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Study Objective: We assess the diagnostic accuracy of plasma neutrophil gelatinase-associated lipocalin (NGAL) to predict acute kidney injury in emergency department (ED) patients with suspected sepsis. Methods: We conducted a secondary analysis of a prospective observational study of a convenience sample of patients from 10 academic medical center EDs. Inclusion criteria were adult patients aged 18 years or older, with suspected infection or a serum lactate level greater than 2.5 mmol/L; 2 or more systemic inflammatory response syndrome criteria; and a subsequent serum creatinine level obtained within 12 to 72 hours of enrollment. Exclusion criteria were pregnancy, do-not-resuscitate status, cardiac arrest, or dialysis dependency. NGAL was measured in plasma collected at ED presentation. Acute kidney injury was defined as an increase in serum creatinine measurement of greater than 0.5 mg/dL during 72 hours. Results: There were 661 patient enrolled, with 24 cases (3.6%) of acute kidney injury that developed within 72 hours after ED presentation. Median plasma NGAL levels were 134 ng/mL (interquartile range 57 to 277 ng/mL) in patients without acute kidney injury and 456 ng/mL (interquartile range 296 to 727 ng/mL) in patients with acute kidney injury. Plasma NGAL concentrations of greater than 150 ng/mL were 96% sensitive (95% confidence interval [CI] 79% to 100%) and 51% (95% CI 47% to 55%) specific for acute kidney injury. In comparison, to achieve equivalent sensitivity with initial serum creatinine level at ED presentation required a cutoff of 0.7 mg/dL and resulted in specificity of 17% (95% CI 14% to 20%). Conclusion: In this preliminary investigation, increased plasma NGAL concentrations measured on presentation to the ED in patients with suspected sepsis were associated with the development of acute kidney injury. Our findings support NGAL as a promising new biomarker for acute kidney injury; however, further research is warranted. [ABSTRACT FROM AUTHOR]

STUDY OBJECTIVE: Since 2003, the Society of Chest Pain Centers (SCPC) has provided hospital accreditation for acute coronary syndrome care processes. Our objective is to evaluate the association between SCPC accreditation and adherence to the American College of Cardiology/American Heart Association (ACC/AHA) evidence-based guidelines for non-ST-segment elevation myocardial infarction (NSTEMI). The secondary objective is to describe the clinical outcomes and the association with accreditation. METHODS: We conducted a secondary analysis of data from patients with NSTEMI enrolled in the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines (CRUSADE) quality improvement initiative in 2005. The analysis explored differences between SCPC-accredited and nonaccredited hospitals in evidence-based therapy given within the first 24 hours (including aspirin, beta-blocker, glycoprotein IIb/IIIa inhibitors, heparin, and ECG within 10 minutes). RESULTS: Of 33,238 patients treated at 21 accredited hospitals and 323 nonaccredited hospitals, those at SCPC-accredited centers (n=3,059) were more likely to receive aspirin (98.1% versus 95.8%; odds ratio [OR] 1.73; 95% confidence interval [CI] 1.06 to 2.83) and beta-blockers (93.4% versus 90.6%; OR 1.68; 95% CI 1.04 to 2.70) within 24 hours than patients at non-SCPC-accredited centers (n=30,179). No difference was observed in obtaining a timely ECG (40.4% versus 35.2%; OR 1.28; 95% CI 0.98 to 1.67), administering a glycoprotein IIb/IIIa inhibitor (OR 1.30; 95% CI 0.93 to 1.80), or administering heparin (OR 1.12; 95% CI 0.74 to 1.70). Also, there was no significant difference in risk-adjusted mortality for patients treated at SCPC hospitals versus nonaccredited hospitals (3.4% versus 3.5%; adjusted OR 1.17; 95% CI 0.88 to 1.55). CONCLUSION: SCPC-accredited hospitals had higher NSTEMI ACC/AHA evidence-based guideline adherence in the first 24 hours of care on 2 of the 5 measures. No difference in outcomes was observed. Further studies are needed to better understand the association between SCPC accreditation and improved care for patients with acute coronary syndrome. [ABSTRACT FROM AUTHOR]

