Prehospital Cardiac Arrest in a Paramedic First-responder System Using the Utstein Style

Objectives. To describe the characteristics of patients found to have cardiac arrest andto evaluate the characteristics predictive of survival after cardiac arrest in a paramedic first-responder model. Methods. All patients who suffered out-of-hospital cardiac arrest in the city of Reading, Ohio, from January 1998 to December 2003 were recorded in the Utstein style. The number andincidence rate of witnessed arrests, initial rhythms, rate of bystander cardiopulmonary resuscitation (CPR), and30-day mortality rate were retrospectively collected. Demographics, time to hospital, andresponse times were evaluated as predictors of survival. Results. Of those patients initially found to be in cardiac arrest, 14.3% were discharged alive. Witnessed arrests were more likely to result in live discharge of the patient. Whether bystander CPR was performed was not found to affect survival, nor was initial rhythm, although no patients initially found in asystole were discharged alive. No demographic characteristics or response times were predictive of survival. Conclusion. The rates of survival in this paramedic first-response system are favorable compared with basic emergency medical technician first-response systems. Further study using direct comparison methodology is warranted to confirm these findings.     

Who Gets Bystander Cardiopulmonary Resuscitation in a Witnessed Arrest?

Objective: To identify characteristics associated with provision of bystander CPR in witnessed out-of-hospital cardiac arrest cases.
Methods: An observational, prospective, cohort study was performed using cardiac arrest cases as identified by emergency medical services (EMS) agencies in Oakland County, MI, from July 1, 1989, to December 31, 1993. All patients who sustained a witnessed arrest prior to arrival of EMS personnel were reviewed.
Results: Of the 927 patients meeting entry criteria, the 229 patients receiving bystander CPR were younger: 60.9 ± 14.7 vs 67.9 ± 14.7 years (p < 0.01). Most (76.6%) cardiac arrests occurred in the home. In a multivariate logistic model, only the location of arrest outside the home was a significant predictor of receiving bystander CPR [odds ratio (OR) 3.8; 99% CI 2.5, 5.9]. Arrests outside the home were associated with significantly improved outcome, with 18.2% of out-of-home and 8.2% of in-home victims discharged from the hospital alive (OR 2.5; 99% CI 1.4, 4.4).
Conclusion: Patients who have had witnessed cardiac arrests outside the home are nearly 4 times more likely to receive bystander CPR, and are twice as likely to survive. This observation emphasizes the need for CPR training of family members in the authors' locale. This phenomenon may also represent a significant con-founder in studies of out-of-hospital cardiac arrest and resuscitation.     

Improvements in Out-of-Hospital Cardiac Arrest Survival from 1998 to 2013

Objectives: Out-of-hospital cardiac arrest (OHCA) remains a major public health burden. Aggregate OHCA survival to hospital discharge has reportedly remained unchanged at 7.6% for almost 30 years from 1970 to 2008. We examined the trends in adult OHCA survival over a 16-year period from 1998 to 2013 within a single EMS agency. Methods: Observational cohort study of adult OHCA patients treated by Tualatin Valley Fire & Rescue (TVF&R) from 1998 to 2013. This is an ALS first response fire agency that maintains an active Utstein style cardiac arrest registry and serves a population of approximately 450,000 in 9 incorporated cities in Oregon. Primary outcomes were survival to hospital discharge in all patients and in the subgroup with witnessed ventricular fibrillation/pulseless ventricular tachycardia (VF/VT). The impact of key covariates on survival was assessed using univariate logistic regression. These included patient factors (age and sex), event factors (location of arrest, witnessed status, and first recorded cardiac arrest rhythm), and EMS system factors (response time interval, bystander CPR, and non-EMS AED shock). We used multivariate logistic regression to examine the impact of year increment on survival after multiple imputation for missing data. Sensitivity analysis was performed with complete cases. Results: During the study period, 2,528 adult OHCA had attempted field resuscitation. The survival rate for treated cases increased from 6.7% to 18.2%, with witnessed VF/VT cases increasing from 14.3% to 31.4% from 1998 to 2013. Univariate analysis showed that younger age, male sex, public location of arrest, bystander or EMS witnessed event, initial rhythm of pulseless electrical activity (PEA) or VF/VT, bystander CPR, non-EMS AED shock, and a shorter EMS response time were independently associated with survival. After adjustment for covariates, the odds of survival increased by 9% (OR 1.09, 95%CI: 1.05–1.12) per year in all treated cases, and by 6% (OR 1.06, 95% 1.01–1.10) per year in witnessed VF/VT subgroups. Findings remained consistent on sensitivity analysis. Conclusions: Overall survival from treated OHCA has increased over the last 16 years in this community. These survival increases demonstrate that OHCA is a treatable condition that warrants further investigation and investment of resources.     

