Risk Adjustment and Outcome Measures for Out-of-hospital Respiratory Distress

The purpose of the Emergency Medical Services Outcomes Project (EMSOP) is to develop a foundation and framework for out-of-hospital outcomes research. In prior work, this group delineated the priority conditions, described conceptual models, suggested core and risk adjustment measures potentially useful to emergency medical services research, and summarized out-of-hospital pain measurement. In this fifth article in the EMSOP series, the authors recommend specific risk-adjustment measures and outcome measures for use in out-of-hospital research on patients presenting with respiratory distress. The methodology included systematic literature searches and a structured review by an expert panel. The EMSOP group recommends use of pulse oximetry, peak expiratory flow rate, and the visual analog dyspnea scale as potential risk-adjustment measures and outcome measures for out-of-hospital research in patients with respiratory distress. Furthermore, using mortality as an outcome measure is also recommended. Future research is needed to alleviate the paucity of validated tools for out-of-hospital outcomes research.     

Out-of-Hospital Research in the Era of Electronic Health Records

Conducting out-of-hospital research is unique and challenging and requires tracking patients across multiple phases of care, using multiple sources of patient records and multiple hospitals. The logistics and strategies used for out-of-hospital research are distinct from other forms of clinical research. The increasing use of electronic health records (EHRs) by hospitals and emergency medical services (EMS) agencies presents a large opportunity for accelerating out-of-hospital research, as well as particular challenges. In this study, we describe seven key aspects of designing and implementing out-of-hospital research in the era of EHRs: (1) selection of research sites, (2) defining the patient population, (3) patient sampling and sample size calculations, (4) EMS data, (5) hospital selection, (6) handling missing data, and (7) statistical analysis. We use examples from a recent prospective out-of-hospital cohort study to illustrate these topics, including lessons learned.     

S TUDY D ESIGN AND O UTCOMES IN O UT-OF-HOSPITAL E MERGENCY M EDICINE R ESEARCH : A T EN-YEAR A NALYSIS

Objective. Lack of rigorous study design and failure to follow diverse patient outcomes have been identified as critical gaps in the medical research literature. This study sought to determine whether similar gaps exist in the literature for out-of-hospital interventions. Methods. A computerized MEDLINE search was conducted for the ten-year period 1985 through 1994 using the MeSH terms “emergency medical services,” “prehospital,” and “transportation of patients.” Using a standard abstraction form, two investigators independently analyzed articles meeting these inclusion criteria: original research evaluating an out-of-hospital intervention and measuring a patient outcome. Study design was categorized in order of scientific rigor, moving from case series to randomized trial. Measures of outcomes were classified into the six Ds: death, disease, discomfort, disability, dissatisfaction, and debt (cost). Results. Interobserver agreement was high (kappa = 0.80). For the ten-year period, 3,686 titles, 1,454 abstracts, and 373 articles were examined serially; all 285 studies meeting inclusion criteria were analyzed. Case series (44%) was the most frequently used design, while only 15% were randomized trials. The majority of the studies were retrospective (53%). A single outcome was assessed in 45% of the articles; 41% measured two outcomes, 13% three outcomes, and 1% four outcomes. Death and disease were the most common outcomes evaluated. Disability, debt, discomfort, and dissatisfaction were infrequently measured. Conclusion. Studies of out-of-hospital emergency medical interventions are limited in the scientific rigor of study design and the diversity of patient outcomes measured. To adequately assess the effectiveness of out-of-hospital care, efforts should be directed toward strengthening study designs and examining the full range of patient outcomes.     

Resuscitation Research: Future Directions and Ethical Issues

Cardiopulmonary resuscitation research is a vital area of research that has made significant contributions to medical care over the last several decades. Abundant information currently exists in the medical literature, as a result of research in the areas of cardiac arrest and outcomes, physiology of cardiac arrest, pharmacologic treatments, mechanical interventions, and societal and ethical issues. Despite numerous clinical trials demonstrating physiologic benefit of various interventions, few interventions have had as much impact on outcomes of cardiac arrest as have improvements in out-of-hospital response times and rapid availability of medical treatment. Although abundant information exists regarding physiologic aspects of resuscitation, relatively little information exists about ethical, psychological, and social aspects of resuscitation. In addition to attempts to improve outcomes of cardiac arrest, researchers should also strive to improve the experiences of patients and families involved. These realities provide future strategies and directions for the best use of resuscitation research resources; although physiologic and pharmacologic research will always have significant roles in the improvement of medical care, the rapid delivery of out-of-hospital care and ethical issues will be indispensable areas of research focus in the future.     

