Blood transfusion and ischaemic outcomes according to anemia and bleeding in patients with non-ST-segment elevation acute coronary syndromes: Insights from the TAO randomized clinical trial

BACKGROUND

The benefits and risks of blood transfusion in patients with acute myocardial infarction who are anemic or who experience bleeding are debated. We sought to study the association between blood transfusion and ischemic outcomes according to haemoglobin nadir and bleeding status in patients with NST-elevation myocardial infarction (NSTEMI).

METHODS

The TAO trial randomized patients with NSTEMI and coronary angiogram scheduled within 72h to heparin plus eptifibatide versus otamixaban. After exclusion of patients who underwent coronary artery bypass surgery, patients were categorized according to transfusion status considering transfusion as a time-varying covariate. The primary ischemic outcome was the composite of all-cause death or MI within 180 days of randomization. Subgroup analyses were performed according to pre-transfusion hemoglobin nadir and bleeding status.

RESULTS

12,547 patients were enrolled. Among these, blood transfusion was used in 489 (3.9%) patients. Patients who received transfusion had a higher rate of death or MI (29.9% vs. 8.1%, p<0.01). This excess risk persisted after adjustment on GRACE score and nadir of hemoglobin (HR 3.36 95%CI 2.63-4.29 p<0.01). Subgroup analyses showed that blood transfusion was associated with a higher risk in patients without overt bleeding (adjusted HR 6.25 vs. 2.85; p-interaction 0.001) as well as in those with hemoglobin nadir > 9.0 g/dl (HR 4.01; p-interaction<0.0001).

CONCLUSION

In patients with NSTEMI, blood transfusion was associated with an overall increased risk of ischaemic events. However, this was mainly driven by patients without overt bleeding and those hemoglobin nadir > 9.0g/dl. This suggests possible harm of transfusion in those groups.

Initial risk stratification and presenting characteristics of patients with evolving myocardial infarctions

OBJECTIVES

To describe the presenting characteristics and risk stratification of patients presenting to the emergency department with chest pain who have a normal initial troponin level followed by a raised troponin level within 12 h (evolving myocardial infarction (EMI)).

METHODS

Data from the Internet Tracking Registry for Acute Coronary Syndromes (i*trACS), a registry of patients presenting with undifferentiated chest pain, were used. This analysis included patients without ST segment elevation with at least two troponin assay results < or = 12 h apart. Patients were stratified into three groups: EMI (initial troponin assay negative, second troponin assay positive), non-ST elevation myocardial infarction (NSTEMI) (initial troponin assay positive) and no MI (all troponin assays negative).

RESULTS

Of 4136 eligible patients, 5% had EMI, 8% had NSTEMI and 87% had no MI. Patients with EMI were more similar to those with NSTEMI than those with no MI with respect to demographic characteristics, presentation, admission patterns and revascularisation. The initial ECG in patients with EMI was most commonly non-diagnostic (51%), but physicians' initial impressions commonly reflected MI, unstable angina or high-risk chest pain (76%). This risk assessment was followed by a high rate of critical care admissions (32%) and revascularisation (percutaneous coronary intervention 17%) among patients with EMI.

CONCLUSION

Patients with EMI appear similar at presentation to those with NSTEMI. Patients with EMI are perceived as being at high risk, evidenced by similar diagnostic impressions, admission practices and revascularisation rates to patients with NSTEMI.

Early use of inhaled corticosteroids in the emergency department treatment of acute asthma

BACKGROUND

Systemic corticosteroid therapy is central to the management of acute asthma The use of inhaled corticosteroids may also be beneficial in this setting.

OBJECTIVES

To determine the benefit of inhaled corticosteroids for the treatment of patients with acute asthma managed in the emergency department (ED).

SEARCH STRATEGY

Randomised controlled trials (RCTs) were identified from the Cochrane Airways Review Group register. Bibliographies from included studies, known reviews, and texts also were searched. The search is considered updated to February of 2003.

