Per Nordberg

Intra-Arrest Transnasal Evaporative Cooling A Randomized, Prehospital, Multicenter Study (PRINCE: Pre-ROSC IntraNasal Cooling Effectiveness)

Background— Transnasal evaporative cooling has sufficient heat transfer capacity for effective intra-arrest cooling and improves survival in swine. The aim of this study was to determine the safety, feasibility, and cooling efficacy of prehospital transnasal cooling in humans and to explore its effects on neurologically intact survival to hospital discharge. Methods and Results— Witnessed cardiac arrest patients with a treatment interval ≤20 minutes were randomized to intra-arrest cooling with a RhinoChill device (treatment group, n=96) versus standard care (control group, n=104). The final analysis included 93 versus 101 patients, respectively. Both groups were cooled after hospital arrival. The patients had similar demographics, initial rhythms, rates of bystander cardiopulmonary resuscitation, and intervals to cardiopulmonary resuscitation and arrival of advanced life support personnel. Eighteen device-related adverse events (1 periorbital emphysema, 3 epistaxis, 1 perioral bleed, and 13 nasal discolorations) were reported. Time to target temperature of 34°C was shorter in the treatment group for both tympanic (102 versus 282 minutes, P=0.03) and core (155 versus 284 minutes, P=0.13) temperature. There were no significant differences in rates of return of spontaneous circulation between the groups (38% in treated subjects versus 43% in control subjects, P=0.48), in overall survival of those admitted alive (44% versus 31%, respectively, P=0.26), or in neurologically intact survival to discharge (Pittsburgh cerebral performance category scale 1 to 2, 34% versus 21%, P=0.21), although the study was not adequately powered to detect changes in these outcomes. Conclusions— Prehospital intra-arrest transnasal cooling is safe and feasible and is associated with a significant improvement in the time intervals required to cool patients. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00808236.

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.).

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.).

Improved outcome in Sweden after out-of-hospital cardiac arrest and possible association with improvements in every link in the chain of survival

AIMS To describe out-of-hospital cardiac arrest (OHCA) in Sweden from a long-term perspective in terms of changes in outcome and circumstances at resuscitation. METHODS AND RESULTS All cases of OHCA (n = 59,926) reported to the Swedish Cardiac Arrest Register from 1992 to 2011 were included. The number of cases reported (n/100,000 person-years) increased from 27 (1992) to 52 (2011). Crew-witnessed cases, cardiopulmonary resuscitation prior to the arrival of the emergency medical service (EMS), and EMS response time increased (P < 0.0001). There was a decrease in the delay from collapse to calling for the EMS in all patients and from collapse to defibrillation among patients found in ventricular fibrillation (P < 0.0001). The proportion of patients found in ventricular fibrillation decreased from 35 to 25% (P < 0.0001). Thirty-day survival increased from 4.8 (1992) to 10.7% (2011) (P < 0.0001), particularly among patients found in a shockable rhythm and patients with return of spontaneous circulation (ROSC) at hospital admission. Among patients hospitalized with ROSC in 2008-2011, 41% underwent therapeutic hypothermia and 28% underwent percutaneous coronary intervention. Among 30-day survivors in 2008-2011, 94% had a cerebral performance category score of 1 or 2 at discharge from hospital and the results were even better if patients were found in a shockable rhythm. CONCLUSION From a long-term perspective, 30-day survival after OHCA in Sweden more than doubled. The increase in survival was most marked among patients found in a shockable rhythm and those hospitalized with ROSC. There were improvements in all four links in the chain of survival, which might explain the improved outcome.

Mobile phone technology identifies and recruits trained citizens to perform CPR on out-of-hospital cardiac arrest victims prior to ambulance arrival

