William J. Meurer

Part 8: Post-cardiac arrest care: 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care

The recommendations in this 2015 American Heart Association (AHA) Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care are based on an extensive evidence review process that was begun by the International Liaison Committee on Resuscitation (ILCOR) after the publication of the 2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations 1,2 and was completed in February 2015.3,4 In this in-depth evidence review process, ILCOR examined topics and then generated a prioritized list of questions for systematic review. Questions were first formulated in PICO (population, intervention, comparator, outcome) format,5 and then search strategies and inclusion and exclusion criteria were defined and a search for relevant articles was performed. The evidence was evaluated by the ILCOR task forces by using the standardized methodological approach proposed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group.6 The quality of the evidence was categorized based on the study methodologies and the 5 core GRADE domains of risk of bias, inconsistency, indirectness, imprecision, and other considerations (including publication bias). Then, where possible, consensus-based treatment recommendations were created. To create this 2015 Guidelines Update, the AHA formed 15 writing groups, with careful attention to manage conflicts of interest, to assess the ILCOR treatment recommendations and to write AHA treatment recommendations by using the AHA Class of Recommendation (COR) and Level of Evidence (LOE) system. The recommendations made in the Guidelines are informed by the ILCOR recommendations and GRADE classification, in the context of the delivery of medical care in North America. The AHA writing group made new recommendations only on topics specifically reviewed by ILCOR in 2015. This chapter delineates instances where the AHA writing group developed recommendations that are significantly stronger or weaker than the ILCOR statements. In the online …

National Trends in Use of Computed Tomography in the Emergency Department

STUDY OBJECTIVE The role of computed tomography (CT) in acute illnesses has increased substantially in recent years; however, little is known about how CT use in the emergency department (ED) has changed over time. METHODS A retrospective study was performed with the 1996 to 2007 National Hospital Ambulatory Medical Care Survey, a large nationwide survey of ED services. We assessed changes during this period in CT use during an ED visit, CT use for specific ED presenting complaints, and disposition after CT use. Main outcomes were presented as adjusted risk ratios (RRs). RESULTS Data from 368,680 patient visits during the 12-year period yielded results for an estimated 1.29 billion weighted ED encounters, among which an estimated 97.1 million (7.5%) patients received at least one CT. Overall, CT use during ED visits increased 330%, from 3.2% of encounters (95% confidence interval [CI] 2.9% to 3.6%) in 1996 to 13.9% (95% CI 12.8% to 14.9%) in 2007. Among the 20 most common complaints presenting to the ED, there was universal increase in CT use. Rates of growth were highest for abdominal pain (adjusted RR comparing 2007 to 1996=9.97; 95% CI 7.47 to 12.02), flank pain (adjusted RR 9.24; 95% CI 6.22 to 11.51), chest pain (adjusted RR 5.54; 95% CI 3.75 to 7.53), and shortness of breath (adjusted RR 5.28; 95% CI 2.76 to 8.34). In multivariable modeling, the likelihood of admission or transfer after a CT scan decreased over the years but has leveled off more recently (adjusted RR comparing admission or transfer after CT in 2007 to 1996=0.42; 95% CI 0.32 to 0.55). CONCLUSION CT use in the ED has increased significantly in recent years across a broad range of presenting complaints. The increase has been associated with a decline in admissions or transfers after CT use, although this effect has stabilized more recently.

Effect of Testing and Treatment on Emergency Department Length of Stay Using a National Database