SELECTION CRITERIA

Only RCTs or quasi-randomised trials were eligible for inclusion. Studies were included if patients presented with acute asthma to the ED or its equivalent, and were treated with inhaled corticosteroids or placebo, in addition to standard therapy. Two reviewers independently selected potentially relevant articles, and then independently selected articles for inclusion. Methodological quality was independently assessed by two reviewers.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two reviewers if the authors were unable to verify the validity of extracted information. Missing data were obtained from the authors or calculated from other data presented in the paper.

MAIN RESULTS

Eight trials were selected for inclusion, but data were not available for one of them. In the seven usable trials, (4 adult, 3 paediatric), a total of 376 patients were studied (191 with inhaled corticosteroids, 185 without). Patients treated with inhaled corticosteroids were less likely to be admitted to hospital (OR: 0.30; 95% CI: 0.16, 0.57). This benefit was evident in the subgroup of patients not receiving concomitant systemic steroids (OR 0.21; 95% CI: 0.08, 0.53). Patients receiving concomitant systemic steroids showed a similar, but non-significant, trend towards reduced admissions compared to placebo treatment (OR 0.45; 95% CI: 0.18, 1.12). Patients receiving inhaled corticosteroids also demonstrated small, significant improvements in peak expiratory flows (PEFR WMD: 8%; 95% CI: 3, 13 %) and forced expiratory volumes (FEV1 WMD: 5%; 95% CI: 0.4, 10 %). The treatment was well tolerated, with few reported adverse side effects. A secondary analysis compared inhaled corticosteroids alone vs systemic steroids alone; in the four trials included, there was significant heterogeneity between the study results for admission rates which precluded meaningful pooling of the study results.

REVIEWER'S CONCLUSIONS

Inhaled steroids reduced admission rates in patients with acute asthma, but it is unclear if there is a benefit of inhaled corticosteroids when used in addition to systemic corticosteroids. There is insufficient evidence that inhaled corticosteroids result in clinically important changes in pulmonary function or clinical scores when used in acute asthma. Similarly, there is insufficient evidence that inhaled corticosteroids alone are as effective as systemic steroids. Further research is needed to clarify if there is a benefit of inhaled corticosteroids when used in addition to systemic steroids.

2000 ACC/AHA guidelines for the management of patients with unstable angina and non-ST-segment elevation myocardial infarction: a practical summary for emergency physicians

There have been numerous significant clinical advances in both the diagnosis and therapy of acute coronary syndrome during the past several years. Even the term "acute coronary syndrome" is a recent creation meant to expand clinical attention in patients with chest pain of coronary origin beyond identification of ST-segment elevation myocardial infarction and prompt initiation of reperfusion therapy and to include the evaluation and management of those patients with unstable angina (UA) or myocardial injury that does not cause ST-segment elevation. Many of these advances have been studied and first implemented outside the emergency department, leading some emergency physicians to be slow to embrace them, and leaving others without a viable practical option to use them outside of the cardiac catheterization laboratory or the coronary care unit. In September 2000, the American College of Cardiology and the American Heart Association issued practice guidelines for the care of patients with UA and non-ST-segment elevation myocardial infarction. The guidelines specifically address the diagnosis and management of UA and non-ST-segment elevation myocardial infarction in the ED, suggesting evidence-based standards for risk stratification, for the use of biologic markers of myocardial damage and other adjunctive diagnostic tests, and for the appropriate use of antiplatelet and antithrombin therapeutic agents. This article provides an overview of the ED-pertinent analyses and recommendations from the 93-page document. A commentary on the implementation of these recommendations in the ED follows in a separate article.

Advances create opportunities: implementing the major tenets of the new unstable angina guidelines in the emergency department

Of all the clinical syndromes with which emergency physicians must deal, chest pain of coronary cause has benefited from the most striking recent advances both in diagnostic approach (cognitive and technologic) and in therapeutic options. Chest pain evaluation and management have become important foci of research in emergency medicine, and entire units are dedicated to its clinical prosecution in emergency departments and elsewhere in the hospital. New diagnostic tools are proposed and studied on a regular basis. Antiplatelet, antithrombin, and fibrinolytic agents unknown in clinical practice as recently as 5 years ago have secured places in the emergency physician's armamentarium for treating acute coronary syndrome. Many of these diagnostic and therapeutic tools have been developed in the coronary care unit and in the cardiac catheterization laboratory. Although intuitively they may also be useful outside of those settings, they have unreliably been brought to the ED for implementation and resultant appropriate prompt and early care of the coronary patient who does not meet fibrinolytic criteria. As emergency physicians seek to bring accurate chest pain risk stratification into their practice and begin to use new therapeutic agents to minimize myocardial damage before turning the patient's care over to other specialists, it is essential that they are familiar with the data supporting these approaches. In this commentary, we seek to place the American College of Cardiology/American Heart Association unstable angina guidelines into the clinical context of the ED.

