Syringe Administration of Epinephrine by Emergency Medical Technicians for Anaphylaxis.

OBJECTIVE: In recent years, the costs of epinephrine autoinjectors (EAIs) in the United States have risen substantially. King County Emergency Medical Services implemented the "Check and Inject" program to replace EAIs by teaching emergency medical technicians (EMTs) to manually aspirate epinephrine from a single-use 1 mg/mL epinephrine vial using a needle and syringe followed by prehospital intramuscular administration of the correct adult or pediatric dose of epinephrine for anaphylaxis or serious allergic reaction. Treatment was guided by an EMT protocol that required a trigger and symptoms. We sought to determine if the "Check and Inject" program was safely implemented by EMTs treating presumed prehospital anaphylaxis or serious allergic reaction. METHODS: We conducted a prospective investigation of all cases treated as part of the "Check and Inject" program from July 2014 through December 2016 in suburban King County, Washington, and January 2016 through December 2016 within the city of Seattle. All cases were prospectively collected using a custom quality improvement data form completed by the first responding EMTs. Two physicians completed a structured review of each EMS medical record to determine if the EMTs followed the Check and Inject protocol and determine if epinephrine was clinically-indicated based on physician review. RESULTS: Of the 411 cases eligible for analysis, EMTs followed the protocol appropriately in 367 (89.3%) cases. In the remaining 44 (10.7%) cases, the EMS incident report form failed to document either a clear inciting allergic trigger or an appropriate symptom from the protocol list. Physician review determined that epinephrine was clinically indicated in 36 of the 44 cases. Among the remaining 8 cases (1.9%) that did not meet protocol criteria and were not clinically-indicated based on physician review, none had a documented adverse reaction to the epinephrine. CONCLUSION: We observed that EMTs successfully implemented the manual "Check and Inject" program for severe allergic reactions and anaphylaxis in a manner that typically agreed with physician review and without any overt identified safety issues.

Determining witnessed status for out-of-hospital cardiac arrest.

OBJECTIVE: Witnessed status is considered a core variable in reporting cardiac arrest data and can be ascertained from either the emergency dispatch recording or the pre-hospital record. The purpose of this study is to compare and assess the quality and consistency of these information sources. METHODS: This retrospective analysis included 1896 cases of out-of-hospital cardiac arrest occurring between September 1, 2012 and December 31, 2014. RESULTS: We found that there was minimal (kappa=0.30, 95% CI 0.27-0.33) to moderate (kappa=0.64, 95% CI 0.59-0.69) agreement between the pre-hospital record and the emergency dispatch recording when these sources of information are used to determine witnessed status. Witnessed status could not be determined from the emergency dispatch recording in 36.2% (n=684) of eligible cases. Survival was similar regardless of the method used to determine witnessed status. Using a combination of the pre-hospital record and the emergency dispatch recording yielded the highest number of witnessed cases. CONCLUSION: The determination of witnessed status in out-of-hospital cardiac arrest may be challenging, as evidenced by the discrepancies in witnessed status when comparing different sources of information. The large number of cases where the witnessed status could not be determined from the emergency dispatch recording precludes its use as the sole source of information. It is reasonable to use the patient care record alone, however it should be recognized that there is misclassification of witnessed status regardless of the method used and this may affect the strength of association between witnessed status and survival.

Cardiac arrest at exercise facilities: implications for placement of automated external defibrillators.

OBJECTIVES: This study sought to characterize the relative frequency, care, and survival of sudden cardiac arrest in traditional indoor exercise facilities, alternative indoor exercise sites, and other indoor sites. BACKGROUND: Little is known about the relative frequency of sudden cardiac arrest at traditional indoor exercise facilities versus other indoor locations where people engage in exercise or about the survival at these sites in comparison with other indoor locations. METHODS: We examined every public indoor sudden cardiac arrest in Seattle and King County from 1996 to 2008 and categorized each event as occurring at a traditional exercise center, an alternative exercise site, or a public indoor location not used for exercise. Arrests were further defined by the classification of the site, activity performed, demographics, characteristics of treatment, and survival. For some location types, annualized site incident rates of cardiac arrests were calculated. RESULTS: We analyzed 849 arrests, with 52 at traditional centers, 84 at alternative exercise sites, and 713 at sites not associated with exercise. The site incident rates of arrests at indoor tennis facilities, indoor ice arenas, and bowling alleys were higher than at traditional fitness centers. Survival to hospital discharge was greater at exercise sites (56% at traditional and 45% at alternative) than at other public indoor locations (34%; p = 0.001). CONCLUSIONS: We observed a higher rate of cardiac arrests at some alternative exercise facilities than at traditional exercise sites. Survival was higher at exercise sites than at nonexercise indoor sites. These data have important implications for automated external defibrillator placement.

