Joseph Bledsoe

Weight-based enoxaparin dosing for venous thromboembolism prophylaxis in the obese trauma patient

BACKGROUND Limited data exist regarding the efficacy of weight-based dosing of low-molecular weight heparin for venous thromboembolism (VTE) prophylaxis in obese trauma patients. METHODS Consecutive obese trauma patients were placed on a weight-based protocol for VTE prophylaxis (enoxaparin .5 mg/kg subcutaneously every 12 hours). Peak anti-Xa levels were drawn, and bilateral lower extremity duplex ultrasound was performed. The incidence of VTE and bleeding complications were recorded. RESULTS Eighty-six patients met the study criteria. Seventy-four patients achieved target prophylactic anti-Xa concentrations, with a mean level of .42 ± .01 IU/mL. Eighteen patients were found to have deep vein thrombosis. However, in 16 of these patients, deep vein thrombosis was diagnosed before weight-based low-molecular weight heparin initiation. No bleeding complications occurred, and no symptomatic pulmonary emboli were identified. CONCLUSIONS In obese trauma patients, weight-based enoxaparin is an efficacious regimen that provides adequate VTE prophylaxis, as measured by anti-Xa levels, and appears to be safe without bleeding complications.

Utility of the Emergency Department Observation Unit in Ensuring Stress Testing in Low-Risk Chest Pain Patients

BACKGROUND Recent research has noted low rates of compliance among ED chest pain patients referred for outpatient stress testing. The practice at our institution, a 39,000 visits per year emergency department (ED), is to place chest pain patients considered low risk for acute coronary syndrome in an observation unit for serial biomarker testing and provocative cardiac testing. Our objective was to determine the rates of positive stress tests among this group and to extrapolate from this the potential missed positive stress tests if these patients were referred instead for outpatient stress testing. METHODS This was a retrospective chart review of all chest pain patients admitted to the ED observation unit between April 2006 and June 2007. Baseline information, including a history of coronary disease, was recorded. Patients underwent a treadmill stress test, nuclear stress test, or coronary CT scan at the discretion of the attending emergency physician and/or the consulting cardiologist. Rates of positive stress test or coronary CT and patient disposition (admission to an inpatient unit versus discharge for outpatient follow-up) were noted. RESULTS A total of 353 patients underwent stress testing or coronary CT during the study period: 257 (72.8%) patients had an exercise treadmill echocardiogram, 61 (17.3%) patients underwent nuclear stress testing, and 35 (9.9%) patients had a coronary CT. Seventy patients (19.8%) had a history of coronary disease but had been considered appropriate for observation by the attending emergency physician. Thirty-nine stress tests were positive (11%) and 11 were indeterminate (3.1%). Among patients with no history of coronary disease, 20 stress tests were positive (7.1%), and 10 were indeterminate (3.5%). Of all patients with a positive stress test, 19 (48.7%) underwent cardiac catheterization and 1 (2.6%) had coronary artery bypass graft. Twenty-one of 39 patients with a positive stress test (54%) were ultimately admitted to an inpatient unit per the recommendation of the consulting cardiologist. Assuming a best-case scenario in which 70% of patients referred for outpatient stress testing actually have the testing done (based on a recent report of outpatient compliance), physicians would miss approximately 3.3% of patients with a positive stress test if these patients were discharged directly from the ED. CONCLUSION Among chest pain patients admitted to an ED observation unit, the rate of positive stress tests was 11%. Approximately 3.3% of patients with positive stress tests may have been missed if these patients were instead referred for outpatient testing.

Assessment of the safety and efficiency of using an age-adjusted D-dimer threshold to exclude suspected pulmonary embolism.

BACKGROUND D-dimer levels increase with age, and research has suggested that using an age-adjusted D-dimer threshold may improve diagnostic efficiency without compromising safety. The objective of this study was to assess the safety of using an age-adjusted D-dimer threshold in the workup of patients with suspected pulmonary embolism (PE). METHODS We report the outcomes of 923 patients aged > 50 years presenting to our ED with suspected PE, a calculated Revised Geneva Score (RGS), and a D-dimer test. All patients underwent CT pulmonary angiography (CTPA). We compared the false-negative rate for PE of a conventional D-dimer threshold with an age-adjusted D-dimer threshold and report the proportion of patients for whom an age-adjusted D-dimer threshold would obviate the need for CTPA. RESULTS Among 104 patients with a negative conventional D-dimer test result and an RGS ≤ 10, no PE was observed within 90 days (false-negative rate, 0%; 95% CI, 0%-2.8%). Among 273 patients with a negative age-adjusted D-dimer result and an RGS ≤ 10, four PEs were observed within 90 days (false-negative rate, 1.5%; 95% CI, 0.4%-3.7%). We observed an 18.3% (95% CI, 15.9%-21.0%) absolute reduction in the proportion of patients aged > 50 years who would merit CTPA by using an age-adjusted D-dimer threshold compared with a conventional D-dimer threshold. CONCLUSIONS Use of an age-adjusted D-dimer threshold reduces imaging among patients aged > 50 years with an RGS ≤ 10. Although the adoption of an age-adjusted D-dimer threshold is probably safe, the CIs surrounding the additional 1.5% of PEs missed necessitate prospective study before this practice can be adopted into routine clinical care.

