Determinants of Persistent, Multi-Year, Frequent Emergency Department Use Among Children and Young Adults in Three US States

OBJECTIVE

This study examines the factors associated with persistent, multi-year, and frequent emergency department (ED) use among children and young adults.

METHODS

We conducted a retrospective secondary analysis using the 2012-2017 Healthcare Cost and Utilization Project State Emergency Department Databases for children and young adults aged 0-19 who visited any ED in Florida, Massachusetts, and New York. We estimated the association between persistent frequent ED use and individuals' characteristics using multivariable logistic regression models.

RESULTS

Among 1.3 million patients with 1.8 million ED visits in 2012, 2.9% (37,558) exhibited frequent ED use (≥4 visits in 2012) and accounted for 10.2% (181,138) of all ED visits. Longitudinal follow-up of frequent ED users indicated that 15.4% (5770) remained frequent users periodically over the next 1 or 2 years, while 2.2% (831) exhibited persistent frequent use over the next 3-5 years. Over the 6-year study period, persistent frequent users had 31,551 ED visits at an average of 38.0 (standard deviation = 16.2) visits. Persistent frequent ED use was associated with higher intensity of ED use in 2012, public health insurance coverage, inconsistent health insurance coverage over time, residence in non-metropolitan and lower-income areas, multimorbidity, and more ED visits for less medically urgent conditions.

CONCLUSIONS

Clinicians and policymakers should consider the diverse characteristics and needs of pediatric persistent frequent ED users compared to broader definitions of frequent users when designing and implementing interventions to improve health outcomes and contain ED visit costs.

The Effect of Prehospital Blood Transfusion on Patient Body Temperature from the Time of Emergency Medical Services Transfusion to Arrival at the Emergency Department

BACKGROUND

Transfusion of blood products is life-saving and time-sensitive in the setting of acute blood-loss anemia, and is increasingly common in the emergency medical services (EMS) setting. Prehospital blood products are generally "cold-stored" at 4°C, then warmed with a portable fluid-warming system for the purpose of preventing the "lethal triad" of hypothermia, acidosis, and coagulopathy. This study aims to evaluate body temperature changes of EMS patients receiving packed red blood cells (PRBC) and/or fresh frozen plasma (FFP) when using the LifeWarmer Quantum Blood & Fluid Warming System (LifeWarmer, https://www.lifewarmer.com/).

METHODS

From 1 January 2020 to 31 August 2021, patients who qualified for and received PRBC and/or FFP were retrospectively reviewed. Body-temperature homeostasis pre- and post-transfusion were evaluated with attention given to those who arrived to the emergency department (ED) hypothermic (<36°C).

RESULTS

For all 69 patients analyzed, the mean initial prehospital temperature (°C) was 36.5 ± 1.0, and the mean initial ED temperature was 36.7 ± 0.6, demonstrating no statically significant change in value pre- or post-transfusion (0.2 ± 0.8, p = .09). Shock index showed a statistically significant decrease following transfusion: 1.5 ± 0.5 to 0.9 ± 0.4 (p < .001).

CONCLUSION

Use of the Quantum prevents the previously identified risk of hypothermia with respect to unwarmed prehospital transfusions. The data is favorable in that body temperature did not decrease in critically ill patients receiving cold-stored blood warmed during administration with the Quantum.

A data driven policy to minimise the tuberculosis testing cost among healthcare workers

Introduction

The Centres for Disease Control and Prevention (CDC) mandates that healthcare employees at high‐risk exposure to Tuberculosis (TB) undergo annual testing. Currently, two methods of TB testing are used: a two‐step skin test (TST) or a whole‐blood test (IGRA). Healthcare leadership's test selection must account for not only direct costs such as procedure and resources but also indirect costs, including employee workplace absence.

Methods

A mathematical model based on Upstate South Carolina's largest health system affecting over 18,000 employees on six campuses was developed to investigate the value loss perspective of these testing methods and assist in decision‐making. A process flow map identified the varied direct and indirect costs for each test for four employee types, and 6 travel‐to‐testing‐site times were calculated.

Results

The switching point between testing procedures that minimised total system costs was most influenced by employee salary compared to travel distance. Switching from the current hospital policy to an integrated TST/IGRA testing could reduce TB compliance costs by 28%.

Conclusions

This study recommends an integrated approach as cost‐effective for large health systems with multiple campuses while considering the direct and indirect costs. When accounting for ‘inconvenience costs’ (stress, etc.) associated with visits, IGRAs are recommended irrespective of employee salary.

High‐risk healthcare workers are required to undergo annual TB testing by CDC

Two methods of TB testing are used: a two‐step skin test (TST) or a whole‐blood test (IGRA)

While considering the testing and other travel costs, an integrated testing approach is cost‐effective for large health systems with multiple employee types and campuses.

However, an IGRA test is recommended for all employees when considering additional inconvenience costs.

Diabetes Patient Surveillance in the Emergency Department: Proof of Concept and Opportunities

Introduction

The purpose of this study was to characterize the at-risk diabetes and prediabetes patient population visiting emergency department (ED) and urgent care (UC) centers in upstate South Carolina.

Methods

We conducted this retrospective study at the largest non-profit healthcare system in South Carolina, using electronic health record (EHR) data of patients who had an ED or UC visit between February 2, 2016–July 31, 2018. Key variables including International Classification of Diseases, 10th Revision codes, laboratory test results, family history, medication, and demographic characteristics were used to classify the patients as healthy, having prediabetes, having diabetes, being at-risk for prediabetes, or being at-risk for diabetes. Patients who were known to have diabetes were classified further as having controlled diabetes, management challenged, or uncontrolled diabetes. Population analysis was stratified by the patient’s annual number of ED/UC visits.

Results

The risk stratification revealed 4.58% unique patients with unrecognized diabetes and 10.34% of the known patients with diabetes considered to be suboptimally controlled. Patients identified as diabetes management challenged had more ED/UC visits. Of note, 33.95% of the patients had unrecognized prediabetes/diabetes risk factors identified during their ED/UC with 87.95% having some form of healthcare insurance.

Conclusion

This study supports the idea that a single ED/UC unscheduled visit can identify individuals with unrecognized diabetes and an at-risk prediabetes population using EHR data. A patient’s ED/UC visit, regardless of their primary reason for seeking care, may be an opportunity to provide early identification and diabetes disease management enrollment to augment the medical care of our community.

Effect of clinical decision rules, patient cost and malpractice information on clinician brain CT image ordering: a randomized controlled trial

Background

The frequency of head computed tomography (CT) imaging for mild head trauma patients has raised safety and cost concerns. Validated clinical decision rules exist in the published literature and on-line sources to guide medical image ordering but are often not used by emergency department (ED) clinicians. Using simulation, we explored whether the presentation of a clinical decision rule (i.e. Canadian CT Head Rule - CCHR), findings from malpractice cases related to clinicians not ordering CT imaging in mild head trauma cases, and estimated patient out-of-pocket cost might influence clinician brain CT ordering. Understanding what type and how information may influence clinical decision making in the ordering advanced medical imaging is important in shaping the optimal design and implementation of related clinical decision support systems.

Methods

Multi-center, double-blinded simulation-based randomized controlled trial. Following standardized clinical vignette presentation, clinicians made an initial imaging decision for the patient. This was followed by additional information on decision support rules, malpractice outcome review, and patient cost; each with opportunity to modify their initial order. The malpractice and cost information differed by assigned group to test the any temporal relationship. The simulation closed with a second vignette and an imaging decision.

Results

One hundred sixteen of the 167 participants (66.9%) initially ordered a brain CT scan. After CCHR presentation, the number of clinicians ordering a CT dropped to 76 (45.8%), representing a 21.1% reduction in CT ordering (P = 0.002). This reduction in CT ordering was maintained, in comparison to initial imaging orders, when presented with malpractice review information (p = 0.002) and patient cost information (p = 0.002). About 57% of clinicians changed their order during study, while 43% never modified their imaging order.

Conclusion

This study suggests that ED clinician brain CT imaging decisions may be influenced by clinical decision support rules, patient out-of-pocket cost information and findings from malpractice case review.

Trial registration

NCT03449862, February 27, 2018, Retrospectively registered.

Electronic supplementary material

The online version of this article (10.1186/s12911-018-0602-1) contains supplementary material, which is available to authorized users.

Effect of System-Wide Interventions on the Assessment and Treatment of Pain by Emergency Medical Services Providers

BACKGROUND

An estimated 20% of patients arriving by ambulance to the emergency department are in moderate to severe pain. However, the management of pain in the prehospital setting has been shown to be inadequate. Untreated pain may have negative physiologic and psychological consequences. The prehospital community has acknowledged this inadequacy and made treatment of pain a priority.

OBJECTIVES

To determine if system-wide pain management improvement efforts (i.e. education and protocol implementation) improve the assessment of pain and treatment with opioid medications in the prehospital setting and to determine if improvements are maintained over time.

METHODS

This was a retrospective before and after study of a countywide prehospital patient care database. The study population included all adult patients transported by EMS between February 2004 and February 2012 with a working assessment of trauma or burn. EMS patient care records were searched for documentation of pain scores and opioid administration. Four time periods were examined: 1) before interventions, 2) after pediatric specific pain management education, 3) after pain management protocol implementation, and 4) maintenance phase. Frequencies and 95% confidence intervals were calculated for all patients meeting the inclusion criteria in each time period and Chi-square was used to compare frequencies between time periods.

