Test Characteristics of Emergency Physician-Performed Limited Compression Ultrasound for Lower-Extremity Deep Vein Thrombosis.

BACKGROUND: The current literature suggests that emergency physician (EP)-performed limited compression ultrasound (LCUS) is a rapid and accurate test for deep vein thrombosis (DVT). OBJECTIVE: Our primary objective was to determine the sensitivity and specificity of LCUS for the diagnosis of DVT when performed by a large heterogeneous group of EPs. METHODS: This was a prospective diagnostic test assessment of LCUS conducted at two urban academic emergency departments. The scanning protocol involved compression at the common femoral, superficial femoral, and popliteal veins. Patients were eligible if undergoing radiology department ultrasound of the lower extremity with moderate or high pretest probability for DVT, or low pretest probability for DVT with a positive d-dimer. The enrolling EP performed LCUS before radiology department ultrasound of the same lower extremity. Sensitivity, specificity, and associated 95% confidence intervals (CIs) were calculated with the radiologist interpretation of the radiology department ultrasound as the criterion standard. RESULTS: A total of 56 EPs enrolled 296 patients for LCUS, with a median age of 50 years and 50% female. Fifty (17%) DVTs were identified by radiology department ultrasound, and another five (2%) cases were deemed indeterminate. The sensitivity and specificity of EP-performed LCUS was 86% (95% CI 73-94%) and 93% (95% CI 89-96%), respectively. CONCLUSIONS: A large heterogeneous group of EPs with limited training can perform LCUS with intermediate diagnostic accuracy. Unfortunately, LCUS performed by EPs with limited ultrasound training is not sufficiently sensitive or specific to rule out or diagnose DVT as a single testing modality.

Effect of Interventional Program on the Utilization of PACS in Point-of-Care Ultrasound.

While the implementation of Picture Archiving and Communication Systems (PACS) has revolutionized the field of radiology, there has been considerably less utilization of PACS by emergency physicians with point-of-care ultrasound. Benefits of PACS archival of images include improved quality assurance, preservation of image quality, and accessibility of images. Our objective was to determine if a simple interventional program would influence the utilization of PACS in point-of-care ultrasound. A before-after study was conducted in an urban, academic emergency department. Data was collected during a 4-week baseline period, a 12-week intervention period, and a 12-week post-intervention period. The percentage of ultrasound studies archived to PACS was recorded during each week of the study. Interventions were designed to encourage the utilization of PACS. A significant increase in the mean percentage of PACS studies was found between the baseline and intervention period (59.4 %; 95 % CI: 34.76-84.08 %; p < 0.001). Mean percentage of PACS studies at 1-month (74.3 %), 2-month (61.0 %), and 3-month (74.8 %) post-intervention periods remained elevated and were all significantly increased compared to baseline values (p < 0.001). Mean percentages of PACS studies at 1-month, 2-month, and 3-month post-intervention periods were not statistically significant from the intervention period (p = 0.977, p = 0.849, p = 0.967, respectively). A simple interventional program for emergency physicians can significantly increase and sustain the utilization of PACS for point-of-care ultrasound.

Is long-axis view superior to short-axis view in ultrasound-guided central venous catheterization?

