Thursday, June 23, 2011

Lit Bits: June 23, 2011

From the medical literature...

1. Patient Outcomes Suffer When the ED Is Crowded

A well-controlled study in Canada shows higher risk for mortality and hospital admission with longer emergency department length of stay.

Guttmann A et al. BMJ 2011 Jun 1; 342:d2983
OBJECTIVE: To determine whether patients who are not admitted to hospital after attending an emergency department during shifts with long waiting times are at risk for adverse events. Design Population based retrospective cohort study using health administrative databases. Setting High volume emergency departments in Ontario, Canada, fiscal years 2003-7.

PARTICIPANTS: All emergency department patients who were not admitted (seen and discharged; left without being seen). Outcome measures Risk of adverse events (admission to hospital or death within seven days) adjusted for important characteristics of patients, shift, and hospital.

RESULTS: 13 934 542 patients were seen and discharged and 617 011 left without being seen. The risk of adverse events increased with the mean length of stay of similar patients in the same shift in the emergency department. For mean length of stay ≥6 v less than 1 hour the adjusted odds ratio (95% confidence interval) was 1.79 (1.24 to 2.59) for death and 1.95 (1.79 to 2.13) for admission in high acuity patients and 1.71 (1.25 to 2.35) for death and 1.66 (1.56 to 1.76) for admission in low acuity patients). Leaving without being seen was not associated with an increase in adverse events at the level of the patient or by annual rates of the hospital.

CONCLUSIONS: Presenting to an emergency department during shifts with longer waiting times, reflected in longer mean length of stay, is associated with a greater risk in the short term of death and admission to hospital in patients who are well enough to leave the department. Patients who leave without being seen are not at higher risk of short term adverse events.


2. CT Angiography for Diagnosing Cerebral Aneurysms

Computed tomographic angiography is a highly accurate technique for diagnosing cerebral aneurysms in symptomatic patients, according to a meta-analysis of CTA studies.

When noncontrast computed tomography (CT) of the head identifies a subarachnoid hemorrhage, the lesion is then typically imaged with CT angiography (CTA). To summarize data on the sensitivity and specificity of CTA for diagnosing cerebral aneurysms in symptomatic patients, researchers conducted a meta-analysis of 45 methodologically rigorous studies of CTA published from January 1995 through February 2010. All 45 used either digital subtraction angiography (DSA) or neurosurgery findings as the gold standard for diagnosis.

Of the 3643 patients in these studies, 77% had a gold-standard diagnosis of cerebral aneurysm. In per-patient analyses, CTA had a pooled sensitivity of 97.2% for detecting aneurysms and a pooled specificity of 97.9% to rule out aneurysms. Sensitivity and specificity were very similar in per-aneurysm analyses. The 16- and 64-slice CT scanners had significantly greater sensitivity than single- and 4-slice scanners, especially for aneurysms with diameters 4 mm.

Comment: This meta-analysis raises the question of whether a negative CTA finding for cerebral aneurysm should be followed by a DSA study. DSA, the current reference technique, is not perfect, even in its 3D-rotational form. Incorporation and verification biases may also come into play when DSA follows CTA. In addition, given that symptomatic patients have a much higher prevalence of aneurysms than the general population, it may be difficult to extrapolate this meta-analysis's findings to other populations — for example, asymptomatic patients with family histories of cerebral aneurysm. Nevertheless, CTA's sensitivity and specificity values were so high that even some potential overestimation should not diminish clinicians' confidence in CTA's diagnostic usefulness.

That said, the level of experience of the physician reviewing the CTA scan (a factor not addressed in this study) matters. Expert review of a scan may not be possible, say, in the middle of the night, when only a resident or a general radiologist is available. Computer-aided diagnosis software, currently used for mammography and colonoscopy, has the potential to alert an image reviewer to a vascular structure that may be an aneurysm and, in theory, preserves the diagnostic accuracy of CTA. DSA is still the gold standard for detecting cerebral aneurysms, but this study raises the possibility of its replacement by a noninvasive technique.

— Max Wintermark, MD. Dr. Wintermark is Associate Professor of Radiology, Neurology, Neurosurgery, and Biomedical Engineering and Chief of Neuroradiology at the University of Virginia.

Published in Journal Watch Neurology May 31, 2011. Citation: Menke J et al. Diagnosing cerebral aneurysms by computed tomographic angiography: Meta-analysis. Ann Neurol 2011 Apr; 69:646.


3. Critical Issues in the Evaluation and Management of Adult Patients Presenting to the ED with Suspected PE

Fesmire FM, et al. Ann Emerg Med. 2011;57:628-652.e75


This clinical policy from the American College of Emergency Physicians is the revision of a 2003 clinical policy on the evaluation and management of adult patients presenting with suspected pulmonary embolism (PE).1 A writing subcommittee reviewed the literature to derive evidence-based recommendations to help clinicians answer the following critical questions: (1) Do objective criteria provide improved risk stratification over gestalt clinical assessment in the evaluation of patients with possible PE? (2) What is the utility of the Pulmonary Embolism Rule-out Criteria (PERC) in the evaluation of patients with suspected PE? (3)What is the role of quantitative D-dimer testing in the exclusion of PE? (4) What is the role of computed tomography pulmonary angiogram of the chest as the sole diagnostic test in the exclusion of PE? (5) What is the role of venous imaging in the evaluation of patients with suspected PE? (6) What are the indications for thrombolytic therapy in patients with PE? Evidence was graded and recommendations were given based on the strength of the available data in the medical literature.


