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Open Access Publications from the University of California

Volume 10, Issue 4, 2009

Volume 10 Issue 4 2009


Factors Associated With False-Positive Emergency Medical Services Triage for Percutaneous Coronary Intervention

Background: In 2005, Orange County California Emergency Medical Services (EMS) initiated a field 12-lead program to minimize time to emergency percutaneous coronary intervention (PCI) for field-identified acute myocardial infarction (MI). As the program matured, “false-positive” (defined as no PCI or coronary artery occlusion upon PCI) field MI activations have been identified as a problem for the program.

Objectives: To identify potentially correctable factors associated with false-positive EMS triage to PCI centers.

Methods: This was a retrospective, outcome study of EMS 12-lead cases from February 2006 to June 2007. The study system exclusively used cardiac monitor internal interpretation algorithms indicating an acute myocardial infarction as the basis for triage. Indicators and variables were defined prior to the study. Data, including outcome, was from the Orange County EMS database, which included copies of 12-lead ECGs used for field triage. Negative odds ratios (OR) of less than 1.0 for positive PCI were the statistical measure of interest.

Results: Five hundred forty-eight patients were triaged from the field for PCI. We excluded 19 cases from the study because of death prior to PCI, refusal of PCI, and co-morbid illness (sepsis, altered consciousness) that precluded PCI. Three hundred ninety-three (74.3%) patients had PCI with significant coronary lesions found. False-positive field triages were associated with underlying cardiac rhythm of sinus tachycardia [OR = 0.38 (95% CI 0.23, 0.62)]; atrial fibrillation [OR = 0.43 (95% CI = 0.20, 0.94)]; an ECG lead not recorded [OR = 0.39 (95% CI = 0.20, 0.76)]; poor ECG baseline [OR = 0.59 (95% CI = 0.25, 1.37)]; One of three brands of monitors used in the field [OR = 0.35 (95% CI = 0.21, 0.59)]; and female gender [OR = 0.50 (95% CI = 0.34, 0.75)]. Age was not associated with false-positive triage as determined by ordinal regression (p=1.00).

Conclusion: For the urban-suburban EMS field 12-lead program studied, age was not associated with false-positive triage. It was unexpected that female gender was associated with false-positive triage. False-positive triage from the field was associated with poor ECG acquisition, underlying rhythms of atrial fibrillation and sinus tachycardia, and one brand of 12-lead monitor.

[West J Emerg Med. 2009;10(4):208-212]

International Disaster Medical Sciences Fellowship: Model Curriculum and Key Considerations for Establishment of an Innovative International Educational Program

As recent events highlight, a global requirement exists for evidence-based training in the emerging field of Disaster Medicine. The following is an example of an International Disaster Medical Sciences Fellowship created to fill this need. We provide here a program description, including educational goals and objectives and a model core curriculum based on current evidence-based literature. In addition, we describe the administrative process to establish the fellowship. Information about this innovative educational program is valuable to international Disaster Medicine scholars, as well as U.S. institutions seeking to establish formal training in Disaster Medical Sciences.

[West J Emerg Med. 2009;10(4):213-219]

Introducing a Clinical Practice Guideline Using Early CT in the Diagnosis of Scaphoid and Other Fractures

Objective: We developed and implemented clinical practice guideline (CPG) using computerized tomography (CT) as the initial imaging method in the emergency department management of scaphoid fractures. We hypothesized that this CPG would decrease unnecessary immobilization and lead to earlier return to work.

Methods: This observational study evaluated implementation of our CPG, which incorporated early wrist CT in patients with “clinical scaphoid fracture”: a mechanism of injury consistent with scaphoid fracture, anatomical snuff box tenderness, and normal initial plain x-rays. Outcome measures were the final diagnosis as determined by orthopaedic review of the clinical and imaging data. Patient outcomes included time to return to work and patient satisfaction as determined by telephone interview at ten days.