OBJECTIVE: To evaluate whether using long-axis or short-axis view during ultrasound-guided internal jugular and subclavian central venous catheterization results in fewer skin breaks, decreased time to cannulation, and fewer posterior wall penetrations. DESIGN: Prospective, randomized crossover study. SETTING: Urban emergency department with approximate annual census of 60,000. SUBJECTS: Emergency medicine resident physicians at the Denver Health Residency in Emergency Medicine, a postgraduate year 1-4 training program. INTERVENTIONS: Resident physicians blinded to the study hypothesis used ultrasound guidance to cannulate the internal jugular and subclavian of a human torso mannequin using the long-axis and short-axis views at each site. MEASUREMENTS AND MAIN RESULTS: An ultrasound fellow recorded skin breaks, redirections, and time to cannulation. An experienced ultrasound fellow or attending used a convex 8-4 MHz transducer during cannulation to monitor the needle path and determine posterior wall penetration. Generalized linear mixed models with a random subject effect were used to compare time to cannulation, number of skin breaks and redirections, and posterior wall penetration of the long axis and short axis at each cannulation site. Twenty-eight resident physicians participated: eight postgraduate year 1, eight postgraduate year 2, five postgraduate year 3, and seven postgraduate year 4. The median (interquartile range) number of total internal jugular central venous catheters placed was 27 (interquartile range, 9-42) and subclavian was six catheters (interquartile range, 2-20). The median number of previous ultrasound-guided internal jugular catheters was 25 (interquartile range, 9-40), and ultrasound-guided subclavian catheters were three (interquartile range, 0-5). The long-axis view was associated with a significant decrease in the number of redirections at the internal jugular and subclavian sites, relative risk 0.4 (95% CI, 0.2-0.9) and relative risk 0.5 (95% CI, 0.3-0.7), respectively. There was no significant difference in the number of skin breaks between the long axis and short axis at the subclavian and internal jugular sites. The long-axis view for subclavian was associated with decreased time to cannulation; there was no significant difference in time between the short-axis and long-axis views at the internal jugular site. The prevalence of posterior wall penetration was internal jugular short axis 25%, internal jugular long axis 21%, subclavian short axis 64%, and subclavian long axis 39%. The odds of posterior wall penetration were significantly less in the subclavian long axis (odds ratio, 0.3; 95% CI, 0.1-0.9). CONCLUSIONS: The long-axis view for the internal jugular was more efficient than the short-axis view with fewer redirections. The long-axis view for subclavian central venous catheterization was also more efficient with decreased time to cannulation and fewer redirections. The long-axis approach to subclavian central venous catheterization is also associated with fewer posterior wall penetrations. Using the long-axis view for subclavian central venous catheterization and avoiding posterior wall penetrations may result in fewer central venous catheter-related complications.

Comparison of bag-valve-mask hand-sealing techniques in a simulated model.

STUDY OBJECTIVE: Bag-valve-mask ventilation remains an essential component of airway management. Rescuers continue to use both traditional 1- or 2-handed mask-face sealing techniques, as well as a newer modified 2-handed technique. We compare the efficacy of 1-handed, 2-handed, and modified 2-handed bag-valve-mask technique. METHODS: In this prospective, crossover study, health care providers performed 1-handed, 2-handed, and modified 2-handed bag-valve-mask ventilation on a standardized ventilation model. Subjects performed each technique for 5 minutes, with 3 minutes' rest between techniques. The primary outcome was expired tidal volume, defined as percentage of total possible expired tidal volume during a 5-minute bout. A specialized inline monitor measured expired tidal volume. We compared 2-handed versus modified 2-handed and 2-handed versus 1-handed techniques. RESULTS: We enrolled 52 subjects: 28 (54%) men, 32 (62%) with greater than or equal to 5 actual emergency bag-valve-mask situations. Median expired tidal volume percentage for 1-handed technique was 31% (95% confidence interval [CI] 17% to 51%); for 2-handed technique, 85% (95% CI 78% to 91%); and for modified 2-handed technique, 85% (95% CI 82% to 90%). Both 2-handed (median difference 47%; 95% CI 34% to 62%) and modified 2-handed technique (median difference 56%; 95% CI 29% to 65%) resulted in significantly higher median expired tidal volume percentages compared with 1-handed technique. The median expired tidal volume percentages between 2-handed and modified 2-handed techniques did not significantly differ from each other (median difference 0; 95% CI -2% to 2%). CONCLUSION: In a simulated model, both 2-handed mask-face sealing techniques resulted in higher ventilatory tidal volumes than 1-handed technique. Tidal volumes from 2-handed and modified 2-handed techniques did not differ. Rescuers should perform bag-valve-mask ventilation with 2-handed techniques.

Sensitivity of systemic inflammatory response syndrome for critical illness among ED patients.

