander CPR was performed for the patients in 5.7% (148/2600) of cases in 2009, 6.7% (190/2857) in 2010, and 12.4% (334/2686) in 2011 (p < 0.001). The survival to discharge rates was 7.1% (2009), 7.1% (2010), and 9.4% (2011) (p = 0.001). Good neurological outcomes occurred in 2.1% (2009), 2.0% (2010), and 3.6% (2011) of cases (p < 0.001). The adjusted ORs (95% CIs) for survival to discharge compared with 2009 were 1.33 (1.07–1.66) in 2011 and 1.12 (0.89–1.41) in 2010. The adjusted ORs (95% CIs) for good neurological outcomes were 1.67 (1.13–2.45) in 2011 and 1.13 (0.74–1.72) in 2010.

Conclusions

An EMS intervention using the DA-CPR protocol was associated with a significant increase in bystander CPR and an improved survival and neurologic outcome after OHCA.     

New treatment bundles improve survival in out-of-hospital cardiac arrest patients: A historical comparison

Introduction

Before the introduction of the new international cardiac arrest treatment guidelines in 2005, patients with out-of-hospital cardiac arrest (OHCA) of cardiac origin in Northern Italy had very poor prognosis. Since 2006, a new bundle of care comprising use of automated external defibrillators (AEDs) and therapeutic hypothermia (TH) was started, while extracorporeal CPR program (ECPR) for selected refractory CA and dispatcher-assisted cardio-pulmonary resuscitation (CPR) was started in January 2010.

Objectives

We hypothesized that a program of bundled care might improve outcome of OHCA patients.

Methods

We analyzed data collected in the OHCA registry of the MB area between September 2007 and August 2011 and compared this with data from 2000 to 2003.

Results

Between 2007 and 2011, 1128 OHCAs occurred in the MB area, 745 received CPR and 461 of these had a CA of presumed cardiac origin. Of these, 125 (27%) achieved sustained ROSC, 60 (13%) survived to 1 month, of whom 51 (11%) were discharged from hospital with a good neurological outcome (CPC ≤ 2), and 9 with a poor neurological outcome (CPC > 2).Compared with data from the 2000 to 2003 periods, survival increased from 5.6% to 13.01% (p < 0.0001). In the 2007–2011 group, low-flow time and bystander CPR were independent markers of survival.

Conclusions

OHCA survival has improved in our region. An increased bystander CPR rate associated with dispatcher-assisted CPR was the most significant cause of increased survival, but duration of CA remains critical for patient outcome.     

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.     

Aspects on the increase in bystander CPR in Sweden and its association with outcome

Aim

To describe changes in the proportion of bystanders performing cardiopulmonary resuscitation (CPR) in out of hospital cardiac arrest (OHCA) in Sweden and to study the impact of bystander CPR on ventricular fibrillation and on survival during various times.

Patients and methods

All patients who suffered from OHCA in Sweden in whom CPR was attempted and who were included in the Swedish cardiac arrest register (SCAR) between 1992 and 2005. Crew witnessed cases were excluded.

Results

In all 34,125 patients were included in the survey. Among witnessed OHCA the proportion of patients receiving bystander CPR increased from 40% in 1992 to 55% in 2005 (p < 0.0001). In non-witnessed OHCA the corresponding proportion increased from 22% to 44% (p < 0.0001). There was a significant increase in bystander CPR regardless of age, sex and place. The increase was only found when CPR was performed by lay persons (21% in 1992 to 40% in 2005; p < 0.0001). Bystander CPR was associated with an increased proportion of patients found in a shockable rhythm and a lower number of shocks to receive return of spontaneous circulation. Bystander CPR was associated with a similar increase in survival early and late in the evaluation.

Conclusion

There was a marked increase in bystander CPR in OHCA, when performed by lay persons, during the last 14 years in Sweden. Bystander CPR was associated with positive effects both on ventricular fibrillation and survival.     

Do dispatcher instructions facilitate bystander-initiated cardiopulmonary resuscitation and improve outcomes in patients with out-of-hospital cardiac arrest? A comparison of family and non-family bystanders

Objectives

Bystander-initiated cardiopulmonary resuscitation (CPR) has been reported to increase the possibility of survival in patients with out-of-hospital cardiopulmonary arrest (OHCA). We evaluated the effects of CPR instructions by emergency medical dispatchers on the frequency of bystander CPR and outcomes, and whether these effects differed between family and non-family bystanders.