Prompt Advanced Life Support Improves Survival from Ventricular Fibrillation

Objective. To determine whether the interval between the arrival of basic life support (BLS) providers and the arrival of advanced life support (ALS) providers is associated with patient outcome after cardiac arrest. Methods. We conducted a retrospective cohort study of all witnessed, out-of-hospital ventricular fibrillation (VF) cardiac arrests between January 1, 1991, and December 31, 2007. Eligible patients (n = 1,781) received full resuscitation efforts from both BLS and ALS providers. Results. The BLS-to-ALS arrival interval was a significant predictor of survival to hospital discharge (odds ratio [OR] 0.96, 95% confidence interval [CI] 0.93–0.99); the likelihood of survival decreased by 4% for every minute that ALS arrival was delayed following BLS arrival. Other significant predictors of survival were whether the arrest occurred in public (OR 1.48, 95% CI 1.19–1.85), whether a bystander administered cardiopulmonary resuscitation (CPR) (OR 1.34, 95% CI 1.07–1.68), and the interval between the 9-1-1 call and BLS arrival (OR 0.78, 95% CI 0.73–0.83). Conclusions. We found that a shorter BLS-to-ALS arrival interval increased the likelihood of survival to hospital discharge after a witnessed, out-of-hospital VF cardiac arrest. We conclude that ALS interventions may provide additional benefits over BLS interventions alone when utilized in a well-established, two-tiered emergency medical services (EMS) system already optimized for rapid defibrillation. The highest priorities in any EMS system should still be early CPR and early defibrillation, but timely ALS services can supplement these crucial interventions.     

NAEMSE Abstracts 2006

Abstract

Objective. Early, high-quality, minimally interrupted bystander cardio-pulmonary resuscitation (BCPR) is essential for out-of-hospital cardiac arrest survival. However, rates of bystander intervention remain low in many geographic areas. Community CPR programs have been initiated to combat these low numbers by teaching compression-only CPR to laypersons. This study examined bystander CPR and the cost-effectiveness of a countywide CPR program to improve out-of-hospital cardiac arrest survival. Methods. A 2-year retrospective review of emergency medical services (EMS) run reports for adult nontraumatic cardiac arrests was performed using existing prehospital EMS quality assurance data. The incidence and success of bystander CPR to produce prehospital return of spontaneous circulation and favorable neurologic outcomes at hospital discharge were analyzed. The outcomes were paired with cost data for the jurisdiction's community CPR program to develop a cost-effectiveness model. Results. During the 23-month study period, a total of 371 nontraumatic adult out-of-hospital cardiac arrests occurred, with a 33.4% incidence of bystander CPR. Incremental cost-effectiveness analysis for the community CPR program demonstrated a total cost of $22,539 per quality-adjusted life-year (QALY). A significantly increased proportion of those who received BCPR also had an automated external defibrillator (AED) applied. There was no correlation between witnessed arrest and performance of BCPR. A significantly increased proportion of those who received BCPR were found to be in a shockable rhythm when the initial ECG was performed. In the home setting, the chances of receiving BCPR were significantly smaller, whereas in the public setting a nearly equal number of people received and did not receive BCPR. Witnessed arrest, AED application, public location, and shockable rhythm on initial ECG were all significantly associated with positive ROSC and neurologic outcomes. A home arrest was significantly associated with worse neurologic outcome. Conclusions. Cost-effectiveness analysis demonstrates that a community CPR outreach program is a cost-effective means for saving lives when compared to other healthcare-related interventions. Bystander CPR showed a clear trend toward improving the neurologic outcome of survivors. The findings of this study indicate a need for additional research into the economic effects of bystander CPR.     