It is estimated that 650,000 to 900,000 individuals each year have fatal or nonfatal acute pulmonary embolism (PE)2 and that as many as 200,000 people in the United States die each year from PE.3 Untreated PE can be rapidly fatal, with the majority of deaths occurring in the first hour.3, 4 Furthermore, survivors of undiagnosed PE can experience disabling morbidity from pulmonary hypertension5 and/or postthrombotic syndrome.6, 7, 8 Because there is a strong association between deep venous thrombosis (DVT) and PE, it is difficult to discuss the diagnostic evaluation of one entity without discussing the other.7 Approximately 50% of patients with documented DVT have perfusion defects on nuclear lung scanning and asymptomatic venous thrombosis is found in approximately 40% of patients with confirmed PE.6, 9, 10

During the past decade, there has been an explosion of published research and development of new diagnostic modalities and therapies relating to patients with suspected PE and DVT, with greater than 1,000 publications appearing in the medical literature per year. This current policy represents a revision of the 2003 American College of Emergency Physicians (ACEP) clinical policy on critical issues in the evaluation and management of adult patients with suspected PE.1 The 2003 policy focused on 4 major areas of interest and/or controversy that existed when the policy was formulated: (1) Can a negative D-dimer result exclude PE?; (2) When can ventilation-perfusion (VQ) scan alone or in combination with venous ultrasonography and/or D-dimer assay exclude PE?; (3) Can spiral computed tomography (CT) replace VQ scanning in the diagnostic evaluation of PE?; and (4) What are the indications for thrombolytic therapy in patients with PE? This current policy focuses on 6 areas of interest and/or controversy that have developed or still exist since the 2003 policy was formulated:

(1) Do objective criteria provide improved risk stratification over general clinical assessment in the evaluation of patients with possible PE?; (2) What is the utility of the Pulmonary Embolism Rule-out Criteria (PERC) in the evaluation of patients with suspected PE? (3)What is the role of quantitative D-dimer testing in the exclusion of PE?; (4) What is the role of CT pulmonary angiogram of the chest as the sole diagnostic test in the exclusion of PE?; (5) What is the role of venous imaging in the exclusion of PE?; and (6) What are the indications for thrombolytic therapy in patients with PE?

This policy does not discuss VQ scanning in the evaluation of patients with suspected PE. The authors do recognize that VQ scanning is used in the evaluation of patients with suspected PE in whom CT scan may be contraindicated.11, 12, 13 Also, with increasing awareness of potential long-term effects of ionizing radiation exposure from repetitive CT scans, there may be additional subgroups of patients for whom a VQ scan may be preferred as the initial imaging modality because of decreased exposure to radiation compared with CT scan.13, 14, 15, 16, 17 Future updates of this policy may directly address these issues.

The rest of the policy, full-text and free:

4. Fewer Emergency Rooms Available as Need Rises

The New York Times. May 17, 2011. By Roni Caryn Rabin

Hospital emergency rooms, particularly those serving the urban poor, are closing at an alarming rate even as emergency visits are rising, according to a report published on Tuesday.

Urban and suburban areas have lost a quarter of their hospital emergency departments over the last 20 years, according to the study, in The Journal of the American Medical Association. In 1990, there were 2,446 hospitalswith emergency departments in nonrural areas. That number dropped to 1,779 in 2009, even as the total number of emergency room visits nationwide increased by roughly 35 percent.

Emergency departments were most likely to have closed if they served large numbers of the poor, were at commercially operated hospitals, were in hospitals with skimpy profit margins or operated in highly competitive markets, the researchers found.

Although the study did not examine emergency care at the remaining facilities, the closings take a toll on the quality of care in all emergency rooms, said Dr. Renee Y. Hsia, an assistant professor of emergency medicine at the University of California, San Francisco, and the lead author of the study.

“Some people think, ‘As long as my emergency room isn’t closing, I feel O.K. and protected,’ ” said Dr. Hsia, whose research was financed by the Robert Wood Johnson Foundation. “But even if they don’t lose the E.R. in their own neighborhood, they do experience the effect of fewer emergency rooms — the waits get longer and longer, and people’s outcomes get worse.”

To read more, see the full article here:

5. Comparison of Clinical Performance of Cranial CT Rules in Patients with Minor Head Injury: A Multicenter Prospective Study

Ro YS, et al. Acad Emerg Med. 2011;18:597-604.

Objectives:  The objective was to compare the predictive performance of three previously derived cranial computed tomography (CT) rules, the Canadian CT Head Rule (CCHR), the New Orleans Criteria (NOC), and National Emergency X-Ray Utilization Study (NEXUS)-II, for detecting clinically important traumatic brain injury (TBI) and the need for neurosurgical intervention in patients with blunt head trauma.

Methods:  This was a prospective, multicenter, observational cohort study of patients with blunt head trauma from June 2008 to May 2009. The historical and physical examination components of the CCHR, NOC, and NEXUS-II were documented on a data collection form and the performance of each of the three rules was compared. Patient eligibility for each specific rule was defined exactly as previously described for each specific rule. To compare the three decision rules in terms of sensitivity and specificity, an intersection cohort satisfying inclusion criteria of all three decision rules was derived. The primary outcome was clinically important TBI, and the secondary outcome was neurosurgical intervention. The sensitivity and specificity of each rule were calculated with 95% confidence intervals (95% CIs). We also calculated the potential reduction rate in cranial CT scan utilization realized by theoretical implementation of these rules.