Relief by naloxone of morphine-induced spasm of the sphincter of Oddi in a post-cholecystectomy patient

Spasm of the sphincter of Oddi is a well-recognized effect of the narcotic class of drugs. Although it is usually clinically silent, such spasm occasionally causes debilitating pain that may be mistaken for more serious disorders. We present the case of a patient who had undergone cholecystectomy previously, but in whom morphine given in the Emergency Department precipitated pain consistent with biliary colic; the pain resolved promptly after administration of naloxone. This entity may considered in the differential diagnosis of acute onset of colicky abdominal pain in the patient given narcotics.

Use of plain radiography to screen for cervical spine injuries

STUDY OBJECTIVE

Standard radiographic screening may fail to reveal any evidence of injury in some patients with spinal injury. The purposes of this investigation were to document the efficacy of standard radiographic views and to categorize the frequencies and types of injuries missed on plain radiographic screening of the cervical spine.

METHODS

All patients with blunt trauma selected for radiographic cervical spine imaging at 21 participating institutions underwent a standard 3-view series (cross-table lateral, anteroposterior, and odontoid views), as well as any other imaging deemed necessary by their physicians. Injuries detected with screening radiography were then compared with final injury status for each patient, as determined by review of all radiographic studies.

RESULTS

The study enrolled 34,069 patients with blunt trauma, including 818 patients (2.40% of all patients; 95% confidence interval [CI] 2.40% to 2.40%) having a total of 1,496 distinct cervical spine injuries. Plain radiographs revealed 932 injuries in 498 patients (1.46% of all patients; 95% CI 1.46% to 1.46%) but missed 564 injuries in 320 patients (0.94% of all patients; 95% CI 0.94% to 0.94%). The majority of missed injuries (436 injuries in 237 patients [representing 0.80% of all patients]; 95% CI 0.80% to 0.80%) occurred in cases in which plain radiographs were interpreted as abnormal (but not diagnostic of injury) or inadequate. However, 23 patients (0.07% of all patients; 95% CI 0.05% to 0.09%) had 35 injuries (including 3 potentially unstable injuries) that were not visualized on adequate plain film imaging. These patients represent 2.81% (95% CI 1.89% to 3.63%) of all injured patients with blunt trauma undergoing radiographic evaluation.

CONCLUSION

Standard 3-view imaging provides reliable screening for most patients with blunt trauma. However, on rare occasions, such imaging may fail to detect significant unstable injuries. In addition, it is difficult to obtain adequate plain radiographic imaging in a substantial minority of patients.

Use of flexion-extension radiographs of the cervical spine in blunt trauma

STUDY OBJECTIVE

Flexion-extension (F/E) radiographs of the cervical spine are often used in patients with blunt trauma when the evaluating physician remains concerned about bony or ligamentous injuries despite negative or nondiagnostic standard radiographs. The use of this approach has never been addressed in a large prospective study. We sought to determine the clinical factors associated with ordering F/E views and the incidence of diagnostic F/E films in patients with a normal 3-view cervical spine series.

METHODS

Patients with blunt trauma selected for radiographic cervical spine imaging at 21 participating institutions in the National Emergency X-Radiography Utilization Study project underwent standard 3-view (cross-table lateral, anteroposterior, and odontoid views) series, as well as any other imaging deemed necessary by their physicians. Injuries detected by means of screening radiography were then compared with final injury status for each patient, as determined by review of all radiographic studies. Patients who underwent F/E views were analyzed separately.

RESULTS

Of 818 patients ultimately found to have cervical spine injury, 86 (10.5%) underwent F/E testing. Two patients sustained stable bony injuries detected only on F/E views. Four other patients had a subluxation detected only on F/E views, but all had other injuries apparent on routine cervical spine imaging.