Socioeconomic Status Is Associated with Provision of Bystander Cardiopulmonary Resuscitation

Objective. Although socioeconomic status (SES) has been linked to multiple health outcomes, there have been few studies of the effect of SES on the provision of bystander cardiopulmonary resuscitation (CPR) during cardiac arrest events and no studies that we know of on the effect of SES on the provision of dispatcher-assisted bystander CPR. This study sought to define the relationship between SES and the provision of bystander CPR in an emergency medical system that includes dispatcher-provided CPR instructions. Methods. This study was a retrospective, cohort analysis of cardiac arrests due to cardiac causes occurring in private residences in King County, Washington, from January 1, 1999, to December 31, 2005. We used the tax-assessed value of the location of the cardiac arrest as an estimate of the SES of potential bystanders as well as multiple measures from 2000 Census data (education, employment, median household income, and race/ethnicity). We also examined the effect of patient and system characteristics that may affect the provision of bystander CPR. Logistic regression models were used to analyze the association of these factors with two outcomes: the provision of bystander CPR with and without dispatcher assistance. Results. Forty-four percent (1,151/2,618) of cardiac arrest victims received bystander CPR. Four hundred fifty-seven people (17.5% of the entire study population, 39.7% of those who received any bystander CPR) received CPR without telephone instructions. A total of 694 people received dispatcher-assisted bystander CPR (25.6% of the entire population, 60.4% of those receiving any bystander CPR). After adjusting for demographic and care factors, we found a strong association between the tax-assessed value of the cardiac arrest location and increased odds of the provision of bystander CPR without dispatcher instructions and bystander CPR with dispatcher assistance compared with no bystander CPR. Conclusions. This study suggests that higher bystander SES is associated with increased rates of bystander CPR with and without dispatcher instructions. CPR training programs that target lower-SES communities and assessment of these training methods may be warranted.     

Dispatcher instruction of chest compression-only CPR increases actual provision of bystander CPR

BackgroundA preceding randomized controlled trial demonstrated that chest compression-only cardiopulmonary resuscitation (CPR) instruction by dispatcher was more effective to increase bystander CPR than conventional CPR instruction. However, the actual condition of implementation of each type of dispatcher instruction (chest compression-only CPR [CCCPR] or conventional CPR with rescue breathing) and provision of bystander CPR in real prehospital settings has not been sufficiently investigated.MethodsThis registry prospectively enrolled patients aged =>18 years suffering an out-of-hospital cardiac arrest (OHCA) of non-traumatic causes before emergency-medical-service (EMS) arrival, who were considered as target subjects of dispatcher instruction, resuscitated by EMS personnel, and transported to medical institutions in Osaka, Japan from January 2005 through December 2012. The primary outcome measure was provision of CPR by a bystander. Multiple logistic regression analysis was used to assess factors that were potentially associated with provision of bystander CPR.ResultsAmong 37,283 target subjects of dispatcher instruction, 5743 received CCCPR instruction and 13,926 received conventional CPR instruction. The proportion of CCCPR instruction increased from 5.7% in 2005 to 25.6% in 2012 (p for trend <0.001). The CCCPR instruction group received bystander CPR more frequently than conventional CPR instruction group (70.0% versus 62.1%, p < 0.001). In the multivariable analysis, CCCPR dispatcher instruction was significantly associated with provision of bystander CPR compared with conventional CPR instruction (adjusted odds ratio 1.44, 95% CI 1.34–1.55).ConclusionsCCCPR dispatcher instruction among adult OHCA patients significantly increased the actual provision of bystander CPR.     