Results: Eighty patients completed the study protocol in a regional emergency department.

In this patient population CT detected 28 fractures in 25 patients, including six scaphoid fractures, five triquetral fractures, four radius fractures, and 13 other related fractures. Fifty-three patients had normal CT. Eight of these patients had significant ongoing pain at follow up and had an MRI, with only two bone bruises identified. The patients with normal CTs avoided prolonged immobilization (mean time in plaster 2.7 days) and had no or minimal time off work (mean 1.6 days). Patient satisfaction was an average 4.2/5.

Conclusion: This CPG resulted in rapid and accurate management of patients with suspected occult scaphoid injury, minimized unnecessary immobilization and was acceptable to patients.

[WestJEM. 2009;10(4):227-232.]

Crowding and Delivery of Healthcare in Emergency Departments: The European Perspective

Emergency department (ED) crowding is a multifactorial problem, resulting in increased ED waiting times, decreased patient satisfaction and deleterious domino effects on the entire hospital. Although difficult to define and once limited to anecdotal evidence, crowding is receiving more attention as attempts are made to quantify the problem objectively. It is a worldwide phenomenon with regional influences, as exemplified when analyzing the problem in Europe compared to that of the United States. In both regions, an aging population, limited hospital resources, staff shortages and delayed ancillary services are key contributors; however, because the structure of healthcare differs from country to country, varying influences affect the issue of crowding. The approach to healthcare delivery as a right of all people, as opposed to a free market commodity, depends on governmental organization and appropriation of funds. Thus, public funding directly influences potential crowding factors, such as number of hospital beds, community care facilities, and staffing. Ultimately ED crowding is a universal problem with distinctly regional root causes; thus, any approach to address the problem must be tailored to regional influences.

[West J Emerg Med. 2009; 10:233-239].

Paramedics’ Ability to Perform Drug Calculations

Background: The ability to perform drug calculations accurately is imperative to patient safety. Research into paramedics’ drug calculation abilities was first published in 2000 and for nurses’ abilities the research dates back to the late 1930s. Yet, there have been no studies investigating an undergraduate paramedic student’s ability to perform drug or basic mathematical calculations. The objective of this study was to review the literature and determine the ability of undergraduate and qualified paramedics to perform drug calculations.

Methods: A search of the prehospital-related electronic databases was undertaken using the Ovid and EMBASE systems available through the Monash University Library. Databases searched included the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, CINAHL, JSTOR, EMBASE and Google Scholar, from their beginning until the end of August 2009. We reviewed references from articles retrieved.

Results: The electronic database search located 1,154 articles for review. Six additional articles were identified from reference lists of retrieved articles. Of these, 59 were considered relevant. After reviewing the 59 articles only three met the inclusion criteria. All articles noted some level of mathematical deficiencies amongst their subjects.

Conclusions: This study identified only three articles. Results from these limited studies indicate a significant lack of mathematical proficiency amongst the paramedics sampled. A need exists to identify if undergraduate paramedic students are capable of performing the required drug calculations in a non-clinical setting.

[WestJEM. 2009;10:240-243.]

Lead Toxicity Resulting from Chronic Ingestion of Opium

A 32-year-old man presented to the emergency department (ED) with lower abdominal pain and constipation. He related chronic ingestion of large amounts of opium. Physical examination showed mild abdominal tenderness and gingival discoloration. Diagnostic studies showed a mild hypochromic, microcytic anemia with basophilic stippling of the red blood cells. Abdominal imaging showed no intra-abdominal pathology. A diagnosis of lead toxicity was confirmed through serum lead levels. The patient was put on chelation therapy and his signs and symptoms started to resolve. As a comprehensive search for other sources of lead was unsuccessful, opium adulterants were considered as the culprit. Chemical analysis of the opium confirmed this. Contaminated drugs have been reported as a source of exposure to toxins such as arsenic or lead. While other reports deal with patients from clinics, this report illustrates lead toxicity from ingestion of contaminated opium in the ED.