CONCLUSION

F/E imaging adds little to the acute evaluation of patients with blunt trauma. Other approaches, including magnetic resonance imaging, computed tomography, or delayed F/E, in the presence of specific clinical concerns would seem to provide a more reasonable approach to adjunctive imaging.

The laryngeal mask airway: a comprehensive review for the Emergency Physician

The Laryngeal Mask Airway (LMA) was developed in the 1980s, but has only recently begun to be used in Emergency Medicine. The LMA affords effective assisted ventilation without requiring endotracheal intubation or visualization of the glottis. In doing so, it is more efficacious than a bag-valve-mask apparatus, although the risk of aspiration of gastric contents persists, particularly if the device is not properly placed. The LMA also has significant potential utility in management of the difficult airway. Most reported clinical experience with the LMA has come from the operating room. This article provides an overview of the extensive potential utility of the LMA in the Emergency Department and prehospital settings as well as a comprehensive review of the pertinent advantages, disadvantages, and complications associated with its use.

Traumatic pneumomediastinum caused by isolated blunt facial trauma: a case report

Traumatic pneumomediastinum is most often identified as an incidental finding in the setting of blunt or penetrating neck, chest, or abdominal trauma. There are only a few cases in the medical literature of a pneumomediastinum following isolated facial trauma. We present a patient who sustained fractures of the lateral and anterior walls of the right maxillary sinus, floor of the right orbit, and right zygomatic arch. Subcutaneous emphysema overlaid the right facial region and extended to the left side of the neck and into the mediastinum. We describe this unusual complication with respect to the anatomic relations of the facial and cervical fascial planes and spaces with the mediastinum.

Fatal tetanus in a drug abuser with "protective" antitetanus antibodies

Tetanus is a rare disease in the United States. From 1995-1997, the average annual incidence of tetanus was 0.15/1,000,000 population. Injecting-drug users, particularly those who use heroin, are among the highest risk population for acquiring tetanus. We present a case of an injecting-drug user who was seen in the emergency department with worsening diffuse midthoracic back pain and spasms. He subsequently developed acute respiratory failure and central nervous system hypoxic injury. Serum obtained before administration of tetanus immune globulin showed a tetanus antibody titer greater than 16 times the level considered protective. Because of limited human data on the minimum protective level of neutralizing antibody, as well as reports of tetanus among individuals with "protective" antibody titers, the diagnosis of tetanus should not be excluded solely on the basis of antitetanus titers.

Successful cricothyrotomy after thrombolytic therapy for acute myocardial infarction: a report of two cases

Cricothyrotomy is an emergency airway procedure that is generally performed after failure of primary methods for securing the airway. Coagulopathy has traditionally been considered a relative contraindication to cricothyrotomy, but there is little evidence in the literature to support this. There have been no reports of successful cricothyrotomy in a patient who had received systemic thrombolytic therapy. This report, from the National Emergency Airway Registry, is the first to describe successful cricothyrotomy in this context. We describe 2 patients who received thrombolytic therapy and then had cricothyrotomy performed after failure of other airway measures. The first patient was a 67-year-old man who developed severe pulmonary edema and respiratory failure less than 30 minutes after administration of tissue plasminogen activator using an accelerated regimen. Both intubation and attempts at ventilation using an esophageal/tracheal double-lumen airway (Combitube, Kendall-Sheridan, Argyle, NY) were unsuccessful, and the emergency physician then performed an uneventful cricothyrotomy using a vertical midline incision. There were no complications, and bleeding was minimal. The second patient was a 45-year-old man who developed severe angioedema with respiratory compromise after receiving streptokinase for acute myocardial infarction. Intubation was impossible, and a cricothyrotomy was performed. Significant bleeding was controlled initially with packing and was semielectively explored later in the ICU with ligation of several small bleeding vessels. Prior administration of thrombolytic therapy does not preclude successful cricothyrotomy.