Methods

We conducted a retrospective cohort study, using Utstein-style records of OHCA taken in a rural area of Japan between January 2004 and December 2009.

Results

Of the 559 patients with non-traumatic OHCA witnessed by laypeople, 231 (41.3%) were given bystander CPR. More OHCA patients received resuscitation when the OHCA was witnessed by non-family bystanders than when it was witnessed by family members (61.4% vs. 34.2%). The patients with non-family-witnessed OHCA were more likely to be given conventional CPR (chest compression plus rescue breathing) or defibrillation with an AED than were those with family-witnessed OHCA. Dispatcher instructions significantly increased the provision of bystander CPR regardless of who the witnesses were. Neurologically favorable survival was increased by CPR in non-family-witnessed, but not in family-witnessed, OHCA patients. No difference in survival rate was observed between the cases provided with dispatcher instructions and those not provided with the instructions.

Conclusions

Dispatcher instructions increased the frequency of bystander CPR, but did not improve the rate of neurologically favorable survival in patients with witnessed OHCA. Efforts to enhance the frequency and quality of resuscitation, especially by family members, are required for dispatcher-assisted CPR.     

Bystander-initiated CPR in an Asian metropolitan: Does the socioeconomic status matter?

Objectives

To determine the association of neighborhood socioeconomic status (SES) with bystander-initiated cardiopulmonary resuscitation (CPR) and patient outcomes of out of hospital cardiac arrests (OHCAs) in an Asian metropolitan area.

Methods

We performed a retrospective study in a prospectively collected cohort from the Utstein registry of adult non-traumatic OHCAs in Taipei, Taiwan. Average real estate value was assessed as the first proxy of SES. Twelve administrative districts in Taipei City were categorized into low versus high SES areas to test the association. The primary outcome was bystander-initiated CPR, and the secondary outcome was patient survival status. Factors associated with bystander-initiated CPR were adjusted for in multivariate analysis. The mean household income was assessed as the second proxy of SES to validate the association.

Results

From January 1, 2008 to December 30, 2009, 3573 OHCAs received prehospital resuscitation in the community. Among these, 617 (17.3%) cases received bystander CPR. The proportion of bystander CPR in low-SES vs. high-SES areas was 14.5% vs. 19.6% (p < 0.01). Odds ratio of receiving bystander-initiated CPR in low-SES areas was 0.72 (95% confidence interval: [0.60–0.88]) after adjusting for age, gender, witnessed status, public collapse, and OHCA unrecognized by the online dispatcher. Survival to discharge rate was significantly lower in low-SES areas vs. high-SES areas (4.3% vs. 6.8%; p < 0.01). All results above remained consistent in the analyses by mean household income.

Conclusions

Patients who experienced an OHCA in low-SES areas were less likely to receive bystander-initiated CPR, and demonstrated worse survival outcomes.     

Multiple cluster analysis for the identification of high-risk census tracts for out-of-hospital cardiac arrest (OHCA) in Denver,Colorado

Background

Prior research has shown that high-risk census tracts for out-of-hospital cardiac arrest (OHCA) can be identified. High-risk neighborhoods are defined as having a high incidence of OHCA and a low prevalence of bystander cardiopulmonary resuscitation (CPR). However, there is no consensus regarding the process for identifying high-risk neighborhoods.

Objective

We propose a novel summary approach to identify high-risk neighborhoods through three separate spatial analysis methods: Empirical Bayes (EB), Local Moran's I (LISA), and Getis Ord Gi* (Gi*) in Denver, Colorado.

Methods

We conducted a secondary analysis of prospectively collected Emergency Medical Services data of OHCA from January 1, 2009 to December 31, 2011 from the City and County of Denver, Colorado. OHCA incidents were restricted to those of cardiac etiology in adults ≥18 years. The OHCA incident locations were geocoded using Centrus. EB smoothed incidence rates were calculated for OHCA using Geoda and LISA and Gi* calculated using ArcGIS 10.

