Existing peer-reviewed literature describing emergency medical technician (EMT) acquisition and transmission of 12-lead electrocardiograms (12L-ECGs), in the absence of a paramedic, is largely limited to feasibility studies.

The objective of this retrospective observational study was to describe the impact of EMT-acquired 12L-ECGs in Suffolk County, New York (USA), both in terms of the diagnostic quality of the transmitted 12L-ECGs and the number of prehospital percutaneous coronary intervention (PCI)-center notifications made as a result of transmitted 12L-ECGs demonstrating a ST-elevation myocardial infarction (STEMI).

A pre-existing database was queried for Emergency Medical Services (EMS) calls on which an EMT acquired a 12L-ECG from program initiation (January 2017) through December 31, 2019. Scanned copies of the 12L-ECGs were requested in order to be reviewed by a blinded emergency physician.

Of the 665 calls, 99 had no 12L-ECG available within the database. For 543 (96%) of the available 12L-ECGs, the quality was sufficient to diagnose the presence or absence of a STEMI. Eighteen notifications were made to PCI-centers about a concern for STEMI. The median time spent on scene and transporting to the hospital were 18 and 11 minutes, respectively. The median time from PCI-center notification to EMS arrival at the emergency department (ED) was seven minutes (IQR 5-14).

In the event a cardiac monitor is available, after a limited educational intervention, EMTs are capable of acquiring a diagnostically useful 12L-ECG and transmitting it to a remote medical control physician for interpretation. This allows for prehospital PCI-center activation for a concern of a 12L-ECG with a STEMI, in the event that a paramedic is not available to care for the patient.

The History, Electrocardiogram (ECG), Age, Risk Factors, and Troponin (HEART) score is a decision aid designed to risk stratify emergency department (ED) patients with acute chest pain. It has been validated for ED use, but it has yet to be evaluated in a prehospital setting.

A prehospital modified HEART score can predict major adverse cardiac events (MACE) among undifferentiated chest pain patients transported to the ED.

A retrospective cohort study of patients with chest pain transported by two county-based Emergency Medical Service (EMS) agencies to a tertiary care center was conducted. Adults without ST-elevation myocardial infarction (STEMI) were included. Inter-facility transfers and those without a prehospital 12-lead ECG or an ED troponin measurement were excluded. Modified HEART scores were calculated by study investigators using a standardized data collection tool for each patient. All MACE (death, myocardial infarction [MI], or coronary revascularization) were determined by record review at 30 days. The sensitivity and negative predictive values (NPVs) for MACE at 30 days were calculated.

Over the study period, 794 patients met inclusion criteria. A MACE at 30 days was present in 10.7% (85/794) of patients with 12 deaths (1.5%), 66 MIs (8.3%), and 12 coronary revascularizations without MI (1.5%). The modified HEART score identified 33.2% (264/794) of patients as low risk. Among low-risk patients, 1.9% (5/264) had MACE (two MIs and three revascularizations without MI). The sensitivity and NPV for 30-day MACE was 94.1% (95% CI, 86.8-98.1) and 98.1% (95% CI, 95.6-99.4), respectively.

Prehospital modified HEART scores have a high NPV for MACE at 30 days. A study in which prehospital providers prospectively apply this decision aid is warranted.

StopyraJP, HarperWS, HigginsTJ, ProkesovaJV, WinslowJE, NelsonRD, AlsonRL, DavisCA, RussellGB, MillerCD, MahlerSA. Prehospital Modified HEART Score Predictive of 30-Day Adverse Cardiac Events. Prehosp Disaster Med. 2018;33(1):58–62.

On 18 July 2001, a train hauling hazardous materials, including hydrochloric acid, hydrofluoric acid, and acetic acid, derailed in the city of Baltimore, Maryland, resulting in a fire that burned under a downtown street for five days. Firefighters were stymied in their efforts to extinguish the fire, and the city was subjected to thick smoke for several days.

To determine whether an urban chemical fire with a hazardous materials spill resulted in a detectable public health impact, and to demo-graphically describe the at-risk population for potential smoke and chemical exposure.

The United States Centers for Disease Control and Prevention (CDC) was consulted about possible side effects from chemical exposure. Total numbers of emergency department (ED) patients and admissions from 15:00 hours (h), 15 July 2001 to 15:00 h, 21 July 2001 were collected from five local hospitals. Patient encounters citing specified chief complaints from 15:00 h, 15 July to 15:00 h, 18 July (pre-accident) were compared with the period from 15:00 h, July 18 to 15:00 h, 21 July (post-accident). Data were analyzed using Fisher's exact test. The United States Census Bureau's Topologically Integrated Geographic Encoding and Referencing (TIGER) digital database of geographic features and ArcView Geographic Information Systems (GIS) were used to create maps of Baltimore and to identify populations at-risk using attribute census data. Results: There were 62,808 people residing in the immediate, affected area. The mean of the values for age was 33.7 ±3.2 years (standard deviation; range = 16 yrs) with 49% (30,927) males and 51% (31,881) females. A total of 2,922 ED patient encounters were screened. Chief complaints included shortness of breath, pre-event = 109 vs. post-event = 148; chest complaints = 90 vs. 113; burns and/or skin irritation = 45 vs. 42; eye irritation 26 vs. 34; throat irritation = 33 vs. 27; and smoke exposure = 0 vs. 15. There was a statistically significant increase (p <0.05) for shortness of breath and smoke exposure-related complaints. No statistically significant increase in numbers of admitted patients with these complaints was found.

In the setting of a large-scale urban chemical fire, local EDs can expect a significant increase in the number of patients presenting to EDs with shortness of breath and/or smoke inhalation. Most do not require inpatient hospitalization. Careful assessment of impact on local EDs should be considered in future city-accident planning. Some official warnings were widely misinterpreted or ignored. Public education on potential hazards and disaster preparedness targeted to populations at-risk should receive a high priority. Geographic information systems (GIS) may serve as useful tools for identifying demographics of populations at-risk for disaster planning and responses.