Abstracts for the 2008 NAEMSP Scientific Assembly

Abstract

Objectives. To date, most patient safety studies have been conducted in relation to the hospital rather than the prehospital setting and data regarding emergency medical services (EMS)-related errors are limited. To address this gap, a study was conducted to gain an in-depth understanding of the views of highly experienced EMS practitioners, educators, administrators, and physicians on major issues pertaining to EMS patient safety. The intent of the study was to identify key issues to give direction to the development of best practices in education, policy, and fieldwork. Methods. A qualitative study was conducted using processes described by Lincoln and Guba (1985) to enhance the quality and credibility of data and analysis. Purposive sampling was used to identify informants with knowledge and expertise regarding policy, practice, and research who could speak to the issue of patient safety. Sixteen participants, the majority of whom were Canadian, participated in in-depth interviews. Results. Two major themes were identified under the category of key issues: clinical decision making and EMS's focus and relationship with health care. An education gap has developed in EMS, and there is tension between the traditional stabilize-and-transport role and the increasingly complex role that has come about through “scope creep.” If, as expected, EMS aligns increasingly with the health sector, then change is needed in the EMS educational structure and process to develop stronger clinical decision-making skills. Conclusion. The results of this study indicate that many individual organizations and health regions are addressing issues related to patient safety in EMS, and there are important lessons to be learned from these groups. The broader issues identified, however, are system-wide and best addressed through policy change from health regions and government.     

U TILIZATION AND I MPACT OF A MBULANCE D IVERSION AT THE C OMMUNITY L EVEL

Objective. To evaluate the utilization and impact of ambulance diversion in the metropolitan area of Syracuse, New York. Methods. This was a retrospective review of the ambulance diversion system operated by the hospitals of Syracuse, New York. This system allows each emergency department to divert incoming ambulances during periods of extreme overcrowding. Data collected included numbers of hours on ambulance diversion by hospital, numbers of hours when all four hospitals were on diversion simultaneously, and numbers of ambulances received while the hospitals were on and off diversion. Results. For three of the five years evaluated, ambulance diversion hours were most numerous during the period between January and March. For the most recent year studied (2000), ambulance diversion hours did not decline after the first quarter. During periods of diversion, hospital emergency departments received 30%–50% fewer ambulances than they did while open. Conclusion. This study demonstrated that, in Syracuse, New York, ambulance diversion was once a seasonal phenomenon, but is increasingly occurring throughout the year because of staff and resource limitations. It also demonstrated that ambulance diversion can be employed to reduce numbers of incoming transports.     

T EMPORAL T RENDS IN A MBULANCE D IVERSION IN A M ID-SIZED M ETROPOLITAN A REA

Objectives. To evaluate the amount of ambulance diversion in an emergency medical services (EMS) system and to investigate potential predictive factors. Methods. Ambulance diversion status of hospitals in the four-county metropolitan Portland, Oregon, area has been recorded for approximately 15 years. These data are used by EMS transporting agencies to determine appropriate hospital destination for their patients. The authors calculated the total yearly hospital ambulance diversion time for “Total Ambulance Divert (TAD)” and “Critical Care Divert (CCD)” for the time period between January 1, 1996, and December 31, 1999. Yearly EMS 9-1-1-generated patient transport volume, hospital emergency department (ED) census volume, total population, amount of health maintenance organization (HMO) penetration, and number of licensed and available hospital beds were calculated for each yearly interval. Kendall's tau-b correlation was used to determine significant secular trends. Potential predictive factors for the amount of ambulance diversion were tested using Pearson's correlation. Results. Total TAD increased 122.5% (p = 0.04), total CCD increased 64.4% (p = 0.50), total EMS transport volume increased 16.1% (p = 0.04), total ED census increased 9.4% (p = 0.04), total licensed beds decreased 5.7% (p = 0.17), total available beds decreased 15.8% (p = 0.17), HMO penetration increased 4.7% (p = 0.04), and total population increased 9.7% (p = 0.04) over the four-year study period. CCD and TAD were not significantly related to each other (p = 0.50). The only significant factor associated with the increase in TAD was number of available beds (p = 0.03). There were no significant factors associated with CCD. Conclusion. TAD increased significantly over time and was associated only with the decrease in available hospital beds.     