Results

A total of 1102 arrests in 142 census tracts occurred during the study period, with 887 arrests included in the final sample. Maps of clusters of high OHCA incidence were overlaid with maps identifying census tracts in the below the Denver County mean for bystander CPR prevalence. Five census tracts identified were designated as Tier 1 high-risk tracts, while an additional 7 census tracts where designated as Tier 2 high-risk tracts.

Conclusion

This is the first study to use these three spatial cluster analysis methods for the detection of high-risk census tracts. These census tracts are possible sites for targeted community-based interventions to improve both cardiovascular health education and CPR training.     

Influence of nationwide policy on citizens’ awareness and willingness to perform bystander cardiopulmonary resuscitation

Aims

Public awareness to cardiopulmonary resuscitation (CPR) and cardiac arrest is influenced by systemic factors including related policies and legislations in the community. Here, we describe and compare the results of the two nationwide CPR surveys in 2007 and 2011 examining public awareness and attitudes to bystander CPR in South Korea along with changes in nationwide CPR policies and systemic factors.

Methods

This population-based study used specially designed questionnaires via telephone surveys. We conducted bi-temporal surveys by stratified cluster sampling to assess the impact of age, gender, and geographic regions in 2007 (n = 1029) and in 2011 (n = 1000). Logistic regression analysis was performed to identify factors associated with willingness to perform bystander CPR.

Results

Public awareness of automated external defibrillators increased from 3.0% in 2007 to 32.6% in 2011. The proportion of the population that underwent CPR training within the previous 2 years increased significantly from 26.9% to 49.0%. The factors most related with intention of bystander CPR were male gender, younger age, CPR awareness, recent CPR training, and qualified CPR learning. In 2011, 75.8% of respondents were more willing to perform bystander CPR for stranger vs. 68.3% in 2007 (p = 0.002). Additional dispatcher hands-only CPR increased this proportion (85.8%, p < 0.001). However, bystander CPR experience rates remained unchanged (3.6–3.9%).

Conclusion

Changes in nationwide CPR policies and systemic factors affected citizens’ awareness and willingness to perform bystander CPR. Additionally, applied dispatcher hands-only CPR and publicity increased public willingness to perform bystander CPR.     

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.     

Association of neighborhood characteristics with incidence of out-of-hospital cardiac arrest and rates of bystander-initiated CPR: Implications for community-based education intervention

Objective

A 10-fold regional variation in survival after out-of-hospital cardiac arrest (OHCA) has been reported in the United States, which partly relates to variability in bystander cardiopulmonary resuscitation (CPR) rates. In order for resources to be focused on areas of greatest need, we conducted a geospatial analysis of variation of CPR rates.

Methods

Using 2010–2011 data from Durham, Mecklenburg, and Wake counties in North Carolina participating in the Cardiac Arrest Registry to Enhance Survival (CARES) program, we included all patients with OHCA for whom resuscitation was attempted. Geocoded data and logistic regression modeling were used to assess incidence of OHCA and patterns of bystander CPR according to census tracts and factors associated herewith.

Results

In total, 1466 patients were included (median age, 65 years [interquartile range 25]; 63.4% men). Bystander CPR by a layperson was initiated in 37.9% of these patients. High-incidence OHCA areas were characterized partly by higher population densities and higher percentages of black race as well as lower levels of education and income. Low rates of bystander CPR were associated with population composition (percent black: OR, 3.73; 95% CI, 2.00–6.97 per 1% increment in black patients; percent elderly: 3.25; 1.41–7.48 per 1% increment in elderly patients; percent living in poverty: 1.77, 1.16–2.71 per 1% increase in patients living in poverty).

Conclusions

In 3 counties in North Carolina, areas with low rates of bystander CPR can be identified using geospatial data, and education efforts can be targeted to improve recognition of cardiac arrest and to augment bystander CPR rates.     

A tale of two cities: The role of neighborhood socioeconomic status in spatial clustering of bystander CPR in Austin and Houston

Background

Despite evidence to suggest significant spatial variation in out-of-hospital cardiac arrest (OHCA) and bystander cardiopulmonary resuscitation (BCPR) rates, geographic information systems (GIS) and spatial analysis have not been widely used to understand the reasons behind this variation. This study employs spatial statistics to identify the location and extent of clusters of bystander CPR in Houston and Travis County, TX.