[West J Emerg Med. 2009;10(4):244-246.]

Thyroid Gland Hematoma After Blunt Neck Trauma

Hemorrhage of a previously normal thyroid gland as a result of blunt trauma is a very rare condition. We report a case of blunt trauma that caused acute hemorrhage into the thyroid gland and presented with hoarseness. The diagnosis of thyroid gland hematoma was made with a combination of fiberoptic laryngoscopy, cervical computed tomography, and carotid angiography. The patient was treated conservatively, had a favorable course without further complications, and was discharged four days after admission.

[West J Emerg Med. 2009;10(4):247-249.]

Wound Botulism in Injection Drug Users: Time to Antitoxin Correlates with Intensive Care Unit Length of Stay

Objectives: We sought to identify factors associated with need for mechanical ventilation (MV), length of intensive care unit (ICU) stay, length of hospital stay, and poor outcome in injection drug users (IDUs) with wound botulism (WB).

Methods: This is a retrospective review of WB patients admitted between 1991-2005. IDUs were included if they had symptoms of WB and diagnostic confirmation. Primary outcome variables were the need for MV, length of ICU stay, length of hospital stay, hospital-related complications, and death.

Results: Twenty-nine patients met inclusion criteria. Twenty-two (76%) admitted to heroin use only and seven (24%) admitted to heroin and methamphetamine use. Chief complaints on initial presentation included visual changes, 13 (45%); weakness, nine (31%); and difficulty swallowing, seven (24%). Skin wounds were documented in 22 (76%). Twenty-one (72%) patients underwent mechanical ventilation (MV). Antitoxin (AT) was administered to 26 (90%) patients but only two received antitoxin in the emergency department (ED). The time from ED presentation to AT administration was associated with increased length of ICU stay (Regression coefficient = 2.5; 95% CI 0.45, 4.5). The time from ED presentation to wound drainage was also associated with increased length of ICU stay (Regression coefficient = 13.7; 95% CI = 2.3, 25.2). There was no relationship between time to antibiotic administration and length of ICU stay.

Conclusion: MV and prolonged ICU stays are common in patients identified with WB. Early AT administration and wound drainage are recommended as these measures may decrease ICU length of stay.

[West J Emerg Med. 2009;10(4):251-256.]

  • 1 supplemental PDF

Terrain Park Injuries

Background: This study examined demographics, injury pattern, and hospital outcome in patients injured in winter resort terrain parks.

Methods: The study included patients >12 years of age who presented to a regional trauma center with an acute injury sustained at a winter resort. Emergency department (ED) research assistants collected patient injury and helmet use information using a prospectively designed questionnaire. ED and hospital data were obtained from trauma registry and hospital records.

Results: Seventy-two patients were injured in a terrain park, and 263 patients were injured on non-terrain park slopes. Patients injured in terrain parks were more likely to be male [68/72 (94%) vs. 176/263 (67%), p<0.0001], younger in age [23 ± 7 vs. 36 ± 17, p<0.0001], live locally [47/72 (65%) vs. 124/263 (47%), p=0.006], use a snowboard [50/72 (69%) vs. 91/263 (35%), p<0.0001], hold a season pass [46/66 (70%) vs. 98/253 (39%), p<0.0001], and sustain an upper extremity injury [29/72 (40%) vs. 52/263 (20%), p<0.001] when compared to patients injured on non-terrain park slopes. There were no differences between the groups in terms of EMS transport to hospital, helmet use, admission rate, hospital length of stay, and patients requiring specialty consultation in the ED.

Conclusions: Patients injured in terrain parks represent a unique demographic within winter resort patrons. Injury severity appears to be similar to those patients injured on non-terrain park slopes.

[West J Emerg Med. 2009;10(4):257-262.]