Dispatcher-assisted cardiopulmonary resuscitation: 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.

Impacting sudden cardiac arrest in the home: a safety and effectiveness study of privately-owned AEDs.

BACKGROUND: Sudden cardiac arrest (SCA) remains a major public health problem. The majority of SCA events occur in the home; however, scant data has been published regarding the effectiveness of privately owned AEDs. METHODS: The study, initiated in 2002 under prescription labeling, continued with over the counter availability in 2004 and was completed in 2009. Surveillance methods included annual surveys, follow-up phone calls, media reports, and use queries upon order of replacement pads. AED owners reporting emergency use of the device were contacted for an in-depth interview, and the ECG and event data in the device's internal memory were evaluated. RESULTS: 25 cases were identified in which an AED was used on a patient in SCA. Two uses were on children. The SCA was witnessed in 76% (19/25) of the cases. In 56% (14/25), the patient presented in VF and at least one shock was delivered. All 14 patients who were shocked had termination of VF; 6 (43%) required more than one shock due to refibrillation. Shock efficacy was 100% (25/25) for termination of VF for all delivered shocks. Of the patients with a witnessed arrest who were shocked, 67% (8/12) survived to hospital discharge. There were no circumstances of unsafe emergency use of the AED or harm to the patient, responder, or bystanders. CONCLUSIONS: People who purchase an AED for their home, even without previous AED experience, are able to use the device successfully in both adults and children. The high survival rate observed in this study demonstrates that lay responders with privately owned AEDs can successfully and safely use the devices.

Chest compression alone cardiopulmonary resuscitation is associated with better long-term survival compared with standard cardiopulmonary resuscitation.

BACKGROUND: Little is known about the long-term survival effects of type-specific bystander cardiopulmonary resuscitation (CPR) in the community. We hypothesized that dispatcher instruction consisting of chest compression alone would be associated with better overall long-term prognosis in comparison with chest compression plus rescue breathing. METHODS AND RESULTS: The investigation was a retrospective cohort study that combined 2 randomized trials comparing the short-term survival effects of dispatcher CPR instruction consisting either of chest compression alone or chest compression plus rescue breathing. Long-term vital status was ascertained by using the respective National and State death records through July 31, 2011. We performed Kaplan-Meier method and Cox regression to evaluate survival according to the type of CPR instruction. Of the 2496 subjects included in the current investigation, 1243 (50%) were randomly assigned to chest compression alone and 1253 (50%) were randomly assigned to chest compression plus rescue breathing. Baseline characteristics were similar between the 2 CPR groups. During the 1153.2 person-years of follow-up, there were 2260 deaths and 236 long-term survivors. Randomization to chest compression alone in comparison with chest compression plus rescue breathing was associated with a lower risk of death after adjustment for potential confounders (adjusted hazard ratio, 0.91; 95% confidence interval, 0.83-0.99; P=0.02). CONCLUSIONS: The findings provide strong support for long-term mortality benefit of dispatcher CPR instruction strategy consisting of chest compression alone rather than chest compression plus rescue breathing among adult patients with cardiac arrest requiring dispatcher assistance.

Impact of changes in resuscitation practice on survival and neurological outcome after out-of-hospital cardiac arrest resulting from nonshockable arrhythmias.