Comparison of out-of-hospital cardiac arrest occurring before and after paramedic arrival: Epidemiology,survival to hospital discharge and 12-month functional recovery

BackgroundDespite immediate resuscitation, survival rates following out-of-hospital cardiac arrests (OHCA) witnessed by emergency medical service (EMS) are reportedly low. We sought to compare survival and 12-month functional recovery outcomes for OHCA occurring before and after EMS arrival.MethodsBetween 1st July 2008 and 30th June 2013, we included 8648 adult OHCA cases receiving an EMS attempted resuscitation from the Victorian Ambulance Cardiac Arrest Registry, and categorised them into five groups: bystander witnessed cases ± bystander CPR, unwitnessed cases ± bystander CPR, and EMS witnessed cases. The main outcomes were survival to hospital and survival to hospital discharge. Twelve-month survival with good functional recovery was measured in a sub-group of patients using the Extended Glasgow Outcome Scale (GOSE).ResultsBaseline and arrest characteristics differed significantly across groups. Unadjusted survival outcomes were highest among bystander witnessed cases receiving bystander CPR and EMS witnessed cases, however outcomes differed significantly between these groups: survival to hospital (46.0% vs. 53.4% respectively, p < 0.001); survival to hospital discharge (21.1% vs. 34.9% respectively, p < 0.001). When compared to bystander witnessed cases receiving bystander CPR, EMS witnessed cases were associated with a significant improvement in the risk adjusted odds of survival to hospital (OR 2.02, 95% CI: 1.75–2.35), survival to hospital discharge (OR 6.16, 95% CI: 5.04–7.52) and survival to 12 months with good functional recovery (OR 5.56, 95% CI: 4.18–7.40).ConclusionWhen compared to OHCA occurring prior to EMS arrival, EMS witnessed arrests were associated with significantly higher survival to hospital discharge rates and favourable neurological recovery at 12-month post-arrest.     

Outcomes of cardiac arrest in the nursing home: Destiny or futility?

Objective. To compare EMS system characteristics and outcomes between nursing home (NH) patients and out-of-hospital cardiac arrest (OHCA) patients whose arrests occurred in a residence (home).

Design. Prospective cohort study reviewing OHCA from July 1989 to December 1993. Variables were age, witnessed arrest, response intervals, automated external defibrillator (AED) use, and arrest rhythms. Outcomes were hospital admission and discharge. Pearson chi-square was used for analysis.

Setting. Suburban EMS system.

Subjects. Patients ≥ 19 years old with arrest of presumed cardiac cause, with locations at home or at a NH.

Results. 2,348 total arrests were complete for analysis, 182 at a NH and 2,166 at home. BLS and ALS response intervals were shorter for the NH patients. The NH patients were more likely to receive CPR on collapse, were older (73.1 vs 67.5 years, p < 0.001), were less likely to have had an AED used (9.9% vs 30.0%, p < 0.001), and were more likely to have an arrest bradyasystolic rhythm (74.7% vs 51.5%, p < 0.001). They were less likely to survive to hospital admission (10.4% vs 18.5%, p < 0.006) and discharge (0.0% vs 5.6%, p < 0.001).

Conclusion. During this four-and-a-half-year study period, no NH patient survived, even though % CPR was increased. Arrest rhythm is an important factor in this finding. EMS initial care for ventricular tachycardia/fibrillation NH patients, with less application of AEDs, was identified. This different response may adversely contribute to dismal NH outcome.     

The impact of prehospital physicians on out-of-hospital nonasystolic cardiac arrest

Objective. To determine whether the presence of an on-scene medical control physician (OSMCP) alters the management and outcome of out-of-hospital nontraumatic, nonasystolic cardiac arrest (CA) patients.

Methods. This was a retrospective case series of CA patients who were cared for in an all advanced life support, third-service, municipal emergency medical services (EMS) system over a one-year period. Excluded from the study were all traumatic CA patients and solely asystolic patients. The remaining CA patients were divided into the two study groups according to the presence of an OSMCP or whether they were cared for by paramedics only (PO). For each group patient age, EMS response time, the number of personnel on the scene, the presence of bystander CPR, the initial cardiac rhythm, and scene time were determined. In addition, time to first defibrillation for patients in ventricular fibrillation, the rate of drug administrations per minute, the return of spontaneous circulation (ROSC) on emergency department (ED) arrival, and survival to hospital discharge were collected for each group.