Results:  A total of 7,131 patients were prospectively enrolled, including 692 (9.7%) with clinical TBI. Among the enrolled population, patients eligible for CCHR, NOC, and NEXUS-II totaled 696, 677, and 2,951, respectively. The sensitivity and specificity for clinically important brain injury were as follows: CCHR, 112 of 144 (79.2%, 95% CI = 70.8% to 86.0%) and 228 of 552 (41.3%, 95% CI = 37.3% to 45.5%); NOC, 91 of 99 (91.9%, 95% CI = 84.7% to 96.5%) and 125 of 558 (22.4%, 95% CI = 19.0% to 26.1%); and NEXUS-II, 511 of 576 (88.7%, 95% CI = 85.8% to 91.2%) and 1,104 of 2,375 (46.5%, 95% CI = 44.5% to 48.5%). The sensitivity and specificity for neurosurgical intervention were as follows: CCHR, 100% (95% CI = 59.0% to 100.0%) and 38.3% (95% CI = 34.5% to 41.9%); NOC, 100% (95% CI = 54.1% to 100.0%) and 20.4% (95% CI = 17.4% to 23.7%); and NEXUS-II, 95.1% (95% CI = 90.1% to 98.0%) and 41.4% (95% CI = 39.5% to 43.2%). Among the enrolled population, intersection patients of CCHR, NOC, and NEXUS-II totaled 588. The sensitivity and specificity for clinically important brain injury were as follows: CCHR, 73 of 98 (74.5%, 95% CI = 64.7% to 82.8%) and 201 of 490 (41.0%, 95% CI = 36.6% to 45.5%); NOC, 89 of 98 (90.8%, 95% CI = 83.3% to 95.7%) and 112 of 490 (22.9%, 95% CI = 19.2% to 26.8%); and NEXUS-II, 82 of 98 (83.7%, 95% CI = 74.8% to 90.4%) and 172 of 490 (35.1%, 95% CI = 30.9% to 39.5%). The potential reduction in emergency CT scans by using these decision rules would have been higher with the NEXUS-II rule (39.6%, 95% CI = 37.8% to 41.4%) than with the CCHR rule (27.0%, 95% CI = 23.7% to 30.3%) or NOC rule (20.2%, 95% CI = 17.2% to 23.3%).

Conclusions:  For clinically important TBI, the three cranial CT decision rules had much lower sensitivities in this population than the original published studies, while the specificities were comparable to those studies. The sensitivities for neurosurgical intervention, however, were comparable to the original studies. The NEXUS-II rule showed the highest reduction rate for CT scans compared to other rules, but failed to identify all undergoing neurosurgical intervention for their original inclusion cohort.

6. Nasal Intubation Review

by Rich Levitan, MD, Emergency Physicians Monthly. June 6, 2011

When the mouth is off limits, nasal intubation can be a valuable technique for gaining an emergency airway.

With or without fiberoptic assistance, nasal intubation remains a valuable technique in some emergency airway situations, despite its overall decline in use. It is best in patients who are not critically hypoxic and in whom there is obvious oral pathology making intubation and ventilation through the mouth problematic. In these situations, when the mouth is off limits, awake intubation must occur through the nose or through the neck. Examples include severe angioedema of the tongue, and mechanical obstructions to mouth opening from mandibular fixation or other oral pathology. I have also used the technique in patients with fixed neck contracture and limited mouth opening. In situations of intrinsic laryngo-tracheal pathology (i.e., tumor etc.) nasal intubation should only be done with fiberoptic assistance.

The procedure is relatively contraindicated in patients who are coagulopathic because of the risk of hemorrhage, and more difficult with poor air excursion (asthma, COPD, etc.). If there is evident disruption of the midface, nasopharynx or roof of the mouth, the nasal route should not be used.

Overview of Nasal Intubation Technique…

The remainder of the essay is here:

See also:

7. ED physicians attribute many test orders to fear of lawsuits

AMA Morning Rounds

The Huffington Post (5/25, Pearson) reported that 53 percent of respondents in a "survey of more than 1,700" emergency department physicians conducted by the American College of Emergency Physicians "said the main reason they conduct the number of tests they do is fear of lawsuits," and another "44 percent said that very fear was the biggest hindrance to cutting ED costs. ... 'We do a lot of these tests to cover ourselves that then give people an awful lot of radiation,'" said ACEP President Dr. Sandra Schneider. This week, ACEP led hundreds of ED physicians "to Capitol Hill to push for medical liability reform." In a press release, ACEP "emphasized the issue of CT scans, calling for doctors who stick to guidelines developed by the Centers for Medicare and Medicaid Services (which suggest limiting the number of head CT scans) in order to be protected against litigation."


8. The prevalence of immediate and delayed intracranial hemorrhage in patients with pre-injury anticoagulant use and head trauma

Clopidogrel Surprisingly Riskier than Warfarin

Nishijima DK, et al. Acad Emerg Med. 2011;18:S180, abstract 468.

Background: Patients on warfarin or clopidogrel are considered at increased risk for traumatic intracranial hemorrhage (tICH) following blunt head trauma. The rate of immediate and delayed tICH in these patients, however, is unknown.

Objectives: We hypothesized that the prevalence of immediate tICH is similar between patients on clopidogrel and warfarin and the rate of delayed tICH in both groups is < 1%.

Methods: This is a prospective, observational, six center study (two trauma centers and four community hospitals) evaluating the prevalence of immediate and delayed tICH in adult patients on warfarin or clopidogrel. Delayed tICH was defined as tICH on cranial CT scan within two weeks after an initial normal CT scan in the absence of repeat head trauma. Patients were enrolled in the emergency department (ED) and followed up after two weeks by phone or medical record review if hospitalized. Measured outcomes included immediate and delayed tICH. Data were analyzed with descriptive statistics.

