Gabriel Riva

Early Cardiopulmonary Resuscitation in Out-of-Hospital Cardiac Arrest

BACKGROUND Three million people in Sweden are trained in cardiopulmonary resuscitation (CPR). Whether this training increases the frequency of bystander CPR or the survival rate among persons who have out-of-hospital cardiac arrests has been questioned. METHODS We analyzed a total of 30,381 out-of-hospital cardiac arrests witnessed in Sweden from January 1, 1990, through December 31, 2011, to determine whether CPR was performed before the arrival of emergency medical services (EMS) and whether early CPR was correlated with survival. RESULTS CPR was performed before the arrival of EMS in 15,512 cases (51.1%) and was not performed before the arrival of EMS in 14,869 cases (48.9%). The 30-day survival rate was 10.5% when CPR was performed before EMS arrival versus 4.0% when CPR was not performed before EMS arrival (P<0.001). When adjustment was made for a propensity score (which included the variables of age, sex, location of cardiac arrest, cause of cardiac arrest, initial cardiac rhythm, EMS response time, time from collapse to call for EMS, and year of event), CPR before the arrival of EMS was associated with an increased 30-day survival rate (odds ratio, 2.15; 95% confidence interval, 1.88 to 2.45). When the time to defibrillation in patients who were found to be in ventricular fibrillation was included in the propensity score, the results were similar. The positive correlation between early CPR and survival rate remained stable over the course of the study period. An association was also observed between the time from collapse to the start of CPR and the 30-day survival rate. CONCLUSIONS CPR performed before EMS arrival was associated with a 30-day survival rate after an out-of-hospital cardiac arrest that was more than twice as high as that associated with no CPR before EMS arrival. (Funded by the Laerdal Foundation for Acute Medicine and others.).

Improved survival after out-of-hospital cardiac arrest is associated with an increase in proportion of emergency crew--witnessed cases and bystander cardiopulmonary resuscitation.

Background— Out-of-hospital cardiac arrest (OHCA) is a major public health problem. We sought to describe changes in 1-month survival after OHCA in patients given cardiopulmonary resuscitation (CPR) during the last 14 years in Sweden. Methods and Results— All patients experiencing OHCA in whom CPR was attempted between 1992 and 2005 and who were reported to the Swedish Cardiac Arrest Register were included in the study. In all, 38 646 patients were included in this survey. The proportion of patients who were admitted alive to a hospital increased from 15.3% in 1992 to 21.7% in 2005 (P for trend <0.0001). The corresponding values for patients being alive after 1 month were 4.8% and 7.3%, respectively (P for trend <0.0001). The increase in 1-month survival was particularly evident among patients found with a shockable rhythm (increase from 12.7% in 1992 to 22.3% in 2005; P for trend <0.0001). The corresponding figures for patients found with a nonshockable rhythm were 1.2% in 1992 and 2.3% in 2005 (P for trend=0.044). Factors that potentially contributed to the improved survival rate were an increase in emergency medical crew–witnessed cases from 9% in 1992 to 15% in 2005 (P for trend <0.0001) and, to a lesser degree, an increase in bystander CPR from 31% in 1992 to 50% in 2005 (P for trend <0.0001). After adjustment for potential risk factors, the increase in survival remained significant. Conclusions— We found a significant increase in survival after OHCA in Sweden over the last 14 years. The increase was particularly marked among patients found with a shockable rhythm and was associated with an increase in the proportion of crew-witnessed cases and, to a lesser degree, an increase in the performance of bystander CPR.

Mobile-Phone Dispatch of Laypersons for CPR in Out-of-Hospital Cardiac Arrest

BACKGROUND Cardiopulmonary resuscitation (CPR) performed by bystanders is associated with increased survival rates among persons with out-of-hospital cardiac arrest. We investigated whether rates of bystander-initiated CPR could be increased with the use of a mobile-phone positioning system that could instantly locate mobile-phone users and dispatch lay volunteers who were trained in CPR to a patient nearby with out-of-hospital cardiac arrest. METHODS We conducted a blinded, randomized, controlled trial in Stockholm from April 2012 through December 2013. A mobile-phone positioning system that was activated when ambulance, fire, and police services were dispatched was used to locate trained volunteers who were within 500 m of patients with out-of-hospital cardiac arrest; volunteers were then dispatched to the patients (the intervention group) or not dispatched to them (the control group). The primary outcome was bystander-initiated CPR before the arrival of ambulance, fire, and police services. RESULTS A total of 5989 lay volunteers who were trained in CPR were recruited initially, and overall 9828 were recruited during the study. The mobile-phone positioning system was activated in 667 out-of-hospital cardiac arrests: 46% (306 patients) in the intervention group and 54% (361 patients) in the control group. The rate of bystander-initiated CPR was 62% (188 of 305 patients) in the intervention group and 48% (172 of 360 patients) in the control group (absolute difference for intervention vs. control, 14 percentage points; 95% confidence interval, 6 to 21; P<0.001). CONCLUSIONS A mobile-phone positioning system to dispatch lay volunteers who were trained in CPR was associated with significantly increased rates of bystander-initiated CPR among persons with out-of-hospital cardiac arrest. (Funded by the Swedish Heart-Lung Foundation and Stockholm County; ClinicalTrials.gov number, NCT01789554.).

