Primary outcomes for resuscitation science studies: a consensus statement from the American Heart Association

BACKGROUND AND PURPOSE

The guidelines presented in this consensus statement are intended to serve researchers, clinicians, reviewers, and regulators in the selection of the most appropriate primary outcome for a clinical trial of cardiac arrest therapies. The American Heart Association guidelines for the treatment of cardiac arrest depend on high-quality clinical trials, which depend on the selection of a meaningful primary outcome. Because this selection process has been the subject of much controversy, a consensus conference was convened with national and international experts, the National Institutes of Health, and the US Food and Drug Administration.

METHODS

The Research Working Group of the American Heart Association Emergency Cardiovascular Care Committee nominated subject leaders, conference attendees, and writing group members on the basis of their expertise in clinical trials and a diverse perspective of cardiovascular and neurological outcomes (see the online-only Data Supplement). Approval was obtained from the Emergency Cardiovascular Care Committee and the American Heart Association Manuscript Oversight Committee. Preconference position papers were circulated for review; the conference was held; and postconference consensus documents were circulated for review and comments were invited from experts, conference attendees, and writing group members. Discussions focused on (1) when after cardiac arrest the measurement time point should occur; (2) what cardiovascular, neurological, and other physiology should be assessed; and (3) the costs associated with various end points. The final document underwent extensive revision and peer review by the Emergency Cardiovascular Care Committee, the American Heart Association Science Advisory and Coordinating Committee, and oversight committees.

RESULTS

There was consensus that no single primary outcome is appropriate for all studies of cardiac arrest. The best outcome measure is the pairing of a time point and physiological condition that will best answer the question under study. Conference participants were asked to assign an outcome to each of 4 hypothetical cases; however, there was not complete agreement on an ideal outcome measure even after extensive discussion and debate. There was general consensus that it is appropriate for earlier studies to enroll fewer patients and to use earlier time points such as return of spontaneous circulation, simple "alive versus dead," hospital mortality, or a hemodynamic parameter. For larger studies, a longer time point after arrest should be considered because neurological assessments fluctuate for at least 90 days after arrest. For large trials designed to have a major impact on public health policy, longer-term end points such as 90 days coupled with neurocognitive and quality-of-life assessments should be considered, as should the additional costs of this approach. For studies that will require regulatory oversight, early discussions with regulatory agencies are strongly advised. For neurological assessment of post-cardiac arrest patients, researchers may wish to use the Cerebral Performance Categories or modified Rankin Scale for global outcomes.

CONCLUSIONS

Although there is no single recommended outcome measure for trials of cardiac arrest care, the simple Cerebral Performance Categories or modified Rankin Scale after 90 days provides a reasonable outcome parameter for many trials. The lack of an easy-to-administer neurological functional outcome measure that is well validated in post-cardiac arrest patients is a major limitation to the field and should be a high priority for future development.

The introduction of public access defibrillation to a university community: the University of Virginia public access defibrillation program

The use of the automatic external defibrillator (AED) can significantly reduce the time to defibrillation in patients with sudden cardiac death. This early defibrillation via the AED can also improve patient outcome, including survival and neurologic status among survivors. We undertook the addition of a public access defibrillation program at a large mid-Atlantic university. In our design of the system, we found little useful information to guide us in the development and construction our system. This article is a review of the process of public access defibrillation AED system development such that other medical and academic leaders at similar institutions can more easily develop such systems.

Higher inpatient medical surgical bed occupancy extends admitted patients' stay

Objective:

Determine the effect that increased medical surgical (med/surg) bed occupancy has on the time interval from admission order to arrival in the bed for the patients admitted from the emergency department (ED).

Methods:

This retrospective observational study compares the total hospital bed occupancy rate and the medical surgical inpatient bed occupancy rate to daily averages for the time interval from admission order (patient posting for admission) to the patient’s arrival in the inpatient bed. Medical surgical inpatient bed occupancy of 92% was chosen because beyond that rate we observed more frequent extended daily transfer times. The data is from a single large tertiary care institute with 590 beds and an annual ED census of 80,000.

