John Freese

Association of Ambient Fine Particles With Out-of-Hospital Cardiac Arrests in New York City

Cardiovascular morbidity has been associated with particulate matter (PM) air pollution, although the relation between pollutants and sudden death from cardiac arrest has not been established. This study examined associations between out-of-hospital cardiac arrests and fine PM (of aerodynamic diameter ≤2.5 μm, or PM(2.5)), ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide in New York City. The authors analyzed 8,216 out-of-hospital cardiac arrests of primary cardiac etiology during the years 2002-2006. Time-series and case-crossover analyses were conducted, controlling for season, day-of-week, same-day, and delayed/apparent temperature. An increased risk of cardiac arrest in time-series (relative risk (RR) = 1.06, 95% confidence interval (CI): 1.02, 1.10) and case-crossover (RR = 1.04, 95% CI: 0.99, 1.08) analysis for a PM(2.5) increase of 10 μg/m³ in the average of 0- and 1-day lags was found. The association was significant in the warm season (RR = 1.09, 95% CI: 1.03, 1.15) but not the cold season (RR = 1.01, 95% CI: 0.95, 1.07). Associations of cardiac arrest with other pollutants were weaker. These findings, consistent with studies implicating acute cardiovascular effects of PM, support a link between PM(2.5) and out-of-hospital cardiac arrests. Since few individuals survive an arrest, air pollution control may help prevent future cardiovascular mortality.

Waveform Analysis–Guided Treatment Versus a Standard Shock-First Protocol for the Treatment of Out-of-Hospital Cardiac Arrest Presenting in Ventricular Fibrillation Results of an International Randomized, Controlled Trial

Background— Ventricular fibrillation (VF) waveform properties have been shown to predict defibrillation success and outcomes among patients treated with immediate defibrillation. We postulated that a waveform analysis algorithm could be used to identify VF unlikely to respond to immediate defibrillation, allowing selective initial treatment with cardiopulmonary resuscitation in an effort to improve overall survival. Methods and Results— In a multicenter, double-blind, randomized study, out-of-hospital cardiac arrest patients in 2 urban emergency medical services systems were treated with automated external defibrillators using either a VF waveform analysis algorithm or the standard shock-first protocol. The VF waveform analysis used a predefined threshold value below which return of spontaneous circulation (ROSC) was unlikely with immediate defibrillation, allowing selective treatment with a 2-minute interval of cardiopulmonary resuscitation before initial defibrillation. The primary end point was survival to hospital discharge. Secondary end points included ROSC, sustained ROSC, and survival to hospital admission. Of 6738 patients enrolled, 987 patients with VF of primary cardiac origin were included in the primary analysis. No immediate or long-term survival benefit was noted for either treatment algorithm (ROSC, 42.5% versus 41.2%, P=0.70; sustained ROSC, 32.4% versus 33.4%, P=0.79; survival to admission, 34.1% versus 36.4%, P=0.46; survival to hospital discharge, 15.6% versus 17.2%, P=0.55, respectively). Conclusions— Use of a waveform analysis algorithm to guide the initial treatment of out-of-hospital cardiac arrest patients presenting in VF did not improve overall survival compared with a standard shock-first protocol. Further study is recommended to examine the role of waveform analysis for the guided management of VF. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00535106.

Utilization of Emergency Medical Services in a Large Urban Area: Description of Call Types and Temporal Trends

ABSTRACT Background. Emergency medical services (EMS) systems are used by the public for a range of medically related problems. Objective. To understand and analyze the patterns of EMS utilization and trends over time in a large urban EMS system so that we may better direct efforts toward improving those services. Methods. The 63 call type designations from all New York City (NYC) 9-1-1 EMS calls between 1999 and 2007 were obtained and grouped into 10 broad and 30 specific medical categories. Aggregated numbers of total EMS calls and individual categories were divided by NYC resident population estimates to determine utilization rates. Temporal trends were evaluated for statistical significance with Spearmans rho (ρ). Results. There were 9,916,904 EMS calls between 1999 and 2007, with an average of 1,101,878 calls/year. Utilization rates increased from 129.5 to 141.9 calls/1,000 residents/year over the study period (average annual rise of 1.16%). Among all medical/surgical call types (excluding trauma), there was an average annual increase of 1.8%/year. The most substantial increases were among “psychiatric/drug related” (+5.6%/year), “generalized illness” (+3.2%/year), and “environmental related” calls (+2.9%/year). The largest decrease was among “respiratory” calls (–1.2%/year), specifically for “asthma” (–5.0%/year). For trauma call types, there was an annual average decrease of 0.4%/year, with the category of “violence related” calls having the greatest decline (–3.3%/year). Conclusion. There was an increase in overall EMS utilization rates, though not all call types rose uniformly. Rather, a number of significant trends were identified reflecting either changing medical needs or changing patterns of EMS utilization in NYCs population.

Impact of a citywide blackout on an urban emergency medical services system.