Results. Eighty CA runs were reviewed, with 49 meeting entry criteria; nine in the OSMCP group and 40 in the PO group. There was no difference between the groups with regard to patient age, response time, scene time, or number of personnel on the scene. The two groups were similarly matched with regard to initial cardiac rhythm, the presence of bystander or first-responder CPR, and time to first defibrillation. The number of drug dosages administered per minute was higher in the OSMCP group (0.62 doses per minute) as compared with the PO group (0.34 doses per minute)[p < 0.03]. ROSC and survival to hospital discharge revealed a nonsignificant tendency toward more frequent ROSC in the OSMCP group [p < 0.07], and a significantly higher incidence of survival to discharge in the OSMCP group [p < 0.009].

Conclusions. Out-of-hospital CA patients treated in the OSMCP group had a trend toward more frequent ROSC upon ED arrival and a higher rate of survival to hospital discharge. The OSMCP group patients received medications at nearly twice the rate of the PO group patients. Although a larger trial is needed, more frequent dosing of drugs during CA may have contributed to increased survival in the OSMCP group.     

A MIODARONE AND R URAL E MERGENCY M EDICAL S ERVICES C ARDIAC A RREST P ATIENTS : A C OST A NALYSIS

Objective: Recent American Heart Association guidelines suggest amiodarone as an antiarrhythmic in refractory ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). The authors sought to assess the impact of amiodarone use on outcomes and cost associated with this practice in a rural emergency medical services (EMS) state. Methods: Statewide EMS records were reviewed for the calendar year 1999. Data reviewed included prehospital diagnosis, medications given by prehospital providers to patients with cardiac arrest, and procedures performed, including cardiopulmonary resuscitation (CPR) and defibrillation. Cost-benefit analysis assumed the cost of amiodarone treatment to be $137.65 per patient encounter. Absolute risk reduction (ARR) and number needed to treat (NNT) analysis utilized resuscitation rates published in the ARREST and ALIVE trials. Results: During the study period, EMS providers diagnosed 2,189 patients as having cardiac arrest. Five hundred thirty-five (24.4%) cardiac arrest patients were defibrillated. One hundred sixty patients (7.3%), including 15 who did not receive defibrillation, were given lidocaine during resuscitation efforts. The annual cost increase from current practice for a statewide amiodarone VF/VT protocol was $21,822.40 (10,572.87%). The initial cost to stock EMS vehicles for this protocol would be $50,115.52. The cost-benefit analysis yielded a potential for one additional patient survival to hospital discharge in Maine per 3.125 years of system-wide practice at a cost of $68,840.00. Conclusion: Based on current data, instituting amiodarone treatment for refractory VF and pulseless VT in a rural EMS setting requires the investment of substantial resources, relative to current treatment strategies, for any potential survival benefit.     

Establishing Arizona's Statewide Cardiac Arrest Reporting andEducational Network

Background. Only a few large cities have published their out-of-hospital cardiac arrest (OHCA) survival statistics using the Utstein style reporting method. To date, to the best of our knowledge there has been no published OHCA survival data for a state. Objective. To describe the process, benefits, andchallenges of establishing a statewide OHCA database andeducational network. Methods. Arizona's Bureau of Emergency Medical Services andTrauma System initiated a statewide, prospective, observational cohort review of all OHCA victims on whom resuscitation was attempted in the field. Emergency medical services (EMS) first care reports, voluntarily submitted by 35 departments in Arizona, were analyzed. We chronicled the development of our data-collection process along with how we obtained patient outcomes anddelivered feedback to field providers. Entry data included time intervals andnodal events conforming to the Utstein style template. Results. In data collected between January 1, 2005, andApril 1, 2006, there were 1,484 OHCAs reported, of which 1,104 were of presumed cardiac etiology occurring prior to EMS arrival. The OHCA incidence was approximately 0.44 per 1,000 population per year. In our database, bystander CPR provided an odds ratio of 3.0 for survival (95% confidence interval 1.3, 6.7). Outcomes for 1,076 patients were obtained. Thirty-seven (3.4%) of the 1,076 cardiac arrest victims survived to hospital discharge. Twenty-seven (8.6%) of the 331 ventricular fibrillation cardiac arrest victims survived to hospital discharge. Conclusion. It is feasible for a public health agency to implement a voluntary, statewide data-collection system andeducational network to determine andimprove survival from OHCA.     