GlideScope Versus Flexible Fiber Optic for Awake Upright Laryngoscopy

STUDY OBJECTIVES We compare laryngoscopic quality and time to highest-grade view between a face-to-face approach with the GlideScope and traditional flexible fiber-optic laryngoscopy in awake, upright volunteers. METHODS This was a prospective, randomized, crossover study in which we performed awake laryngoscopy under local anesthesia on 23 healthy volunteers, using both a GlideScope video laryngoscopy face-to-face technique with the blade held upside down and flexible fiber-optic laryngoscopy. Operator reports of Cormack-Lehane laryngoscopic views and video-reviewed time to highest-grade view, as well as number of attempts, were recorded. RESULTS Ten women and 13 men participated. A grade II or better view was obtained with GlideScope video laryngoscopy in 22 of 23 (95.6%) participants and in 23 of 23 (100%) participants with flexible fiber-optic laryngoscopy (relative risk GlideScope video laryngoscopy versus flexible fiber-optic laryngoscopy 0.96; 95% confidence interval 0.88 to 1.04). Median time to highest-grade view for GlideScope video laryngoscopy was 16 seconds (interquartile range 9 to 34) versus 51 seconds (interquartile range 35 to 96) for flexible fiber-optic laryngoscopy. A distribution of interindividual differences demonstrated that GlideScope video laryngoscopy was, on average, 39 seconds faster than flexible fiber-optic laryngoscopy (95% confidence interval 0.2 to 76.9 seconds). CONCLUSION GlideScope video laryngoscopy can be used to obtain a Cormack-Lehane grade II or better view in the majority of awake, healthy volunteers when an upright face-to-face approach is used and was slightly faster than traditional flexible fiber-optic laryngoscopy. However, flexible fiber-optic laryngoscopy may be more reliable at obtaining high-grade views of the larynx. Awake, face-to-face GlideScope use may offer an alternative approach to the difficulty airway, particularly among providers uncomfortable with flexible fiber-optic laryngoscopy.

Protecting trauma patients from duplicated computed tomography scans: the relevance of integrated care systems

BACKGROUND Duplicated computed tomography (CT) scans in transferred trauma patients have been described in university-based trauma systems. This study compares CT utilization between a university-based nonintegrated system (NIS) and a vertically integrated regional healthcare system (IS). METHODS Trauma patients transferred to 2 Level I trauma centers were prospectively identified at the time of transfer. Imaging obtained before and subsequent to transfer and the reason for CT imaging at the Level I center were captured by real-time reporting. RESULTS Four hundred eighty-one patients were reviewed (207 at NIS and 274 at IS). Ninety-nine patients (48%) at NIS and 45 (16%) at IS underwent duplicate scanning of at least one body region. Inadequate scan quality and incomplete imaging were the most common reason category reported at NIS (54%) and IS (78%). CONCLUSIONS Fewer patients received duplicated scans within the vertically IS as compared with a traditional university-based referral system. Our findings suggest that the adoption of features of a vertically IS, particularly improved transferability of radiographic studies, may improve patient care in other system types.

A new ST-segment elevation myocardial infarction equivalent pattern? Prominent T wave and J-point depression in the precordial leads associated with ST-segment elevation in lead aVr.

Certain acute coronary syndrome electrocardiographic (ECG) patterns, which do not include ST-segment elevation, are indicative of acute coronary syndrome caused by significant arterial occlusion; these patterns are, of course, associated with significant risk to the patient and mandate a rapid response from the health care team. One such high-risk ECG pattern includes the association of the prominent T wave and J-point depression producing ST-segment depression seen in the precordial leads coupled with ST-segment elevation in lead aVr. This ECG presentation is associated with significant left anterior descending artery obstruction. We report the case of a patient with this ECG presentation who progressed over a very short time to ST-segment elevation myocardial infarction of the anterior wall.