Methods

Data were extracted from the Cardiac Arrest Registry to Enhance Survival for two U.S. sites – Austin-Travis County EMS and the Houston Fire Department – between October 1, 2006 and December 31, 2009. Hierarchical logistic regression models were used to assess the relationship between income and racial/ethnic composition of a neighborhood and BCPR for OHCA and to adjust expected counts of BCPR for spatial cluster analysis. The spatial scan statistic was used to find the geographic extent of clusters of high and low BCPR.

Results

Results indicate spatial clusters of lower than expected BCPR rates in Houston. Compared to BCPR rates in the rest of the community, there was a circular area of 4.2 km radius where BCPR rates were lower than expected (RR = 0.62; p < 0.0001 and RR = 0.55; p = 0.037) which persist when adjusted for individual-level patient characteristics (RR = 0.34; p = 0.027) and neighborhood-level race (RR = 0.34; p = 0.034) and household income (RR = 0.34; p = 0.046). We also find a spatial cluster of higher than expected BCPR in Austin. Compared to the rest of the community, there was a 23.8 km radius area where BCPR rates were higher than expected (RR = 1.75; p = 0.07) which disappears after controlling for individual-level characteristics.

Conclusions

A geographically targeted CPR training strategy which is tailored to individual and neighborhood population characteristics may be effective in reducing existing disparities in the provision of bystander CPR for out-of-hospital cardiac arrest.     

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.     

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

Background

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

Methods

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

Results

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

Conclusions

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

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.     

Validity of reported data in the Swedish Cardiac Arrest Register in selected parts in Sweden

Aim

To describe differences and similarities between reported and non-reported data in the Swedish Cardiac Arrest Register in selected parts in Sweden.

Methods

Prospective and retrospective data for treated OHCA patients in Sweden, 2008–2010, were compared in the Swedish Cardiac Arrest Register. Data were investigated in three Swedish counties, which represented one third of the population. The recording models varied. Prospective data are those reported by the emergency medical service (EMS) crews, while retrospective data are those missed by the EMS crews but discovered afterwards by cross-checking with the local ambulance register.

Result

In 2008–2010, the number of prospectively (n = 2398) and retrospectively (n = 800) reported OHCA cases was n = 3198, which indicates a 25% missing rate.When comparing the two groups, the mean age was higher in patients who were reported retrospectively (69 years vs. 67 years; p = 0.003). There was no difference between groups with regard to gender, time of day and year of OHCA, witnessed status or initial rhythm. Bystander cardiopulmonary resuscitation (CPR) was more frequent among patients who were reported prospectively (65% vs. 60%; p = 0.023), whereas survival to one month was higher among patients who were reported retrospectively (9.2% vs. 11.9%; p = 0.035).

Conclusion

Among 3198 cases of OHCA in three counties in Sweden, 800 (25%) were not reported prospectively by the EMS crews but were discovered retrospectively as missing cases. Patients who were reported retrospectively differed from prospectively reported cases by being older, having less frequently received bystander CPR but having a higher survival rate. Our data suggest that reports on OHCA from national quality registers which are based on prospectively recorded data may be influenced by selection bias.     

The dispatcher assisted resuscitation trial: Indirect benefits of emergency research

Objective

Conduct of emergency research under waiver of consent produces special challenges. Moreover, the act of performing research may have unintended effects, potentially beneficial or detrimental. The Dispatcher-Assisted Randomized Trial (DART) was designed to compare 2 types of dispatcher cardiopulmonary (CPR) instruction, but not intended to affect the proportion of arrest victims that received bystander CPR. We sought to determine whether odds of receiving bystander CPR were higher during DART than during the periods before and after.

Methods

We conducted an observational cohort study of 8626 adults who suffered non-traumatic out-of-hospital cardiac arrest prior to emergency medical services (EMS) arrival in greater King County, Washington, between January 1, 1999, and December 31, 2011. Bystander CPR status was assessed through review of dispatch recordings and EMS reports to classify any bystander CPR (any B-CPR), and further categorized as bystander CPR with or without dispatcher assistance (DA-CPR and B-CPR, no DA). We used multivariable logistic regression to evaluate odds of B-CPR before, during, and after DART.