STUDY OBJECTIVE: Although regionalized care for ST-segment elevation myocardial infarction (STEMI) has improved the use of timely reperfusion therapy, its effect on patient outcomes has been difficult to assess. Our objective is to explore temporal trends in STEMI mortality with the implementation of a statewide STEMI regionalization program (Reperfusion of Acute Myocardial Infarction in North Carolina Emergency Departments [RACE]). METHODS: We compared trends in inpatient mortality among STEMI patients treated at North Carolina (NC) hospitals participating in the RACE program, relative to those not participating, using state inpatient claims data. Using Medicare claims data, we compared trends in 30-day mortality among Medicare beneficiaries in NC with those nationally. Logistic models with random effects were used to evaluate the association of the program with mortality. RESULTS: From 2005 to 2007, inpatient mortality for 6,565 STEMI patients treated at NC hospitals participating in RACE decreased from 11.6% to 10.1% (risk difference -1.5%; 95% confidence interval [CI] -3.0% to 0.04%), whereas inpatient mortality among 5,850 STEMI patients treated at NC nonparticipating hospitals decreased from 10.2% to 8.6% (risk difference -1.6%; 95% CI -3.1% to 0.10%); (adjusted odds ratio 1.28; 95% CI 0.88 to 1.85 for temporal differences between groups). During the same period, 30-day STEMI mortality among Medicare beneficiaries decreased from 22.7% to 21.4% in NC (risk difference -1.28%; 95% CI -3.60% to 1.03%) and from 22.3% to 21.6% nationally (risk difference -0.71%, 95% CI -1.13% to -0.29%; adjusted odds ratio 0.99, 95% CI 0.85 to 1.15 for temporal differences between regions). CONCLUSION: The initiation of a statewide STEMI collaborative care model was associated with a reduction in mortality rates according to claims data, yet these changes were similar to those seen nationally. Further study is needed to evaluate regionalized systems of STEMI care and to determine the role of claims data to evaluate population-based STEMI outcomes. [ABSTRACT FROM AUTHOR]

Barriers to informed consent are ubiquitous in the conduct of emergency care research across a wide range of conditions and clinical contexts. They are largely unavoidable; can be related to time constraints, physical symptoms, emotional stress, and cognitive impairment; and affect patients and surrogates. US regulations permit an exception from informed consent for certain clinical trials in emergency settings, but these regulations have generally been used to facilitate trials in which patients are unconscious and no surrogate is available. Most emergency care research, however, involves conscious patients, and surrogates are often available. Unfortunately, there is neither clear regulatory guidance nor established ethical standards in regard to consent in these settings. In this report-the result of a workshop convened by the National Institutes of Health Office of Emergency Care Research and Department of Bioethics to address ethical challenges in emergency care research-we clarify potential gaps in ethical understanding and federal regulations about research in emergency care in which limited involvement of patients or surrogates in enrollment decisions is possible. We propose a spectrum of approaches directed toward realistic ethical goals and a research and policy agenda for addressing these issues to facilitate clinical research necessary to improve emergency care., (Copyright © 2015 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.)

Acute respiratory failure is commonly encountered in the emergency department (ED), and early treatment can have effects on long-term outcome. Noninvasive ventilation is commonly used for patients with respiratory failure and has been demonstrated to improve outcomes in acute exacerbations of chronic obstructive lung disease and congestive heart failure, but should be used carefully, if at all, in the management of asthma, pneumonia, and acute respiratory distress syndrome. Lung-protective tidal volumes should be used for all patients receiving mechanical ventilation, and FiO2 should be reduced after intubation to achieve a goal of less than 60%. For refractory hypoxemia, new rescue therapies have emerged to help improve the oxygenation, and in some cases mortality, and should be considered in ED patients when necessary, as deferring until ICU admission may be deleterious. This review article summarizes the pathophysiology of acute respiratory failure, management options, and rescue therapies including airway pressure release ventilation, continuous neuromuscular blockade, inhaled nitric oxide, and extracorporeal membrane oxygenation., (Copyright © 2015 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.)