Results: Eight hundred and seventy patients with a median age of 78 years (IQR 70–85) were enrolled (capture rate of 83%). Anticoagulant use included warfarin (622 patients, 71%) and clopidogrel 248 patients, 29%). Both warfarin and clopidogrel groups had similar patient characteristics (see the Table). Of patients receiving a CT in the ED, the rate of immediate tICH on CT was higher in patients on clopidogrel (29/231, 13%; 95% CI 8.6–18%) than on warfarin (27/591, 4.6%; 95% CI 3.0–6.6%). Delayed tICH was identified in 4/563 (0.71%; 95% CI 0.19–1.8%) patients on warfarin and 0/201 (0%; 95% CI 0–1.8%) patients on clopidogrel.

Conclusion: Patients on clopidogrel had a significantly higher rate of tICH on CT scan as compared to those on warfarin. Routine cranial CT scanning is indicated in patients on clopidogrel with blunt head trauma. The rate of delayed tICH was very low and only occurred in patients on warfarin. Discharging these patients from the ED after a normal CT scan is safe but appropriate instructions are required as delayed ICH may occur.

9. Randomized Clinical Trial Comparing the Safety and Efficacy of a Hydromorphone Titration Protocol to Usual Care in the Management of Adult ED Patients with Acute Severe Pain

Chang AK, et al. Ann Emerg Med. 2011; in press.

Study objective: We test the efficacy and safety of the “1+1” (1 mg plus 1 mg 15 minutes later if needed) hydromorphone protocol against usual care of emergency department (ED) patients with acute severe pain.

Methods: This was a prospective, randomized clinical trial of ED patients with acute severe pain. The 1+1 protocol specifies administration of 1 mg intravenous hydromorphone, followed by a second dose of 1 mg intravenous hydromorphone 15 minutes after the first bolus if the patient answers yes to the question, “Do you want more pain medication?” Usual care is the administration of any intravenous opioid, with type and dose chosen by the ED attending physician. Usual care patients who wanted more medication at 15 minutes were treated at the physician's discretion. At 60 minutes, all patients were asked again whether they wanted more pain medication. The primary outcome was successful treatment defined a priori as not wanting additional analgesia at either 15 or 60 minutes after the initial bolus. The primary endpoint was the difference in the proportion of patients with successful treatment who received the complete 1+1 protocol versus usual care with a per-protocol analysis. An intention-to-treat analysis was also performed. A 10% difference in rate of successful treatment was chosen a priori as a clinically meaningful difference.

Results: Of 167 patients in the 1+1 group, 156 received the full 1+1 protocol, whereas 171 received usual care. Of patients who received the 1+1 protocol, 92.3% (144/156) had successful treatment versus 76.6% (131/171) of usual care patients (difference=15.7%; 95% confidence interval 7.9% to 23.3%). In the intention-to-treat analysis, 86.8% (145/167) of patients randomized to the 1+1 group received successful treatment versus 76.6% (131/171) of usual care patients (difference=10.2%; 95% confidence interval 2.0% to 18.3%). No patient required naloxone. One patient in the 1+1 group and 2 patients in the usual care group had transient oxygen saturation less than 95%. The incidence of all adverse effects was similar in both groups.

Conclusion: When analyzed per protocol or with the more conservative intention-to-treat analysis, the 1+1 hydromorphone protocol is statistically and clinically more efficacious than usual care. Safety profiles were similar in both groups.

10. The ER, 50 Years On

Arthur L. Kellermann, M.D., M.P.H., and Ricardo Martinez, M.D.

N Engl J Med 2011; 364:2278-2279.

Five decades ago, the Journal published an article by the leaders of Hartford Hospital in Hartford, Connecticut, about emergency-room use. Their study was prompted “by rising apprehensions about the adequacy of physical facilities and supervision of clinical work performed in the emergency unit.”1 Over the 11 preceding years (1944 to 1955), visits to Hartford Hospital's emergency room (ER) had grown sixfold, from 3000 to roughly 18,000. The ER's case mix had changed as well. In little more than a decade, the “accident unit” of 1944 had evolved into a broad-based “emergency unit” used by almost every service in the hospital. Although the ER was intended for emergencies, the authors were surprised to discover that only 200 of a sample of 1232 patients (16%) were admitted to the hospital. The rest were treated and sent home.

To determine whether their experience was unusual, the authors surveyed 90 hospitals in the Midwest and on the Atlantic seaboard. Representatives from 63 facilities, ranging in size from 150 to 1000 beds, responded. Most reported that ER use at their hospital had increased nearly 400% between 1940 and 1955, even in communities with little or no population growth.

Up to that point, conventional wisdom had held that ER use had grown most rapidly during World War II, when many U.S. doctors were deployed overseas. The Hartford study found otherwise. Its data revealed that the most dramatic increase in ER use occurred during the post-war period, after the doctors came home.

Apparently, the return of these doctors did not noticeably improve access to care, at least for acute problems. When asked “to what do you attribute the change in use of the emergency room?,” nearly half of responding hospitals cited “the inability of patients to reach physicians on weekends, nights or holidays for either emergency or urgent appointments and the orientation of the public to the hospital as a place where one can receive aid at all times.” Twenty percent of respondents attributed growth in ER use to an increase in accidents, particularly car crashes (this study preceded the auto-safety movement); 13% stated that physicians were “using the emergency room for procedures formerly performed in their offices”; and 11% cited “third party payment for emergency-room care.”