BACKGROUND: Little is known about the diagnostic accuracy of systemic inflammatory response syndrome (SIRS) criteria for critical illness among emergency department (ED) patients with and without infection. Our objective was to assess the diagnostic accuracy of SIRS criteria for critical illness in ED patients. METHODS: This was a retrospective cohort study of ED patients at an urban academic hospital. Standardized chart abstraction was performed on a random sample of all adult ED medical patients admitted to the hospital during a 1-year period, excluding repeat visits, transfers, ED deaths, and primary surgical or psychiatric admissions. The binary composite outcome of critical illness was defined as 24 hours or longer in intensive care or inhospital death. Presumed infection was defined as receiving antibiotics within 48 hours of admission. Systemic inflammatory response syndrome criteria were calculated using ED triage vital signs and initial white blood cell count. RESULTS: We studied 1152 patients; 39% had SIRS, 27% had presumed infection, and 23% had critical illness (2% had inhospital mortality, and 22% had ≥24 hours in intensive care). Of patients with SIRS, 38% had presumed infection. Of patients without SIRS, 21% had presumed infection. The sensitivity of SIRS criteria for critical illness was 52% (95% confidence interval [CI], 46%-58%) in all patients, 66% (95% CI, 56%-75%) in patients with presumed infection, and 43% (95% CI, 36%-51%) in patients without presumed infection. CONCLUSIONS: Systemic inflammatory response syndrome at ED triage, as currently defined, has poor sensitivity for critical illness in medical patients admitted from the ED.

Validation of the Simplified Motor Score in the out-of-hospital setting for the prediction of outcomes after traumatic brain injury.

STUDY OBJECTIVE: The Glasgow Coma Scale (GCS) score is widely used to assess patients with head injury but has been criticized for its complexity and poor interrater reliability. A 3-point Simplified Motor Score (SMS) (defined as obeys commands=2, localizes pain=1, and withdraws to pain or worse=0) was created to address these limitations. Our goal is to validate the SMS in the out-of-hospital setting, with the hypothesis that it is equivalent to the GCS score for discriminating brain injury outcomes. METHODS: This was a secondary analysis of an urban Level I trauma registry. Four outcomes and their composite were studied: emergency tracheal intubation, clinically meaningful brain injury, need for neurosurgical intervention, and mortality. The out-of-hospital GCS score and SMS were evaluated by comparing areas under the receiver operating characteristic curve with a paired nonparametric approach. Multiple imputation was used for missing data. A clinically significant difference in areas under the receiver operating characteristic curve was defined as greater than or equal to 0.05, according to previous literature. RESULTS: We included 19,408 patients, of whom 18% were tracheally intubated, 18% had brain injuries, 8% required neurosurgical intervention, and 6% died. The difference between the area under the receiver operating characteristic curve for the out-of-hospital GCS score and SMS was 0.05 (95% confidence interval [CI] -0.01 to 0.11) for emergency tracheal intubation, 0.05 (95% CI 0 to 0.09) for brain injury, 0.04 (95% CI -0.01 to 0.09) for neurosurgical intervention, 0.08 (95% CI 0.02 to 0.15) for mortality, and 0.05 (95% CI 0 to 0.10) for the composite outcome. CONCLUSION: In this external validation, SMS was similar to the GCS score for predicting outcomes in traumatic brain injury in the out-of-hospital setting.

Successful resuscitation of a patient in asystole after a TASER injury using a hypothermia protocol.

New studies have shown the benefit of initiating a hypothermia protocol in the survivors of cardiac arrest. Although the data have shown an improved neurologic end point in patients initially in ventricular fibrillation or pulseless ventricular tachycardia, there is still debate about whether patients initially in other rhythms would benefit from hypothermia after return of spontaneous circulation. This is a report of a 17-year-old male found to be in asystole after sustaining a TASER injury, who was treated with a hypothermia protocol after return of spontaneous circulation and left the hospital with intact neurologic function.

Experience with emergency ultrasound training by Canadian emergency medicine residents.

INTRODUCTION: Starting in 2008, emergency ultrasound (EUS) was introduced as a core competency to the Royal College of Physicians and Surgeons of Canada (Royal College) emergency medicine (EM) training standards. The Royal College accredits postgraduate EM specialty training in Canada through 5-year residency programs. The objective of this study is to describe both the current experience with and the perceptions of EUS by Canadian Royal College EM senior residents. METHODS: This was a web-based survey conducted from January to March 2011 of all 39 Canadian Royal College postgraduate fifth-year (PGY-5) EM residents. Main outcome measures were characteristics of EUS training and perceptions of EUS. RESULTS: Survey response rate was 95% (37/39). EUS was part of the formal residency curriculum for 86% of respondents (32/37). Residents most commonly received training in focused assessment with sonography for trauma, intrauterine pregnancy, abdominal aortic aneurysm, cardiac, and procedural guidance. Although the most commonly provided instructional material (86% [32/37]) was an ultrasound course, 73% (27/37) of residents used educational resources outside of residency training to supplement their ultrasound knowledge. Most residents (95% [35/37]) made clinical decisions and patient dispositions based on their EUS interpretation without a consultative study by radiology. Residents had very favorable perceptions and opinions of EUS. CONCLUSION: EUS training in Royal College EM programs was prevalent and perceived favorably by residents, but there was heterogeneity in resident training and practice of EUS. This suggests variability in both the level and quality of EUS training in Canadian Royal College EM residency programs. [West J Emerg Med. 2014;15(3):306-311.].