Study Objective: The National Institutes of Health (NIH) formed an NIH Task Force on Research in Emergency Medicine to enhance NIH support for emergency care research. The NIH Trauma Research Roundtable was convened on June 22 to 23, 2009. The objectives of the roundtable are to identify key research questions essential to advancing the scientific underpinnings of emergency trauma care and to discuss the barriers and best means to advance research by exploring the role of trauma research networks and collaboration between NIH and the emergency trauma care community., Methods: Before the roundtable, the emergency care domains to be discussed were selected and experts in each of the fields were invited to participate in the roundtable. Domain experts were asked to identify research priorities and challenges and separate them into mechanistic, translational, and clinical categories. During and after the conference, the lists were circulated among the participants and revised to reach a consensus., Results: Emergency trauma care research is characterized by focus on the timing, sequence, and time sensitivity of disease processes and treatment effects. Rapidly identifying the phenotype of patients on the time spectrum of acuity and severity after injury and the mechanistic reasons for heterogeneity in outcome are important challenges in emergency trauma research. Other research priorities include the need to elucidate the timing, sequence, and duration of causal molecular and cellular events involved in time-critical injuries, and the development of treatments capable of halting or reversing them; the need for novel experimental models of acute injury; the need to assess the effect of development and aging on the postinjury response; and the need to understand why there are regional differences in outcomes after injury. Important barriers to emergency care research include a limited number of trained investigators and experienced mentors, limited research infrastructure and support, and regulatory hurdles., Conclusion: The science of emergency trauma care may be advanced by facilitating the following: (1) development of an acute injury template for clinical research; (2) developing emergency trauma clinical research networks; (3) integrating emergency trauma research into Clinical and Translational Science Awards; (4) developing emergency care-specific initiatives within the existing structure of NIH institutes and centers; (5) involving acute trauma and emergency specialists in grant review and research advisory processes; (6) supporting learn-phase or small, clinical trials; (7) performing research to address ethical and regulatory issues; and (8) training emergency care investigators with research training programs., (Copyright © 2010 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.)

Study Objective: Although 80-lead ECG body surface mapping is more sensitive for ST-elevation myocardial infarction (STEMI) than the 12-lead ECG, its clinical utility in chest pain in the emergency department (ED) has not been studied. We sought to determine the prevalence, clinical care patterns, and clinical outcomes of patients with STEMI identified on 80-lead but not on 12-lead (80-lead-only STEMI)., Methods: The Optimal Cardiovascular Diagnostic Evaluation Enabling Faster Treatment of Myocardial Infarction trial was a multicenter prospective observational study of moderate- to high-risk chest pain patients presenting to the ED. Patients received simultaneous 12-lead and 80-lead ECGs as part of their initial evaluation and were treated according to the standard of care, with clinicians blinded to the 80-lead results. The primary outcome of the trial was door-to-sheath time in patients with 80-lead-only STEMI versus patients with STEMI identified by 12-lead alone (12-lead STEMI). Secondary outcomes included angiographic and clinical outcomes at 30 days., Results: One thousand eight hundred thirty patients were evaluated, 91 had a discharge diagnosis of 12-lead STEMI, and 25 patients met criteria for 80-lead-only STEMI. Eighty-four of the 91 12-lead STEMI patients underwent cardiac catheterization, with a median door-to-sheath time of 54 minutes, versus 14 of the 25 80-lead-only STEMI patients, with a door-to-sheath time of 1,002 minutes (estimated treatment difference in median=881; 95% confidence interval 181 to 1,079 minutes). Clinical outcomes and revascularization rates, however, were similar between 80-lead-only STEMI and 12-lead STEMI patients., Conclusion: The 80-lead ECG provides an incremental 27.5% increase in STEMI detection versus the 12-lead. Patients with 80-lead-only STEMI have adverse outcomes similar to those of 12-lead STEMI patients but are treated with delayed or conservative invasive strategies.