Locating AED Enabled Medical Drones to Enhance Cardiac Arrest Response Times

Background: Out-of-hospital cardiac arrest (OOHCA) is prevalent in the United States. Each year between 180,000 and 400,000 people die due to cardiac arrest. The automated external defibrillator (AED) has greatly enhanced survival rates for OOHCA. However, one of the important components of successful cardiac arrest treatment is emergency medical services (EMS) response time (i.e., the time from EMS “wheels rolling” until arrival at the OOHCA scene). Unmanned Aerial Vehicles (UAV) have regularly been used for remote sensing and aerial imagery collection, but there are new opportunities to use drones for medical emergencies. Objective: The purpose of this study is to develop a geographic approach to the placement of a network of medical drones, equipped with an automated external defibrillator, designed to minimize travel time to victims of out-of-hospital cardiac arrest. Our goal was to have one drone on scene within one minute for at least 90% of demand for AED shock therapy, while minimizing implementation costs. Methods: In our study, the current estimated travel times were evaluated in Salt Lake County using geographical information systems (GIS) and compared to the estimated travel times of a network of AED enabled medical drones. We employed a location model, the Maximum Coverage Location Problem (MCLP), to determine the best configuration of drones to increase service coverage within one minute. Results: We found that, using traditional vehicles, only 4.3% of the demand can be reached (travel time) within one minute utilizing current EMS agency locations, while 96.4% of demand can be reached within five minutes using current EMS vehicles and facility locations. Analyses show that using existing EMS stations to launch drones resulted in 80.1% of cardiac arrest demand being reached within one minute Allowing new sites to launch drones resulted in 90.3% of demand being reached within one minute. Finally, using existing EMS and new sites resulted in 90.3% of demand being reached while greatly reducing estimated overall costs. Conclusion: Although there are still many factors to consider, drone networks show potential to greatly reduce life-saving equipment travel times for victims of cardiac arrest.     

Results of the first five years of the prehospital automatic external defibrillation project in Singapore in the "Utstein style"

In 1994, all emergency medical services (EMS) ambulance officers in Singapore were trained to perform pre-hospital defibrillation with semi-automated external defibrillators (AED). All non-traumatic cardiac arrest patients over 10 years old were included, excluding those who were obviously dead and children below 36 kg. The data were collected by the ambulance officers according to the Utstein guidelines. From 1 February 1994 to 31 January 1999; resuscitation was attempted in 968 non-trauma cardiac arrests. Fifteen percent of the cases were of non-cardiac origin. The overall survival rate was 40/968 (4.1%, 95% CI 2.9-5.6%). Of 968 patients, 22/136 (16.2%, 95% CI 10.4-23.5%), 18/622 (2.9%, 95% CI 1.7-4.5%) and 0/210 (0%, 95% CI 0-1.7%) survived in the EMS witnessed, bystander witnessed and un-witnessed groups, respectively (P < 0.001). Within the EMS witnessed group, those with an initial rhythm of VF/VT had a higher survival rate (30.6%) than those without VF/VT (4.1%). P < 0.001, OR = 10.3, 95% CI 2.9-36.9. Similarly, the VF/VT survival rate in the bystander witnessed group (4.5%) was higher than the non-VF/VT (1.0%) (P = 0.011, OR = 4.4, 95% CI 1.3-15.4). The survival rate of patients with bystander witnessed VF/VT arrest who received bystander CPR was 9.4% compared to 1.0% in those who did not (P = 0.037, OR = 4.4, 95% CI 1.01-20.1). Our survival rate of bystander witnessed VF/VT arrest is comparable to large metropolitan cities in the USA. The determinants of survival include EMS witnessed arrest and VF/VT arrest. Increased quantity and quality of bystander CPR rate may improve the outcome in bystander witnessed cardiac arrest.     