OBJECTIVES Testing and treatment are essential aspects of the delivery of emergency care. Recognition of the effects of these activities on emergency department (ED) length of stay (LOS) has implications for administrators planning efficient operations, providers, and patients regarding expectations for length of visit; researchers in creating better models to predict LOS; and policy-makers concerned about ED crowding. METHODS A secondary analysis was performed using years 2006 through 2008 of the National Hospital Ambulatory Medical Care Survey (NHAMCS), a nationwide study of ED services. In univariate and bivariate analyses, the authors assessed ED LOS and frequency of testing (blood test, urinalysis, electrocardiogram [ECG], radiograph, ultrasound, computed tomography [CT], or magnetic resonance imaging [MRI]) and treatment (providing a medication or performance of a procedure) according to disposition (discharged or admitted status). Two sets of multivariable models were developed to assess the contribution of testing and treatment to LOS, also stratified by disposition. The first was a series of logistic regression models to provide an overview of how testing and treatment activity affects three dichotomized LOS cutoffs at 2, 4, and 6 hours. The second was a generalized linear model (GLM) with a log-link function and gamma distribution to fit skewed LOS data, which provided time costs associated with tests and treatment. RESULTS Among 360 million weighted ED visits included in this analysis, 227 million (63%) involved testing, 304 million (85%) involved treatment, and 201 million (56%) involved both. Overall, visits with any testing were associated with longer LOS (median = 196 minutes; interquartile range [IQR] = 125 to 305 minutes) than those with any treatment (median = 159 minutes; IQR = 91 to 262 minutes). This difference was more pronounced among discharged patients than admitted patients. Obtaining a test was associated with an adjusted odds ratio (OR) of 2.29 (95% confidence interval [CI] = 1.86 to 2.83) for experiencing a more than 4-hour LOS, while performing a treatment had no effect (adjusted OR = 0.84; 95% CI = 0.68 to 1.03). The most time-costly testing modalities included blood test (adjusted marginal effects on LOS = +72 minutes; 95% CI = 66 to 78 minutes), MRI (+64 minutes; 95% CI = 36 to 93 minutes), CT (+59 minutes; 95% CI = 54 to 65 minutes), and ultrasound (US; +56 minutes; 95% CI = 45 to 67 minutes). Treatment time costs were less substantial: performing a procedure (+24 minutes; 95% CI = 20 to 28 minutes) and providing a medication (+15 minutes; 95% CI = 8 to 21 minutes). CONCLUSIONS Testing and less substantially treatment were associated with prolonged LOS in the ED, particularly for blood testing and advanced imaging. This knowledge may better direct efforts at streamlining delivery of care for the most time-costly diagnostic modalities or suggest areas for future research into improving processes of care. Developing systems to improve efficient utilization of these services in the ED may improve patient and provider satisfaction. Such practice improvements could then be examined to determine their effects on ED crowding.

Part 11: Adult Stroke 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

Advances in stroke care will have the greatest effect on stroke outcome if care is delivered within a regional stroke system designed to improve both efficiency and effectiveness. The ultimate goal of stroke care is to minimize ongoing injury, emergently recanalize acute vascular occlusions, and begin secondary measures to maximize functional recovery. These efforts will provide stroke patients with the greatest opportunity for a return to previous quality of life and decrease the overall societal burden of stroke.

Central Nervous System Infections

Central nervous system infections have long been recognized as among the most devastating of diseases. This article describes the changing pattern and epidemiology of a variety of common central nervous system infections, including meningitis, encephalitis, and brain abscesses, and reviews pathophysiology and the most current approach to clinical diagnosis, treatment, and disposition from the emergency physician perspective.

Persistent ischemic stroke disparities despite declining incidence in Mexican Americans

To determine trends in ischemic stroke incidence among Mexican Americans and non‐Hispanic whites.

Gender and ethnic differences in subarachnoid hemorrhage

Background: Mexican Americans (MAs) comprise the largest component of the largest minority group within the United States. The purpose of this study was to examine ethnic and gender differences in the epidemiology, presentation, and outcomes after subarachnoid hemorrhage (SAH) in a representative United States community. Targeted public health interventions are dependent on accurate assessments of groups at highest disease risk. Methods: All patients with nontraumatic SAH older than 44 years were prospectively identified from January 1, 2000, to December 31, 2006, as part of the Brain Attack Surveillance In Corpus Christi project, an urban population-based study in southeast Texas. Risk ratios for cumulative SAH incidence comparing MAs with non Hispanic whites (NHWs) and women with men were calculated. Descriptive statistics for other clinical and demographic variables were computed overall, by gender, and by ethnicity. Results: A total of 107 patients had a SAH during the time period (7-year cumulative incidence: 11/10,000); of these, 43 were NHW (40% of cases vs 53% of the population) and 64 were MA (60% of cases vs 48% of the population). The overall age-adjusted risk ratio for SAH in MAs compared with NHWs was 1.67 (95% CI: 1.13, 2.47), and in women compared to men was 1.74 (95% CI 1.16, 2.62). Overall in-hospital mortality was 32.2%. No ethnic difference was observed for discharge disability or in-hospital mortality. Conclusions: Subarachnoid hemorrhage disproportionately affects Mexican Americans and women. Public health interventions should target these groups to reduce the impact of this severe disease.

The Causative Classification of Stroke system: an international reliability and optimization study.