Study Objective: Attrition rates in emergency medicine have been reported as high as 25% in 10 years. The number of women entering emergency medicine has been increasing, as has the number of female medical school graduates. No studies have identified factors that increase female emergency physician career satisfaction. We assess career satisfaction in women emergency physicians in the American College of Emergency Physicians (ACEP) and identify factors associated with career satisfaction., Methods: The survey questionnaire was developed by querying 3 groups: (1) ACEP women in the American Association of Women Emergency Physicians, the (2) Society for Academic Emergency Medicine Mentoring Women Interest Group, and (3) nonaffiliated female emergency physicians. Their responses were categorized into 6 main areas: schedule, relationships with colleagues, administrative support and mentoring, patient/work-related issues, career advancement opportunities, and financial. The study cohort for the survey included all female members of ACEP with a known e-mail address. All contact with survey recipients was exclusively through the e-mail that contained a uniform resource locator link to the survey itself., Results: Two thousand five hundred two ACEP female members were sent the uniform resource locator link. The Web survey was accessed a total of 1,851 times, with a total of 1,380 surveys completed, an overall response rate of 56%. Most women were satisfied with their career as an emergency physician, 492 (35.5%) very satisfied, 610 (44.0%) satisfied, 154 (11.1%) neutral, 99 (7.1%) not satisfied, and 31 (2.3%) very unsatisfied. Significant factors for career satisfaction included amount of recognition at work, career advancement, schedule flexibility, and the fairness of financial compensation. Workplace factors associated with high satisfaction included academic practice setting and sex-equal opportunity for advancement and sex-equal financial compensation., Conclusion: Most of the ACEP female physicians surveyed were satisfied with their career choice of emergency medicine. Opportunities for career advancement, fairness in financial compensation, and schedule flexibility were key factors in career satisfaction among female emergency physicians.

Study Objective: Emergency department (ED) -based clinical research has the potential to include patient populations that are typically underrepresented in clinical research. The objective of this study is to assess how emergency clinical care and research processes, informed consent, and patient demographic factors (age, sex, and ethnicity/race) affect enrollment and consent in clinical research in the ED., Methods: This was an analysis of prospectively collected data of all patients (aged 2 to 101 years) eligible for one of 7 clinical research studies from February 2005 to April 2007 in an academic ED. We measured rates of enrollment and consent in the clinical studies., Results: One thousand two hundred two of the 4418 patients screened for participation in 7 clinical studies were clinically eligible for enrollment. Of the 868 patients who were able to provide a voluntary decision regarding consent, 639 (73.6%) agreed to participate; an overall enrollment rate of 53.2%. The mean age of patients enrolled was 51.8 years (range 3 to 98 years). Black patients (49.2% enrollment) and Latino patients (18.4% enrollment) were less likely to be enrolled in comparison with white patients (58.3% enrollment) (adjusted odds ratio [OR] of enrollment for blacks=0.64; 95% confidence interval [CI] 0.50 to 0.82; adjusted OR of enrollment for Latinos=0.16; 95% CI 0.08 to 0.33). Enrollment rates were lower among pediatric (40.0%) and geriatric patients (49.1%) in comparison with adult patients ages 18 to 64 years (55.5%) (adjusted OR of enrollment for pediatric patients=0.70, 95% CI 0.34 to 1.43; adjusted OR of enrollment for geriatric patients=0.69, 95% CI 0.53 to 0.90). Unique issues contributing to underenrollment included challenges in consent among pediatric and elderly patients, language issues in Latino patients, reduced voluntary consent rates among black patients, and perhaps underuse of minimal risk waivers., Conclusion: In a large academic ED, minority, pediatric, and geriatric patients were less likely to be enrolled in acute care clinical research studies than middle-aged whites. Enrollment and consent strategies designed to enhance research participation in these important patient populations may be necessary to address disparities in the development and application of evidence-based emergency and acute care.