The three-phase model of cardiac arrest as applied to ventricular fibrillation in a large, urban emergency medical services system

BACKGROUND: Cardiac arrest is responsible for significant morbidity and mortality, with consistently poor outcomes despite the rapid availability of prehospital personnel for defibrillation attempts in patients with ventricular fibrillation (VF). Recent evidence suggests a period of cardiopulmonary resuscitation (CPR) prior to defibrillation attempts may improve outcomes in patients with moderate time since collapse (4-10 min). OBJECTIVES: To determine cardiac arrest outcomes in our community and explore the relationship between time since collapse, performance of bystander CPR, and survival. METHODS: Non-traumatic cardiac arrest data were collected prospectively over an 18-month period. Patients were excluded for: age <18 years, a "Do Not Attempt Resuscitation" (DNAR) directive, determination of a non-cardiac etiology for arrest, and an initially recorded rhythm other than VF. Patients were stratified by time since collapse (<4, 4-10, > 10 min, and unknown) and compared with regard to survival and neurological outcome. In addition, patients with and without bystander CPR were compared with regard to survival. RESULTS:: A total of 1141 adult non-traumatic cardiac arrest victims were identified over the 18-month study period. This included 272 patients with VF as the initially recorded rhythm. Of these, 185 had a suspected cardiac etiology for the arrest; survival to hospital discharge was 15% in this group, with 82% of these having a good outcome or only moderate disability. Survival was highest among patients with time since collapse of less than 4 min and decreased with increasing time since collapse. There were no survivors among patients with time since collapse greater than 10 min. Among patients with time since collapse of 4 min or longer, survival was significantly higher with the performance of bystander CPR; there was no survival advantage to bystander CPR among patients with time since collapse less than 4 min. CONCLUSIONS: The performance of bystander CPR prior to defibrillation by EMS personnel is associated with improved survival among patients with time since collapse longer than 4 min but not less than 4 min. These data are consistent with the three-phase model of cardiac arrest.     

Bystander vs EMS First–responder CPR: Initial Rhythm and Outcome in Witnessed Nonmonitored Out–of–hospital Cardiac Arrest

Objectives: To assess whether outcome and first–monitored rhythm for patients who sustain a witnessed, nonmonitored, out–of–hospital cardiac arrest are associated with on–scene CPR provider group.
Methods: A retrospective, cohort analysis was conducted in a suburban, heterogeneous EMS system. Patients studied were ± 19 years of age, had had an arrest of presumed cardiac origin between July 1989 and January 1993, had gone into cardiac arrest prior to ALS arrival, and had received CPR on collapse. First–monitored rhythms and survival rates were compared for two patient groups who on collapse either: 1) had received CPR by nonprofessional bystanders (BCPR) or 2) had received CPR by on–scene EMS system first responders (FRCPR).
Results: Of 217 cardiac arrest victims, 153 (71%) had received BCPR and 64 (29%) had received FRCPR. The BCPR patients were slightly younger (62. 4 vs 68. 4 years, p = 0. 01) and had slightly shorter ALS response intervals (6. 4 vs 7. 7 minutes, p = 0. 02). There was no difference in BLS response time intervals or automatic external defibrillator (AED) use rates. The percentage of patients with a first–monitored rhythm of pulseless ventricular tachycardia/ventricular fibrillation (VT/VF) and the percentage of patients grouped by CPR provider who survived to hospital admission or to hospital discharge were:
Controlling for age, the odds ratio for VT/VF with BCPR was 5. 45 (95% CI 2. 8, 10. 3).
Conclusion: Patients who receive BCPR more often have a first–monitored rhythm of VT/VF than do FRCPR patients, despite both CPR–provider groups' initiating CPR essentially immediately after patient collapse. Hence, BCPR and FRCPR groups have different first–monitored arrest rhythms, which may affect survival rate. These patient populations should not be considered to be homogeneous groups in CPR research.     

CPR Training and CPR Performance: Do CPR‐trained Bystanders Perform CPR?