Low-risk young adult patients with chest pain may not benefit from routine cardiac stress testing: a Bayesian analysis.

INTRODUCTION Low-risk emergency department (ED) chest pain patients with a nondiagnostic electrocardiogram (ECG) and negative cardiac biomarkers are commonly evaluated with cardiac stress testing to detect undiagnosed coronary artery disease. Provocative testing incurs certain costs and may require additional time investment either in the ED or in an observation setting. Recent research has questioned the utility of provocative testing in young adults with negative cardiac biomarkers and nondiagnostic ECG. We sought to evaluate the utility of cardiac stress testing in our population of young adult patients with chest pain. METHODS We performed a retrospective chart review of all chest pain patients aged 40 years and younger who were admitted to our ED observation unit over the 14-month period between April 2006 and May 2007. We included all patients who were admitted to the observation unit for serial biomarkers and provocative testing and had normal or nondiagnostic ECG, no history of coronary disease, and an initial negative troponin. We recorded baseline characteristics and stress test results of these patients and reviewed the patient charts for the 30-day period following discharge to identify repeat hospital visits and adverse events. We used Bayesian analysis to estimate the rate of true-positive stress testing in this population, using the only prior study of unit patients showing as high as 2 of 220 patients testing positive as a prior estimate. RESULTS A total of 36 patients met inclusion criteria; average age was 34.6 years old (range: 22-40 years) and 61% were male. Patient risk factors included hypertension (19%), diabetes (6%), family history (42%), and smoking (44%). All patients had negative serial cardiac biomarkers and a negative treadmill stress echocardiogram. Thirty-day follow-up demonstrated no adverse cardiac events. We performed Bayesian analysis through the addition of the 36 patients to the 220 patients represented by prior data. The posterior probability distribution changed slightly in location and scale gave a median estimated rate of positive stress testing in this population of 1.04% (95% credible interval, 0.24%-2.78%). CONCLUSIONS The population of chest pain patients younger than 40 years with no history of coronary disease, a nondiagnostic ECG, and negative serial biomarkers may not benefit from provocative testing. Our findings complement those reported previously on the limited utility of cardiac stress testing in this population.

Appropriately screened geriatric chest pain patients in an observation unit are not admitted at a higher rate than nongeriatric patients.

OBJECTIVE Observation units may exclude geriatric patients (defined as age >or=65) due to the high rate of observation failure (admission to an inpatient unit) among these patients. We evaluated whether geriatric patients on a chest pain protocol are admitted to an inpatient unit from an emergency department (ED) observation unit at a higher rate than nongeriatric patients. METHODS This was a retrospective chart review of all patients placed in the ED observation unit at the University of Utah Medical Center over a 14-month period from April 2006 to June 2007. The observation unit did not exclude geriatric patients nor did it exclude patients with a history of coronary disease; patients were admitted per the discretion of the attending ED physician. Patient information, including age, date of admission, history of coronary disease (defined as a previous myocardial infarction, stent, or coronary artery bypass graft), and admission to an inpatient unit from the observation unit, was recorded. Decision to admit to an inpatient unit was made by the consulting cardiologist. Results were analyzed using chi2 statistics. RESULTS One hundred thirty-four geriatric patients were admitted to the observation unit under the chest pain protocol during the study period. Seventeen percent of these patients were admitted to an inpatient unit from the observation unit versus 10.7% of the 394 chest pain patients who were under age 65 (P = 0.048). Geriatric patients were more likely to have coronary disease (31.3%) than nongeriatric patients (20.8%; P = 0.013). We then performed a subanalysis on the 404 patients (92 geriatric, 312 nongeriatric) who had no history of coronary disease. Geriatric patients without a history of coronary disease had a 12% inpatient admission rate from the observation unit versus a 7.7% admission rate for nongeriatric patients without a history of coronary disease (P = 0.2). CONCLUSION Geriatric patients without a history of coronary artery disease were admitted to an inpatient unit at a rate consistent with a generally accepted observation failure rate of 10%. When screened appropriately, these patients may be appropriate for chest pain evaluation in the ED observation unit.