Pay for performance is gaining momentum as a means to improve the quality of clinical care. Recently, the Centers for Medicare & Medicaid Services has expanded pay for performance initiatives to incorporate 9 emergency care metrics, including indicators for cardiac, pneumonia, and stroke care. The American College of Cardiology and American Heart Association (ACC/AHA) have published methodology for the selection and creation of performance measures for quantifying the quality of cardiovascular care. The purpose of this study is to grade each of the 9 Physician Quality Reporting Initiative emergency medicine process measures according to the ACC/AHA criteria related to clinical evidence (yes, no, indeterminate). Five of the 9 recently selected metrics in emergency medicine do not appear to meet all of the ACC/AHA criteria for measurement selection. Several of the metrics, including aspirin for acute myocardial infarction (mean hospital adherence 94.7%; SD 6.7%) and pulse oximetry for community-acquired pneumonia (mean 99.4%; SD 2.0%), already have high levels of performance nationally, which raises uncertainty about the overall cost-effectiveness of quality improvement interventions for these measures. Formal methodology needs to be established for future selection of performance measures for quality improvement programs in emergency care. These performance measures should focus on unique aspects of emergency and acute care, including recognition and treatment of time-sensitive life-threatening conditions, assessment of patients with undifferentiated signs and symptoms, and care of all-inclusive geographically based patient populations. In key emergency therapeutic areas, the evidence linking treatment and improved patient outcomes will require additional study before inclusion in pay for performance programs. New research initiatives are needed to assess the effect of timely administration of emergency department interventions on patient outcomes.

Study Objective: Early countershock of ventricular fibrillation (VF) has been shown to improve immediate and long-term outcome of out-of-hospital cardiac arrest. However, studies indicate that countershock of prolonged VF most commonly results in asystole or a nonperfusing bradyarrhythmia (pulseless electrical activity [PEA]), which rarely respond to current therapy. The cause of these postcountershock rhythm disturbances is not well understood but may be related to electrical injury of the globally ischemic myocardium or to local metabolic abnormalities that impair impulse formation and cardiac contraction. The purpose of this study was to evaluate changes in serum potassium and free calcium homeostasis during cardiac arrest and advanced cardiac life support (ACLS) interventions., Methods: After sedation, intubation, anesthesia, and instrumentation, VF was induced in 13 dogs. After 7.5 minutes of VF, animals were immediately countershocked, standard closed-chest CPR was initiated, and epinephrine was administered (1 mg in repeated doses if necessary)., Results: Ten animals could not be resuscitated despite 20 minutes of ACLS interventions. In these animals, a progressive increase in serum potassium was observed from the onset of ACLS to the termination of resuscitation efforts (4.3+/-.6 to 6.0+/-.8 mEq/L, P<.01). A significant increase was observed within 10 minutes of beginning ACLS measures. This was accompanied by a decrease in ionized calcium concentration over the same period (4.95+/-.40 to 3.44 mg/dL, P<.01). The decrease in ionized calcium was significant within 5 minutes of ACLS interventions. Nine of these 10 animals had either postcountershock asystole or PEA at the termination of resuscitative efforts. The increase in potassium was not related to acidemia. Successfully resuscitated animals did not demonstrate these electrolyte changes., Conclusion: Ionized hypocalcemia and hyperkalemia occur during prolonged resuscitative efforts and may be related to dysfunctional transcellular ionic transport mechanisms. These cations play important roles in cardiac electrical and contractile activity and may play a role in refractory postcountershock rhythm disturbances.