RESULTS

15,228 adult patients transported by EMS during the study period met the inclusion criteria. Subject demographics were similar between the four time periods. Pain score documentation improved between the time periods but was not maintained over time (13% [95%CI 12-15%] to 32% [95%CI 31-34%] to 29% [95 CI 27-30%] to 19% [95%CI 18-21%]). Opioid administration also improved between the time periods and was maintained over time (7% [95%CI 6-8%] to 18% [95%CI 16-19%] to 24% [95%CI 22-25%] to 23% [95% CI 22-24%]).

CONCLUSIONS

In adult patients both pediatric-focused education and pain protocol implementation improved the administration of opioid pain medications. Documentation and assessment of pain scores was less affected by specific pain management improvement efforts.

A Geospatial Analysis of Severe Firearm Injuries Compared to Other Injury Mechanisms: Event Characteristics, Location, Timing, and Outcomes

OBJECTIVES

Relatively little is known about the context and location of firearm injury events. Using a prospective cohort of trauma patients, we describe and compare severe firearm injury events to other violent and nonviolent injury mechanisms regarding incident location, proximity to home, time of day, spatial clustering, and outcomes.

METHODS

This was a secondary analysis of a prospective cohort of injured children and adults with hypotension or Glasgow Coma Scale score ≤ 8, injured by one of four primary injury mechanisms (firearm, stabbing, assault, and motor vehicle collision [MVC]) who were transported by emergency medical services to a Level I or II trauma center in 10 regions of the United States and Canada from January 1, 2010, through June 30, 2011. We used descriptive statistics and geospatial analyses to compare the injury groups, distance from home, outcomes, and spatial clustering.

RESULTS

There were 2,079 persons available for analysis, including 506 (24.3%) firearm injuries, 297 (14.3%) stabbings, 339 (16.3%) assaults, and 950 (45.7%) MVCs. Firearm injuries resulted in the highest proportion of serious injuries (66.3%), early critical resources (75.3%), and in-hospital mortality (53.5%). Injury events occurring within 1 mile of a patient's home included 53.9% of stabbings, 49.2% of firearm events, 41.3% of assaults, and 20.0% of MVCs; the non-MVC events frequently occurred at home. While there was geospatial clustering, 94.4% of firearm events occurred outside of geographic clusters.

CONCLUSIONS

Severe firearm events tend to occur within a patient's own neighborhood, often at home, and generally outside of geospatial clusters. Public health efforts should focus on the home in all types of neighborhoods to reduce firearm violence.

A Novel Use of a Metronome in Dispatcher-assisted Cardiopulmonary Resuscitation

Abstract Early, high-quality cardiopulmonary resuscitation (CPR) is the key to increasing the likelihood of successful resuscitation in cardiac arrest. The use of dispatch-assisted (DA) CPR can increase the likelihood of bystander CPR. We describe a case in which a metronome was introduced to guide DA-CPR. The wife of a 52-year-old male activated 9-1-1 after her husband suffered a cardiac arrest. During her 9-1-1 call she received CPR instructions and heard a metronome over the phone while following the instructions. Return of spontaneous circulation of the patient occurred during paramedic on scene care. The patient was transported to hospital and discharged 6 days later with no neurological deficit. This case supports the use of a metronome by emergency medical dispatchers during the provision of DA-CPR to improve bystander CPR.

A consensus-based gold standard for the evaluation of mass casualty triage systems

INTRODUCTION

Accuracy and effectiveness analyses of mass casualty triage systems are limited because there are no gold standard definitions for each of the triage categories. Until there is agreement on which patients should be identified by each triage category, it will be impossible to calculate sensitivity and specificity or to compare accuracy between triage systems.

OBJECTIVE

To develop a consensus-based, functional gold standard definition for each mass casualty triage category.

METHODS

National experts were recruited through the lead investigators' contacts and their suggested contacts. Key informant interviews were conducted to develop a list of potential criteria for defining each triage category. Panelists were interviewed in order of their availability until redundancy of themes was achieved. Panelists were blinded to each other's responses during the interviews. A modified Delphi survey was developed with the potential criteria identified during the interview and delivered to all recruited experts. In the early rounds, panelists could add, remove, or modify criteria. In the final rounds edits were made to the criteria until at least 80% agreement was achieved.

RESULTS

Thirteen national and local experts were recruited to participate in the project. Six interviews were conducted. Three rounds of voting were performed, with 12 panelists participating in the first round, 12 in the second round, and 13 in the third round. After the first two rounds, the criteria were modified according to respondent suggestions. In the final round, over 90% agreement was achieved for all but one criterion. A single e-mail vote was conducted on edits to the final criterion and consensus was achieved.

CONCLUSION

A consensus-based, functional gold standard definition for each mass casualty triage category was developed. These gold standard definitions can be used to evaluate the accuracy of mass casualty triage systems after an actual incident, during training, or for research.

One-year outcomes of out-of-hospital administration of intravenous glucose, insulin, and potassium (GIK) in patients with suspected acute coronary syndromes (from the IMMEDIATE [Immediate Myocardial Metabolic Enhancement During Initial Assessment and Treatment in Emergency Care] Trial)

The Immediate Myocardial Metabolic Enhancement During Initial Assessment and Treatment in Emergency care Trial of very early intravenous glucose-insulin-potassium (GIK) for acute coronary syndromes (ACS) in out-of-hospital emergency medical service (EMS) settings showed 80% reduction in infarct size at 30 days, suggesting potential longer-term benefits. Here we report 1-year outcomes. Prespecified 1-year end points of this randomized, placebo-controlled, double-blind, effectiveness trial included all-cause mortality and composites including cardiac arrest, mortality, or hospitalization for heart failure (HF). Of 871 participants randomized to GIK versus placebo, death occurred within 1 year in 11.6% versus 13.5%, respectively (unadjusted hazard ratio [HR] 0.83, 95% confidence interval [CI] 0.57 to 1.23, p = 0.36). The composite of cardiac arrest or 1-year mortality was 12.8% versus 17.0% (HR 0.71, 95% CI 0.50 to 1.02, p = 0.06). The composite of hospitalization for HF or mortality within 1 year was 17.2% versus 17.2% (HR 0.98, 95% CI 0.70 to 1.37, p = 0.92). The composite of mortality, cardiac arrest, or HF hospitalization within 1 year was 18.1% versus 20.4% (HR 0.85, 95% CI 0.62 to 1.16, p = 0.30). In patients presenting with suspected ST elevation myocardial infarction, HRs for 1-year mortality and the 3 composites were, respectively, 0.65 (95% CI 0.33 to 1.27, p = 0.21), 0.52 (95% CI 0.30 to 0.92, p = 0.03), 0.63 (95% CI 0.35 to 1.16, p = 0.14), and 0.51 (95% CI 0.30 to 0.87, p = 0.01). In patients with suspected acute coronary syndromes, serious end points generally were lower with GIK than placebo, but the differences were not statistically significant. However, in those with ST elevation myocardial infarction, the composites of cardiac arrest or 1-year mortality, and of cardiac arrest, mortality, or HF hospitalization within 1 year, were significantly reduced.

Behavioral Health Risk Factors of United States Emergency Medical Technicians: The LEADS Project

Objective:

Personal risk behaviors are modifiable. This report describes the 2002 national baseline of behavioral health risk factors of US emergency medical technicians (EMTs) that can guide policy and program development in improving EMT well-being.

Methods:

A 19-item Health Behavioral Risk Survey (Appendix) was added to the 2002 Longitudinal Emergency Medical Technician Demographic Study mail survey. Risk survey questions covering physical activity, tobacco use, and alcohol use were modeled after the Centers for Disease Control and Prevention 2002 Behavioral Risk Factor Surveillance System (BRFSS) questionnaire. Personal, non-work related seatbelt use and motor vehicle driving questions were adopted from the 2002 US National Highway Traffic Safety Administration (NHTSA) Motor Vehicle Occupant Safety Survey (MVOSS). Post-stratification adjustment factors were used to allow comparisons with BRFSS and MVOSS national estimates.

Results:

A total of 1,919 EMT respondents were compared with 239,866 BRFSS and 5,220 MVOSS respondents. These comparisons indicate that EMT-Basics drove more slowly than paramedics; male EMTs drove faster, drank more, and wore their seatbelts less often than did female EMTs; female EMTs smoked more and engaged in vigorous exercise less than males. Those EMTs who reported to be in fair or poor health, smoked more and exercised less than those who reported to be in good or excellent health. Regardless of gender, age, or race, EMTs, on average, wore their seatbelts less often, drove faster than, and were less likely to engage in moderate physical exercise, compared to US adults.

Conclusion:

Stereotypical gender differences in risk behaviors exist among EMTs. An EMT's self-reported health positively correlates with smoking and exercising. Compared to US national estimates, except for smoking and vigorous exercise, EMTs have increased risk behaviors.

Out-of-hospital administration of intravenous glucose-insulin-potassium in patients with suspected acute coronary syndromes: the IMMEDIATE randomized controlled trial

CONTEXT

Laboratory studies suggest that in the setting of cardiac ischemia, immediate intravenous glucose-insulin-potassium (GIK) reduces ischemia-related arrhythmias and myocardial injury. Clinical trials have not consistently shown these benefits, possibly due to delayed administration.