Update on emerging infections from the Centers for Disease Control and Prevention. Outbreak of Vibrio parahaemolyticus infection associated with eating raw oysters and clams harvested from Long Island Sound--Connecticut, New Jersey, and New York, 1998

This article is part of a regular series on emerging infections from the Centers for Disease Control and Prevention (CDC) and the EMERGEncy ID NET, an emergency department-based and CDC-collaborative surveillance network. Important infectious disease public health information with relevance to emergency physicians is reported. The goal of this series is to advance knowledge about communicable diseases in emergency medicine, and foster cooperation between the front line of clinical medicine and public health agencies.

Prospective multicenter study of relapse following treatment for acute asthma among adults presenting to the emergency department. MARC investigators. Multicenter Asthma Research Collaboration

STUDY OBJECTIVE

To identify factors associated with relapse following treatment for acute asthma among adults presenting to the emergency department (ED).

DESIGN

Prospective inception cohort study performed during October 1996 to December 1996 and April 1997 to June 1997, as part of the Multicenter Asthma Research Collaboration.

SETTING

Thirty-six EDs in 18 states.

PATIENTS

ED patients, aged 18 to 54 years, with physician diagnosis of acute asthma. For the present analysis, we restricted the cohort to patients sent home from the ED (n = 971), then further excluded patients with comorbid respiratory conditions (n = 32). This left 939 eligible subjects to have follow-up data.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Two weeks after being sent home from the ED, patients were contacted by telephone. A relapse was defined as an urgent or unscheduled visit to any physician for worsening asthma symptoms during the 14-day follow-up period. Complete follow-up data were available for 641 patients, of whom 17% reported relapse (95% confidence interval, 14 to 20). There was no significant difference in peak expiratory flow rate (PEFR) between patients who suffered relapse and those who did not. In a multivariate logistic regression analysis (controlling for age, gender, race, and primary care provider status), patients who suffered relapse were more likely to have a history of numerous ED (odds ratio [OD] 1.3 per 5 visits) and urgent clinic visits (OR 1.4 per 5 visits) for asthma in the past year, use a home nebulizer (OR 2.2), report multiple triggers of their asthma (OR 1.1 per trigger), and report a longer duration of symptoms (OR 2.5 for 1 to 7 days).

CONCLUSION

Among patients sent home from the ED following acute asthma therapy, 17% will have a relapse and PEFR does not predict who will develop this outcome. By contrast, several historical features were associated with increased risk. Further research should focus on ways to decrease the relapse rate among these high-risk patients. The clinician may wish to consider these historical factors when making ED decisions.

Facial injury and airway threat from inhalant abuse: a case report

Fluorinated hydrocarbons cause toxicity in humans via their dysrhythmogenic potential and their local physical effects on the skin and mucous membranes. The former is generally the more life-threatening toxic consequence. We present a case of fluorinated hydrocarbon injury resulting from an intentional inhalation exposure that created facial frostbite, which threatened the patient's airway. The clinical range and management of these tissue-toxic effects are reviewed.

Heavy metal toxicity, part II: lead and metal fume fever

This review is the second of a two-part review of heavy metal toxicity. This part will identify the salient features of the toxicopathophysiology, clinical presentation, and emergency department management of lead toxicity and metal fume fever.

Beyond the twelve-lead electrocardiogram: diagnostic tests in the evaluation for suspected acute myocardial infarction in the emergency department, Part II

On a daily basis the emergency physician is faced with the difficult task of determining whether or not a patient with acute chest pain is sustaining an acute myocardial infarction. In most cases this is not a straightforward decision. Although observation units are being used more often for chest pain evaluations, many emergency physicians currently admit such patients to an intensive care setting. Because fewer than one-third of emergency department chest pain patients actually suffer an acute myocardial infarction, expensive resources are, in retrospect, used unnecessarily. Conversely, patients who are infarcting, and are inadvertently discharged home from the emergency department, have a worse prognosis than those admitted. This two-part series reviews the newer modalities available that may help the emergency physician arrive at a more accurate diagnosis. This article, Part II, will review the use of biochemical assays of cardiac proteins and discuss the Chest Pain Observation Unit.