Out-of-hospital cardiac arrest

Myocardial disease and death from cardiac arrest remain significant public health problems. Sudden death events and out-of-hospital cardiac arrests (OHCA) are encountered frequently by emergency medical services. Despite more than 30 years of research, survival rates remain extremely low. This article reviews access and presentations, demographics, OHCA outcomes, and response systems and processes in treatment of patients with arrest in this setting.     

Paramedic Perceptions of Challenges in Out-of-Hospital Endotracheal Intubation

Objective. Paramedics often perform endotracheal intubation (ETI), insertion of a breathing tube, on critically ill out-of-hospital patients. Recent studies highlight important paramedic ETI shortcomings including adverse events, errors, andpoor outcomes resulting from this procedure. Little is known about workforce perceptions of these events. We sought to identify paramedic andphysician perceptions regarding the challenges andpitfalls of out-of-hospital ETI. Methods. We conducted a qualitative study involving paramedic focus groups sessions andindividual interviews with Emergency Medical Services (EMS) physician medical directors. We recorded andtranscribed all sessions. We used inductive theory construction to examine, organize, andclassify thematic patterns. Results. Fourteen paramedics and6 physicians participated. Although paramedics andphysicians recognized problems with paramedic ETI, all participants strongly felt that paramedics should continue to perform the procedure. Physicians andparamedics disagreed about the ability of paramedics to perform neuromuscular blockade-assisted intubation. Both groups identified aspects of paramedic education, skills acquisition, andmaintenance as core issues. Participants also identified broader factors about the structure of emergency services, the role of the medical director, andworkforce culture andprofessionalism. Conclusion. Paramedics andEMS physicians attribute paramedic ETI performance to a myriad of factors involving EMS education, organization, oversight, retention, andprofessionalism. Efforts to improve ETI must include strategies to address multiple aspects of EMS operations andculture.     

S PINAL I MMOBILIZATION IN THE F IELD : C LINICAL C LEARANCE C RITERIA AND I MPLEMENTATION

Awareness of the health and financial repercussions of unnecessary immobilization has made cervical spinal immobilization controversial in out-of-hospital care. Clinical criteria for clearance of the cervical spine in the hospital based on mechanism of injury have been supported by many trauma centers. However, implementation of clinical criteria for cervical spinal clearance in out-of-hospital settings is not as well validated by multicenter studies or accepted by many emergency departments. This consensus group recommends that clinical criteria to determine “low-risk” patients be available for use by emergency medical services providers in out-of-hospital settings; however, training, audits, quality management, integration into the medical community, and extent of program implementation should be decided based on individual emergency medical services systems.     

Out-of-hospital medication storage temperatures:: a review of the literature and directions for the future

The United States Pharmacopeia (USP) National Formulary prescribes the packaging, storage, and distribution of medications. Most of the medications commonly used by emergency medical services (EMS) are intended for storage at “controlled room temperature.” The USP definition of controlled room temperature is multifaceted and complex, and cannot be easily described as a simple range of acceptable temperatures, or even as an average temperature. The out-of-hospital environment is notoriously uncontrolled, and one of the uncontrolled aspects of that environment is temperature. This report reviews and summarizes the past 15 years of published research relating to out-of-hospital medication temperature exposures. Although the evidence is clear that EMS medication storage is not consistent with the USP definition of controlled room temperature, the impact of EMS medication storage on medication stability and potency remains unclear. Further research is needed to determine the true extent of the EMS medication storage problem, and to develop and validate appropriate solutions.     