Results:

Group 1 includes 38 days with (med/surg) inpatient bed occupancy rate of less than 92%, with an average ED daily wait of 2.5 hrs (95% confidence interval 2.23–2.96) for transfer from the ED to the appropriate hospital bed. Group 2 includes 68 days with med/surg census greater than 92% with an average ED daily wait of 4.1 hours (95% confidence interval 3.7–4.5). Minimum daily average for the two groups was 1.2 hrs and 1.3 hrs, respectively. The maximum average was 5.6 hrs for group 1 and 8.6 hrs for group 2. Comparison of group 1 to 2 for wait time to hospital bed yielded p <0.01. Total reported hospital occupied capacity shows a correlation coefficient of 0.16 to transfer time interval, which indicates a weak relationship between total occupancy and transfer time into the hospital. Med/surg occupancy, the beds typically used by ED patients, has a 0.62 correlation coefficient for a moderately strong relationship.

Conclusions:

Med/surg bed occupancy has a better correlation to extended transfer times, and occupancy over 92% at 5 AM in our institution corresponds to an increased frequency of extended transfer times from the ED. The process of ED evaluation, hospital admission, and subsequent transfer into the hospital are all complex processes. This study begins to demonstrate one variable, med/surg occupancy, as one of the intervals that can be followed to evaluate the process of ED admission and hospital flow.

The diagnosis and management of seizures and status epilepticus in the prehospital setting

Seizure is one of the most common complaints encountered in the prehospital setting. In this review the authors discuss the prehospital management of seizures and review the evidence for specific treatment approaches. Specific attention is devoted to prehospital care of the pediatric seizure patient. Topics of interest to Emergency Medical Services directors such as patient refusal, resource allocation, and dispatch priority are also addressed.

Regional Systems of Care for Out-of-Hospital Cardiac Arrest

Out-of-hospital cardiac arrest continues to be an important public health problem, with large and important regional variations in outcomes. Survival rates vary widely among patients treated with out-of-hospital cardiac arrest by emergency medical services and among patients transported to the hospital after return of spontaneous circulation. Most regions lack a well-coordinated approach to post–cardiac arrest care. Effective hospital-based interventions for out-of-hospital cardiac arrest exist but are used infrequently. Barriers to implementation of these interventions include lack of knowledge, experience, personnel, resources, and infrastructure. A well-defined relationship between an increased volume of patients or procedures and better outcomes among individual providers and hospitals has been observed for several other clinical disorders. Regional systems of care have improved provider experience and patient outcomes for those with ST-elevation myocardial infarction and life-threatening traumatic injury. This statement describes the rationale for regional systems of care for patients resuscitated from cardiac arrest and the preliminary recommended elements of such systems. Many more people could potentially survive out-of-hospital cardiac arrest if regional systems of cardiac resuscitation were established. A national process is necessary to develop and implement evidence-based guidelines for such systems that must include standards for the categorization, verification, and designation of components of such systems. The time to do so is now.

Urban sprawl and delayed ambulance arrival in the U.S

BACKGROUND

Minimizing emergency medical service (EMS) response time is a central objective of prehospital care, yet the potential influence of built environment features such as urban sprawl on EMS system performance is often not considered.

PURPOSE

This study measures the association between urban sprawl and EMS response time to test the hypothesis that features of sprawling development increase the probability of delayed ambulance arrival.

METHODS

In 2008, EMS response times for 43,424 motor-vehicle crashes were obtained from the Fatal Analysis Reporting System, a national census of crashes involving > or =1 fatality. Sprawl at each crash location was measured using a continuous county-level index previously developed by Ewing et al. The association between sprawl and the probability of a delayed ambulance arrival (> or =8 minutes) was then measured using generalized linear mixed modeling to account for correlation among crashes from the same county.