Much has changed since 1958. Three more decades would pass before hearses stopped doing double-duty as ambulances and emergency medical technicians replaced “ambulance drivers.” These changes meant that ERs began receiving patients who previously would not have reached the hospital alive. The type of physicians who staff ERs changed as well. In 1955, many hospitals used unsupervised house staff to cover their ER.1 Others relied on a hodgepodge of community physicians who alternated covering the ER one day at a time.1,2 Beginning in the 1970s and accelerating through the 1980s and 1990s, the dominant model of physician staffing shifted from part-time coverage by community physicians, house staff, and moonlighters to full-time coverage by board-certified emergency physicians.2

The science of emergency care advanced as well. As a result, modern ERs are capable of evaluating and, when necessary, resuscitating patients with an extraordinary range of problems. And with each passing year, emergency physicians and their on-call colleagues have more diagnostic technologies and therapeutic options to consider. To streamline care, many hospitals have developed time-sensitive clinical pathways administered by multidisciplinary teams to treat patients with major trauma, acute myocardial infarction, stroke, or other life-threatening emergencies.2

The remainder of the essay can be found here:

11. Should Asymptomatic ED Patients With High INR Be Admitted?

NEW YORK (Reuters Health) Jun 13 - When asymptomatic patients with a supratherapeutic INR (international normalized ratio) come to the emergency department, can they be treated as outpatients or should they be admitted? There's very little published evidence to guide that decision, but what there is does not indicate that the management approach affects outcomes, a new review shows.

More than 25% of emergency department patients on warfarin have a supratherapeutic INR, and such patients are usually admitted, according to Dr. Michael Levine, with Banner Good Samaritan Medical Center in Phoenix, Arizona and colleagues.

Led by Dr. Levine, the team conducted a literature review to look at evidence for or against outpatient treatment of asymptomatic patients with a supratherapeutic INR. As reported online May 30th in Annals of Emergency Medicine, they found no randomized trials comparing inpatient and outpatient management.

Several studies did examine outcomes after outpatient treatment. The authors summarize four of the most relevant studies in their report. For example, in one study of 89 patients with an INR above 10, 75 of the patients without "worrying symptoms" (e.g., headache) were managed as outpatients. Only three of them developed significant bleeding within three days, and these were in a group that did not receive vitamin K.

In another study, 114 patients with an INR above 6 were followed as outpatients and were not treated with vitamin K. Five patients had major bleeding in the first two weeks. A third study found that when 1,043 patients with an INR between 5 and 10 were treated with vitamin K as outpatients, one patient had a major bleeding episode within 30 days and six had thromboembolic events.

"According to this review, it is certainly within the standard of care to manage patients with an asymptomatic, supratherapeutic INR as outpatients," Dr. Levine and colleagues conclude.

They add, "We were unable to find any studies that support a reduced risk of warfarin-associated bleeding caused by rapid INR reversal or inpatient admission."

Ann Emerg Med 2011. In press

12. Advanced Management of Acute Iliofemoral Deep Venous Thrombosis: ED and Beyond

Charles V. Pollack Jr, MD, MA. Ann Emerg Med 2011;57:590-599.

Recent attention to the increasing incidence of venous thromboembolism has included a call to action from the surgeon general and new guidelines from various specialty organizations. The standard of care for treatment of deep venous thrombosis in the emergency department (ED), supported by the 2008 American College of Chest Physicians (ACCP) guidelines, involves initiation of anticoagulation with low-molecular-weight heparin, pentasaccharide, or unfractionated heparin. For selected appropriate patients with extensive acute proximal deep venous thrombosis, the ACCP guidelines now recommend thrombolysis in addition to anticoagulation to reduce not only the risk of pulmonary embolism but also the risk of subsequent postthrombotic syndrome and recurrent deep venous thrombosis. Postthrombotic syndrome is a potentially debilitating chronic cluster of lower-extremity symptoms occurring in 20% to 50% of deep venous thrombosis patients subsequent to the acute insult, sometimes not until years later. A strategy of early thrombus burden reduction or frank removal might reduce the incidence of postthrombotic syndrome, as per natural history studies, venous thrombectomy data, observations after systemic and catheter-directed thrombolysis, and the still-limited number of randomized trials of catheter-directed thrombolysis (with anticoagulation) versus anticoagulation alone.

Contemporary invasive (endovascular) treatments mitigate the drawbacks historically associated with thrombolytic approaches by means of intrathrombus delivery of drugs with greater fibrin specificity and lower allergenicity, followed by mechanical dispersion to accelerate lysis and then aspiration of remaining drug and clot debris. With a 2016 target completion date, the National Heart, Lung, and Blood Institute–sponsored Acute Venous Thrombosis: Thrombus Removal With Adjunctive Catheter-Directed Thrombolysis trial is comparing the safety and efficacy, in terms of both deep venous thrombosis and postthrombotic syndrome parameters, of the most evolved pharmacomechanical catheter-directed thrombolysis devices versus standard anticoagulation therapy alone.

This article reviews the grounds for use of adjunctive thrombolysis in patients with acute proximal deep venous thrombosis and begins to identify types of deep venous thrombosis patients encountered in the ED who might benefit most from multidisciplinary consideration of early referral for possible endovascular therapy.

More on the AVT Study:

13. Accuracy of Noninvasive Multiwave Pulse Oximetry Compared With Carboxyhemoglobin from Blood Gas Analysis in Unselected ED Patients

Roth D, et al. Ann Emerg Med. 2011;58:74-79.

Study objective: Accurate and timely diagnosis of carbon monoxide (CO) poisoning is difficult because of nonspecific symptoms. Multiwave pulse oximetry might facilitate the screening for occult poisoning by noninvasive measurement of carboxyhemoglobin (COHb), but its reliability is still unknown. We assess bias and precision of COHb oximetry compared with the criterion standard blood gas analysis.