Heavy metal toxicity, Part I: arsenic and mercury

This review is Part I of a two-part series focusing on heavy metal toxicity. Part I will cover arsenic and mercury toxicity. Acute and chronic arsenic toxicity, as well as arsine gas toxicity, will be reviewed. The clinical presentation, with focus on the nervous, cardiovascular, pulmonary, gastrointestinal, hepatic, renal, hematopoietic, and dermatologic systems, is delineated. Mercury exposure, including exposure to short chain alkyl mercury, elemental mercury, and acute inorganic salt, is reviewed. The discussion of clinical toxicity focuses on the nervous, cardiovascular, pulmonary, gastrointestinal, and renal systems, as well as on the teratogenic effects of mercury. Recommendations for diagnostic tests and management plans are discussed, including chelation regimens.

Beyond the twelve-lead electrocardiogram: diagnostic tests in the evaluation for suspected acute myocardial infarction in the emergency department, part I

On a daily basis the emergency physician is faced with the difficult task of determining whether or not a patient with acute chest pain is sustaining an acute myocardial infarction. In most cases, this is not a straightforward decision. Although observation units are being used more often for chest pain evaluations, many emergency physicians currently admit such patients to an intensive care setting. Because fewer than one-third of emergency department chest pain patients actually suffer an acute myocardial infarction, expensive resources are, in retrospect, used unnecessarily. Conversely, patients who are infarcting, and are inadvertently discharged home from the emergency department, have a worse prognosis than those admitted. This two-part series reviews the newer modalities available that may help the emergency physician arrive at a more accurate diagnosis. The current article, Part I, examines the use of myocardial imaging, computer assisted diagnostic protocols, and newer uses of the electrocardiogram. Part II reviews the use of biochemical assays of cardiac proteins and the Chest Pain Observation Unit.

Respiratory pearls, pitfalls, and updates

The scope of respiratory and ventilatory support offered in the emergency department (ED) has expanded substantially in the last 10 years. Emergency physicians are now much more aggressive and sophisticated in their management of bronchospasm, pulmonary edema, and acute respiratory failure. New medications and new technologies that have been tested in intensive care units should also be considered appropriate for use in the ED; indeed, from a respiratory support standpoint, the ED should be viewed as an intensive care unit. In this article, the authors outline these new concepts and treatments that allow initiation of "intensive care" in the ED.

Incision and drainage of cutaneous abscesses is not associated with bacteremia in afebrile adults

STUDY OBJECTIVE

To determine the prevalence of bacteremia associated with incision and drainage (I&D) of cutaneous abscesses in afebrile adult emergency department patients. Such information has implications for the ED management of immunocompromised patients, patients with history of endocarditis, and patients with prosthetic appliances such as heart valves and artificial joints.

METHODS

We conducted a prospective clinical study in the adult ED of an urban tertiary care teaching hospital. Our subjects were afebrile patients aged 18 to 65 years with localized, nondraining, purulent cutaneous abscesses requiring outpatient surgical management. Before I&D, blood for aerobic and anaerobic blood culture was drawn under sterile conditions. The wound was opened and samples for aerobic wound culture were obtained. Two and 10 minutes after I&D, blood was again drawn, from separate venipunctures. All patients were discharged home with ED follow-up scheduled 48 hours later.

RESULTS

From the 50 patients who completed the study, 150 blood samples (50 before and 100 after I&D) and 50 wound samples were obtained. No blood culture was positive, but 30 wound cultures (64%) were positive; the most commonly isolated organism was Staphylococcus aureus.

CONCLUSION

I&D of localized cutaneous abscesses in afebrile adults is unlikely to result in transient bacteremia. Larger studies are needed to determine whether routine antibiotic prophylaxis is necessary for afebrile patients undergoing I&D.

An unusual complication of missed appendicitis

A case of necrotizing fasciitis complicating missed appendicitis with perforation and abscess formation in a 63-year-old diabetic is presented. The case emphasizes the importance of thorough, conservative evaluation and management in elderly diabetic patients. The ED management of patients with necrotizing fasciitis is also briefly reviewed.