This article addresses issues involved in the development of hemoglobin-based oxygen carriers and provides a focused overview of the 4 hemoglobin-based oxygen carriers with emergency medicine application currently in clinical trials.

This article provides information supporting the need for new outcome measures in emergency care. It also addresses the use of outcome measures in emergency care, the impact of emergency care, identification of at-risk groups, new approaches to measuring patient satisfaction, quality of life and cost-effectiveness, and the unique related implications for emergency medicine. [Cairns CB, Garrison HG, Hedges JR, Schriger DL, Valenzuela TD: Development of new methods to assess the outcomes of emergency care. Ann Emerg Med February 1998;31:166-171.].

Study Objective: To determine whether the plateau phase of the expiratory capnogram (dco2/dt) can detect bronchospasm in adult asthma patients in the emergency department and to assess the correlation between dco2/dt and the peak expiratory flow rate (PEFR) in spontaneously breathing patients with asthma and in normal, healthy volunteers., Methods: We carried out a prospective, blinded study in a university hospital ED. Twenty adults (12 women) with acute asthma and 28 normal adult volunteers (15 women) breathed through the sampling probe of an end-tidal CO2 monitor, and the expired CO2 waveform was recorded. The dco2/dt of the plateau (alveolar) phase for five consecutive regular expirations was measured and a mean value calculated for each patient. The best of three PEFRs was determined. The PEFR and dco2/dt were also recorded after treatment of the asthmatic patients with inhaled beta-agonists., Results: The mean +/- SD PEFR of the asthmatic subjects was 274 +/- 96 L/minute (57% of the predicted value), whereas that of the normal volunteers was 527 +/- 96 L/minute (103% of the predicted value) (P < .001). The mean dco2/dt of the asthmatic subjects (.26 +/- .06) was significantly steeper than that of the normal volunteers (.13 +/- .06) (P < .001). The dco2/dt was correlated with PEFR (r = .84, P < .001). In 18 asthmatic subjects the pretreatment and posttreatment percent predicted PEFRS were 58% +/- 17% and 74% +/- 17%, respectively (P < .001), whereas the dco2/dt values were .27 +/- .05 and .19 +/- .07, respectively (P < .005)., Conclusion: The dco2/dt is an effort-independent, rapid noninvasive measure that indicates significant bronchospasm in ED adult patients with asthma. The dco2/dt value is correlated with PEFR, an effort-dependent measure of airway obstruction. The change in dco2/dt with inhaled beta-agonists may be useful in monitoring the therapy of acute asthma.

Study Objective: To investigate the finding of increased alveolar-arterial (A-a) gradient in adult patients with measles who have normal results on both pulmonary auscultation and chest radiography., Design: Retrospective, descriptive case series., Setting: An urban county teaching hospital in southern California., Participants: Consecutive adult patients with the clinical diagnosis of measles seen in the emergency department., Methods: Patients were considered to have pneumonitis if they had any of the following: ED diagnosis of pneumonia; an A-a gradient of more than 30 mm Hg; one or more infiltrates on chest radiograph., Results: Seventy-five patients, including 44 men and 31 women (median age, 25 years; 25% to 75% interquartile range [IQR], 20 to 28 years) were seen during the 36-month study period. Forty-three patients (57%; 95% confidence interval [CI], 45% to 69%) had pneumonitis, with a median A-a gradient of 42 mm Hg (IQR, 34 to 48 mm Hg). Twenty-seven of the 43 patients with pneumonitis (63%; CI, 48% to 77%) had both normal pulmonary auscultation findings and normal chest radiographs; this represented 36% of the study population (CI, 25% to 50%). Thirty-eight of the 43 patients with pneumonitis were admitted; one patient was later intubated after respiratory failure developed. Two of the 5 patients with pneumonitis who were sent home were admitted the following day for worsening symptoms. All 75 patients eventually did well., Conclusion: A significant percentage of adult patients with measles presenting to an ED with both normal pulmonary auscultation and normal chest radiographs have increased A-a gradients. These patients warrant close follow-up and perhaps hospital admission.