OBJECTIVE

To test out-of hospital emergency medical service (EMS) administration of GIK in the first hours of suspected acute coronary syndromes (ACS).

DESIGN, SETTING, AND PARTICIPANTS

Randomized, placebo-controlled, double-blind effectiveness trial in 13 US cities (36 EMS agencies), from December 2006 through July 31, 2011, in which paramedics, aided by electrocardiograph (ECG)-based decision support, randomized 911 (871 enrolled) patients (mean age, 63.6 years; 71.0% men) with high probability of ACS.

INTERVENTION

Intravenous GIK solution (n = 411) or identical-appearing 5% glucose placebo (n = 460) administered by paramedics in the out-of-hospital setting and continued for 12 hours.

MAIN OUTCOME MEASURES

The prespecified primary end point was progression of ACS to myocardial infarction (MI) within 24 hours, as assessed by biomarkers and ECG evidence. Prespecified secondary end points included survival at 30 days and a composite of prehospital or in-hospital cardiac arrest or in-hospital mortality, analyzed by intent-to-treat and by presentation with ST-segment elevation.

RESULTS

There was no significant difference in the rate of progression to MI among patients who received GIK (n = 200; 48.7%) vs those who received placebo (n = 242; 52.6%) (odds ratio [OR], 0.88; 95% CI, 0.66-1.13; P = .28). Thirty-day mortality was 4.4% with GIK vs 6.1% with placebo (hazard ratio [HR], 0.72; 95% CI, 0.40-1.29; P = .27). The composite of cardiac arrest or in-hospital mortality occurred in 4.4% with GIK vs 8.7% with placebo (OR, 0.48; 95% CI, 0.27-0.85; P = .01). Among patients with ST-segment elevation (163 with GIK and 194 with placebo), progression to MI was 85.3% with GIK vs 88.7% with placebo (OR, 0.74; 95% CI, 0.40-1.38; P = .34); 30-day mortality was 4.9% with GIK vs 7.7% with placebo (HR, 0.63; 95% CI, 0.27-1.49; P = .29). The composite outcome of cardiac arrest or in-hospital mortality was 6.1% with GIK vs 14.4% with placebo (OR, 0.39; 95% CI, 0.18-0.82; P = .01). Serious adverse events occurred in 6.8% (n = 28) with GIK vs 8.9% (n = 41) with placebo (P = .26).

CONCLUSIONS

Among patients with suspected ACS, out-of-hospital administration of intravenous GIK, compared with glucose placebo, did not reduce progression to MI. Compared with placebo, GIK administration was not associated with improvement in 30-day survival but was associated with lower rates of the composite outcome of cardiac arrest or in-hospital mortality.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00091507.

The core content of emergency medical services medicine

On September 23, 2010, the American Board of Medical Specialties (ABMS) approved emergency medical services (EMS) as a subspecialty of emergency medicine. As a result, the American Board of Emergency Medicine (ABEM) is planning to award the first certificates in EMS medicine in the fall of 2013. The purpose of subspecialty certification in EMS, as defined by ABEM, is to standardize physician training and qualifications for EMS practice, to improve patient safety and enhance the quality of emergency medical care provided to patients in the prehospital environment, and to facilitate integration of prehospital patient treatment into the continuum of patient care. In February 2011, ABEM established the EMS Examination Task Force to develop the Core Content of EMS Medicine (Core Content) that would be used to define the subspecialty and from which questions would be written for the examinations, to develop a blueprint for the examinations, and to develop a bank of test questions for use on the examinations. The Core Content defines the training parameters, resources, and knowledge of the treatment of prehospital patients necessary to practice EMS medicine. Additionally, it is intended to inform fellowship directors and candidates for certification of the full range of content that might appear on the examinations. This article describes the development of the Core Content and presents the Core Content in its entirety.

A trial of an impedance threshold device in out-of-hospital cardiac arrest

BACKGROUND

The impedance threshold device (ITD) is designed to enhance venous return and cardiac output during cardiopulmonary resuscitation (CPR) by increasing the degree of negative intrathoracic pressure. Previous studies have suggested that the use of an ITD during CPR may improve survival rates after cardiac arrest.

METHODS

We compared the use of an active ITD with that of a sham ITD in patients with out-of-hospital cardiac arrest who underwent standard CPR at 10 sites in the United States and Canada. Patients, investigators, study coordinators, and all care providers were unaware of the treatment assignments. The primary outcome was survival to hospital discharge with satisfactory function (i.e., a score of ≤3 on the modified Rankin scale, which ranges from 0 to 6, with higher scores indicating greater disability).

RESULTS

Of 8718 patients included in the analysis, 4345 were randomly assigned to treatment with a sham ITD and 4373 to treatment with an active device. A total of 260 patients (6.0%) in the sham-ITD group and 254 patients (5.8%) in the active-ITD group met the primary outcome (risk difference adjusted for sequential monitoring, -0.1 percentage points; 95% confidence interval, -1.1 to 0.8; P=0.71). There were also no significant differences in the secondary outcomes, including rates of return of spontaneous circulation on arrival at the emergency department, survival to hospital admission, and survival to hospital discharge.

CONCLUSIONS

Use of the ITD did not significantly improve survival with satisfactory function among patients with out-of-hospital cardiac arrest receiving standard CPR. (Funded by the National Heart, Lung, and Blood Institute and others; ROC PRIMED ClinicalTrials.gov number, NCT00394706.).

Early versus later rhythm analysis in patients with out-of-hospital cardiac arrest

BACKGROUND

In a departure from the previous strategy of immediate defibrillation, the 2005 resuscitation guidelines from the American Heart Association-International Liaison Committee on Resuscitation suggested that emergency medical service (EMS) personnel could provide 2 minutes of cardiopulmonary resuscitation (CPR) before the first analysis of cardiac rhythm. We compared the strategy of a brief period of CPR with early analysis of rhythm with the strategy of a longer period of CPR with delayed analysis of rhythm.

METHODS

We conducted a cluster-randomized trial involving adults with out-of-hospital cardiac arrest at 10 Resuscitation Outcomes Consortium sites in the United States and Canada. Patients in the early-analysis group were assigned to receive 30 to 60 seconds of EMS-administered CPR and those in the later-analysis group were assigned to receive 180 seconds of CPR, before the initial electrocardiographic analysis. The primary outcome was survival to hospital discharge with satisfactory functional status (a modified Rankin scale score of ≤3, on a scale of 0 to 6, with higher scores indicating greater disability).

RESULTS

We included 9933 patients, of whom 5290 were assigned to early analysis of cardiac rhythm and 4643 to later analysis. A total of 273 patients (5.9%) in the later-analysis group and 310 patients (5.9%) in the early-analysis group met the criteria for the primary outcome, with a cluster-adjusted difference of -0.2 percentage points (95% confidence interval, -1.1 to 0.7; P=0.59). Analyses of the data with adjustment for confounding factors, as well as subgroup analyses, also showed no survival benefit for either study group.

CONCLUSIONS

Among patients who had an out-of-hospital cardiac arrest, we found no difference in the outcomes with a brief period, as compared with a longer period, of EMS-administered CPR before the first analysis of cardiac rhythm. (Funded by the National Heart, Lung, and Blood Institute and others; ROC PRIMED ClinicalTrials.gov number, NCT00394706.).

Emergency medical service predictive instrument-aided diagnosis and treatment of acute coronary syndromes and ST-segment elevation myocardial infarction in the IMMEDIATE trial

BACKGROUND

A challenge for emergency medical service (EMS) is accurate identification of acute coronary syndromes (ACS) and ST-segment elevation myocardial infarction (STEMI) for immediate treatment and transport. The electrocardiograph-based acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI) and the thrombolytic predictive instrument (TPI) have been shown to improve diagnosis and treatment in emergency departments (EDs), but their use by paramedics in the community has been less studied.

OBJECTIVE

To identify candidates for participation in the Immediate Myocardial Metabolic Enhancement During Initial Assessment and Treatment in Emergency Care (IMMEDIATE) Trial, we implemented EMS use of the ACI-TIPI and the TPI in out-of-hospital electrocardiographs and evaluated its impact on paramedic on-site identification of ACS and STEMI as a community-based approach to improving emergency cardiac care.

METHODS

Ambulances in the study municipalities were outfitted with electrocardiographs with ACI-TIPI and TPI software. Using a before-after quasi-experimental design, in Phase 1, for seven months, paramedics were provided with the ACI-TIPI/TPI continuous 0-100% predictions automatically printed on electrocardiogram (ECG) text headers to supplement their identification of ACS; in Phase 2, for 11 months, paramedics were told to identify ACS based on an ACI-TIPI cutoff probability of ACS ≥ 75% and/or TPI detection of STEMI. In Phase 3, this cutoff approach was used in seven additional municipalities. Confirmed diagnoses of ACS, acute myocardial infarction (AMI), and STEMI were made by blinded physician review for 100% of patients.

RESULTS

In Phase 1, paramedics identified 107 patients as having ACS; in Phase 2, 104. In Phase 1, 45.8% (49) of patients so identified had ACS confirmed, which increased to 76.0% (79) in Phase 2 (p < 0.001). Of those with ACS, 59.2% (29) had AMI in Phase 1 versus 84.8% (67) with AMI in Phase 2 (p < 0.01), and STEMI was confirmed in 40.8% (20) versus 68.4% (54), respectively (p < 0.01). In Phase 3, of 226 patients identified by paramedics as having ACS, 74.3% (168) had ACS confirmed, of whom 81.0% (136) had AMI and 65.5% (110) had STEMI. Among patients with ACS, the proportion who received percutaneous coronary intervention (PCI) was 30.6% (15) in Phase 1, increasing to 57.0% (45) in Phase 2 (p < 0.004) and 50.6% (85) in Phase 3, and the proportions of patients with STEMI receiving PCI rose from 75.0% (15) to 83.3% (45) (p < 0.4) and 82.7% (91).