Ultrasound-guided small vessel cannulation: long-axis approach is equivalent to short-axis in novice sonographers experienced with landmark-based cannulation.

INTRODUCTION: Our primary objective was to describe the time to vessel penetration and difficulty of long-axis and short-axis approaches for ultrasound-guided small vessel penetration in novice sonographers experienced with landmark-based small vessel penetration. METHODS: This was a prospective, observational study of experienced certified emergency nurses attempting ultrasound-guided small vessel cannulation on a vascular access phantom. We conducted a standardized training, practice, and experiment session for each participant. Five long-axis and five short-axis approaches were attempted in alternating sequence. The primary outcome was time to vessel penetration. Secondary outcomes were number of skin penetrations and number of catheter redirections. We compared long-axis and short-axis approaches using multivariable regression adjusting for repeated measures, vessel depth, and vessel caliber. RESULTS: Each of 10 novice sonographers made 10 attempts for a total of 100 attempts. Median time to vessel penetration in the long-axis and short-axis was 11 (95% confidence interval [CI] 7-12) and 10 (95% CI 6-13) seconds, respectively. Skin penetrations and catheter redirections were equivalent and near optimal between approaches. The median caliber of cannulated vessels in the long-axis and short-axis was 4.6 (95% CI 4.1-5.5) and 5.6 (95% CI 5.1-6.2) millimeters, respectively. Both axes had equal success rates of 100% for all 50 attempts. In multivariable regression analysis, long-axis attempts were 32% (95% CI 11%-48%; p=0.009) faster than short-axis attempts. CONCLUSION: Novice sonographers, highly proficient with peripheral IV cannulation, can perform after instruction ultrasound-guided small vessel penetration successfully with similar time to vessel penetration in either the long-axis or short-axis approach on phantom models.

Use of ultrasound guidance for central venous catheter placement: survey from the American Board of Emergency Medicine Longitudinal Study of Emergency Physicians.

OBJECTIVES: The objective was to survey practicing emergency physicians (EPs) across the United States regarding the frequency of using ultrasound (US) guidance in central venous catheter (CVC) placement and, secondarily, to determine factors associated with the use or barriers to the use of US guidance. METHODS: This was a cross-sectional survey mailed to presumed practicing EPs as part of the American Board of Emergency Medicine (ABEM)'s longitudinal study of EPs. The selection process used stratified, random sampling of cohorts thought to represent four different stages within the development of the specialty of emergency medicine (EM). Multivariable logistic regression was used to identify independent factors associated with both high comfort using US guidance and high-percentage usage of US guidance. RESULTS: The survey was mailed to 1,165 subjects, and the response rate was 79%. The median number of years of practice was 20 (interquartile range [IQR]=7 to 28 years). As their primary practice setting, 64% work in private or community hospitals, 60% received training in US-guided vascular access, and 44% never use US guidance in placing CVCs. Barriers differed in those who never use US and those who sometimes or always used US guidance. In those who never use US, top barriers were insufficient training (67%) and lack of equipment (25%). In those who use US, top barriers were the perceptions that US was too time-consuming (27%) and that the preferred site was not amenable to US (24%). Independent factors associated with high comfort and high-percentage use of US guidance were training in US-guided vascular access (adjusted odds ratio=5.1 [high comfort]; 95% confidence interval [CI]=2.6 to 10.1; adjusted odds ratio 11.1=(high percentage); 95% CI=5.0 to 24.8) and being a recent residency graduate. CONCLUSIONS: Among EPs, the translation of evidence to clinical practice regarding the benefits of US guidance for CVC placement is poor and still faces many barriers. Training and education are potentially the best ways to overcome such barriers.

Prediction of postinjury multiple-organ failure in the emergency department: development of the Denver Emergency Department Trauma Organ Failure score.