Out-of-hospital characteristics and care of patients with severe sepsis: A cohort study

PurposeEarly recognition and treatment in severe sepsis improve outcomes. However, out-of-hospital patient characteristics and emergency medical services (EMS) care in severe sepsis is understudied. Our goals were to describe out-of-hospital characteristics and EMS care in patients with severe sepsis and to evaluate associations between out-of-hospital characteristics and severity of organ dysfunction in the emergency department (ED).Materials and MethodsWe performed a secondary data analysis of existing data from patients with severe sepsis transported by EMS to an academic medical center. We constructed multivariable linear regression models to determine if out-of-hospital factors are associated with serum lactate and sequential organ failure assessment (SOFA) in the ED.ResultsTwo hundred sixteen patients with severe sepsis arrived by EMS. Median serum lactate in the ED was 3.0 mmol/L (interquartile range, 2.0-5.0) and median SOFA score was 4 (interquartile range, 2-6). Sixty-three percent (135) of patients were transported by advanced life support providers and 30% (62) received intravenous fluid. Lower out-of-hospital Glasgow Coma Scale score was independently associated with elevated serum lactate (P < .01). Out-of-hospital hypotension, greater respiratory rate, and lower Glasgow Coma Scale score were associated with greater SOFA (P < .01).ConclusionsOut-of-hospital fluid resuscitation occurred in less than one third of patients with severe sepsis, and routinely measured out-of-hospital variables were associated with greater serum lactate and SOFA in the ED.     

EMS Management of Acute Stroke—Out-of-Hospital Treatment andStroke System Development (Resource Document to NAEMSP Position Statement)

The American Heart Association estimates an annual incidence of stroke in the United States at 700,000, leading to over 150,000 deaths. Of all strokes, approximately 88% are ischemic and12% are hemorrhagic. Almost half of all stroke deaths occur in the out-of-hospital environment. Within a given region, the emergency medical services (EMS) system has an important role in the management of the acute stroke patient. Decisions made by EMS personnel can affect treatment andcontribute to the immediate, short-term, andlong-term outcomes of the patient. Because the patient may require emergent treatment regardless if the stroke is ischemic or hemorrhagic, EMS personnel should manage all potential stroke patients in a time-dependent nature. Proper treatment anddisposition of the stroke patient begins in the out-of-hospital environment, continues in the emergency department, andthen extends to the inpatient admission. This article reviews the literature on the out-of-hospital treatment of stroke patients andthe role of EMS in the development of stroke systems of care.     

S UBCUTANEOUS E PINEPHRINE IN THE P REHOSPITAL S ETTING

The United States Pharmacopeia (USP) National Formulary prescribes the packaging, storage, and distribution of medications. Most of the medications commonly used by emergency medical services (EMS) are intended for storage at “controlled room temperature.” The USP definition of controlled room temperature is multifaceted and complex, and cannot be easily described as a simple range of acceptable temperatures, or even as an average temperature. The out-of-hospital environment is notoriously uncontrolled, and one of the uncontrolled aspects of that environment is temperature. This report reviews and summarizes the past 15 years of published research relating to out-of-hospital medication temperature exposures. Although the evidence is clear that EMS medication storage is not consistent with the USP definition of controlled room temperature, the impact of EMS medication storage on medication stability and potency remains unclear. Further research is needed to determine the true extent of the EMS medication storage problem, and to develop and validate appropriate solutions.     

Impact of the Privacy Rule on the Study of Out-of-Hospital Pediatric Cardiac Arrest

Introduction. The Privacy Rule, a follow-up to the Health Insurance Portability andAccountability Act, limits distribution of protected health information. Compliance with the Privacy Rule is particularly challenging for prehospital research, because investigators often seek data from multiple emergency medical services (EMS) andreceiving hospitals. Objective. To describe the impact of the Privacy Rule on prehospital research andto present strategies to optimize data collection in compliance with the Privacy Rule. Methods. The CanAm Pediatric Cardiopulmonary Arrest Study Group has previously conducted a multicentered observational study involving children with out-of-hospital cardiac arrest. In the current study, we used a survey to assess site-specific methods of compliance with the Privacy Rule andthe extent to which such strategies were successful. Results. The previously conducted observational study included collection of data from a total of 66 EMS agencies (range of 1–37 per site). Data collection from EMS providers was complicated by the lack of a systematic approval mechanism for the research use of EMS records andby incomplete resuscitation records. Agencies approached for approval to release EMS data for study purposes included Department of Health Institutional Review Boards, Fire Commissioners, andCommissioners of Health. The observational study included collection of data from a total of 164 receiving hospitals (range of 1–63 per site). Data collection from receiving hospitals was complicated by the varying requirements of receiving hospitals for the release of patient survival data. Conclusions. Obtaining complete EMS andhospital data is challenging but is vital to the conduct of prehospital research. Obtaining approval from city or state level IRBs or Privacy Boards may help optimize data collection. Uniformity of methods to adhere to regulatory requirements would ease the conduct of prehospital research.     