CONCLUSIONS

In a wide range of EMS systems, use of electrocardiographs with ACI-TIPI and TPI decision support using a 75% ACI-TIPI cutoff improves paramedic diagnostic performance for ACS, AMI, and STEMI and increases the proportions of patients who receive PCI.

The frequency and consequences of cardiopulmonary resuscitation performed by bystanders on patients who are not in cardiac arrest

BACKGROUND

The American Heart Association encourages trained and untrained bystanders to perform, at a minimum, chest compressions on anyone who suddenly collapses. It is possible that people who are not in cardiac arrest may receive bystander cardiopulmonary resuscitation (CPR), from which the potential for injury is unknown.

OBJECTIVES

To determine the number of victims who received bystander CPR but were not in cardiac arrest and to identify any injuries resulting from receiving bystander CPR.

METHODS

Retrospective review of patient care records from a countywide emergency medical services (EMS) database. All patients treated by EMS between March 2003 and February 2009 who received bystander CPR were queried. Victims who were determined not to be in cardiac arrest upon EMS personnel assessment were identified as likely not in cardiac arrest. Hospital medical records for transported patients were reviewed for injuries possibly related to CPR. Patient demographics were collected and descriptive statistics were used for analysis.

RESULTS

Six hundred seventy-two incidents of bystander CPR occurred, with 77 (11.5%) cases not being identified as cardiac arrests by EMS. Twenty-three percent of the patients were less than 19 years of age. Emergency medical services arrived in less than 6 minutes for 68% of patients. Seventy-two patients were evaluable for injury; of those, 53% were admitted to the intensive care unit. One patient (1.4%) had an injury that was documented in the medical record as possibly CPR-related: rhabdomyolysis.

CONCLUSIONS

Bystanders provide CPR for patients who are not in cardiac arrest at a relatively low frequency. Short-duration bystander CPR caused injury in less than 2% of victims. Our results suggest that the benefits of bystander CPR for adults who suddenly collapse outweigh the risk of injury for those not in cardiac arrest.

A model for the association of the call volume and the unavailable-for-response interval on the delayed ambulance response for out-of-hospital cardiac arrest using a geographic information system

BACKGROUND

An optimal ambulance response interval is desirable for emergency medical services (EMS) operations. Arriving on scene within a treatment time window is often delayed for many reasons, including overwhelming call volume.

OBJECTIVE

To determine whether an association exists between the ambulance call volume (ACV), the unavailable-for-response (UFR) interval, and the delayed ambulance response for out-of-hospital cardiac arrest (OHCA) patients.

METHODS

This was a retrospective observational study conducted in Seoul, Republic of Korea. The EMS ambulance logs from the metropolitan city's 22 EMS agencies, from January 1, 2006, to June 30, 2007, were obtained from the National Emergency Management Agency. These data included patient demographics and call location addresses. The addresses of the call locations and ambulance stations were geocoded and configured with a polygon expressing the optimal coverage areas in which an ambulance could travel within 4 minutes from their base station. The median ACV and mean UFR interval of each EMS agency were calculated. An actual response time interval greater than 4 minutes compared with the optimal coverage area was defined as a suboptimal response. Potential influencing factors on suboptimal response were analyzed using a multivariate logistic regression model to calculated the odds ratio (OR) and 95% confidence interval (95% CI).

RESULTS

Geocoding was successful for 255,961 calls, and 3,644 cardiac arrests occurred within the configured optimal response coverage areas. The response rate intervals for cardiac arrest patients, however, were optimal in only 22.6% of calls. Influencing factors for suboptimal response (occurring in 77.4% of the cases) were the median ACV and the mean UFR interval of each EMS agency. When the median ACV was seven or more, the OR of suboptimal response was 1.407 (1.142-1.734). If the mean UFR interval was 55 minutes or more, the OR for suboptimal response was 1.770 (1.345-2.329).

CONCLUSION

The ambulance response time intervals in this study setting were associated with EMS agencies with higher ACVs and longer UFR intervals.

Rearrest after prehospital resuscitation

OBJECTIVES

To determine how often out-of-hospital cardiac arrest (OHCA) patients who achieve return of spontaneous circulation (ROSC) experience rearrest during their emergency medical services (EMS) care and to analyze their arrest characteristics, including survival to hospital discharge.

METHODS

A retrospective patient care record review was conducted for all treated OHCA patients between January 1, 2000, and February 28, 2008. Data were obtained from a countywide EMS patient care database that included treating EMS provider documentation and receiving hospital patient outcomes. If resuscitation was attempted, all OHCA patients, regardless of age, were included in the study. Those who achieved ROSC were identified and the number of patients who experienced rearrest was determined. Return of spontaneous circulation was defined as EMS documentation of a palpable pulse, and rearrest was defined as a change in cardiac rhythm associated with loss of a palpable pulse, regardless of duration. Cardiac arrest characteristics were analyzed using chi-square and t-test for resuscitated patients who experienced rearrest compared with those who did not.

RESULTS

During the study period, OHCA resuscitation was attempted on 7,296 patients. Of these, 2,454 had field ROSC (34%; 95% confidence interval [CI]: 33%-35%). Of those who achieved ROSC, 951 experienced rearrest prior to hospital arrival (39%; 95% CI: 37%-41%). The average age of the patients who experienced rearrest was 2 years higher than those who did not experience rearrest (64 years vs. 62 years; p < 0.011). The proportion of women in the rearrest group was less than that in the non-rearrest group (40% vs. 46%; p < 0.008). Bystander-witnessed arrest rates were similar between the two groups (65% vs. 68%; p < 0.124). Fewer patients who experienced rearrest survived to hospital admission (53% vs. 85%; p < 0.000) and hospital discharge (15% vs. 35%; p < 0.000). Of those who experienced rearrest, 102 (11%) experienced rearrest while being transported. There was no difference in survival for those whose rearrests occurred prior to transport (14%) compared with those whose rearrests occurred during transport (16%) (p < 0.671).

CONCLUSION

A significant number of OHCA patients who achieved field ROSC experienced rearrest prior to hospital arrival. Patients who experienced rearrest were less likely to survive.

Use of SALT triage in a simulated mass-casualty incident

OBJECTIVES

To determine the accuracy of SALT (sort-assess-lifesaving interventions-treatment/transport) triage during a simulated mass-casualty incident, the average time it takes to make triage designations, and providers' opinions of SALT triage.

METHODS

Seventy-three trainees participating in one of two disaster courses were taught to use SALT triage during a 30-minute lecture. The following day they participated in teams, in one of eight simulated mass-casualty incidents. For each incident trainees were told to assess and prioritize all victims. Each scenario comprised 28 to 30 victims, including 10 to 11 moulaged manikins and 18 to 20 moulaged actors. Each victim had a card that stated the victim's respiratory effort, pulse quality, and ability to follow commands. Initial and final assigned triage categories were recorded and compared with the intended category. Ten of the victims were equipped with stopwatches to measure the triage time interval. Timing began when the trainee approached the victim and ended when the trainee verbalized his or her triage designation. The times were averaged and standard deviations were calculated. After the drill, trainees were asked to complete a survey regarding their experience.

RESULTS

There were 217 victim observations. The initial triage was correct for 81% of the observations; 8% were overtriaged and 11% were undertriaged. The final triage was correct for 83% of the observations; 6% were overtriaged and 10% were undertriaged. The mean triage interval was 28 seconds (+/- 22; range: 4-94). Nine percent reported that prior to the drill they felt very confident using SALT triage and 33% were not confident. After the drill, no one reported not feeling confident using SALT triage, 26% were at the same level of confidence, 74% felt more confident, and none felt less confident. Before the drill, 53% of the respondents felt SALT triage was easier to use than their current disaster triage protocol, 44% felt it was similar, and 3% felt it was more difficult. After the drill, no one reported that SALT triage was more difficult to use.

CONCLUSION

We found that assessments using SALT triage were accurate and made quickly during a simulated incident. The accuracy rate was higher than those published for other triage systems and of similar speed. Providers also felt confident using SALT triage and found it was similar or easier to use than their current triage protocol. Using SALT triage during a drill improved confidence.

The association between emergency medical services staffing patterns and out-of-hospital cardiac arrest survival

OBJECTIVE

To determine whether the number of advanced life support-trained personnel at the scene of an out-of-hospital cardiac arrest (OHCA) was associated with return of spontaneous circulation (ROSC) or survival to hospital discharge.

METHODS

A retrospective database review using Utstein-style reporting definitions was conducted in Milwaukee County. All adult (>or= 18 years of age) OHCA cases of presumed cardiac etiology from January 1993 through December 2005 were eligible for inclusion in the study. Cardiac arrests resulting from a drug overdose, suicide, drowning, hypoxia, exsanguination, stroke, or trauma were excluded from the study. Also excluded were cases in which no crew configuration or responding unit was available, cases in which no resuscitation effort was attempted, and cases in which no time data were available. Return of spontaneous circulation and survival to hospital discharge for OHCA patients treated by a crew with two paramedics were compared to those patients treated by crews with three or more paramedics. Multivariable logistic regression was used for the analysis and the results are reported as odds ratios (ORs).