Methods: This was a prospective diagnostic accuracy study according to STARD (Standards for the Reporting of Diagnostic accuracy studies) criteria, performed at a tertiary care hospital emergency department. We included all patients for whom both invasive and noninvasive measurement within 60 minutes was available, regardless of their complaints, during a 1-year period.

Results: One thousand five hundred seventy-eight subjects were studied, of whom 17 (1.1%) received a diagnosis of CO poisoning. In accordance with this limited patient cohort, we found a bias of 2.99% COHb (1.50% for smokers, 4.33% for nonsmokers) and a precision of 3.27% COHb (2.90% for smokers, 2.98% for nonsmokers), limits of agreement from −3.55% to 9.53% COHb (−4.30% to 7.30% for smokers, −1.63% to 10.29% for nonsmokers). Upper limit of normal cutoff of 6.6% COHb had the highest sensitivity in screening for CO poisoning. Smoking status and COHb level had the most influence on the deviation between measurements.

Conclusion: Multiwave pulse oximetry was found to measure COHb with an acceptable bias and precision. These results suggest it can be used to screen large numbers of patients for occult CO poisoning.

14. A Novel ED Dysphagia Screen for Patients Presenting With Acute Stroke

Schrock JW, et al. Acad Emerg Med. 2011;18:584–589.

Objectives:  Dysphagia is a common complication for emergency department (ED) patients presenting with acute stroke (AS). Recent stroke recommendations have suggested that EDs screen patients with AS for dysphagia prior to administering anything by mouth. This study sought to develop and test a novel ED dysphagia screen to be used in this population.

Methods:  A multidisciplinary approach was used to create a novel dysphagia screen performed by ED nurses during the initial evaluation of patients with suspected AS. The screen consists of five questions of which any single affirmative answer signified possible dysphagia. A prospective cohort study was conducted to evaluate the performance of this screen in detecting dysphagia after AS. Patients were followed for 30 days, and true dysphagia was determined if the patient had an abnormal modified barium swallow study (MBS), had placement of a feeding tube, or was placed on a dysphagia diet after assessment by a speech pathologist. The authors performed a substudy to determine agreement using a blinded kappa (κ) assessment with a convenience sample of 40 patients.

Results:  Over a 21-month period, 283 patients met eligibility for analysis. The rate of cerebral infarction in this cohort was 245 (87%). The rates for true dysphagia, pneumonia, and death were 91 (32%), 26 (9%), and 18 (6%), respectively. The dysphagia screen had a sensitivity of 95% (95% confidence [CI] = 88% to 98%) and a negative likelihood ratio of 0.1 (95% CI = 0.04 to 0.2). The inter-rater agreement assessed by kappa was substantial (0.69, 95% CI = 0.55 to 0.83).

Conclusions:  These data suggest that this dysphagia screen may be a valuable tool for detecting dysphagia in ED patients presenting with AS. The simple screen can be performed by nursing personnel and appears to perform well with good agreement. Given the overall rate of dysphagia in one-third of AS patients, the use of an ED dysphagia screen appears warranted.

Table 1. MetroHealth Dysphagia Screen One or more “yes” answers are considered a positive screen for possible dysphagia.

1. Is alertness level insufficient to remain awake for 10 minutes while sitting upright?
2. Is voice weak, wet, or abnormal in any way? (If cannot speak, circle yes)
3. Does the patient drool?
4. Is speech slurred?
5. Is the patient’s cough weak or inaudible? (If cannot cough, circle yes)

15. Rapid IV Rehydration Not Recommended in Kids

Brian Hoyle. May 6, 2011 (Denver, Colorado) — A blinded and randomized trial comparing a rapid intravenous rehydration (RIVR) protocol with the standard approach in a statistically significant population of pediatric patients with gastroenteritis has failed to find any benefit with the rapid approach. The increased risks that accompany RIVR do not warrant its recommended use, researchers report.

The findings were presented by Stephen Freedman, MDCM, from The Hospital for Sick Children, Toronto, Ontario, Canada, here at the Pediatric Academic Societies and Asian Society for Pediatric Research 2011 Annual Meeting.

"Oral rehydration therapy for children is appropriate but is underused. In particular, rapid intravenous rehydration lacks a standard definition and evidence of efficacy. Given the potential risks associated with this approach, our data indicate that its use should be reconsidered," Dr. Freedman told Medscape Medical News.

The study, which involved 226 children 3 months to 11 years of age who were recruited from December 2006 through April 2010, compared standard intravenous (IV) rehydration (0.9% saline, 20 mL/kg, over 1 h; n = 112) with RIVR (0.9% saline, 60 mL/kg, over 1 h; n = 114). Both groups subsequently received IV fluids for another 3 hours and standard oral rehydration therapy. Patients, nurses, and attending physicians were blinded to the treatment group (the IV pump was sound-proofed to mask any differences).

The primary outcome was clinical evidence of rehydration within 2 hours of starting the IV. Secondary outcomes included the need for longer-term therapy (hospital admission at the time of presentation or within 72 hours, or emergency department stay exceeding 6 hours once treatment was started), clinical rehydration scores (determined every 30 minutes for 4 hours), time to discharge, and return visit(s) to the hospital. A battery of statistical analyses conducted throughout the study clarified the clinical significance of both approaches over time.