Antibiotic use in the emergency department. IV: Single-dose therapy and parenteral-loading dose therapy

There are a number of infectious diseases that can be treated efficaciously with a single dose of an antimicrobial agent. Other infections that can be treated with oral antibiotics on an outpatient basis may resolve more quickly if a parenteral loading dose is given in the emergency department (ED) prior to discharge. This article reviews the supporting literature and indications for single-dose and parenteral first-dose-loading antimicrobial therapy in the ED. This approach may be appropriate for such diverse infections as streptococcal pharyngotonsillitis, otitis media, urinary tract infections, chlamydial genital infections, vaginitis due to yeast, bacteria, or trichomoniasis, pneumonia, gonorrhea and pelvic inflammatory disease, and pediatric fever without a source.

Antibiotic use in the emergency department. III. The quinolones, new beta lactams, beta lactam combination agents, and miscellaneous antibiotics

This article reviews several new, relatively broad-spectrum antibiotics that have utility in the emergency department (ED). The quinolones have excellent activity against gram-negative organisms, including gonococcus, and are characterized by very high bioavailability after oral administration. The new beta-lactams aztreonam and imipenem have broad spectra but limited usefulness to the emergency physician, and should be reserved for judicious use in severe infections, particularly those involving Pseudomonas. Clavulanate, sulbactam, and tazobactam are themselves antimicrobials that have been combined with beta-lactams such as ampicillin and ticarcillin to produce agents with significant potential utility in the ED; these are typically not first-line agents, however, and their use should be governed by both clinical and cost concerns. Finally, three older antibiotics--vancomycin, metronidazole, and clindamycin--are reviewed with respect to updated indications for their use in the ED.

Antibiotic use in the emergency department. II The aminoglycosides, macrolides, tetracyclines, sulfa drugs, and urinary antiseptics

The aminoglycoside, macrolide, tetracycline, and sulfa classes of antibiotics provide antimicrobial coverage pertinent to many infectious diseases diagnosed in the emergency department (ED). The aminoglycosides are parenteral agents that are useful in Gram-negative infections and as synergistic drugs in the management of some Gram-positive infections. The macrolides, of which erythromycin is the prototype, are used for a number of Gram-positive and atypical bacterial infections, while the tetracyclines are appropriate for ED treatment of a diverse group of infections such as chlamydiae, spirochetes, and rickettsiae. The sulfa agents are appropriate for many urinary and respiratory tract infections, and also have particular utility in some infections encountered primarily in patients with AIDS. The urinary antiseptics are a group of antimicrobials that may be effective for cystitis but have no systemic efficacy. This article, which is the second in a four-part series on antibiotic use in the ED, reviews the pharmacology and clinical utility of these diverse agents for the emergency physician.

Antibiotic use in the emergency department: I. The penicillins and cephalosporins

The penicillins and cephalosporins are beta-lactam agents that provide broad-spectrum antimicrobial coverage pertinent to many infectious diseases diagnosed in the emergency department. These groups of drugs also have in common their classification into subcategories or "generations" that delineate their usefulness in specific clinical scenarios such as infections with Gram-positive or -negative bacteria, Pseudomonas infections, or febrile neutropenic patients. Understanding these subcategories is essential to both efficacious and cost-effective use of these agents. This article reviews the pharmacology and clinical utility of the beta-lactams--including a new class of antibiotics, the carbacephams--for the emergency physician.

Treatment of acute bronchospasm with beta-adrenergic agonist aerosols delivered by a nasal bilevel positive airway pressure circuit

STUDY OBJECTIVE

To determine whether beta-adrenergic agonist aerosols are more effective in treating acute bronchospasm if delivered by nasal bilevel positive airway pressure (BiPAP) than by a small-volume nebulizer (SVN). We hypothesized that BiPAP would reduce the work of breathing in asthmatic patients and thereby hasten improvement of bronchospasm from beta-agonist therapy. Previous trials with aerosols given by intermittent positive-pressure breathing were unrewarding, but BiPAP is unique in that inspiratory (IPAP) and expiratory (EPAP) support pressures may be set separately.

DESIGN

Convenience-randomized prospective clinical study.

SETTING

Emergency department of an urban tertiary care teaching hospital.

PARTICIPANTS

Afebrile, wheezing patients between 18 and 40 years of age.