RESULTS

During the study period, there were 10,298 OHCAs of cardiac etiology. Of those, 10,057 (98%) cases had sufficient data to be included in the analysis. There were 4,229 patients treated by two paramedics (9% survived to discharge), 4,459 patients treated by three paramedics (9% survived to discharge), and 1,369 patients treated by four or more paramedics (8% survived to discharge). In the multivariable analysis, when referenced against crews with two paramedics and controlled for factors that have a known correlation with cardiac arrest survival, patients treated by crews with three paramedics (0.83, 95% confidence interval [CI] 0.70 to 0.97, p = 0.02) and crews with four or more paramedics (0.66, 95% CI 0.52 to 0.83, p < 0.01) were associated with reduced survival to hospital discharge. Return of spontaneous circulation was not influenced by the number of paramedics present.

CONCLUSIONS

The presence of three or more paramedics at the scene of OHCA was not associated with improved survival to hospital discharge when compared to crews with two paramedics. Additional research is needed to determine the potential cause of this finding.

Gauging U.S. Emergency Medical Services workers' willingness to respond to pandemic influenza using a threat- and efficacy-based assessment framework

Background

Emergency Medical Services workers' willingness to report to duty in an influenza pandemic is essential to healthcare system surge amidst a global threat. Application of Witte's Extended Parallel Process Model (EPPM) has shown utility for revealing influences of perceived threat and efficacy on non-EMS public health providers' willingness to respond in an influenza pandemic. We thus propose using an EPPM-informed assessment of EMS workers' perspectives toward fulfilling their influenza pandemic response roles.

Methodology/Principal Findings

We administered an EPPM-informed snapshot survey about attitudes and beliefs toward pandemic influenza response, to a nationally representative, stratified random sample of 1,537 U.S. EMS workers from May–June 2009 (overall response rate: 49%). Of the 586 respondents who met inclusion criteria (currently active EMS providers in primarily EMS response roles), 12% indicated they would not voluntarily report to duty in a pandemic influenza emergency if asked, 7% if required. A majority (52%) indicated their unwillingness to report to work if risk of disease transmission to family existed. Confidence in personal safety at work (OR = 3.3) and a high threat/high efficacy (“concerned and confident”) EPPM profile (OR = 4.7) distinguished those who were more likely to voluntarily report to duty. Although 96% of EMS workers indicated that they would probably or definitely report to work if they were guaranteed a pandemic influenza vaccine, only 59% had received an influenza immunization in the preceding 12 months.

Conclusions/Significance

EMS workers' response willingness gaps pose a substantial challenge to prehospital surge capacity in an influenza pandemic. “Concerned and confident” EMS workers are more than four times as likely to fulfill pandemic influenza response expectations. Confidence in workplace safety is a positively influential modifier of their response willingness. These findings can inform insights into interventions for enhancing EMS workers' willingness to respond in the face of a global infectious disease threat.

PREHOSPITAL PAIN MANAGEMENT

OBJECTIVE

To assess the knowledge of emergency medical technicians-paramedics (EMT-Ps) and compare their practice perceptions with actual pain management interventions in adults and pediatric patients (adolescents and children) with chest pain (CP), extremity injuries, or burns.

METHODS

This study included a cross-sectional survey of EMT-Ps and review of the emergency medical services (EMS) system patient care database. EMT-Ps were surveyed for: 1) knowledge of pain treatment protocol; 2) estimated number of CP, extremity injury, or burn encounters and the frequency of morphine administration; and 3) barriers to providing morphine. Data on patients transported with any above conditions and those who received morphine were abstracted from the EMS patient care database. Data were analyzed using descriptive statistics, and 95% confidence intervals (CIs) were calculated.

RESULTS

Of 202 EMT-Ps, 155 (77%) completed the survey. Eighty-two percent reported knowledge of pain treatment protocol for both adults and pediatric patients. For adults, EMT-Ps estimated they administered morphine to 37% with CP (95% CI 35, 40), 24% with extremity injuries (95% CI 17, 30), and 89% with burns (95% CI 52, 99). In children and adolescents, inability to assess pain (93%) was the most common reason for withholding morphine. According to the EMS database, 5% of adults with CP (95% CI 4, 5), 12% extremity injuries (95% CI 8, 15), and 14% burns (95% CI 8, 20) received morphine. In children and adolescents, 3% with extremity injuries (95% CI 1, 5) and 9% with burns (95% CI 0, 26) received morphine. Pain score was documented in 67.0% of adult patients, compared with only 4.0% in pediatric patients (Delta = 63.0%, 95% CI: 60, 65).

CONCLUSIONS

Significant disparity exists between EMT-Ps' perceptions of acute pain assessment and the frequency of providing analgesia and their actual practice. Children and adolescents had less documentation of pain assessment and received less analgesic interventions compared with adults. Inability to assess pain may be an important barrier to the provision of analgesia.

The Changing Incidence of Ventricular Fibrillation in Milwaukee, Wisconsin (1992–2002)

OBJECTIVES

To investigate the changes in annual incidence and survival of out-of-hospital cardiac-etiology arrests of different initial rhythms, particularly ventricular fibrillation (VF) and ventricular tachycardia (VT), among adults (> 21 years old) in Milwaukee County between 1992 and 2002 and establish correlations with patient and emergency medical services (EMS) system-dependent factors.

METHODS

The study was a retrospective, observational study of all adult (> 21-year-old) patients with out-of-hospital cardiac-etiology arrests with identifiable rhythm and resuscitation attempted by the Milwaukee County EMS system from 1992 to 2002. Nine thousand one hundred seventy cases were enrolled. Primary outcome measures were changes in annual incidence of initial cardiac arrest rhythm, with a focus on VF/VT. Secondary outcome measures were changes in survival to hospital admission and hospital discharge for VF and VT. Patient and EMS system factors potentially affecting the outcome measures were identified and modeled using multivariate logistic regression.

RESULTS

The incidence of out-of-hospital VF/VT arrests decreased steadily from 37.1 per 100,000 in 1992 to 19.4 per 100,000 in 2002. While the incidences of pulseless electrical activity and overall cardiac arrest remained unchanged, the incidence of asystole during the study period increased from 27.3/100,000 to 44.9/100,000. Multivariate regression analyses revealed that age < 80 years, male gender, white race, previous cardiac surgery, and cardiac history were patient-dependent factors predictive of VF/VT. Witnessed arrest, public location, and shorter response time were EMS system-dependent factors predictive of VF/VT. Based on observed trends, none of these correlated factors could explain the decrease in the incidence of VF/VT arrests. Rates of patient survival to hospital admission and discharge were not significantly changed over time. EMS system factors predictive of survival to admission and discharge were witnessed arrest, public location, and decreased number of defibrillations. Prior cardiac surgery and absence of chronic problems were the only patient factors predictive of survival to hospital admission but were not significantly related to survival to hospital discharge.

CONCLUSIONS

The incidence of out-of-hospital cardiac arrests in adult patients with presenting rhythm of VF/VT declined, while an increase in asystole occurred. This was not explained by any patient or EMS system-dependent factor. Rate of survival for VF/VT arrest did not significantly change over time. Survival was primarily influenced by EMS system factors and unrelated to patient-dependent factors.

Does the number of system paramedics affect clinical benchmark thresholds?

OBJECTIVE

Competency is affected by skill exposure, skill complexity, and training program quality. The purpose of this study was to reevaluate the biennial (24-month) critical care skill and experience benchmark thresholds established by the Milwaukee County Emergency Medical Services (MCEMS) system in 1997.

METHODS

This was a retrospective review of annual experience profiles for paramedics working during 2001-2005 using the MCEMS patient care record (PCR) database. The number of patient contacts, role as team leader/report writer, adult and pediatric endotracheal intubations, adult and pediatric intravenous (IV) access initiations, medication administration, and 12-lead electrocardiogram (ECG) acquisitions were analyzed. t-tests and descriptive statistics were performed for comparison with the 1997 study.

RESULTS

Over the five-year study period, 1,215 paramedic profiles gleaned from 107,524 PCRs documented a total of 297,900 patient contacts. Annual means+/-standard deviations [ranges] were as follows: patient contacts 245+/-133 [12-788]; team leader: 106+/-119 [0-739]; intubations: adult 2.57+/-2.54 [0-20], pediatric 0.1+/-0.3 [0-3]; IV starts: adult 44+/-37 [0-267], pediatric 0.34+/-0.77 [0-5]; treated cardiac arrests: adult 8+/-6 [0-34], pediatric 0.26+/-0.61 [0-4]; treated hypotensive trauma: 5+/-6 [0-42]; and ECGs acquired: 31+/-19 [0-144]. The 1997 analysis (1987-1996 data) included 1,450 paramedic profiles representing 467,559 patient contacts generated from 172,131 filed PCRs. All comparable experiences decreased significantly between the 1997 analysis and the current study, except medication administration, which increased 25%.

CONCLUSION

These data show a decreased opportunity and a wide variability in the frequency of successfully completed paramedic technical skills and experiences in this EMS system. Limited exposure to critically ill adult and pediatric patients reaffirms that high-risk skills are performed infrequently. A multifaceted approach should be considered for maintaining provider competency.