AIM In a two-parted study, evaluate a new concept were mobile phone technology is used to dispatch lay responders to nearby out-of-hospital cardiac arrests (OHCAs). METHODS Mobile phone positioning systems (MPS) can geographically locate selected mobile phone users at any given moment. A mobile phone service using MPS was developed and named Mobile Life Saver (MLS). Simulation study: 25 volunteers named mobile responders (MRs) were connected to MLS. Ambulance time intervals from 22 consecutive OHCAs in 2005 were used as controls. The MRs randomly moved in Stockholm city centre and were dispatched to simulated OHCAs (identical to controls) if they were within a 350 m distance. Real life study: during 25 weeks 1271-1801 MRs trained in CPR were connected to MLS. MLS was activated at the dispatch centre in parallel with ambulance dispatch when an OHCA was suspected. The MRs were dispatched if they were within 500 m from the suspected OHCA. RESULTS Simulation study: mean response time for the MRs compared to historical ambulance time intervals was reduced by 2 min 20s (44%), p<0.001, (95% CI, 1 min 5s - 3 min 35s). The MRs reached the simulated OHCA prior to the historical control in 72% of cases. Real life study: the MLS was triggered 92 times. In 45% of all suspected and in 56% of all true OHCAs the MRs arrived prior to ambulance. CPR was performed by MRs in 17% of all true OHCAs and in 30% of all true OHCAs if MRs arrived prior to ambulance. CONCLUSION Mobile phone technology can be used to identify and recruit nearby CPR-trained citizens to OHCAs for bystander CPR prior to ambulance arrival.

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.

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.

Out-of-hospital cardiac arrest in the elderly: A large-scale population-based study☆

BACKGROUND There is little information on elderly people who suffer from out-of-hospital cardiac arrest (OHCA). AIM To determine 30-day mortality and neurological outcome in elderly patients with OHCA. METHODS OHCA patients ≥ 70 years of age who were registered in the Swedish Cardiopulmonary Resuscitation Register between 1990 and 2013 were included and divided into three age categories (70-79, 80-89, and ≥ 90 years). Multiple logistic regression analyses were performed to identify independent predictors of 30-day survival. RESULTS Altogether, 36,605 cases were included in the study. Thirty-day survival was 6.7% in patients aged 70-79 years, 4.4% in patients aged 80-89 years, and 2.4% in those over 90 years. For patients with witnessed OHCA of cardiac aetiology found in a shockable rhythm, survival was higher: 20%, 15%, and 11%, respectively. In 30-day survivors, the distribution according to the cerebral performance categories (CPC) score at discharge from hospital was similar in the three age groups. In multivariate analysis, in patients over 70 years of age, the following factors were associated with increased chance of 30-day survival: younger age, OHCA outside the home, witnessed OHCA, CPR before arrival of EMS, shockable first-recorded rhythm, and short emergency response time. CONCLUSIONS Advanced age is an independent predictor of mortality in OHCA patients over 70 years of age. However, even in patients above 90 years of age, defined subsets with a survival rate of more than 10% exist. In survivors, the neurological outcome remains similar regardless of age.

The implementation of a dual dispatch system in out-of-hospital cardiac arrest is associated with improved short and long term survival.

Aims: To determine the impact of a dual dispatch system, using fire fighters as first responders, in out-of-hospital cardiac arrest (OHCA) on short (30 days) and long term (three years) survival, and, to investigate the potential differences regarding in-hospital factors and interventions between the patient groups, such as the use of therapeutic hypothermia and cardiac catheterization. Methods and results: OHCAs from 2004 (historical controls) and 2006–2009 (intervention period) were included. During the intervention period, fire fighters equipped with automated external defibrillators (AEDs) were dispatched in suspected OHCA. Logistic regression analyses of outcome data included: the intervention with dual dispatch, sex, age, location, aetiology, witnessed status, bystander-cardiopulmonary resuscitation, first rhythm and therapeutic hypothermia. In total, 2581 OHCAs were included (historical controls n=620, intervention period n=1961). Fire fighters initiated cardiopulmonary resuscitation and connected an AED before emergency medical services’ arrival in 41% of the cases. The median time from dispatch to arrival of first responder or emergency medical services shortened from 7.7 in the control period to 6.7 min in the intervention period (p<0.001). The 30-day survival improved from 3.9% to 7.6% (p=0.001), adjusted odds ratio 2.8 (confidence interval 1.6–4.9). Survival to three years increased from 2.4% to 6.5% (p<0.001), adjusted odds ratio 3.8 (confidence interval 1.9–7.6). In the logistic regression analysis including in-hospital factors we found no outcome benefit of therapeutic hypothermia. Conclusions: The implementation of a dual dispatch system using fire fighters in OHCA was associated with increased 30-day and three-year survival. No major differences in the in-hospital treatment were seen between the studied patient groups.

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.