RESULTS

Urban sprawl is significantly associated with increased EMS response time and a higher probability of delayed ambulance arrival (p=0.03). This probability increases quadratically as the severity of sprawl increases while controlling for nighttime crash occurrence, road conditions, and presence of construction. For example, in sprawling counties (e.g., Fayette County GA), the probability of a delayed ambulance arrival for daytime crashes in dry conditions without construction was 69% (95% CI=66%, 72%) compared with 31% (95% CI=28%, 35%) in counties with prominent smart-growth characteristics (e.g., Delaware County PA).

CONCLUSIONS

Urban sprawl is significantly associated with increased EMS response time and a higher probability of delayed ambulance arrival following motor-vehicle crashes in the U.S. The results of this study suggest that promotion of community design and development that follows smart-growth principles and regulates urban sprawl may improve EMS performance and reliability.

Evaluating emergency care research networks: what are the right metrics?

Research networks can enable the inclusion of large, diverse patient populations in different settings. However, the optimal measures of a research network's failure or success are not well defined or standardized. To define a framework for metrics used to measure the performance and effectiveness of emergency care research networks (ECRN), a conference for emergency care investigators, funding agencies, patient advocacy groups, and other stakeholders was held and yielded the following major recommendations: 1) ECRN metrics should be measurable, explicitly defined, and customizable for the multiple stakeholders involved and 2) continuing to develop and institute metrics to evaluate ECRNs will be critical for their accountability and sustainability.

The importance of emergency medicine in organ donation: successful donation is more likely when potential donors are referred from the emergency department

OBJECTIVES

This study sought to identify factors that are associated with successful organ retrieval among patients referred to organ procurement services for potential organ donation. Particular attention was paid to the frequency, patient characteristics, and outcomes of patients referred for donation from the emergency department (ED).

METHODS

For this retrospective cohort study, data were collected on all solid-organ donor referrals made to a single organ procurement organization serving 78 hospitals over a 45-month period. Data retrieved included patient age, sex, race, referral site (ED vs. inpatient), and mechanism of injury. Outcome of referral (organs retrieved or not) was the primary outcome variable. Pearson chi-square and Student's t-tests were used for bivariate statistical analysis. Multiple logistic regression analysis was used to determine which variables remained associated with organ retrieval after controlling for potential confounders.

RESULTS

A total of 6,886 donor referrals were made in the study population. Of these, 155 were excluded due to incomplete data, leaving 6,731 subjects for analysis. Using bivariate statistical analysis, we found that successful organ retrieval was associated with younger age (donor mean age 40.8 years, 95% confidence interval [CI] = 39.1 to 42.5 vs. nondonor mean age 59.4, 95% CI = 58.9 to 59.9), mechanism of injury (p < 0.001), and referral from the ED (ED 15.5% retrieved, inpatient 5.9%, odds ratio [OR] = 2.92, 95% CI = 2.32 to 3.67). After controlling for potential confounders with multiple logistic regression, referral from the ED remained significantly associated with successful organ retrieval (OR = 1.52, 95% CI = 1.18 to 1.97), as did age (OR = 0.96, 95% CI = 0.96 to 0.97) and mechanism of injury (p < 0.001). On regression analysis, race emerged as a significant predictor of organ retrieval (p < 0.001). Medically suitable patients referred from the ED were significantly more likely on bivariate analysis to have consent for donation granted compared to patients referred from inpatient settings (OR = 1.48, 95% CI = 1.03 to 2.12), but this association was not found to be significant on regression analysis (OR = 1.37, 95% CI = 0.93 to 2.02).

CONCLUSIONS

Referral of potential organ donors from the ED is associated with an increased likelihood of successful organ retrieval. The authors conclude that further attention and resources should be directed toward the role of emergency medicine (EM) in the organ procurement process, owing to the relatively high likelihood of successful organ retrieval among patients referred from the ED.