The Resuscitation Outcomes Consortium Epistry-Trauma: design, development, and implementation of a North American epidemiologic prehospital trauma registry

Injury is a major public health problem generating substantial morbidity, mortality, and economic burden on society. The majority of seriously injured persons are initially evaluated and cared for by prehospital providers, however the effect of emergency medical services (EMS) systems, EMS clinical care, and EMS interventions on trauma patient outcomes is largely unknown. Outcome-based information to guide future EMS care has been hampered by the lack of comprehensive, standardized, multi-center prehospital data resources that include meaningful patient outcomes. In this paper, we describe the background, design, development, implementation, content, and potential uses of the first North American comprehensive epidemiologic prehospital data registry for injured persons. This data registry samples patients from 264 EMS agencies transporting to 287 acute care hospitals in both the United States and Canada.

Rationale, development and implementation of the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest

OBJECTIVE

To describe the development, design and consequent scientific implications of the Resuscitation Outcomes Consortium (ROC) population-based registry; ROC Epistry-Cardiac Arrest.

METHODS

The ROC Epistry--Cardiac Arrest is designed as a prospective population-based registry of all Emergency Medical Services (EMSs)-attended 9-1-1 calls for patients with out-of-hospital cardiac arrest occurring in the geographical area described by the eight US and three Canadian regions. The dataset was derived by an North American interdisciplinary steering committee. Enrolled cases include individuals of all ages who experience cardiac arrest outside the hospital, with evaluation by organized EMS personnel and: (a) attempts at external defibrillation (by lay responders or emergency personnel), or chest compressions by organized EMS personnel; (b) were pulseless but did not receive attempts to defibrillate or CPR by EMS personnel. Selected data items are categorized as mandatory or optional and undergo revisions approximately every 12 months. Where possible all definitions are referenced to existing literature. Where a common definition did not exist one was developed. Optional items include standardized CPR process data elements. It is anticipated the ROC Epistry--Cardiac Arrest will enroll between approximately 9000 and 13,500 treated all rhythm arrests and 4000 and 5000 ventricular fibrillation arrests annually and approximately 8000 EMS-attended but untreated arrests.

CONCLUSION

We describe the rationale, development, design and future implications of the ROC Epistry--Cardiac Arrest. This paper will serve as the reference for subsequent ROC manuscripts and for the common data elements captured in both ROC Epistry--Cardiac Arrest and the ROC trials.

Adverse events associated with lay emergency response programs: the public access defibrillation trial experience

The adverse event (AE) profile of lay volunteer CPR and public access defibrillation (PAD) programs is unknown. We undertook to investigate the frequency, severity, and type of AE's occurring in widespread PAD implementation.

DESIGN

A randomized-controlled clinical trial.

SETTING

One thousand two hundred and sixty public and residential facilities in the US and Canada.

PARTICIPANTS

On-site, volunteer, lay personnel trained in CPR only compared to CPR plus automated external defibrillators (AEDs).

INTERVENTION

Persons experiencing possible cardiac arrest receiving lay volunteer first response with CPR+AED compared with CPR alone.

MAIN OUTCOME MEASURE

An AE is defined as an event of significance that caused, or had the potential to cause, harm to a patient or volunteer, or a criminal act. AE data were collected prospectively.

RESULTS

Twenty thousand three hundred and ninety six lay volunteers were trained in either CPR or CPR+AED. One thousand seven hundred and sixteen AEDs were placed in units randomized to the AED arm. There were 26,389 exposure months. Only 36 AE's were reported. There were two patient-related AEs: both patients experienced rib fractures. There were seven volunteer-related AE's: one had a muscle pull, four experienced significant emotional distress and two reported pressure by their employee to participate. There were 27 AED-related AEs: 17 episodes of theft involving 20 devices, three involved AEDs that were placed in locations inaccessible to the volunteer, four AEDs had mechanical problems not affecting patient safety, and three devices were improperly maintained by the facility. There were no inappropriate shocks and no failures to shock when indicated (95% upper bound for probability of inappropriate shock or failure to shock = 0.0012).

CONCLUSIONS

AED use following widespread training of lay-persons in CPR and AED is generally safe for the volunteer and the patient. Lay volunteers may report significant, usually transient, emotional stress following response to a potential cardiac arrest. Within the context of this prospective, randomized multi-center study, AEDs have an exceptionally high safety profile when used by trained lay responders.

Incomplete chest wall decompression: a clinical evaluation of CPR performance by trained laypersons and an assessment of alternative manual chest compression-decompression techniques

BACKGROUND

Complete chest wall recoil improves hemodynamics during CPR by generating relatively negative intrathoracic pressure, which draws venous blood back to the heart, providing cardiac preload prior to the next chest compression.

OBJECTIVE

This study was designed to assess the quality of CPR delivered by trained laypersons and to determine if a change in CPR technique or hand position would improve complete chest wall recoil, while maintaining adequate duty cycle, compression depth, and proper hand position placement. Standard manual CPR and three alternative manual CPR approaches were assessed.

METHODS

This randomized prospective trial was performed on an electronic test manikin. Thirty laypersons (mean age of 40.6 years (range 28-55)), who were trained in CPR within the last 24 months, signed an informed consent and participated in the trial. Subjects performed 3 min of CPR on a Laerdal Skill Reportertrade mark CPR manikin using the Standard Hand Position followed by 3 min of CPR (in random order) using three alternative CPR techniques: (1) Two-Finger Fulcrum Technique - lifting the heel of the hand slightly but completely off the chest during the decompression phase of CPR using the thumb and little finger as a fulcrum; (2) Five-Finger Fulcrum Technique - lifting the heel of the hand slightly but completely off the chest during the decompression phase of CPR using all five fingers as a fulcrum; (3) Hands-Off Technique - lifting the heel and all fingers of the hand slightly but completely off the chest during the decompression phase of CPR. The participants did not know the purpose of the study prior to, or during this investigation.

RESULTS

Adequate compression depth was poor for all hand positions tested and ranged only from 18.6 to 35.7% of all compressions. When compared with the Standard Hand Position, the Hands-Off Technique decreased the mean compression duty cycle from 39.0 +/- 1.0 to 33.5 +/- 1.0%, (P < 0.0001) but achieved the highest rate of complete chest wall recoil (92.5% versus 24.1%, P < 0.0001) and was 46.3 times more likely to provide complete chest wall recoil (OR: 46.3; CI: 16.4-130.3). There were no significant differences in accuracy of hand placement, adequate depth of compression, or perceived discomfort with its use compared with the Standard Hand Position.

CONCLUSIONS

The Hands-Off Technique decreased compression duty cycle but was 46.3 times more likely to provide complete chest wall recoil (OR: 46.3; CI: 16.4-130.3) compared to the Standard Hand Position without differences in accuracy of hand placement, adequate depth of compression, or perceived discomfort with its use. All forms of manual CPR tested (including the Standard Hand Position) in trained laypersons produced an inadequate depth of compression for two-thirds of the time. These data support development and testing of more effective layperson CPR training programmes and more effective means to deliver manual as well as mechanical CPR.

Clinical and hemodynamic comparison of 15:2 and 30:2 compression-to-ventilation ratios for cardiopulmonary resuscitation*

OBJECTIVE

To compare cardiopulmonary resuscitation (CPR) with a compression to ventilation (C:V) ratio of 15:2 vs. 30:2, with and without use of an impedance threshold device (ITD).

DESIGN

Prospective randomized animal and manikin study.

SETTING

Animal laboratory and emergency medical technician training facilities.

SUBJECTS

Twenty female pigs and 20 Basic Life Support (BLS)-certified rescuers.

INTERVENTIONS, MEASUREMENTS, AND MAIN RESULTS

ANIMALS

Acid-base status, cerebral, and cardiovascular hemodynamics were evaluated in 18 pigs in cardiac arrest randomized to a C:V ratio of 15:2 or 30:2. After 6 mins of cardiac arrest and 6 mins of CPR, an ITD was added. Compared to 15:2, 30:2 significantly increased diastolic blood pressure (20 +/- 1 to 26 +/- 1; p < .01); coronary perfusion pressure (18 +/- 1 to 25 +/- 2; p = .04); cerebral perfusion pressure (16 +/- 3 to 18 +/- 3; p = .07); common carotid blood flow (48 +/- 5 to 82 +/- 5 mL/min; p < .001); end-tidal CO2 (7.7 +/- 0.9 to 15.7 +/- 2.4; p < .0001); and mixed venous oxygen saturation (26 +/- 5 to 36 +/- 5, p < .05). Hemodynamics improved further with the ITD. Oxygenation and arterial pH were similar. Only one of nine pigs had return of spontaneous circulation with 15:2, vs. six of nine with 30:2 (p < 0.03). HUMANS: Fatigue and quality of CPR performance were evaluated in 20 BLS-certified rescuers randomized to perform CPR for 5 mins at 15:2 or 30:2 on a recording CPR manikin. There were no significant differences in the quality of CPR performance or measurement of fatigue. Significantly more compressions per minute were delivered with 30:2 in both the animal and human studies.

CONCLUSIONS

These data strongly support the contention that a ratio of 30:2 is superior to 15:2 during manual CPR and that the ITD further enhances circulation with both C:V ratios.