The "Vertical Response Time": Barriers to Ambulance Response in an Urban Area

Background: Ambulance response time is typically reported as the time interval from call dispatch to arrival on-scene. However, the often unmeasured "vertical response time" from arrival on-scene to arrival at the patient's side may be substantial, particularly in urban areas with high-rise buildings or other barriers to access.
Objectives: To measure the time interval from arrival on-scene to the patient in a large metropolitan area and to identify barriers to emergency medical services arrival.
Methods: This was a prospective observational study of response times for high-priority call types in the New York City 9-1-1 emergency medical services system. Research assistants riding with paramedics enrolled a convenience sample of calls between 2001 and 2003.
Results: A total of 449 paramedic calls were included, with a median time from call dispatch to arrival on-scene of 5.2 minutes. The median on-scene to patient arrival interval was 2.1 minutes, leading to an actual response interval (dispatch to patient) of 7.6 minutes. The median on-scene to patient interval was 2.8 minutes for residential buildings, 2.7 minutes for office complexes, 1.3 minutes for private homes (less than four stories), and 0.5 minutes for outdoor calls. Overall, for all calls, the on-scene to patient interval accounted for 28% of the actual response interval. When an on-scene escort provided assistance in locating and reaching the patient, the on-scene to patient interval decreased from 2.3 to 1.9 minutes. The total dispatch to patient arrival interval was less than 4 minutes in 8.7%, less than 6 minutes in 28.5%, and less than 8 minutes in 55.7% of calls.
Conclusions: The time from arrival on-scene to the patient's side is an important component of overall response time in large urban areas, particularly in multistory buildings.     

An Evidence-based Guideline for the Air Medical Transportation of Prehospital Trauma Patients

Abstract

Background. Decisions about the transportation of trauma patients by helicopter are often not well informed by research assessing the risks, benefits, and costs of such transport. Objective. The objective of this evidence-based guideline (EBG) is to recommend a strategy for the selection of prehospital trauma patients who would benefit most from aeromedical transportation. Methods. A multidisciplinary panel was recruited consisting of experts in trauma, EBG development, and emergency medical services (EMS) outcomes research. Representatives of the Federal Interagency Committee on Emergency Medical Services (FICEMS), the National Highway Traffic Safety Administration (NHTSA) (funding agency), and the Children's National Medical Center (investigative team) also contributed to the process. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology to guide question formulation, evidence retrieval, appraisal/synthesis, and formulate recommendations. The process followed the National Evidence-Based Guideline Model Process, which has been approved by the Federal Interagency Committee on EMS and the National EMS Advisory Council. Results. Two strong and three weak recommendations emerged from the process, all supported only by low or very low quality evidence. The panel strongly recommended that the 2011 CDC Guideline for the Field Triage of Injured Patients be used as the initial step in the triage process, and that ground emergency medical services (GEMS) be used for patients not meeting CDC anatomic, physiologic, and situational high-acuity criteria. The panel issued a weak recommendation to use helicopter emergency medical services (HEMS) for higher-acuity patients if there is a time-savings versus GEMS, or if an appropriate hospital is not accessible by GEMS due to systemic/logistical factors. The panel strongly recommended that online medical direction should not be required for activating HEMS. Special consideration was given to the potential need for local adaptation. Conclusions. Systematic and transparent methodology was used to develop an evidence-based guideline for the transportation of prehospital trauma patients. The recommendations provide specific guidance regarding the activation of GEMS and HEMS for patients of varying acuity. Future research is required to strengthen the data and recommendations, define optimal approaches for guideline implementation, and determine the impact of implementation on safety and outcomes including cost.     