Population Density, Automated External Defibrillator Use, and Survival in Rural Cardiac Arrest

Objective: To determine whether population density is an independent predictor of survival from out-of-hospital cardiac arrest managed by basic life support (BLS) services using automated external defibrillators (AEDs).
Methods: A retrospective, observational study in Kentucky of 34 BLS services covering 22 counties during the years 1992 to 1994 who used AEDs to treat patients who had out-of-hospital cardiac arrests.
Results: Of 311 patients who had out-of-hospital cardiac arrests, 110 (35%) were defibrillated, 46 (15%) were resuscitated to hospital admission, and 19 (6%) survived to hospital discharge. Univariate predictors for survival to hospital discharge were emergency medical services response interval (from call receipt to ambulance arrival) <8 minutes, defibrillation by the AED, initial rhythm of ventricular fibrillation or ventricular tachycardia (VF/VT), and population density >100/square mile (sq mi) for the BLS service area (p < 0.001). A forced logistic regression model of survival to hospital discharge, using these 4 factors plus the presence of a witnessed arrest or bystander CPR, demonstrated that population density >100/sq mi was highly significant (OR 9.4, 95% CI: 1.7 to 51.4, p < 0.01). Stepwise logistic regression models with combinations of these 6 factors found that survival to hospital discharge was best predicted by an initial rhythm of VF/VT (p = 0.004) and population density >100/sq mi (p = 0.011).
Conclusions: Population density is strongly associated with survival from out-of-hospital cardiac arrest. BLS services within areas with population densities ≤100/sq mi sustained little benefit from the addition of AEDs to their treatment of patients who had out-of-hospital cardiac arrests.     

Can lay responder defibrillation programmes improve survival to hospital discharge following an out-of-hospital cardiac arrest?

INTRODUCTION: The importance of early defibrillation in improving outcomes and reducing morbidity following out-of-hospital cardiac arrest underscores the importance of examining novel approaches to treatment access. The increasing evidence to support the importance of early defibrillation has increased attention on the potential for lay responders to deliver this therapy. AIM: This paper seeks to critically review the literature that evaluates the impact of lay responder defibrillator programs on survival to hospital discharge following an out-of-hospital cardiac arrest in the adult population. METHOD: The electronic databases, Medline and CINAHL, were searched using keywords including; "first responder", "lay responder", "defibrillation" and "cardiac arrest". The reference lists of retrieved articles and the Internet were also searched. Articles were included in the review if they reported primary data, in the English language, which described the effect of a lay responder defibrillation program on survival to hospital discharge from out-of-hospital cardiac arrest in adults. RESULTS: Eleven studies met the inclusion criteria. The small number of published studies, heterogeneity of study populations and study outcome methods prohibited formal meta-analysis. Therefore, narrative analysis was undertaken. Studies included in this report provided inconsistent findings in relation to survival to hospital discharge following out-of-hospital cardiac arrest. CONCLUSION: Although there are limited data, the role of the lay responder appears promising in improving the outcome from out-of-hospital cardiac arrest following early defibrillation. Despite the inherent methodological difficulties in studying this population, future research should address outcomes related to morbidity, mortality and cost-effectiveness.     

Patient Refusal of Care in the Out-of-hospital Setting

A case vignette of out-of-hospital refusal of emergency care is reported with accompanying discussion. This case illustrates the challenges faced by out-of-hospital emergency care personnel in these scenarios and provides guidance to the emergency physician and emergency medical technician. Recommendations are provided for preparing the emergency medical services system to handle these cases.     

Disaster Medicine: Current Assessment and Blueprint for the Future

Emergency services for disaster-affected populations require the application of out-of-hospital planning, curative acute medical skills, and public health principles. SAEM can play an important role in promoting the research and educational agendas for disaster medicine through its network of EM educators at academic health centers. Testing of disaster medicine principles as part of the EM certification process will emphasize the importance of disaster medicine in the overall training of EPs. Postgraduate fellowships in disaster medicine also should be promoted and closely linked to disaster response organizations. Overall professional training must encompass the many facets described in this paper to prepare physicians to meet the challenges of disaster medicine.     