INTRODUCTION On 14 August 2003, New York City and a large portion of the northeastern United States experienced the largest blackout in the history of the country. An analysis of such a widespread disaster on emergency medical service (EMS) operations may assist in planning for and managing such disasters in the future. METHODS A retrospective review of all EMS activity within New York Citys 9-1-1 emergency telephone system during the 29 hours during which all or parts of the city were without power (16:11 hours (h) on 14 August 2003 until 21:03 h on 15 August 2003) was performed. Control periods were established utilizing identical time periods during the five weeks preceding the blackout. RESULTS Significant increases were identified in the overall EMS demand (7,844 incidents vs. 3,860 incidents; p < 0.001) as well as in 20 of the 62 call-types of the system, including cardiac arrests (119 vs. 76, p = 0.043). Significant decreases were found only among calls related to psychological emergencies (114 vs. 221; p = 0.006) and drug- or alcohol-related emergencies (78 vs. 146; p = 0.009). Though median response times increased by only 60 seconds, median call-processing times within the 9-1-1 emergency telephone system EMS dispatch center of the city increased from 1.1 to 5.5 minutes. CONCLUSIONS The citywide blackout resulted in dramatic changes in the demands upon the EMS system of New York City, the types of patients for whom EMS providers were assigned to provide care, and the dispositions for those assignments. During this time of increased, system-wide demand, the use of cross-trained firefighter and first-responder engine companies resulted in improved response times to cardiac arrest patients. Finally, the ability of the EMS dispatch center to process the increased requests for EMS assistance proved to be the rate-limiting step in responding to these emergencies. These findings will prove useful in planning for future blackouts or any disaster that may broadly impact the infrastructure of a city.

From door-to-balloon time to contact-to-device time: predictors of achieving target times in patients with ST-elevation myocardial infarction.

The 2013 American College of Cardiology Foundation/American Heart Association ST‐segment elevation myocardial infarction (STEMI) guidelines have shifted focus from door‐to‐balloon (D2B) time to the time from first medical contact to device activation (contact‐to‐device time [C2D] ).

A modified simple triage and rapid treatment algorithm from the New York City (USA) Fire Department

INTRODUCTION The objective of this study was to determine if modification of the Simple Triage and Rapid Treatment (START) system by the addition of an Orange category, intermediate between the most critically injured (Red) and the non-critical, non-ambulatory injured (Yellow), would reduce over- and under-triage rates in a simulated mass-casualty incident (MCI) exercise. METHODS A computer-simulation exercise of identical presentations of an MCI scenario involving a 2-train collision, with 28 case scenarios, was provided for triaging to two groups: the Fire Department of the City of New York (FDNY; n=1,347) using modified START, and the Emergency Medical Services (EMS) providers from the Eagles 2012 EMS conference (Lafayette, Louisiana USA; n=110) using unmodified START. Percent correct by triage category was calculated for each group. Performance was then compared between the two EMS groups on the five cases where Orange was the correct answer under the modified START system. RESULTS Overall, FDNY-EMS providers correctly triaged 91.2% of cases using FDNY-START whereas non-FDNY-Eagles providers correctly triaged 87.1% of cases using unmodified START. In analysis of the five Orange cases (chest pain or dyspnea without obvious trauma), FDNY-EMS performed significantly better using FDNY-START, correctly triaging 86.3% of cases (over-triage 1.5%; under-triage 12.2%), whereas the non-FDNY-Eagles group using unmodified START correctly triaged 81.5% of cases (over-triage 17.3%; under-triage 1.3%), a difference of 4.9% (95% CI, 1.5-8.2). CONCLUSIONS The FDNY-START system may allow providers to prioritize casualties using an intermediate category (Orange) more properly aligned to meet patient needs, and as such, may reduce the rates of over-triage compared with START. The FDNY-START system decreases the variability in patient sorting while maintaining high field utility without needing computer assistance or extensive retraining. Comparison of triage algorithms at actual MCIs is needed; however, initial feedback is promising, suggesting that FDNY-START can improve triage with minimal additional training and cost.

Response to Letter Regarding Article, “Waveform Analysis–Guided Treatment Versus a Standard Shock-First Protocol for the Treatment of Out-of-Hospital Cardiac Arrest Presenting in Ventricular Fibrillation: Results of an International Randomized, Controlled Trial”

We appreciate the correspondence from Drs Ristagno and Li. We also thank them and their colleagues for their many contributions to the resuscitation literature and for the most recent in their series of work on the use of amplitude spectrum area both for the prediction of defibrillation success and as a surrogate marker for cardiopulmonary resuscitation (CPR) quality. Ventricular fibrillation (VF) has long been viewed as a ubiquitous condition best treated with immediate defibrillation, yet the evolution of our understanding of this lethal arrhythmia, the optimal timing for defibrillatory shocks, and the interaction between CPR quality and changes in the VF waveform has only recently begun to flourish. The threshold value chosen for our study1 did, as the authors of the letter suggest, have …