Mickey S. Eisenberg

Increasing Use of Cardiopulmonary Resuscitation During Out-of-Hospital Ventricular Fibrillation Arrest. Survival Implications of Guideline Changes

Background— The most recent resuscitation guidelines have sought to improve the interface between defibrillation and cardiopulmonary resuscitation; the survival impact of these changes is unknown, however. A year before issuance of the most recent guidelines, we implemented protocol changes that provided a single shock without rhythm reanalysis, stacked shocks, or postdefibrillation pulse check, and extended the period of cardiopulmonary resuscitation from 1 to 2 minutes. We hypothesized that survival would be better with the new protocol. Methods and Results— The present study took place in a community with a 2-tiered emergency medical services response and an established system of cardiac arrest surveillance, training, and review. The investigation was a cohort study of persons who had bystander-witnessed out-of-hospital ventricular fibrillation arrest because of heart disease, comparing a prospectively defined intervention group (January 1, 2005, to January 31, 2006) with a historical control group that was treated according to previous guidelines of rhythm reanalysis, stacked shocks, and postdefibrillation pulse checks (January 1, 2002, to December 31, 2004). The primary outcome was survival to hospital discharge. The proportion of treated arrests that met inclusion criteria was similar for intervention and control periods (15.4% [134/869] versus 16.6% [374/2255]). Survival to hospital discharge was significantly greater during the intervention period compared with the control period (46% [61/134] versus 33% [122/374], P=0.008) and corresponded to a decrease in the interval from shock to start of chest compressions (28 versus 7 seconds). Adjustment for covariates did not alter the survival association. Conclusions— These results suggest the new resuscitation guidelines will alter the interface between defibrillation and cardiopulmonary resuscitation and in turn may improve outcomes.

Emergency CPR instruction via telephone.

We initiated a program of telephone CPR (cardiopulmonary resuscitation) instruction provided by emergency dispatchers to increase the percentage of bystander-initiated CPR for out-of-hospital cardiac arrest. Cardiac arrests in King County, Washington were studied for 20 months before and after the telephone CPR program began. Bystander-initiated CPR increased from 86 of 191 (45 per cent) cardiac arrests before the program to 143 of 255 (56 per cent) cardiac arrests after the program. During the after period, 58 patients received CPR as a result of telephone instruction, 12 of whom were discharged. We estimate that four lives may have been saved by the program. A review of hospital records revealed no excess morbidity in the group of patients receiving dispatcher-assisted CPR.

Health status of survivors of cardiac arrest and of myocardial infarction controls.

We interviewed 308 survivors of out-of-hospital cardiac arrest and matched controls who had suffered a myocardial infarction. The Sickness Impact Profile (SIP) scores of controls were somewhat lower (better) than those of cases, but responses of cases and controls to additional questions about stair climbing, irritability and mood were virtually identical. Half as many (18 per cent) controls as cases (38 per cent) reported poorer memory function; nevertheless, 63 per cent of cases and 79 per cent of controls who had been working outside the home at the time of the event were employed at the time of the interview.

Cardiac arrest in schools

Background— The purpose of the present study is to improve understanding of the epidemiology of cardiac arrest in the school setting, with a special focus on the role of school-based automated external defibrillators. Methods and Results— The investigation was a retrospective study of emergency medical service–treated, nontraumatic, out-of-hospital cardiac arrests in Seattle and King County, Washington, that occurred in schools between 1990 and 2005. Cases were identified with cardiac arrest location data from emergency medical service cardiac arrest registries. Patient characteristics, cardiac arrest characteristics, and outcome information were abstracted from the registries and incident report forms. During the study period, 97 cardiac arrests occurred in schools, accounting for 0.4% of all treated cardiac arrests and 2.6% of public location cardiac arrests. Of the 97 cases, 12 cardiac arrests were among students, 33 among faculty and staff, and 45 among adults not employed by the school (7 adults with indeterminate school association). School-based cardiac arrest occurred on average in 1 of 111 schools annually, with a greater annual incidence among colleges (1 cardiac arrest per 8 colleges) than high schools (1 per 125 high schools) or lower-level schools (1 cardiac arrest per 200 preschools through middle schools). The estimated annual incidence of cardiac arrest was 0.18 per 100 000 person-years among students and 4.51 per 100 000 person-years for school faculty and staff. Conclusions— The present study characterizes school-setting cardiac arrest and provides a framework within which to consider preparation efforts and outcome expectations.

Paramedic programs and out-of-hospital cardiac arrest: II. Impact on community mortality.

Out-of-hospital cardiac arrest was studied in suburban King County, Washington in an attempt to determine the impact of paramedic services on community cardiac mortality. A portion of the study area received paramedic services and the remainder received basic emergency medical technician (EMT) services. A surveillance system identified all prehospital cardiac arrest incidents. The etiology and outcome were determined. Deaths due to primary heart disease (ICDA) codes 410-414) were compared to community cardiac mortality figures for the same period of time and in the paramedic and EMT areas. Between April 1, 1976 and August 31, 1977, 1,449 deaths due to primary heart disease occurred (annual rate of 19.2/10,000 in the EMT area and 13.4/10,000 in the paramedic area). For the same period, 487 patients with out-of-hospital cardiac arrest received emergency resuscitation. The annual incidence of out-of-hospital cardiac arrest was similar in the EMT and paramedic areas (5.6 and 6.0/10,000 respectively). Proportionately more lives of persons with cardiac arrest were saved in the paramedic area than in the MET area. During this 17 month period, the reduction in community cardiac mortality was 8.4 per cent in the paramedic area and 1.3 per cent in the EMT area. These findings suggest that paramedic services have a small but measurable effect on community cardiac mortality.