Background: Valid and reliable ischemic stroke subtype determination is crucial for well-powered multicenter studies. The Causative Classification of Stroke System (CCS, available at http://ccs.mgh.harvard.edu) is a computerized, evidence-based algorithm that provides both causative and phenotypic stroke subtypes in a rule-based manner. We determined whether CCS demonstrates high interrater reliability in order to be useful for international multicenter studies. Methods: Twenty members of the International Stroke Genetics Consortium from 13 centers in 8 countries, who were not involved in the design and development of the CCS, independently assessed the same 50 consecutive patients with acute ischemic stroke through reviews of abstracted case summaries. Agreement among ratings was measured by kappa statistic. Results: The κ value for causative classification was 0.80 (95% confidence interval [CI] 0.78–0.81) for the 5-subtype, 0.79 (95% CI 0.77–0.80) for the 8-subtype, and 0.70 (95% CI 0.69–0.71) for the 16-subtype CCS. Correction of a software-related factor that generated ambiguity improved agreement: κ = 0.81 (95% CI 0.79–0.82) for the 5-subtype, 0.79 (95% CI 0.77–0.80) for the 8-subtype, and 0.79 (95% CI 0.78–0.80) for the 16-subtype CCS. The κ value for phenotypic classification was 0.79 (95% CI 0.77–0.82) for supra-aortic large artery atherosclerosis, 0.95 (95% CI 0.93–0.98) for cardioembolism, 0.88 (95% CI 0.85–0.91) for small artery occlusion, and 0.79 (0.76–0.82) for other uncommon causes. Conclusions: CCS allows classification of stroke subtypes by multiple investigators with high reliability, supporting its potential for improving stroke classification in multicenter studies and ensuring accurate means of communication among different researchers, institutions, and eras.

Small Area Variations in Out-of-Hospital Cardiac Arrest: Does the Neighborhood Matter?

BACKGROUND The incidence and outcomes of out-of-hospital cardiac arrest vary widely across cities. It is unknown whether similar differences exist at the neighborhood level. OBJECTIVE To determine the extent to which neighborhoods have persistently high rates of cardiac arrest but low rates of bystander cardiopulmonary resuscitation (CPR). DESIGN Multilevel Poisson regression of 1108 cardiac arrests from 161 census tracts as captured by the Cardiac Arrest Registry to Enhance Survival (CARES). SETTING Fulton County, Georgia, between 1 October 2005 to 30 November 2008. MEASUREMENTS Incidence of cardiac arrest, by census tract and year and by rates of bystander CPR. RESULTS Adjusted rates of cardiac arrest varied across neighborhoods (interquartile range [IQR], 0.57 to 0.73 per 1000 persons; mean, 0.64 per 1000 persons [SD, 0.11]) but were stable from year to year (intraclass correlation, 0.36 [95% CI, 0.26 to 0.50]; P < 0.001). Adjusted bystander CPR rates also varied by census tract (IQR, 19% to 29%; mean, 25% [SD, 10%]). LIMITATION Analysis was based on data from a single county. CONCLUSION Surveillance data can identify neighborhoods with a persistently high incidence of cardiac arrest and low rates of bystander CPR. These neighborhoods are promising targets for community-based interventions. PRIMARY FUNDING SOURCE Robert Wood Johnson Foundation Clinical Scholars Program, National Institutes of Health, and Centers for Disease Control and Prevention.

The Stroke Hyperglycemia Insulin Network Effort (SHINE) trial protocol: a randomized, blinded, efficacy trial of standard vs. intensive hyperglycemia management in acute stroke

Rationale Patients with acute ischemic stroke and hyperglycemia have worse outcomes than those without hyperglycemia. Intensive glucose control during acute stroke is feasible and can be accomplished safely but has not been fully assessed for efficacy. Aims The Stroke Hyperglycemia Insulin Network Effort trial aims to determine the safety and efficacy of standard vs. intensive glucose control with insulin in hyperglycemic acute ischemic stroke patients. Design This is a randomized, blinded, multicenter, phase III trial of approximately 1400 hyperglycemic patients who receive either standard sliding scale subcutaneous insulin (blood glucose range 80–179 mg/dL, 4·44–9·93 mmol/L) or continuous intravenous insulin (target blood glucose 80–130 mg/dL, 4·44–7·21 mmol/L) for up to 72 h, starting within 12 h of stroke symptom onset. The acute treatment phase is single blind (for the patients), but the final outcome assessment is double blind. The study is powered to detect a 7% absolute difference in favorable outcome at 90 days. Study outcomes The primary outcome is a baseline severity adjusted 90-day modified Rankin Scale score, defined as 0, 0–1, or 0–2, if the baseline National Institutes of Health Stroke Scale score is 3–7, 8–14, or 15–22, respectively. The primary safety outcome is the rate of severe hypoglycemia (<40 mg/dL, <2·22 mmol/L). Discussion This trial will provide important novel information about preferred management of acute ischemic stroke patients with hyperglycemia. It will determine the potential benefits and risks of intensive glucose control during acute stroke.