Study Background: Free or ionized calcium (Ca+2) is known to play a critical role in normal cardiovascular function, and Ca+2 administration in the setting of ionized hypocalcemia has been shown to improve indexes of cardiac function. The value of Ca+2 administration in the setting of cardiac arrest and resuscitation is unproven and controversial, in large part because ionized Ca+2 levels during cardiac arrest and resuscitation have not been adequately studied and exogenous calcium therapy may worsen ischemic cellular injury., Study Purpose: To measure free calcium during prolonged cardiac arrest and CPR in a canine model., Methods and Measurements: Central arterial and venous catheters were positioned in nine dogs, and ventricular fibrillation (VF) was induced electrically. After seven and one-half minutes of VF, countershocks were administered, and CPR was initiated and performed in accordance with current recommendations for 20 minutes. At five-minute intervals during resuscitation efforts, arterial pH, ionized Ca+2, and lactate as well as aortic pressure were measured., Results: During resuscitation, average systolic arterial pressure was 50 mm Hg. Within five minutes of instituting CPR, ionized Ca+2 significantly decreased from control values (5.1 +/- 0.1 at control to 4.0 +/- 0.1 mg/dL); after 20 minutes of attempted resuscitation, it averaged 3.2 +/- 0.2 mg/dL (P less than .05 vs control). There was no change in total Ca+2 during the arrest period (9.2 +/- 0.5 at control to 8.6 +/- 0.8 mg/dL at 27.5 minutes). Arterial lactate significantly increased throughout the arrest and resuscitation period (1.9 +/- 0.2 at control to 7.5 +/- 0.4 mM/L at 27.5 minutes). A significant correlation was demonstrated between ionized Ca+2 and lactate concentrations (r = -.72, P less than .001) but not between ionized calcium and pH (r = -.22, P greater than .20)., Conclusion: Ionized hypocalcemia occurs during prolonged cardiac arrest and resuscitation, and ionized hypocalcemia during prolonged arrest and resuscitation may be due to binding by lactate, as has been demonstrated in vitro.

Study Purpose: To evaluate the efficacy of adenosine in the treatment of emergency department patients with spontaneous paroxysmal supraventricular tachycardia (PSVT)., Design: An eight-month prospective outcome study., Population: Patients 16 or more years old with PSVT by surface ECG criteria. Patients were excluded if there was clinical or hemodynamic evidence of hypoperfusion., Measurements: Patient age, sex, PSVT rate, pretreatment blood pressure, history of cardiac disease, chronic drug therapy, and response to IV adenosine., Results: Twenty-three patients with 27 episodes of suspected PSVT met inclusion criteria. After IV adenosine, two patients were found to have atrial flutter, and one was found to have ventricular tachycardia. Twenty-four episodes of PSVT were diagnosed in the remaining 21 patients. There were eight male and 13 female patients with a mean age of 51 +/- 19 years (range, 16 to 80 years). Sixteen patients related a history of cardiovascular disease. The mean QRS rate during PSVT was 181 +/- 23. Twenty-three of 24 episodes (96%) were converted to sinus rhythm within 20 to 45 seconds of adenosine therapy. However, 13 of 23 of initial conversions (57%) were followed by recurrence of PSVT within five minutes. All 13 recurrences required therapy with other antiarrhythmic drugs for conversion to and maintenance of sinus rhythm. Complications of adenosine were noted in only four patients and were transient and clinically unimportant., Conclusion: IV adenosine effectively terminates PSVT in ED patients with spontaneous PSVT; recurrence of PSVT after adenosine is common in the ED population and should be treated with other antiarrhythmic agents, not repeated doses of adenosine; adenosine is useful in the differential diagnosis of tachyarrhythmias; and doubling the initial dose of adenosine to 12 mg would increase the likelihood of conversion with the first dose.