The various baseline characteristics were similar between the 2 groups. Clinical rehydration was not significantly different between the RIVR group and the standard group (36.0% vs 29.5%; 95% confidence interval [CI] of the absolute difference, –5.7 to 18.7; P = .32). Even after adjustment for weight, dehydration score at baseline, and pH at baseline, RIVR did not influence the primary outcome (odds ratio [OR], 1.8; 95% CI, 0.90 to 3.5; P = .10). The proportion of patients requiring prolonged therapy was similar in the RIVR and standard groups (51.8% vs 42.9%; 95% CI of the absolute difference, 21.0 to –5.0; P = .19).

Although the clinical dehydration scores were consistently similar between the RIVR and standard groups (P = .69), as were revisits (14% vs 12%), those treated with RIVR remained in the hospital longer (median time to discharge, 6.3 vs 5.0 h; P = .03).

"For those patients in our hospital who required intravenous rehydration, the use of rapid and large-volume rehydration did not improve the clinical outcome," Dr. Freedman told Medscape Medical News.

The rapid rehydration might have failed because of the possibility of hyperchloremic metabolic acidosis resulting from the administration of a larger volume of fluid, lag time in initiating treatment, and altered dehydration scores by undefined factors.

For the time being, the risks for rapid rehydration outweigh the benefits, Dr. Freedman asserted.

"This is a very good study that reflects the need to establish how fast we rehydrate. Could we rehydrate with the standard volume in a shorter time, for example? These data show the need to reassess current practice," Christine Seroogy, MD, associate professor of pediatrics at the University of Wisconsin–Madison, told Medscape Medical News.

The authors and Dr. Seroogy have disclosed no relevant financial relationships.

Pediatric Academic Societies (PAS) and Asian Society for Pediatric Research 2011 Annual Meeting: Abstract 4135.2. Presented May 3, 2011.

16. Images in Emergency Medicine

Graves’ Disease

Bilateral Hilar and Mediastinal Lymphadenopathy

Hydropic Gallbladder

Fat Embolism Syndrome

Man with Generalized Weakness

Elderly Female with Syncope

Women with Left Wrist Pain

Woman with Right Eye Pain and Swelling

17. Predictors of 30-day Cardiovascular Events in Patients with Prior PCI or CABG

Esposito EC, et al. Acad Emerg Med. 2011;18:613-618.

Objectives:  Risk stratification of patients with potential acute coronary syndrome (ACS) is difficult. Patients with prior revascularization are considered higher risk, but they can also have symptoms from noncardiac causes. This study evaluated whether the presenting clinical characteristics were predictive of an increased risk of 30-day cardiovascular events in patients with prior revascularization presenting to the emergency department (ED) with symptoms of potential ACS.

Methods:  This was a secondary analysis of the DISPO-ACS study, a 2000-patient, four-site, randomized controlled trial of patients presenting with potential ACS. Process outcomes were evaluated using point-of-care cardiac markers compared to standard laboratory-based markers. Data included demographics, history, presenting symptoms, laboratory and electrocardiogram (ECG) results, hospital course, and 30-day cardiovascular events (death, acute myocardial infarction [AMI], revascularization). The association between presenting characteristics and 30-day cardiovascular events was assessed using univariable analysis and logistic regression; odds ratios (ORs) with 95% confidence intervals (CIs) are given.

Results:  Of 2,000 patients enrolled, 611 had prior revascularization (538 percutaneous coronary intervention [PCI], 232 coronary artery bypass graft [CABG], 159 both). The mean (±SD) age was 66 (±14) years, 44% were female, and 22% were black. By 30 days, 101 patients (17%) had cardiovascular events (81 during the index visit, 20 during follow-up). There were four deaths, 28 AMIs, and 67 revascularizations within 30 days; 20 patients had multiple endpoints. Being male (OR = 1.67, 95% CI = 1.07 to 2.62) or nonblack (OR = 1.95, 95% CI = 1.07 to 3.56) or having a family history of coronary artery disease (CAD; OR = 2.09, 95% CI = 1.32 to 3.3), elevated lipids (OR = 1.71, 95% CI = 1.04 to 2.82), prior AMI (OR = 1.79, 95% CI = 1.16 to 2.76), abnormal ECG on arrival (OR = 2.1, 95% CI = 1.33 to 3.34), and a positive initial troponin (OR = 14.7, 95% CI = 6.8 to 32.2) were predictive of cardiovascular events. The multivariable model found family history of CAD (OR = 2.06, 95% CI = 1.26 to 3.36), abnormal initial ECG (OR = 1.89, 95% CI = 1.16 to 3.09), and positive initial troponin (OR = 13.3, 95% CI = 5.9 to 29.6) remained predictive of 30-day cardiovascular events.

Conclusions:  In patients with prior revascularization, the initial ECG and early cardiac marker elevations, but not clinical presentation, predict odds of 30-day death, AMI, or revascularization.

18. Don't Forget About Ventilation/Perfusion Scanning

This diagnostic tool still has a role in suspected pulmonary embolism.

Salaun P-Y et al. Chest 2011 Jun; 139:1294.

BACKGROUND: We designed a simple and integrated diagnostic algorithm for acute pulmonary embolism (PE). Diagnosis was based on clinical probability assessment, plasma D-dimer testing, then sequential testing to include lower limb venous compression ultrasonography, ventilation perfusion lung scan, and chest multidetector CT (MDCT) imaging.

METHODS: We included 321 consecutive patients presenting at Brest University Hospital in Brest, France, with clinically suspected PE and positive d-dimer or high clinical probability. Patients in whom VTE was deemed absent were not given anticoagulants and were followed up for 3 months.