  • 1 supplemental PDF

The Utility of Bedside Ultrasound in the Detection of a Ruptured Globe in a Porcine Model

Background: Recent case reports have shown that ultrasonography can be used to diagnose ocular pathology in an emergency setting. Ultrasound may be especially useful when periorbital edema and pain interfere with the examination of the post-traumatic eye.

Objective: This study evaluated the ability of emergency physicians to detect a ruptured globe in an ex-vivo porcine model.

Methods: Following a brief training lecture, 15 emergency medicine residents and 4 emergency medicine attending physicians used ultrasonography to evaluate 18 porcine eyes, randomized as normal, ruptured, or completely devoid of vitreous humor. The consequences of ultrasound applanation with this method were evaluated by measuring intraocular pressure changes with and without a 1mm clear plastic shield.

Results: Our study participants were able to identify abnormal eyes with a sensitivity of 79% (95% CI 73% to 84%) and a specificity of 51% (95% CI 41% to 61%). Intraocular pressure increased 5% with ultrasound applanation, though with a 1mm thick plastic shield there was no measurable change.

Conclusions: Ultrasound imaging may be a future modality to be used by trained emergency physicians to expedite the identification of a rupture globe, but it is unlikely to replace more definitive imaging techniques. The use of a clear plastic barrier in this porcine model prevents an increase in intra-ocular pressure without affecting image quality, and should be used in any future studies on this method.

[West J Emerg Med. 2009;10(4):263-266.]

Emergency Department Patients with Psychiatric Complaints Return at Higher Rates than Controls

Study objective: At our 35,000 visit/year emergency department (ED), we studied whether patients presenting to the ED with psychiatric complaints were admitted to the hospital at a higher rate than non-psychiatric patients, and whether these patients had a higher rate of reevaluation in the ED within 30 days following the index visit.

Methods: We reviewed the electronic records of all ED patients receiving a psychiatric evaluation from January to February 2007 and compared these patients to 300 randomly selected patients presenting during the study period for non-psychiatric complaints. Patients were followed for 30 days, and admission rates and return visits were compared.

Results: Two hundred thirty-four patients presented to the ED and were evaluated for psychiatric complaints during the study period. Twenty-four point seven percent of psychiatric patients were admitted upon initial presentation versus 20.7% of non-psychiatric patients (p = 0.258). Twenty-one percent of discharged psychiatric patients returned to the ED within 30 days versus 13.4% of discharged non-psychiatric patients (p=0.041). Patients returning to the ED within 30 days had a 17.1% versus 21.6% admission rate for the psychiatric and non-psychiatric groups, respectively (p=0.485).

Conclusion: Patients presenting to this ED with psychiatric complaints were not admitted at a significantly higher rate than non-psychiatric patients. These psychiatric patients did, however, have a significantly higher return rate to the ED when compared to non-psychiatric patients.

[West J Emerg Med. 2009;10(4):268-272.]

The Clinical Differentiation of Cerebellar Infarction from Common Vertigo Syndromes

This article summarizes the emergency department approach to diagnosing cerebellar infarction in the patient presenting with vertigo. Vertigo is defined and identification of a vertigo syndrome is discussed. The differentiation of common vertigo syndromes such as benign paroxysmal positional vertigo, Meniere’s disease, migrainous vertigo, and vestibular neuritis is summarized. Confirmation of a peripheral vertigo syndrome substantially lowers the likelihood of cerebellar infarction, as do indicators of a peripheral disorder such as an abnormal head impulse test. Approximately 10% of patients with cerebellar infarction present with vertigo and no localizing neurologic deficits. The majority of these may have other signs of central vertigo, specifically direction-changing nystagmus and severe ataxia.

[West J Emerg Med. 2009;10(4):273-277.]