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) claims millions of lives worldwide each year. OHCA survival from shockable arrhythmias (ventricular fibrillation/ tachycardia) improved in several communities after implementation of American Heart Association resuscitation guidelines that eliminated "stacked" shocks and emphasized chest compressions. "Nonshockable" rhythms are now the predominant presentation of OHCA; the benefit of such treatments on nonshockable rhythms is uncertain. METHODS AND RESULTS: We studied 3960 patients with nontraumatic OHCA from nonshockable initial rhythms treated by prehospital providers in King County, Washington, over a 10-year period. Outcomes during a 5-year intervention period after adoption of new resuscitation guidelines were compared with the previous 5-year historical control period. The primary outcome was 1-year survival. Patient demographics and resuscitation characteristics were similar between the control (n=1774) and intervention (n=2186) groups, among whom 471 of 1774 patients (27%) versus 742 of 2186 patients (34%), respectively, achieved return of spontaneous circulation; 82 (4.6%) versus 149 (6.8%) were discharged from hospital, 60 (3.4%) versus 112 (5.1%) with favorable neurological outcome; 73 (4.1%) versus 135 (6.2%) survived 1 month; and 48 (2.7%) versus 106 patients (4.9%) survived 1 year (all P≤0.005). After adjustment for potential confounders, the intervention period was associated with an improved odds of 1.50 (95% confidence interval, 1.29-1.74) for return of spontaneous circulation, 1.53 (95% confidence interval, 1.14-2.05) for hospital survival, 1.56 (95% confidence interval, 1.11-2.18) for favorable neurological status, 1.54 (95% confidence interval, 1.14-2.10) for 1-month survival, and 1.85 (95% confidence interval, 1.29-2.66) for 1-year survival. CONCLUSION: Outcomes from OHCA resulting from nonshockable rhythms, although poor by comparison with shockable rhythm presentations, improved significantly after implementation of resuscitation guideline changes, suggesting their potential to benefit all presentations of OHCA.

CPR with chest compression alone or with rescue breathing.

BACKGROUND: The role of rescue breathing in cardiopulmonary resuscitation (CPR) performed by a layperson is uncertain. We hypothesized that the dispatcher instructions to bystanders to provide chest compression alone would result in improved survival as compared with instructions to provide chest compression plus rescue breathing. METHODS: We conducted a multicenter, randomized trial of dispatcher instructions to bystanders for performing CPR. The patients were persons 18 years of age or older with out-of-hospital cardiac arrest for whom dispatchers initiated CPR instruction to bystanders. Patients were randomly assigned to receive chest compression alone or chest compression plus rescue breathing. The primary outcome was survival to hospital discharge. Secondary outcomes included a favorable neurologic outcome at discharge. RESULTS: Of the 1941 patients who met the inclusion criteria, 981 were randomly assigned to receive chest compression alone and 960 to receive chest compression plus rescue breathing. We observed no significant difference between the two groups in the proportion of patients who survived to hospital discharge (12.5% with chest compression alone and 11.0% with chest compression plus rescue breathing, P=0.31) or in the proportion who survived with a favorable neurologic outcome in the two sites that assessed this secondary outcome (14.4% and 11.5%, respectively; P=0.13). Prespecified subgroup analyses showed a trend toward a higher proportion of patients surviving to hospital discharge with chest compression alone as compared with chest compression plus rescue breathing for patients with a cardiac cause of arrest (15.5% vs. 12.3%, P=0.09) and for those with shockable rhythms (31.9% vs. 25.7%, P=0.09). CONCLUSIONS: Dispatcher instruction consisting of chest compression alone did not increase the survival rate overall, although there was a trend toward better outcomes in key clinical subgroups. The results support a strategy for CPR performed by laypersons that emphasizes chest compression and minimizes the role of rescue breathing. (Funded in part by the Laerdal Foundation for Acute Medicine and the Medic One Foundation; ClinicalTrials.gov number, NCT00219687.)

Procainamide and survival in ventricular fibrillation out-of-hospital cardiac arrest.