The effect of Combitube use on paramedic experience in endotracheal intubation

OBJECTIVE

To determine the change in number of endotracheal intubations per paramedic after the implementation of Combitube use and to explore consequences.

METHODS

Before-and-after study; urban/suburban EMS system; population 1 million. Number of patients 16 years and older, type of airway used, attempts, and successes were abstracted for time periods before and after the use of Combitubes. The number of endotracheal intubations/paramedic for each period was calculated.

RESULTS

Three-year pre-Combitube: patients 50983; 6.6% arrests; 3142 received an endotracheal intubation attempt with 93.5% success. The average annual number of paramedics was 153 with 6.9 +/- 6.4 intubations per paramedic per year. Three-year post-Combitube: patients 55959; 6.0% arrests; 2913 received an advanced airway attempt: 860 Combitubes, success 89.4%; 2144 endotracheal intubations, success 91.6% (95% confidence interval success rate difference, 0.5-3.3; P = .007). The average annual number of paramedics was 177 with 3.7 +/- 3.3 intubations per paramedic per year.

CONCLUSION

After implementation of the Combitube, the number of endotracheal intubation attempts/paramedic and success rates decreased.

Effect of an inspiratory impedance threshold device on hemodynamics during conventional manual cardiopulmonary resuscitation

BACKGROUND

In animals in cardiac arrest, an inspiratory impedance threshold device (ITD) has been shown to improve hemodynamics and neurologically intact survival. The objective of this study was to determine whether an ITD would improve blood pressure (BP) in patients receiving CPR for out-of-hospital cardiac arrest.

METHODS

This prospective, randomized, double-blind, intention-to-treat study was conducted in the Milwaukee, WI, emergency medical services (EMS) system. EMS personnel used an active (functional) or sham (non-functional) ITD on a tracheal tube on adults in cardiac arrest of presumed cardiac etiology. Care between groups was similar except for ITD type. Low dose epinephrine (1mg) was used per American Heart Association Guidelines. Femoral arterial BP (mmHg) was measured invasively during CPR.

RESULTS

Mean+/-S.D. time from ITD placement to first invasive BP recording was approximately 14 min. Twelve patients were treated with a sham ITD versus 10 patients with an active ITD. Systolic BPs (mean+/-S.D.) [number of patients treated at given time point] at T = 0 (time of first arterial BP measurement), and T=2, 5 and 7 min were 85+/-29 [10], 85+/-23 [10], 85+/-16 [9] and 69+/-22 [8] in the group receiving an active ITD compared with 43+/-15 [12], 47+/-16 [12], 47+/-20 [9], and 52+/-23 [9] in subjects treated with a sham ITD, respectively (p < 0.01 for all times). Diastolic BPs at T = 0, 2, 5 and 7 min were 20+/-12, 21+/-13, 23+/-15 and 25+/-14 in the group receiving an active ITD compared with 15+/-9, 17+/-8, 17+/-9 and 19+/-8 in subjects treated with a sham ITD, respectively (p = NS for all times). No significant adverse device events were reported.

CONCLUSIONS

Use of the active ITD was found to increase systolic pressures safely and significantly in patients in cardiac arrest compared with sham controls.

Clinical evaluation of an inspiratory impedance threshold device during standard cardiopulmonary resuscitation in patients with out-of-hospital cardiac arrest*

OBJECTIVE

To determine whether an impedance threshold device, designed to enhance circulation, would increase acute resuscitation rates for patients in cardiac arrest receiving conventional manual cardiopulmonary resuscitation.

DESIGN

Prospective, randomized, double-blind, intention-to-treat.

SETTING

Out-of-hospital trial conducted in the Milwaukee, WI, emergency medical services system.

PATIENTS

Adults in cardiac arrest of presumed cardiac etiology.

INTERVENTIONS

On arrival of advanced life support, patients were treated with standard cardiopulmonary resuscitation combined with either an active or a sham impedance threshold device.

MEASUREMENTS AND MAIN RESULTS

We measured safety and efficacy of the impedance threshold device; the primary end point was intensive care unit admission. Statistical analyses performed included the chi-square test and multivariate regression analysis. One hundred sixteen patients were treated with a sham impedance threshold device, and 114 patients were treated with an active impedance threshold device. Overall intensive care unit admission rates were 17% with the sham device vs. 25% in the active impedance threshold device (p = .13; odds ratio, 1.64; 95% confidence interval, 0.87, 3.10). Patients in the subgroup presenting with pulseless electrical activity had intensive care unit admission and 24-hr survival rates of 20% and 12% in sham (n = 25) vs. 52% and 30% in active impedance threshold device groups (n = 27) (p = .018, odds ratio, 4.31; 95% confidence interval, 1.28, 14.5, and p = .12, odds ratio, 3.09; 95% confidence interval, 0.74, 13.0, respectively). A post hoc analysis of patients with pulseless electrical activity at any time during the cardiac arrest revealed that intensive care unit and 24-hr survival rates were 20% and 11% in the sham (n = 56) vs. 41% and 27% in the active impedance threshold device groups (n = 49) (p = .018, odds ratio, 2.82; 95% confidence interval, 1.19, 6.67, and p = .037, odds ratio, 3.01; 95% confidence interval, 1.07, 8.96, respectively). There were no statistically significant differences in outcomes for patients presenting in ventricular fibrillation and asystole. Adverse event and complication rates were also similar.

CONCLUSIONS

During this first clinical trial of the impedance threshold device during standard cardiopulmonary resuscitation, use of the new device more than doubled short-term survival rates in patients presenting with pulseless electrical activity. A larger clinical trial is underway to determine the potential longer term benefits of the impedance threshold device in cardiac arrest.

Incomplete chest wall decompression: a clinical evaluation of CPR performance by EMS personnel and assessment of alternative manual chest compression–decompression techniques

BACKGROUND

Complete chest wall recoil improves hemodynamics during cardiopulmonary resuscitation (CPR) by generating relatively negative intrathoracic pressure and thus draws venous blood back to the heart, providing cardiac preload prior to the next chest compression phase.

OBJECTIVE

Phase I was an observational case series to evaluate the quality of chest wall recoil during CPR performed by emergency medical services (EMS) personnel on patients with an out-of-hospital cardiac arrest. Phase II was designed to assess the quality of CPR delivered by EMS personnel using an electronic test manikin. The goal was to determine if a change in CPR technique or hand position would improve complete chest wall recoil, while maintaining adequate duty cycle, compression depth, and correct hand position placement. Standard manual CPR and three alternative manual CPR approaches were assessed.

METHODS AND RESULTS

Phase I--The clinical observational study was performed by an independent observer noting incomplete chest wall decompression and correlating that observation with electronically measured airway pressures during CPR in adult patients with out-of-hospital cardiac arrest. Rescuers were observed to maintain some residual and continuous pressure on the chest wall during the decompression phase of CPR, preventing full chest wall recoil, at some time during resuscitative efforts in 6 (46%) of 13 consecutive adults (average +/- S.D. age 63 +/-5.8 years). Airway pressures were consistently positive during the decompression phase (>0 mmHg) during those observations. Phase II: This randomized prospective trial was performed on an electronic test manikin. Thirty EMS providers (14 EMT-Basics, 5 EMT-Intermediates, and 11 EMT-Paramedics), with an average age +/- S.D. of 32 +/- 8 years and 6.5 +/- 4.2 years of EMS experience, performed 3 min of CPR on a Laerdal Skill Reporter CPR manikin using the Standard Hand Position followed by 3 min of CPR (in random order) using three alternative CPR techniques: (1) Two-Finger Fulcrum Technique--lifting the heel of the hand slightly but completely off the chest during the decompression phase of CPR using the thumb and little finger as a fulcrum; (2) Five-Finger Fulcrum Technique--lifting the heel of the hand slightly but completely off the chest during the decompression phase of CPR using all five fingers as a fulcrum; and (3) Hands-Off Technique--lifting the heel and all fingers of the hand slightly but completely off the chest during the decompression phase of CPR. These EMS personnel did not know the purpose of the studies prior to or during this investigation. Adequate compression depth was poor for all hand positions tested and ranged only from 29.9 to 48.5% of all compressions. When compared with the Standard Hand Position, the Hands-Off Technique decreased mean compression duty cycle from 46.9 +/- 6.4% to 33.3 +/- 4.6%, (P < 0.0001) but achieved the highest rate of complete chest wall recoil (95.0% versus 16.3%, P < 0.0001) and was 129 times more likely to provide complete chest wall recoil (OR: 129.0; CI: 43.4-382.0). There were no significant differences in accuracy of hand placement, depth of compression, or reported increase in fatigue or discomfort with its use compared with the Standard Hand Position.

CONCLUSIONS

Incomplete chest wall decompression was observed at some time during resuscitative efforts in 6 (46%) of 13 consecutive adult out-of-hospital cardiac arrests. The Hands-Off Technique decreased compression duty cycle but was 129 times more likely to provide complete chest wall recoil (OR: 129.0; CI: 43.4-382.0) compared to the Standard Hand Position without differences in accuracy of hand placement, depth of compression, or reported increase in fatigue or discomfort with its use. All forms of manual CPR tested (including the Standard Hand Position) in professional EMS rescuers using a recording manikin produced an inadequate depth of compression more than half the time. These data support development and testing of more effective means to deliver manual as well as mechanical CPR.