Objectives: To determine factors associated with cardiopulmonary resuscitation (CPR) provision by CPR‐trained bystanders and to determine factors associated with CPR performance by trained bystanders. Methods: The authors performed a prospective, observational study (January 1997 to May 2003) of individuals who called 911 (bystanders) at the time of an out‐of‐hospital cardiac arrest. A structured telephone interview of adult cardiac‐arrest bystanders was performed beginning two weeks after the incident. Elements gathered during interviews included bystander and patient demographics, identifying whether the bystander was CPR trained, when and by whom the CPR was performed, and describing the circumstances of the event. If CPR was not performed, we asked the bystanders why CPR was not performed. Logistic regression was used to calculate odds ratios and 95% confidence intervals (95% CI) for factors associated with CPR performance. Results: Of 868 cardiac arrests, 684 (78.1%) bystander interviews were completed. Of all bystanders interviewed, 69.6% were family members of the victims, 36.8% of the bystanders had more than a high‐school education, and 54.1% had been taught CPR at some time. In 21.2% of patients, the bystander immediately started CPR, and in 33.6% of cases, someone started CPR before the arrival of emergency medical services (EMS). Important overall predictors of CPR performance were the following: witnessed arrest (OR = 2.3; 95% CI = 1.4 to 3.8); bystander was CPR trained (OR = 6.6; 95% CI = 3.5 to 12.5); bystander had more than a high‐school education (OR = 2.0; 95% CI = 1.2 to 3.1), or arrest occurred in a public location (OR = 3.1; 95% CI = 1.7 to 5.8). These variables were significant predictors of CPR performance among CPR‐trained bystanders, as was CPR training within five years (OR = 4.5; 95% CI = 2.8 to 7.3). Common reasons that the CPR‐trained bystanders cited for not performing CPR were the following: 37.5% stated that they panicked, 9.1% perceived that they would not be able to do CPR correctly, and 1.1% thought that they would hurt the patient. Surprisingly, only 1.1% objected to performing mouth‐to‐mouth resuscitation. Conclusions: A minority of CPR‐trained bystanders performed CPR. CPR provision was more common in CPR‐trained bystanders with more than a high‐school education and when CPR training had been within five years. Previously espoused reasons for not doing CPR (mouth‐to‐mouth, infectious‐disease risk) were not the reasons that bystanders cited for not doing CPR. Further work is needed to maximize CPR provision after CPR training.     

Association of response time interval with neurological outcomes after out-of-hospital cardiac arrest according to bystander CPR

BackgroundThis study intended to find out how association between response time interval (RTI) and good neurological outcome is affected by bystander CPR. We hypothesized that bystander CPR will ensure positive effect in relationship between RTI and clinical outcome.MethodsA retrospective, observational study was made with Pan-Asian Resuscitation Outcome Study data from January 2009 to December 2016. Six cities from four Asian countries were selected. EMS-treated, non-traumatic witnessed out-of-hospital cardiac arrest (OHCA) cases were included. General demographic data, prehospital cardiac arrest details and clinical outcome were collected and analyzed according to whether bystander CPR was performed. Good neurological outcome and survival discharge were primary and secondary outcomes.ResultsA total of 13,245 OHCA cases were analyzed. Median EMS response time intervals were 6 min, regardless of bystander CPR. Dividing into RTI time range by 3 min, good neurological outcome and survival discharge were only significant in 3 to 6 minutes group (adjusted odds ratio [AOR] 1.42, 1.17–1.73 95% confidence interval [CI] and AOR 1.31, 1.15–1.51 95% CI) in non-bystander CPR group but in bystander CPR group significant RTI time range was 3 to 9 min (AOR 2.02, 1.82, 1.62–2.52, 1.48–2.25 95% CI for primary, AOR 1.66, 1.43, 1.41–1.96, 1.22–1.67 95% CI for secondary).ConclusionsAs response time interval increased, slower deterioration of good neurological outcome and survival discharge was shown in cardiac arrest patients with bystander CPR performed. If bystander CPR is provided, RTI time range showing significant neurological outcome and survival improvement seems to be relatively lengthened.