Dual Dispatch Early Defibrillation in Out-Of-Hospital Cardiac Arrest : The SALSA Pilot

AIMS Out-of-hospital cardiac arrest (OHCA) is a major public health problem. The objective of this study is to explore the effects of a dual dispatch early defibrillation programme. METHODS AND RESULTS In this pilot study, automated external defibrillators (AEDs) were provided to all 43 fire stations in Stockholm during 2005. Fire-fighters were dispatched in parallel with traditional emergency medical responders (EMS) to all suspected cases of OHCA. Additionally, 65 larger public venues were equipped with AEDs. All 863 OHCA from December 2005 to December 2006 were included during the intervention, whereas all 657 OHCA from 2004 served as historical controls. Among dual dispatches, fire-fighters assisted with cardiopulmonary resuscitation (CPR) in 94% of the cases and arrived first on scene in 36%. The median time from call to arrival of first responder decreased from 7.5 min during the control period to 7.1 min during the intervention (P = 0.004). The proportion of patients in shockable rhythm remained unchanged. The proportion of patients alive 1 month after OHCA rose from 4.4 to 6.8% [adjusted odds ratio (OR): 1.6; 95% confidence interval (CI): 0.9-2.9]. One-month survival in witnessed cases rose from 5.7 to 9.7% (adjusted OR: 2.0; 95% CI: 1.1-3.7). Survival after OHCA in the rest of Sweden (Stockholm excluded) declined from 8.3 to 6.6% during the corresponding time period (unadjusted OR: 0.8; 95% CI: 0.6-1.0). Only three OHCA occurred at public venues equipped with AEDs. CONCLUSION An introduction of a dual dispatch early defibrillation programme in Stockholm has shortened response times and is likely to have improved survival in patients with OHCA, especially in the group of witnessed cardiac arrests. The increase in survival is believed to be associated with improved CPR and shortened time intervals.

The survival benefit of dual dispatch of EMS and fire-fighters in out-of-hospital cardiac arrest may differ depending on population density – A prospective cohort study

BACKGROUND Outcome after out-of-hospital cardiac arrest (OHCA) varies between contexts. Dual dispatching of fire-fighters or police in addition to emergency medical services (EMS) has the potential to increase survival, but the effect in urban vs. rural areas is unknown. The aim of this study was to determine the effects of dual dispatching on response times and outcome in regions with different population density. METHODS AND RESULTS The study design was a prospective cohort study of EMS-treated OHCAs from 2004 (historical controls, only EMS dispatch) and 2006-2009 (intervention, dual dispatch of EMS and fire-fighters), with data on exact geographical coordinates. Patients were divided into four subgroups depending on population density: rural (<250 persons/km2), suburban (250-2999/km2), urban (3000-5999/km2) and downtown (≥6000/km2). Totally, 2513 OHCAs were included (historical controls, n=571 and intervention, n=1942). Median time to arrival of first unit shortened significantly in all subgroups, ranging from 0.8 to 3.2 min, with the main time gain in the rural area. There were significant differences in 30-day survival between the historical controls vs. the intervention group in the suburban population (3.1% vs. 7.0%, p=0.02) and in downtown (4.1 vs. 14.6, p=0.04). In the urban population the difference was 2.7 vs. 6.9% (p=0.06) and in the rural population (4.7 vs. 5.3, p=0.82). CONCLUSIONS Dual dispatch of fire-fighters and EMS in OHCA significantly reduced response times in all studied regions. The 30-day survival increased significantly in the downtown and suburban populations, while a limited impact was seen in the rural areas.

A smartphone application for dispatch of lay responders to out-of-hospital cardiac arrests

BACKGROUND Dispatch of lay volunteers trained in cardiopulmonary resuscitation (CPR) and equipped with automated external defibrillators (AEDs) may improve survival in cases of out-of-hospital cardiac arrest (OHCA). The aim of this study was to investigate the functionality and performance of a smartphone application for locating and alerting nearby trained laymen/women in cases of OHCA. METHODS A system using a smartphone application activated by Emergency Dispatch Centres was used to locate and alert laymen/women to nearby suspected OHCAs. Lay responders were instructed either to perform CPR or collect a nearby AED. An online survey was carried out among the responders. RESULTS From February to August 2016, the system was activated in 685 cases of suspected OHCA. Among these, 224 cases were Emergency Medical Services (EMSs)-treated OHCAs (33%). EMS-witnessed cases (n = 11) and cases with missing survey data (n = 15) were excluded. In the remaining 198 OHCAs, lay responders arrived at the scene in 116 cases (58%), and prior to EMSs in 51 cases (26%). An AED was attached in 17 cases (9%) and 4 (2%) were defibrillated. Lay responders performed CPR in 54 cases (27%). Median distance to the OHCA was 560 m (IQR 332-860 m), and 1280 m (IQR 748-1776 m) via AED pick-up. The survey-answering rate was 82%. CONCLUSION A smartphone application can be used to alert CPR-trained lay volunteers to OHCAs for CPR. Further improvements are needed to shorten the time to defibrillation before EMS arrival.