Treatment of Low-risk Pulmonary Embolism Patients in a Chest Pain Unit

BACKGROUND Several studies have proposed the Pulmonary Embolism Severity Index (PESI) as a risk stratification tool for discharge of low-risk pulmonary embolism (PE) patients from the emergency department (ED) and treatment as outpatients, but this has not become accepted standard of care in the United States. Chest pain units (CPUs) may serve as ideal locations for the treatment and risk-stratification of low-risk PE patients, thus avoiding lengthy inpatient stays while assuring patients are appropriate for outpatient therapy for PE. We sought to characterize the number of patients at our institution who may be eligible for a short stay in our CPU and then established a protocol for the treatment of low-risk patients in the CPU. METHODS We identified all patients admitted to the University of Utah Medical Center from the ED with a diagnosis of PE over the 6-year period between 2002 and 2007. We retrospectively reviewed the electronic medical records to identify clinical variables to calculate a PESI score for each patient. Patients who were considered to be low-risk, on the basis of PESI score (class I and II), were considered eligible for treatment in the CPU, and, on the basis of this, we estimated numbers of patients to be treated in the CPU and patient demographics. We determined results of transthoracic echocardiography (TTE) and bilateral lower extremity (BLE) venous duplex ultrasound for PE patients to estimate potential inpatient admission rates from the CPU. We reviewed the electronic medical records during the 30-day period after hospital admission for patient mortality. We then created a protocol for the treatment of these low-risk patients in the CPU. RESULTS A total of 545 patients were admitted with PE during the 6-year period. Of these patients, 282 were considered low risk and potentially appropriate for treatment of PE in the CPU. Of those, 43.3% were male, and the average age was 43.9 years (range: 14-92 years). Mortality was 0% for the low-risk group over the 30 days after hospital admission. A total of 108 patients had TTE performed and, of these, 30 had evidence of right heart strain. Ninety patients had BLE venous duplex and, of these, 15 had a deep venous thrombosis proximal to the popliteal veins. On the basis of our findings, we created a protocol for treatment of low-risk PE patients in the CPU. Patients who are low risk according to PESI score are admitted to the CPU with administration of low-molecular-weight heparin in the ED and initiation of oral anticoagulation therapy. Patients are monitored on telemetry for at least 12 hours, with performance of BLE duplex and TTE while in the CPU. Patients are admitted to an inpatient unit from the CPU if during their stay they exhibit unstable vital signs, a new arrhythmia, deep venous thrombosis proximal to the popliteal veins on BLE duplex, or signs of right heart strain on TTE. Patients who do not meet these criteria are considered appropriate for outpatient treatment and discharged with low-molecular-weight heparin and oral anticoagulation with thrombosis clinic follow-up. Given our findings from the retrospective chart review, we estimated that, at our institution, 4 patients per month would be eligible for treatment of PE in the CPU. With the findings on TTE and BLE duplex, we estimated that 25.3% of eligible patients would eventually require inpatient admission from the CPU. CONCLUSIONS We identified a number of low-risk patients who may be eligible for treatment of PE in our CPU. Given the resources of the CPU, this may serve as an ideal location for the treatment of low-risk PE patients and allow further risk stratification and consultation beyond that typically readily available in the ED. We described the creation of a protocol for the treatment of low-risk patients with PE in a CPU.

Patients with coronary disease fail observation status at higher rates than patients without coronary disease

BACKGROUND Few studies have evaluated emergency department (ED) observation unit chest pain protocols for optimal patient characteristics and admission rates. At our 35 000-visits/y ED, we implemented a chest pain protocol for our observation unit that allowed emergency physicians to admit patients with known coronary artery disease (CAD). METHODS We performed a retrospective chart review of all observation unit patients admitted under the chest pain protocol from April 1, 2006, to May 31, 2007. We compared the outcomes of patients who had a history of CAD with those who did not. RESULTS Five hundred thirty-one patients were admitted to the observation unit under the chest pain protocol for the 14-month study period. Of these patients, 125 (23.5%) had a history of CAD. Patients with a history of CAD had a higher inpatient admission rate ( 24% vs 8.6%; P < .001), higher rate of a positive stress test or positive coronary computed tomographic scan (32.3% vs 6.9%; P < .001), a higher rate of cardiac catheterization (12% vs 5.9%; P = .02), and a higher rate of stent placement or coronary artery bypass graft (CABG) (7.2% vs 2.2%; P = .007). In multivariate analysis, patient history of CAD was an independent predictor of hospital admission (P = .005) and stent placement or CABG (P = .030). CONCLUSION Patients with known CAD who were admitted to the ED observation unit failed observation status (ie, required hospitalization) and had higher rates of positive testing than those without CAD.