Hypothermia and cardiac arrest: the promise of intra-arrest cooling

Over the past several years, the implementation of therapeutic hypothermia has provided an exciting opportunity toward improving survival from out-of-hospital cardiac arrest. There are compelling data to support the prompt use of therapeutic hypothermia for initial survivors from out-of-hospital cardiac arrest, but animal data have suggested that initiation of therapeutic hypothermia during the intra-arrest period may significantly improve outcomes even further. In the first feasibility study in humans, Bruel and colleagues report on the implementation of this intra-arrest approach among patients suffering out-of-hospital cardiac arrest, an exciting prospect that is discussed in the present commentary.     

NAEMSE Abstracts 2006

Abstract

Objective. Early, high-quality, minimally interrupted bystander cardio-pulmonary resuscitation (BCPR) is essential for out-of-hospital cardiac arrest survival. However, rates of bystander intervention remain low in many geographic areas. Community CPR programs have been initiated to combat these low numbers by teaching compression-only CPR to laypersons. This study examined bystander CPR and the cost-effectiveness of a countywide CPR program to improve out-of-hospital cardiac arrest survival. Methods. A 2-year retrospective review of emergency medical services (EMS) run reports for adult nontraumatic cardiac arrests was performed using existing prehospital EMS quality assurance data. The incidence and success of bystander CPR to produce prehospital return of spontaneous circulation and favorable neurologic outcomes at hospital discharge were analyzed. The outcomes were paired with cost data for the jurisdiction's community CPR program to develop a cost-effectiveness model. Results. During the 23-month study period, a total of 371 nontraumatic adult out-of-hospital cardiac arrests occurred, with a 33.4% incidence of bystander CPR. Incremental cost-effectiveness analysis for the community CPR program demonstrated a total cost of $22,539 per quality-adjusted life-year (QALY). A significantly increased proportion of those who received BCPR also had an automated external defibrillator (AED) applied. There was no correlation between witnessed arrest and performance of BCPR. A significantly increased proportion of those who received BCPR were found to be in a shockable rhythm when the initial ECG was performed. In the home setting, the chances of receiving BCPR were significantly smaller, whereas in the public setting a nearly equal number of people received and did not receive BCPR. Witnessed arrest, AED application, public location, and shockable rhythm on initial ECG were all significantly associated with positive ROSC and neurologic outcomes. A home arrest was significantly associated with worse neurologic outcome. Conclusions. Cost-effectiveness analysis demonstrates that a community CPR outreach program is a cost-effective means for saving lives when compared to other healthcare-related interventions. Bystander CPR showed a clear trend toward improving the neurologic outcome of survivors. The findings of this study indicate a need for additional research into the economic effects of bystander CPR.     

Emergency Medical Service Providers' Attitudes andExperiences Regarding Enrolling Patients in Clinical Research Trials

Objective: The purpose of this study was to evaluate Emergency Medical Services (EMS) providers' attitudes andexperiences about enrolling patients in clinical research trials utilizing the federal rules for exception from informed consent. We hypothesized that Emergency Medical Technicians (EMTs) would have varied attitudes about research using an exception from informed consent which could have an impact on the research. Methods andsetting: Since January 2007, the EMS system has been participating in a randomized, multi-center interventional trial in which out-of-hospital providers enroll critically injured trauma patients using exception from informed consent.A voluntary, anonymous, written survey was administered to EMS providers during an in-service. The survey included demographics andLikert-type questions about their experiences with andattitudes towards research in general, andresearch using an exception from informed consent for an out-of-hospital clinical trial. Results: The response rate was 79.3% (844/1067). Most respondents, 93.3%, agreed that “research in EMS care is important.” However, 38.5% also agreed that individual EMTs/paramedics should maintain the personal right of refusal to enroll patients in EMS trials. Fifty-four percent of respondents agreed with the statement that “the right of research subjects to make their own choices is more important than the interests of the general community.” In response to statements about the current study, 11.3% agreed that “the study is unethical because the patient cannot consent” and69.2% responded that they would personally be willing to be enrolled in the study before they were able to give consent if they were seriously injured. Those who had not enrolled a patient into the study (681 respondents) were asked their reasons: 76.8% had not encountered an eligible patient or did not work for an agency that carried the fluid; 4.3% did not have time; 4.1% forgot and1.1% stated that they were opposed to enrolling patients in studies without their consent. Conclusion: The majority of EMS personnel in one community support EMS research andthis specific out-of-hospital clinical trial being conducted under an exception from informed consent. Potential barriers to enrollment were identified. Further study in other systems is warranted to better understand EMS provider perspectives about exception from informed consent research.