OBJECTIVES: Procainamide is an antiarrhythmic drug of unproven efficacy in cardiac arrest. The association between procainamide and survival from out-of-hospital cardiac arrest was investigated to better determine the drug's potential role in resuscitation. METHODS: The authors conducted a 10-year study of all witnessed, out-of-hospital, ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) cardiac arrests treated by emergency medical services (EMS) in King County, Washington. Patients were considered eligible for procainamide if they received more than three defibrillation shocks and intravenous (IV) bolus lidocaine. Four logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CI) describing the relationship between procainamide and survival. RESULTS: Of the 665 eligible patients, 176 received procainamide, and 489 did not. On average, procainamide recipients received more shocks and pharmacologic interventions and had lengthier resuscitations. Adjusted for their clinical and resuscitation characteristics, procainamide recipients had a lower likelihood of survival to hospital discharge (OR = 0.52; 95% CI = 0.36 to 0.75). Further adjustment for receipt of other cardiac medications during resuscitation negated this apparent adverse association (OR = 1.02; 95% CI = 0.66 to 1.57). CONCLUSIONS: In this observational study of out-of-hospital VF and pulseless VT arrest, procainamide as second-line antiarrhythmic treatment was not associated with survival in models attempting to best account for confounding. The results suggest that procainamide, as administered in this investigation, does not have a large impact on outcome, but cannot eliminate the possibility of a smaller, clinically relevant effect on survival.

A comprehensive investigation of cardiac arrest before and after arrival of emergency medical services.

OBJECTIVE: Many of the factors that affect survival from out-of-hospital cardiac arrest are not relevant in patients who arrest after arrival of emergency medical services (EMS). Because all arrests that occur after arrival of EMS are witnessed and care is immediate, one might expect survival to be very high. Several studies have described communities' experiences of arrest after arrival but few have compared survival rates stratified by rhythm and witness status. The purpose of this paper was to describe the characteristics of patients who arrested after arrival of EMS and to compare survival in this population to those who had witnessed and unwitnessed arrests before EMS arrival. METHODS: We conducted a retrospective cohort study in King County, WA, USA. Descriptive statistics were calculated in patients whose arrests were not witnessed, in patients whose arrests were witnessed by citizens, and in those whose arrests were witnessed by EMS personnel. RESULTS: The majority of bystander- and EMS-witnessed arrests were initially in ventricular fibrillation (VF), but EMS-witnessed arrests were more likely to initially have been in pulseless electrical activity (PEA) than bystander-witnessed events. Patients whose arrests were witnessed by EMS had the greatest likelihood of survival compared to patients whose arrests were not witnessed or were witnessed by bystanders. Patients whose arrests were witnessed by EMS and were initially in VF had the highest rates of survival (59%). CONCLUSIONS: Patients whose arrests were witnessed by EMS were more likely to have survived their cardiac arrests than those who arrested before EMS arrived. We suggest that survival rates from VF arrests that occur after EMS arrival should be widely reported in order to measure overall EMS performance since many factors such as response times, bystander actions, and witness status are equalized in this subset of patients.

The relationship between time to arrival of emergency medical services (EMS) and survival from out-of-hospital ventricular fibrillation cardiac arrest.

AIM: We examined the relationship between time from collapse to arrival of emergency medical services (EMS) and survival to hospital discharge for out-of-hospital ventricular fibrillation cardiac arrests in order to determine meaningful interpretations of this association. METHODS: We calculated survival rates in 1-min intervals from collapse to EMS arrival. Additionally, we used logistic regression to determine the absolute probability of survival per minute of delayed EMS arrival. We created a logistic regression model with spline terms for the time variable to examine the decline in survival in intervals that are hypothesized to be physiologically relevant. RESULTS: The observed data showed survival declined, on average, by 3% for each minute that EMS was delayed following collapse. Survival rates did not decline appreciably if the time between collapse and arrival of EMS was 4 min or less but they declined by 5.2% per minute between 5 and 10 min. EMS arrival 11-15 min after collapse showed a less steep decline in survival of 1.9% per minute. The spline model that incorporated changes in slope in the time interval variable modeled this relationship more accurately than a model with a continuous term for time (p=0.01). CONCLUSIONS: The results of our analyses show that survival from out-of-hospital cardiac arrest does not decline at a constant rate following collapse. Models that incorporate changes that reflect the physiological alterations that occur following cardiac arrests are a more accurate way to describe changes in survival rates over time than models that include only a continuous term for time.