The Back Alley Revisited: Sepsis after Attempted Self-Induced Abortion

While unsafe abortions have become rare in the United States, the practice persists. We present a 24-year-old female with a 21-week twin gestation who presented to the emergency department with complications of an attempted self-induced abortion. Her complicated clinical course included sepsis, chorioamnionitis, fetal demise, and a total abdominal hysterectomy with bilateral salpingo-oophorectomy for complications of endomyometritis. We discuss unsafe abortions, risk factors, and the management of septic abortion. Prompt recognition by the emergency physician and aggressive management of septic abortion is critical to decreasing maternal morbidity and mortality.

[West J Emerg Med. 2009;10(4):278-280.]

Non-Traumatic Urologic Emergencies in Men: A Clinical Review

Although true urologic emergencies are extremely rare, they are a vital part of any emergency physician’s (EP) knowledge base, as delays in treatment lead to permanent damage. The four urologic emergencies discussed are priapism, paraphimosis, testicular torsion, and Fournier’s gangrene. An overview is given for each, including causes, pathophysiology, diagnosis, treatment, and new developments. The focus for priapism is on diagnosis and distinguishing high-flow from low-flow forms, as the latter requires emergent treatment. For paraphimosis, we describe various methods of relieving the stricture, from manual reduction to surgery in extreme cases. For testicular torsion, the most important factor in salvaging the testicle is decreasing time to treatment. This is accomplished through experience and understanding which signs and symptoms strongly suggest it, so that time-consuming tests are avoided. Lastly, Fournier’s gangrene is potentially fatal. While aggressive medical and surgical therapy will improve chances of survival and outcome, it is vital for the emergency department (ED) physician to diagnose Fournier’s. It often presents in the elderly, immunocompromised, or those with depressed mental status. The goal of this paper is to arm EPs with information to recognize urological emergencies and intervene quickly to preserve tissue, fertility, and life.

[West J Emerg Med. 2009;10(4):281-287.]

Bilateral Psoas Abscess in the Emergency Department

We present the case of a 45-year-old female who presented multiple times to the emergency department with acute low back pain and was subsequently diagnosed with bilateral psoas muscle abscess. Psoas abscess is an uncommon cause of acute low back pain that is associated with high morbidity and mortality. The onset of symptoms is frequently insidious and the clinical presentation vague. Proper diagnosis requires vigilance of the physician to recognize signs in the history and physical examination that are suggestive of a potentially serious spinal condition and initiate further workup. While most patients with acute low back pain have a benign etiology, this case report demonstrates the challenge of diagnosing a patient with bilateral psoas abscess who had few known risk factors and symptoms typical of mechanical low back pain.

[West J Emerg Med. 2009;10(4):288-291.]

Lidocaine Toxicity Misinterpreted as a Stroke

For more than 50 years lidocaine has been used to treat ventricular arrhythmias. Neurologic dysfunction, manifested as a stroke, occurred acutely in an 87-year-old woman after she had been administered repeated doses of lidocaine, a lidocaine infusion, then an intravenous amiodarone infusion for ventricular tachycardia. This was ultimately diagnosed as lidocaine toxicity with a serum lidocaine level of 7.9 mg/L (1.5 - 6.0 mg/L). We discuss lidocaine toxicity and risk factors leading to its development, which include particularly hepatic dysfunction, cardiac dysfunction, advanced age and other drug administration.

[West J Emerg Med. 2009;10(4):292-294.]

Molar Pregnancy in the Emergency Department

A 15-year-old female presented to the emergency department with complaints of vaginal bleeding. She was pale, anxious, cool and clammy with tachycardic, thready peripheral pulses and hemoglobin of 2.4g/dL. Her abdomen was gravid appearing, approximately early to mid-second trimester in size. Pelvic examination revealed 2 cm open cervical os with spontaneous discharge of blood, clots and a copious amount of champagne-colored grapelike spongy material. After 2L boluses of normal saline and two units of crossmatched blood, patient was transported to the operating room. Surgical pathology confirmed a complete hydatidiform mole.

[West J Emerg Med. 2009;10(4):295-296.]

Non-traumatic Shoulder Dislocation

[West J Emerg Med. 2009;10(4):304.]