Dispatcher-Assisted CPR: Time to Identify Cardiac Arrest and Deliver Chest Compression Instructions

Background— Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR), in which 9-1-1 dispatchers provide CPR instructions over the telephone, has been shown to nearly double the rate of bystander CPR. We sought to identify factors that hampered the identification of cardiac arrest by 9-1-1 dispatchers and prevented or delayed the provision of dispatcher-assisted CPR chest compressions. Methods and Results— We reviewed dispatch recordings for 476 out-of-hospital cardiac arrests occurring between January 1, 2011, and December 31, 2011. We found that the dispatcher correctly identified cardiac arrest in 80% of reviewed cases and 92% of cases in which they were able to assess patient consciousness and breathing. The median time to recognition of the arrest was 75 seconds. Chest compressions following dispatcher-assisted CPR instructions occurred in 62% of cases when the dispatcher had the opportunity to asses for consciousness and breathing and bystander CPR was not already started. The median time to first dispatcher-assisted CPR chest compression was 176 seconds. Conclusions— Dispatchers are able to accurately diagnose cardiac arrest over the telephone, but recognition is likely not possible in all circumstances. In some cases, recognition of cardiac arrest may be improved through training in the detection of agonal respirations. Delays in the delivery of dispatcher-assisted CPR chest compressions are common and are attributable to a mixture of dispatcher behavior and factors beyond the control of the dispatcher. Performance standards for the successful and quick recognition of cardiac arrest and delivery of first chest compressions should be adopted as metrics against which emergency medical services systems can measure their performance.

Health status of survivors of out-of-hospital cardiac arrest six months later.

The health status of long-term survivors of out-of-hospital cardiac arrest was studied six months after the event. Although Sickness Impact Profile scores for arrest survivors were higher (worse) than scores of enrollees in a prepaid closed panel health plan, in most cases problems of survivors were not incapacitating. Approximately three-fifths of survivors reported same or better memory function and stair climbing ability compared to that at time of arrest. Three-fifths of those who had been working continued to do so.

Incidence and significance of gasping or agonal respirations in cardiac arrest patients.

Purpose of reviewThis review examines the clinical significance of agonal respirations associated with cardiac arrest. Recent findingsObservational data indicate that agonal respirations are frequent (55% of witnessed cardiac arrests and probably higher) and that they are associated with successful resuscitation. They also are found more commonly in ventricular fibrillation compared with other rhythms. Agonal respirations pose the greatest challenge to bystanders at the scene and to emergency dispatchers. Bystanders are often lulled into thinking the person is still breathing thus identification of cardiac arrest may be missed by the dispatcher. In a study from King County, Washington, cardiopulmonary resuscitation instructions were not provided by emergency dispatchers in 20% of cardiac arrest cases because the caller reported signs of life – typically abnormal breathing. SummaryAgonal respirations occur frequently in cardiac arrest. Emergency dispatchers and the general public must be more aware of their presence and significance.

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.

The Unacceptable Disparity in Cardiac Arrest Survival Among American Communities

The community in which an individual lives is the biggest factor determining whether survival or death follows out-ofhospital cardiac arrest. Consider the facts. Survival (discharged alive from hospital) from ventricular fibrillation in US cities ranges from 0% to 46%. Ample studies during several decades, including a recent publication from the Resuscitation Outcomes Consortium, document this disparity: Detroit, 0%; Chicago, 3%; New York, 5%; Los Angeles, 7%; Alabama, 8%; Salt Lake City, 8%; Dallas, 10%; Rochester, NY, 10%; Memphis, 12%; Tucson, 12%; San Francisco, 15%; Fresno, 15%; Houston, 15%; Minneapolis, 20%; Pittsburgh, 22%; Portland, OR, 23%; Iowa, 23%; Miami, 24%; Milwaukee 26%, Seattle, 46% (L. Cobb, personal communication, January 2009 [data are quoted for witnessed cases of ventricular fibrillation]), Rochester, MN, 46%; and King County, 46%. We include here only studies with at least 100 cases of ventricular fibrillation. Also, some of the above rates are for all cases of ventricular fibrillation and some used witnessed ventricular fibrillation for the denominator, but we think the point is clear. Variability in survival is only part of the problem. In more than 4 decades of out-of-hospital cardiac arrest research, it is notable that fewer than 50 communities have reported their experience. Is the situation in the rest of the country good, bad, or terrible? We simply don’t know. Whatever the service or product, we expect a reasonable standard of quality and a reasonable level of consistency from community to community. For some products and services, we actually have national standards and national enforcement. But with cardiac arrest, we have no such standards, no agency monitoring the quality of service, no political groundswell demanding improvements, and no public outcry for change. Admittedly there are large differences in community resources between rural and urban communities, and any future standards must take these differences into account, much like the National Fire Protection Academy Standard 1710 proposes different performance standards for different types of fire departments. It is likely that defined