P REHOSPITAL C ARE R ESEARCH F ORUM /NAEMSE 2002

Objectives. Emergency medical dispatch (EMD) protocols are intended to match response resources with patient needs. In a small city that previously sent a first-responder basic life support (BLS) engine company lights-and-siren response to every emergency medical services (EMS) call, regardless of nature or severity, an EMD system was implemented in order to reduce the number of such responses. The study objectives were to determine the effects of the EMD system on first-responder call volume andto assess the safety of the system. Methods. This was a prospective, before–after trial. Using computer-assisted dispatch (CAD) records, all EMS calls in the 120 days before implementation of the EMD protocol andthe 120 days after implementation were identified (excluding a one-month wash-in period). In the “after” phase, patient care reports of a random sample of cases in which an ambulance was dispatched with no first responders was manually reviewed to assess whether there might have been any benefit to first-responder dispatch. Given the lack of accepted clinical criteria for need for first responders, the investigators' clinical judgment was used. Paired t-tests were used to compare groups. Results. There were 9,820 EMS calls in the “before” phase, with 8,278 first-responder engine runs (84.3%), and9,943 EMS calls in the “after” phase, with 3,804 first-responder engine runs (39.1%). The first-responder companies were dispatched to a median of 5.65 runs/day (range 1.1–12.7) in the “before” phase, and3.17 runs/day (range 0.6–5.0) in the “after” phase (p = 0.0008 by paired t-test). Review of 1,816 “after” phase ambulance-only patient care reports (PCRs) found ten (0.55%) in which first-responder dispatch might have been beneficial, but review of EMS andemergency department (ED) records found no adverse outcomes in these ten patients. Conclusions. This study suggests that a formal EMD system can reduce first-responder call volume by roughly one-half. The system appears to be safe for patients, with an undertriage rate of about one-half of one percent.     

A review of infection control practices,risk reduction,and legislative regulations for blood-borne disease: Applications for emergency medical services

Objective. To determine the time saving associated with lights and siren (L&S) use during emergency response in an urban EMS system. Methods. This prospective study evaluated ambulance response times from the location at time of dispatch to the scene of an emergency in an urban area. A control group of responses using L&S was compared with an experimental group that did not use L&S. An observer was assigned to ride along with ambulance crews and record actual times for all L&S responses. At a later date, an observer and an off-duty paramedic in an identical ambulance retraced the route—at the same time of day on the same day of the week—without using L&S and recorded the travel time. Response times for the two groups were compared using paired t-test. Results. The 32 responses with L&S averaged 105.8 seconds (1 minute, 46 seconds) faster than those without (95% confidence interval: 60.2 to 151.5 seconds, p = 0.0001). The time difference ranged from 425 seconds (7 minutes, 5 seconds) faster with L&S to 210 seconds (3 minutes, 30 seconds) slower with L&S. Conclusion. In this urban EMS system, L&S reduce ambulance response times by an average of 1 minute, 46 seconds. Although statistically significant, this time saving is likely to be clinically relevant in only a very few cases. A large-scale multicenter L&S trial may help address this issue on a national level.     

A Meta-Analysis of Prehospital Care Times for Trauma

Background. Time to definitive care is a major determinant of trauma patient outcomes yet little is empirically known about prehospital times at the national level. We sought to determine national averages for prehospital times based on a systematic review of published literature. Methods. We performed a systematic literature search for all articles reporting prehospital times for trauma patients transported by helicopter andground ambulance over a 30-year period. Forty-nine articles were included in a final meta-analysis. Activation time, response time, on-scene time, andtransport time were abstracted from these articles. Prehospital times were also divided into urban, suburban, rural, andair transports. Statistical tests were computed using weighted arithmetic means andstandard deviations. Results. The data were drawn from 20 states in all four U.S. Census Regions andrepresent the prehospital experience of 155,179 patients. Average duration in minutes for urban, suburban, andrural ground ambulances for the total prehospital interval were 30.96, 30.97, and43.17; for the response interval were 5.25, 5.21, and7.72; for the on-scene interval were 13.40, 13.39, and14.59; andfor the transport interval were 10.77, 10.86, and17.28. Average helicopter ambulance times were response 23.25, on-scene 20.43, andtransport 29.80 minutes. Conclusions. Despite the emphasis on time in the prehospital andtrauma literature there has been no national effort to empirically define average prehospital time intervals for trauma patients. We provide points of reference for prehospital intervals so that policymakers can compare individual emergency medical systems to national norms.     