Results

The proportions receiving any B-CPR were 52% before DART (1817/3468), 59% during DART (2093/3527), and 54% after DART (885/1631). Compared to the period before DART, odds of receiving any B-CPR were higher during DART (OR = 1.35, 95% CI = 1.23–1.49), but no different after (OR = 1.10, 0.98–1.24). Compared to the before period, odds of DA-CPR were higher during DART (OR = 1.79, 1.59–2.02) but no different after (OR = 0.94, 0.80–1.10).

Conclusions

Odds of bystander CPR were higher during the trial, an increase related to higher likelihood of DA-CPR. The finding suggests a possible indirect community-wide benefit due to the interventional trial.     

Comparison of Medical Priority Dispatch (MPD) and Criteria Based Dispatch (CBD) relating to cardiac arrest calls

Background

Prompt emergency medical service (EMS) system activation with rapid delivery of pre-hospital treatment is essential for patients suffering out-of-hospital cardiac arrest (OHCA). The two most commonly used dispatch tools are Medical Priority Dispatch (MPD) and Criteria Based Dispatch (CBD). We compared cardiac arrest call processing using these two dispatch tools in two different dispatch centres.

Methods

Observational study of adult EMS confirmed (non-EMS witnessed) OHCA calls during one year in Richmond, USA (MPD) and Oslo, Norway (CBD). Patients receiving CPR prior to call, interrupted calls or calls where the caller did not have access to the patients were excluded from analysis. Dispatch logs, ambulance records and digitalized dispatcher and caller voice recordings were compared.

Results

The MPDS-site processed 182 cardiac arrest calls and the CBD-site 232, of which 100 and 140 calls met the inclusion criteria, respectively. The recognition of cardiac arrest was not different in the MPD and CBD systems; 82% vs. 77% (p = 0.42), and pre-EMS arrival CPR instructions were offered to 81% vs. 74% (p = 0.22) of callers, respectively. Time to ambulance dispatch was median (95% confidence interval) 15 (13, 17) vs. 33 (29, 36) seconds (p < 0.001) and time to chest compression delivery; 4.3 (3.7, 4.9) vs. 3.7 (3.0, 4.1) min for the MPD and CBD systems, respectively (p = 0.05).

Conclusion

Pre-arrival CPR instructions were offered faster and more frequently in the CBD system, but in both systems chest compressions were delayed 3–4 min. Earlier recognition of cardiac arrest and improved CPR instructions may facilitate earlier lay rescuer CPR.     

Chest compression depth and survival in out-of-hospital cardiac arrest

Aim

Outcomes from out-of-hospital cardiac arrest (OHCA) may improve if rescuers perform chest compressions (CCs) deeper than the previous recommendation of 38–51 mm and consistent with the 2010 AHA Guideline recommendation of at least 51 mm. The aim of this study was to assess the relationship between CC depth and OHCA survival.

Methods

Prospective analysis of CC depth and outcomes in consecutive adult OHCA of presumed cardiac etiology from two EMS agencies participating in comprehensive CPR quality improvement initiatives. Analysis: Multivariable logistic regression to calculate adjusted odds ratios (aORs) for survival to hospital discharge and favorable functional outcome.

Results

Among 593 OHCAs, 136 patients (22.9%) achieved return of spontaneous circulation, 63 patients (10.6%) survived and 50 had favorable functional outcome (8.4%). Mean CC depth was 49.8 ± 11.0 mm and mean CC rate was 113.9 ± 18.1 CC min⁻¹. Mean depth was significantly deeper in survivors (53.6 mm, 95% CI: 50.5–56.7) than non-survivors (48.8 mm, 95% CI: 47.6–50.0). Each 5 mm increase in mean CC depth significantly increased the odds of survival and survival with favorable functional outcome: aORs were 1.29 (95% CI 1.00–1.65) and 1.30 (95% CI 1.00–1.70) respectively.

Conclusion

Deeper chest compressions were associated with improved survival and functional outcome following OHCA. Our results suggest that adhering to the 2010 AHA Guideline-recommended depth of at least 51 mm could improve outcomes for victims of OHCA.