BACKGROUND: Multiple-organ failure (MOF) is common among the most seriously injured trauma patients. The ability to easily and accurately identify trauma patients in the emergency department at risk for MOF would be valuable. The aim of this study was to derive and internally validate an instrument to predict the development of MOF in adult trauma patients using clinical and laboratory data available in the emergency department. METHODS: We enrolled consecutive adult trauma patients from 2005 to 2008 from the Denver Health Trauma Registry, a prospectively collected database from an urban Level 1 trauma center. Multivariable logistic regression was used to develop a clinical prediction instrument. The outcome was the development of MOF within 7 days of admission as defined by the Sequential Organ Failure Assessment (SOFA) score. A risk score was created from the final regression model by rounding the regression ß coefficients to the nearest integer. Calibration and discrimination were assessed using 10-fold cross-validation. RESULTS: A total of 4,355 patients were included in this study. The median age was 37 years (interquartile range [IQR], 26-51 years), and 72% were male. The median Injury Severity Score (ISS) was 9 (IQR, 4-16), and 78% of the patients had blunt injury mechanisms. MOF occurred in 216 patients (5%; 95% confidence interval, 4-6%). The final risk score included patient age, intubation, systolic blood pressure, hematocrit, blood urea nitrogen, and white blood cell count and ranged from 0 to 9. The prevalence of MOF increased in an approximate exponential fashion as the score increased. The model demonstrated excellent calibration and discrimination (calibration slope, 1.0; c statistic, 0.92). CONCLUSION: We derived a simple, internally valid instrument to predict MOF in adults following trauma. The use of this score may allow early identification of patients at risk for MOF and result in more aggressive targeted resuscitation and improved resource allocation. LEVEL OF EVIDENCE: Prognostic and epidemiologic study, level III.

Safety of prehospital intravenous fentanyl for adult trauma patients.

BACKGROUND: Little is known about the safety of intravenous fentanyl for adult trauma patients in the prehospital setting. Our objective was to study the hemodynamic effect of prehospital intravenous fentanyl in initially normotensive adult trauma patients. METHODS: A quasi-experimental design was used to compare adult trauma patients who received intravenous fentanyl and those who did not receive fentanyl in a large regional prehospital system and its affiliated Level I trauma center. Emergent adult trauma patients were included with an initial prehospital Glasgow Coma Scale score of ≥13 and systolic blood pressure >90 mm Hg. Patients were stratified into two groups, those who received a single dose of intravenous fentanyl (100 µg) and those who did not. The outcome was initial emergency department (ED) shock index (heart rate divided by systolic blood pressure). Multivariable linear regression was used to estimate the effect of fentanyl on ED shock index while adjusting for prehospital shock index, age, gender, Trauma Injury Severity Score, and the propensity for receiving fentanyl. RESULTS: Seven hundred sixty-three patients were included, of whom 217 (28%) received fentanyl. The groups had comparable demographics (age, gender, and race/ethnicity) but different clinical characteristics (ED vital signs, Injury Severity Score, mechanism, and ED disposition). The adjusted ED shock index of fentanyl patients improved (-0.03; 95% confidence interval: -0.05 to 0.00; p = 0.02) compared with no fentanyl. CONCLUSION: Prehospital intravenous fentanyl did not adversely affect the initial ED shock index in adult trauma patients. Additional research should be performed to confirm and extend our findings. LEVEL OF EVIDENCE: III.

The current state of ultrasound training in canadian emergency medicine programs: perspectives from program directors.

OBJECTIVES: There is a paucity of data about emergency ultrasound (EUS) training in emergency medicine (EM) residency programs accredited by the Royal College of Physicians and Surgeons of Canada (Royal College) and the College of Family Physicians of Canada (CFPC). Historically the progress of EUS in Canada has been different from that in the United States. We describe the current state of EUS training in both Royal College and CFPC-EM programs. METHODS: All Royal College EM program directors and all CFPC-EM program directors were invited to participate in a website-based survey. Main outcome measures were characteristics of currently offered EUS training. RESULTS: The response rate of the survey was 100% (30/30). EUS is part of the formal residency curriculum in 100% (13/13) of Royal College EM programs and in 88% (15/17) of CFPC-EM programs. EM resident rotations in ultrasound (US) are provided by 77% (10/13) of Royal College programs but only 47% (8/17) of CFPC-EM programs. There are specific requirements for numbers of EUS exams to be completed by graduation in 77% (10/13) of Royal College programs and 47% (8/17) of CFPC-EM programs. EM faculty and residents make clinical decisions and patient dispositions based on their EUS interpretation without a consultative study by radiology in 100% (13/13) of Royal College programs and 88% (15/17) of CFPC-EM programs. However, 69% (9/13) of Royal College programs and 53% (9/17) of CFPC-EM programs have no formal quality assurance program in place. CONCLUSIONS: EUS training in Canadian EM programs is prevalent, but there are considerable discrepancies among residency programs in scope of training, curricula, determination of proficiency, and quality assurance. These findings suggest variability in both the level and the quality of EUS training in Canada.