Comparison of Crashes Involving Ambulances with Those of Similar-Sized Vehicles

Objective. To describe the characteristics andassociated occupant injuries of motor vehicle collisions (MVCs) involving ambulances as compared with MVCs involving similar-sized vehicles. Methods. Motor vehicle crash data in Pennsylvania from 1997–2001 were analyzed to compare the characteristics of crashes involving ambulances with those involving vehicles of a similar size. Crash demographics (e.g., location of crash, roadway conditions, intersection type) andassociated injuries were examined andcompared using chi-square tests andFisher's exact test. Results. 2,038 ambulance MVCs and23,155 crashes involving similar-sized vehicles were identified. Weather androad surface conditions were similar, but ambulance MVCs occurred with increased frequency on evenings andweekends. Ambulances were more likely to be involved in four-way intersection crashes (43% vs. 23%, p = 0.001), angled collisions (45% vs. 29%, p = 0.001), andcollisions at traffic signals (37% vs. 18%, p = 0.001). More people were involved in ambulance MVCs (p = 0.001), with 84% of ambulance MVCs involving three or more people and33% involving five or more people. Injuries were reported in more ambulance MVCs (76% vs. 61%, p = 0.001). Pedestrian involvement was rare (< 5% in both groups). Conclusion. Ambulance crashes occur more frequently at intersections andtraffic signals andinvolve more people andmore injuries than those of similar-sized vehicles.     

NAEMSP 2002 A NNUAL M EETING

Abstract

Background. A common tenet in emergency medical services (EMS) is that faster response equates to better patient outcome, translated by some EMS operations into a goal of a response time of 8 minutes or less for advanced life support (ALS) units responding to life-threatening events. Objective. To explore whether an 8-minute EMS response time was associated with mortality. Methods. This was a one-year retrospective cohort study of adults with a life-threatening event as assessed at the time of the 9-1-1 call (Medical Priority Dispatch System Echo- or Delta-level event). The study setting was an urban all-ALS EMS system serving a population of approximately 1 million. Response time was defined as 9-1-1 call receipt to ALS unit arrival on scene, and outcome was defined as all-cause mortality at hospital discharge. Potential covariates included patient acuity, age, gender, and combined scene and transport interval time. Stratified analysis and logistic regression were used to assess the response time–mortality association. Results. There were 7,760 unit responses that met the inclusion criteria; 1,865 (24%) were ≥8 minutes. The average patient age was 56.7 years (standard deviation = 21.5). For patients with a response time ≥8 minutes, 7.1% died, compared with 6.4% for patients with a response time ≤7 minutes 59 seconds (risk difference 0.7%; 95% confidence interval [CI]: –0.5%, 2.0%). The adjusted odds ratio of mortality for ≥8 minutes was 1.19 (95% CI: 0.97, 1.47). An exploratory analysis suggested there may be a small beneficial effect of response ≤7 minutes 59 seconds for those who survived to become an inpatient (adjusted odds ratio = 1.30; 95% CI: 1.00, 1.69). Conclusions. These results call into question the clinical effectiveness of a dichotomous 8-minute ALS response time on decreasing mortality for the majority of adult patients identified as having a life-threatening event at the time of the 9-1-1 call. However, this study does not suggest that rapid EMS response is undesirable or unimportant for certain patients. This analysis highlights the need for further research on who may benefit from rapid EMS response, whether these individuals can be identified at the time of the 9-1-1 call, and what the optimum response time is.     

E MERGENCY M EDICAL S ERVICES AND C ULTURAL D ETERMINANTS OF AN E MERGENCY IN K ARACHI,P AKISTAN

Objectives. The study was conducted to understand the prehospital system in Karachi, the mode of transport that adult inpatients use to reach the emergency departments (EDs), and the barriers to the use of ambulances. Methods. The study consisted of two parts. The first part involved interviewing the administrators of major ambulance services in Karachi. The second part consisted of a structured interview of randomly selected adult inpatients admitted to one government and one private hospital. Results. Seven ambulance service administrators were interviewed. The interviews revealed that ambulances in Karachi are mainly involved in transporting patients from hospital to hospital or to home. A large number of calls are for transporting dead bodies. A total of 92 patients were interviewed (58 male, 34 female). Admission complaints included abdominal pain (22), blunt trauma (11), penetrating trauma (3), chest pain (6), shortness of breath (4), hematemesis (3), acute focal weakness (4), high fever (4), and other (32). The most common mode of transport to the ED was taxi (53, 58%), followed by private car (21, 23%). Specific reasons for not using ambulances included a perception that the patient was not sick enough (34, 45%), slow response of the ambulance services (17, 23%), not knowing how to find one (8, 11%), and the high cost (6, 8%). Conclusion. In case of a medical emergency, most people in Karachi do not use ambulances. The reasons for this low usage include not only poor accessibility, but also cultural barriers and lack of education in recognition of danger signs.     

NAEMSP 2006 Annual Meeting

The following abstracts are the oral andposter presentations at the National Association of EMS Physicians 2006 Annual Meeting, January 19–21, Tucson, Arizona.