RESULTS: Detection of DVT by ultrasonography established the diagnosis of PE in 43 (13%). Lung scan associated with clinical probability was diagnostic in 243 (76%) of the remaining patients. MDCT scan was required in only 35 (11%) of the patients. The 3-month thromboembolic risk in patients not given anticoagulants, based on the results of the diagnostic protocol, was 0.53% (95% CI, 0.09-2.94).

CONCLUSIONS: A diagnostic strategy combining clinical assessment, d-dimer, ultrasonography, and lung scan gave a noninvasive diagnosis in the majority of outpatients with suspected PE and appeared to be safe.

19. Use of a β-hCG Discriminatory Zone with Bedside Pelvic Ultrasonography

Wang R, et al. Ann Emerg Med. 2011;58:12-20.

Study objective: We seek to assess the performance of the β human chorionic gonadotropin (β-hCG) “discriminatory zone” when using bedside pelvic ultrasonography in the evaluation of symptomatic pregnant emergency department (ED) patients.

Methods: This was a cross-sectional study of bedside pelvic ultrasonography performed on consecutive pregnant patients in the first trimester who presented to the ED with abdominal pain or vaginal bleeding. Patients received pelvic ultrasonography, serum β-hCG testing, and blinded formal radiologic ultrasonography. All patients were followed for 8 weeks to determine outcomes. The sensitivity and specificity of a discriminatory β-hCG level of 3,000 mIU/mL for the diagnosis of ectopic pregnancy were calculated for patients without an intrauterine pregnancy visualized by bedside ultrasonography.

Results: Thirty-six faculty physicians performed bedside pelvic ultrasonography on 256 patients. There were 161 cases with a confirmed visualizable intrauterine pregnancy and 29 ectopic pregnancies. Bedside ultrasonography identified 115 intrauterine pregnancies. The range of β-hCG for cases of confirmed visualizable intrauterine pregnancy with a nondiagnostic bedside ultrasonography was 15 mIU/mL to 123,368 mIU/mL (median 6,633; interquartile range 1,551 to 32,699). For patients with nondiagnostic bedside ultrasonography, using a discriminatory β-hCG level of 3,000 mIU/mL to further assess for ectopic pregnancy showed sensitivity of 35% (95% confidence interval [CI] 18% to 54%) and specificity of 58% (95% CI 48% to 67%). Finally, the overall sensitivity of bedside pelvic ultrasonography for the detection of intrauterine pregnancy was 71% (95% CI 63% to 78%), and the specificity was 99% (95% CI 94% to 100%).

Conclusion: When bedside pelvic ultrasonography does not demonstrate an intrauterine pregnancy, serum β-hCG level is not helpful in differentiating intrauterine from ectopic pregnancy in symptomatic ED patients.

20. "Bath Salts" Intoxication

Investigation into a cluster of cases in Michigan leads to characterization of this new recreational drug.

In early 2011, a Michigan poison control center received reports of several patients injecting, inhaling, or ingesting "bath salts" as recreational drugs. Purchased at a local store, the "bath salts," which have no legitimate use for bathing, contained the stimulant compounds 3,4-methylenedioxypyrovalerone (MDPV) or 4-methylmethcathinone (mephedrone). Subsequent statewide investigation identified 35 patients (age range, 22–50) who presented to emergency departments with "bath salt" intoxication during 5 months.

Nearly half of patients had histories of psychiatric illness, and 69% had self-reported histories of drug abuse. Ninety-one percent presented with neurological symptoms (e.g., mydriasis, motor automatisms), 77% exhibited cardiovascular symptoms (e.g., hypertension, tachycardia), and 49% showed psychological symptoms (e.g., delusions, hallucinations, agitation, paranoia). One patient was dead on arrival, and 17 were admitted (9 to intensive care). Most patients were treated with benzodiazepines and observed; all recovered uneventfully.

Comment: The Drug Enforcement Administration has identified "bath salts" as a drug of concern. For emergency providers, the emergence of this new drug of abuse should lead to questions about use of "bath salts" when patients present with psychiatric, cardiovascular, and neurological symptoms consistent with stimulant use. Treatment is the same as for other sympathomimetics — titrated doses of benzodiazepines and general supportive measures.

— Diane M. Birnbaumer, MD, FACEP. Published in Journal Watch Emergency Medicine June 3, 2011

Citation: Centers for Disease Control and Prevention (CDC). Emergency department visits after use of a drug sold as "bath salts" — Michigan, November 13, 2010–March 31, 2011. MMWR Morb Mortal Wkly Rep 2011 May 20; 60:624.

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21. Decade's Top 10 Public Health Achievements

CDC Says U.S. Is Making Strides in the Fight Against AIDS and Other Diseases

Bill Hendrick. May 19, 2011 — Controlling infectious diseases like AIDS and tuberculosis, doing a better job of fighting tobacco use, improving motor vehicle safety, and reducing heart disease and death have been named by the CDC as being among the 10 top public health achievements of the first decade of the 21st century.

Others include improvements in vaccine-preventable diseases, better maternal and infant health, better cancer prevention, improved occupational safety, and aggressive steps that have led to fewer childhood lead poisonings, the CDC says.

Also, major strides have been made in public safety preparedness since the terrorist attacks of Sept. 11, 2001, the agency says in its Morbidity and Mortality Weekly Report for May 20.

"Americans are living longer, healthier and more productive lives than ever before thanks in part to extraordinary achievements in public health over the past decade," CDC Director Thomas R. Frieden, MD, MPH, says in a news release.

But he says much more can and should be done to protect and promote public health. "Continued investments in prevention will help us and our children live even longer, healthier and more productive lives while bringing down health care costs," Frieden says.

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