Effects of incomplete chest wall decompression during cardiopulmonary resuscitation on coronary and cerebral perfusion pressures in a porcine model of cardiac arrest

INTRODUCTION

Recent data suggest that generation of negative intrathoracic pressure during the decompression phase of CPR improves hemodynamics, organ perfusion and survival.

HYPOTHESIS

Incomplete chest wall recoil during the decompression phase of standard CPR increases intrathoracic pressure and right atrial pressure, impedes venous return, decreases compression-induced aortic pressures and results in a decrease of mean arterial pressure, coronary and cerebral perfusion pressure.

METHODS

Nine pigs in ventricular fibrillation (VF) for 6 min, were treated with an automated compression/decompression device with a compression rate of 100 min(-1), a depth of 25% of the anterior-posterior diameter, and a compression to ventilation ratio of 15:2 with 100% decompression (standard CPR) for 3 min. Compression was then reduced to 75% of complete decompression for 1 min of CPR and then restored for another 1 min of CPR to 100% full decompression. Coronary perfusion pressure (CPP) was calculated as the diastolic (aortic (Ao)-right atrial (RA) pressure). Cerebral perfusion pressure (CerPP) was calculated multiple ways: (1) the positive area (in mmHg s) between aortic pressure and intracranial pressure (ICP) waveforms, (2) the coincident difference in systolic and diastolic aortic and intracranial pressures (mmHg), and (3) CerPP = MAP--ICP. ANOVA was used for statistical analysis and all values were expressed as mean +/- S.E.M. The power of the study for an alpha level of significance set at 0.05 was >0.90.

RESULTS

With CPR performed with 100%-75%-100% of complete chest wall recoil, respectively, the CPP was 23.3 +/- 1.9, 15.1 +/- 1.6, 16.6 +/- 1.9, p = 0.003; CerPP was: (1) area: 313.8 +/- 104, 89.2 +/- 39, 170.5 +/- 42.9, p = 0.03, (2) systolic aortic minus intracranial pressure difference: 22.8 +/- 3.6, 16.5 +/- 4, 23.7 +/- 4.5, p = n.s., and diastolic pressure difference: 5.7 +/- 3, -2.4 +/- 2.4, 3.2 +/- 2.5, p = 0.04 and (3) mean: 14.3 +/- 3, 7 +/- 2.9, 12.4 +/- 2.9, p = 0.03, diastolic aortic pressure was 28.1 +/- 2.5, 20.7 +/- 1.9, 20.9 +/- 2.1, p = 0.0125; ICP during decompression was 22.8 +/- 1.7, 23 +/- 1.5, 19.7 +/- 1.7, p = n.s. and mean ICP was 37.1 +/- 2.3, 35.5 +/- 2.2, 35.2 +/- 2.4, p = n.s.; RA diastolic pressure 4.8 +/- 1.3, 5.6 +/- 1.2, 4.3 +/- 1.2 p = 0.1; MAP was 52 +/- 2.9, 43.3 +/- 3, 48.3 +/- 2.9, p = 0.04; decompression endotracheal pressure, -0.7 +/- 0.1, -0.3 +/- 0.1, -0.75 +/- 0.1, p = 0.045.

CONCLUSIONS

Incomplete chest wall recoil during the decompression phase of CPR increases endotracheal pressure, impedes venous return and decreases mean arterial pressure, and coronary and cerebral perfusion pressures.

Cost-effectiveness of Project ADAM: a project to prevent sudden cardiac death in high school students

Public access defibrillation (PAD) in the adult population is thought to be both efficacious and cost-effective. Similar programs aimed at children and adolescents have not been evaluated for their cost-effectiveness. This study evaluates the potential cost-effectiveness of implementing Project ADAM, a program targeting children and adolescents in high schools in the Milwaukee Public School System. Project ADAM provides education about cardiopulmonary resuscitation (CPR) and the warning signs of sudden cardiac death (SCD) and training in the use and placement of automated external defibrillators (AEDs) in high schools. We developed decision analysis models to evaluate the cost-effectiveness of the decision to implement Project ADAM in public high schools in Milwaukee. We examined clinical model and public policy applications. Data on costs included estimates of hospital-based charges derived from a pediatric medical center where a series of patients were treated for SCD, educational programming, and the direct costs of one AED and training for 15 personnel per school. We performed sensitivity analyses to assess the variation in outputs with respect to changes to input data. The main outcome measures were Life years saved and incremental cost-effectiveness ratios. At an arbitrary societal willingness to pay $100,000 per life year saved, the policy to implement Project ADAM in schools is a cost-effective strategy at a threshold of approximately 5 patients over 5 years for the clinical model and approximately 8 patients over 5 years for the public policy model. Implementation of Project ADAM in high schools in the United States is potentially associated with an incremental cost-effectiveness ratio that is favorable.

Lessons learned from an emergency medical services fire safety intervention

OBJECTIVE

The authors conducted a pilot study, finding that many households that experienced fires had received prior emergency medical services (EMS) visits, but few had operational smoke alarms. The study hypothesis is that dwellings that received smoke alarms and/or batteries during an EMS call were more likely to have an operational alarm, less property dollar loss, and decreased morbidity and mortality at the time of a subsequent fire.

METHODS

Smoke detectors and batteries were provided to an urban fire department for placement in unprotected homes at the time of an EMS call from March 1, 1999, through January 31, 2001. After addressing the reason for the 911 EMS call, verification or installation of an operational smoke alarm was performed. The authors examined records for dwellings that had a subsequent fire for outcomes of smoke alarm status, estimated property dollar loss, and number of injuries and fatalities.

RESULTS

This program placed 1,335 smoke detectors. Of these, 99 dwellings were found to have a fire or smoke condition with 20 exclusions. Our final number was 79; 28 (35%) still had an operating smoke alarm. In homes with operational alarms, the mean dollar loss was 2,870 dollars (U.S. 2001) (95% confidence interval [CI], 143-5,596). In homes without operational alarms, mean loss was 10,468 dollars (U.S. 2001) (95% CI, 5,875-15,061). No injuries or fatalities occurred in either group.

CONCLUSION

This program was successful in placing 1,335 smoke alarms in at-risk dwellings and reaffirmed that an operational smoke alarm significantly decreases property dollar loss. However, if the goal is to have all homes protected by smoke alarms, this program has long-term effectiveness limitations.

Hyperventilation-Induced Hypotension During Cardiopulmonary Resuscitation

Background— A clinical observational study revealed that rescuers consistently hyperventilated patients during out-of-hospital cardiopulmonary resuscitation (CPR). The objective of this study was to quantify the degree of excessive ventilation in humans and determine if comparable excessive ventilation rates during CPR in animals significantly decrease coronary perfusion pressure and survival.

Methods and Results— In humans, ventilation rate and duration during CPR was electronically recorded by professional rescuers. In 13 consecutive adults (average age, 63±5.8 years) receiving CPR (7 men), average ventilation rate was 30±3.2 per minute (range, 15 to 49). Average duration per breath was 1.0±0.07 per second. No patient survived. Hemodynamics were studied in 9 pigs in cardiac arrest ventilated in random order with 12, 20, or 30 breaths per minute. Survival rates were then studied in 3 groups of 7 pigs in cardiac arrest that were ventilated at 12 breaths per minute (100% O 2 ), 30 breaths per minute (100% O 2 ), or 30 breaths per minute (5% CO 2 /95% O 2 ). In animals treated with 12, 20, and 30 breaths per minute, the mean intrathoracic pressure (mm Hg/min) and coronary perfusion pressure (mm Hg) were 7.1±0.7, 11.6±0.7, 17.5±1.0 ( P <0.0001), and 23.4±1.0, 19.5±1.8, and 16.9±1.8 ( P =0.03), respectively. Survival rates were 6/7, 1/7, and 1/7 with 12, 30, and 30+ CO 2 breaths per minute, respectively ( P =0.006).

Conclusions— Professional rescuers were observed to excessively ventilate patients during out-of-hospital CPR. Subsequent animal studies demonstrated that similar excessive ventilation rates resulted in significantly increased intrathoracic pressure and markedly decreased coronary perfusion pressures and survival rates.

Management of the violent patient

Emergency medical services (EMS) providers must often manage violent or combative patients. The data regarding violence against EMS personnel are poor, but according to studies conducted thus far, between 0.8% and 5.0% of incidents to which EMS personnel respond involve violence or the threat of violence. Physical or chemical restraint is usually the only option available to emergency care providers to control violent patients. Physical restraint, however, can lead to sudden death in otherwise healthy patients, possibly as a result of positional asphyxia, severe acidosis, or a patient's excited delirium. Chemical restraint has traditionally consisted of either neuroleptics or benzodiazepines, but those drugs also have drawbacks. Haloperidol and droperidol, the neuroleptics most frequently used for restraint, can cause serious side effects such as extrapyramidal symptoms or QTc (QT interval corrected for heart rate) prolongation. The Food and Drug Administration recently issued a black box warning regarding the use of droperidol, because the QTc prolongation associated with the drug has led to fatal torsades de pointes in some patients. Benzodiazepines are also associated with adverse effects, such as sedation and respiratory depression, especially when the drugs are mixed with alcohol. The atypical antipsychotics, a new option that may be available soon, are less likely to cause such effects and therefore may be preferred over the neuroleptics. Liquid and injectable formulations of various atypical antipsychotics are currently in clinical trials. Because few options are currently available to EMS personnel for managing violent patients outside of the hospital, more research regarding violence against emergency care providers is necessary.