Bacterial contamination and cleanliness of emergency department ultrasound probes.

OBJECTIVES: As ultrasonography is increasingly used in the emergency department (ED), ultrasound equipment has become a potential threat to infection control. Improperly cleaned ultrasound probes may serve as a vector for pathogens such as methicillin-resistant Staphylococcus aureus (MRSA). The primary objective of this study was to determine the prevalence of MRSA colonization on ultrasound probes used in a busy, urban ED. It was hypothesized that cultures of our ED ultrasound probes would yield a significant number of positive results for MRSA. METHODS: In this observational study, 11 ED ultrasound probes were randomly sampled on 10 different occasions. Samples were taken using a RODAC plate method and were cultured for MRSA and methicillin-sensitive Staphylococcus aureus (MSSA). On half of the randomly assigned sampling occasions, a visual inspection of each ultrasound probe for general cleanliness was conducted and recorded. Data were stratified by ultrasound location in the ED and analyzed using the Fisher exact test, with p < 0.05 deemed to be statistically significant. RESULTS: Of 110 samples, no isolates of MRSA were cultured. One probe yielded a positive culture for MSSA. Probes in the medicine, trauma, and pediatrics areas were found to be clean 65%, 33%, and 70% of the time, respectively. This variability in probe cleanliness by ED location was found to be statistically significant (p < 0.01). CONCLUSIONS: Contrary to our hypothesis, MRSA contamination of ultrasound probes was not found. This finding suggests that the spread of MRSA by ED ultrasound machines in a high-volume urban ED is unlikely. Further research at different centres with larger sample sizes is required before these results can be generalized.

The "guitar pick" sign: a novel sign of retrobulbar hemorrhage.

Retrobulbar hemorrhage is a rare complication of blunt ocular trauma. Without prompt intervention, permanent reduction in visual acuity can develop in as little as 90 minutes. We report a novel bedside ultrasound finding of conical deformation of the posterior ocular globe: the "guitar pick" sign. In our elderly patient, the ocular globe shape normalized post-lateral canthotomy and inferior cantholysis. Identifying this sonographic finding may add to the clinical examination when deciding whether to perform decompression.

Salmeterol use and risk of hospitalization among emergency department patients with acute asthma.

BACKGROUND: The safety of inhaled long-acting beta2-agonists (LABAs) in the treatment of chronic asthma remains controversial and has not been evaluated in emergency department (ED) patients with acute asthma. OBJECTIVE: To determine whether ED patients undergoing long-term LABA therapy would have increased risk of asthma-related hospitalization compared with those not undergoing LABA therapy and whether concurrent long-term inhaled corticosteroid (ICS) therapy would mitigate this risk. METHODS: Prospective cohort study of patients aged 12 to 54 years with acute asthma in 115 EDs. Four patient groups were created based on their asthma regimen: no ICS or salmeterol (group A), salmeterol monotherapy (group B), ICS monotherapy (group C), and combination ICS and salmeterol (group D). RESULTS: Of the 2,236 included patients, group A had 1,221 patients (55%), group B had 48 patients (2%), group C had 787 patients (35%), and group D had 180 patients (8%); 489 patients (22%) required hospitalization. In a multivariable model controlling for 20 factors and using group A as the reference, group B had an increased risk of hospitalization (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.0-4.9), whereas groups C (OR, 1.1; 95% CI, 0.8-1.5) and D (OR, 1.2; 95% CI, 0.8-1.9) did not. CONCLUSION: Among ED patients with acute asthma, those undergoing salmeterol monotherapy had an increased risk of hospitalization; however, this risk was not seen among patients undergoing combination ICS-salmeterol therapy. Our findings provide data from a unique ED population on clinical response to acute asthma treatment among patients undergoing long-term LABA therapy.