INTERVENTIONS

Patients were randomly assigned to receive two doses of aerosolized albuterol (2.5 mg in 3 mL normal saline solution), 20 minutes apart, delivered by either SVN (n = 40) or BiPAP (n = 60) by nosemask or facemask (IPAP, 10 cm H2O; EPAP, 5 cm H2O).

RESULTS

Peak expiratory flow rate (PEFR), arterial blood oxygen saturation (by pulse oximetry), and pulse and respiratory rates were measured at baseline and after each treatment. The two treatment groups had similar values for pulse oximetry, pulse rate, respiratory rate, and percent of predicted peak expiratory flow rate (%PPEFR) at entry, and all patients experienced similar changes in the first three of these variables through the course of treatment. BiPAP patients had a significantly greater increase in %PPEFR after each treatment (P = .0011) and from baseline to completion (P = .0013). Increase in absolute PEFR was greater in the BiPAP group (from 211 +/- 89 [mean +/- SD] to 357 +/- 108 L/minute for BiPAP, from 183 +/- 60 to 280 +/- 87 L/minute for SVN; P = .0001).

CONCLUSION

In this population, response to initial ED management of bronchospasm, as measured by PEFR, was better with aerosols delivered by BiPAP than with those delivered by SVN.

Outpatient management of acute urticaria: the role of prednisone

STUDY OBJECTIVE

To evaluate the efficacy of a 4-day "burst" course of prednisone added to standard treatment with H1 antihistamines for the management of acute urticaria in outpatients.

DESIGN

Prospective, randomized, double-blinded, clinical trial.

SETTING

Emergency department of an urban tertiary care teaching hospital.

PARTICIPANTS

Adult patients with urticarial rash of no more than 24 hours' duration, regardless of cause. Patients were excluded if they manifested wheezing, stridor, or angioedema or if they had taken antihistamines or glucocorticoids within 5 days of arrival at the ED. Patients also were excluded if there was a history of diabetes or active peptic ulcer disease.

INTERVENTIONS

All patients were asked to evaluate the severity of pruritus ("itch score") on a 10-cm visual analog scale. Patients were then given diphenhydramine, 50 mg intramuscularly, and discharged home on a regimen of hydroxyzine, 25 mg orally, every 4 to 8 hours for pruritus, plus either prednisone, 20 mg, or placebo orally every 12 hours for 4 days. Patients' conditions were reassessed clinically, with itch score calculated again 2 days later, and again at 5 days by telephone.

RESULTS

Forty-three patients were enrolled; 24 received prednisone and 19 received placebo. The two groups had similar itch scores at enrollment (prednisone, 8.1 +/- 1.7; placebo, 7.4 +/- 2.1, P = .25 [ANOVA]), but at 2- and 5-day follow-up the prednisone group had significantly lower itch scores (1.3 +/- 1.3 and .0 +/- .0 versus 4.4 +/- 2.2 and 1.6 +/- 1.0, respectively; P < .0001 [ANCOVA] at each interval) and greater clinical improvement in rash. Response did not correlate with age, sex, or identification of an allergen. No adverse effects were noted in either group.

CONCLUSION

The addition of a prednisone burst improves the symptomatic and clinical response of acute urticaria to antihistamines. Patients' conditions improved more quickly and more completely when prednisone was administered, without any apparent adverse effects.

Emphysematous cystitis presenting as painless gross hematuria

A case of emphysematous cystitis in an immunocompetent male is described. The diagnosis is generally rare, but may be made in the Emergency Department. A history of pneumaturia is highly suggestive of the entity, but is rarely offered by the patient. The evaluation and management of emphysematous cystitis are discussed.

Hydropneumothorax due to tuberculosis

Pulmonary tuberculosis, a disease largely limited to third-world populations only 15 years ago, is increasingly becoming a public health problem again in the U.S. We review an emergent presenting feature of tuberculosis--spontaneous pneumothorax--that may now be seen more commonly in emergency departments (EDs). Pneumothorax must be quickly and effectively managed in the ED. In addition, the emergency physician should readily consider tuberculosis as an etiology in any patient with a spontaneous pneumothorax and a significant prodromal illness or a history of exposure to tuberculosis so that contagion precautions may be instituted promptly.