Lit Bits: February 4, 2006

From the recent medical literature...

1. Administration of steroids in acute exacerbations of COPD

Shweta Gidwani, Clinical Effectiveness Fellow and Craig Ferguson, Clinical Research Fellow. Manchester Royal Infirmary . Emerg Med J 2006; 23:142-143.

A short cut review was carried out to establish whether post discharge steroids are beneficial in acute exacerbations of COPD. 237 papers were found using the reported search, of which one presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of this best paper are tabulated. It is concluded that post-discharge steroids are beneficial in the short term.

Clinical scenario
A 55 year old man, known to have COPD, attends the Emergency Department complaining of being more short of breath than usual and having a productive cough. You treat him with continuous nebulised bronchodilator therapy, oral steroids and antibiotics. He starts to improve and, on reassessing him clinically after reviewing his chest x-ray and blood tests you decide to discharge him with community follow up. You wonder whether he should continue on a short course of steroids in addition to his antibiotics.

Three part question
In [patients with an acute exacerbation of COPD] are [steroids prior to discharge better than no steroids] at [improving outcome and hastening recovery]?

Search strategy (details not included)
COCHRANE LIBRARY Issue 4 2005
Ovid MEDLINE 1966-November 2005
Embase 1980–2005 Week 47

Outcome
237 papers found of which one was a recently updated well done systematic review found

Comments
Treatment of patients with acute exacerbations of COPD with corticosteroids is a common practice. The evidence shows that this significantly improves lung function and breathlessness up to the first 72 hours. It also reduces the treatment failure within the first 30 days. However, these effects appear to be short lived and there is no effect on mortality. Also there is an increased incidence of adverse effects related to steroids. However, the studies were not designed to look at long term mortality outcomes and this seems reasonable as the intervention was a short course of steroids and hence the effects were observed for a maximum period of 30 days.

CLINICAL BOTTOM LINE: The use of steroids has clear benefit in the acute management of the patient but with added risk of adverse drug effects and with no clear long term benefit in improvement in lung function or increased life expectancy

2. Model identifies low-risk patients with pulmonary embolism, so low-risk that outpt management is considered safe

January 25, 2006

NEW YORK (Reuters Health) - A simple rule based on 10 demographic, history, and clinical factors predicts 30-day risk of mortality among patients with pulmonary embolism (PE) and identifies those who could be safely treated as outpatients, investigators report in the Archives of Internal Medicine for January 23.

Authors of two other papers in the Archives observe that bedside testing, including testing for D-dimer, can identify some patients at low risk of PE who don't require imaging studies.

Although evidence is growing that outpatient treatment is safe for selected patients with nonmassive PE, there are no explicit clinical criteria to accurately identify those who are at low risk of adverse outcomes, Dr. Drahomir Aujesky, from Centre Hospitalier Universitaire Vaudois in Lausanne, Switzerland, and colleagues note in their report (this abstract follows the news report below).

They identified patients with PE treated between 2000 and 2002 whose data were registered in the Pennsylvania Health Care Cost Containment Council database. They derived a prediction rule using classification tree analysis, with 30-day mortality as the outcome and demographic and clinical variables as predictors.

The final 10 predictors were age 70 or older, a history of five comorbid diseases (cancer, heart failure, chronic lung disease, chronic renal disease, and cerebrovascular disease), and the presence of four clinical abnormalities (pulse rate 110 beats/minute or higher, systolic blood pressure < 100 mm Hg, altered mental status, and arterial oxygen saturation < 90%). In the 10,354-patient derivation sample, overall 30-day mortality was 9.2%. Among the 21.6% of subjects deemed to be at low risk based on the model, 30-day mortality was 0.6%.

In the investigators' internal validation sample, which included 5177 patients, overall 30-day mortality was 9.5%. It was 1.5% among the 21.6% found to be at low risk, based on the prediction rule. They externally validated their sample using 221 patients treated at three hospitals in Switzerland and France. The overall mortality was 2.7%. Among the 33.9% estimated to be at low risk, none died within 30 days of the initial examination.

Dr. Aujesky's team calculates that the prediction rule has a sensitivity of 97% to 100% and negative predictive value of 98% to 100% for predicting 30-day mortality. They estimate that up to $91 million per year could be saved in the US if 20% of patients with low-risk PE were treated as outpatients. However, they recommend that their prediction rule be validated in a prospective study.

For the second study, Dr. Marc A. Rodger, from the University of Ottawa in Ontario, Canada, and his associates randomly assigned patients suspected of having PE to an initial ventilation-perfusion (V/Q) scan or to BIOPED (bedside investigation of pulmonary embolism diagnosis) that evaluated clinical variables, a D-dimer test, and alveolar dead-space fraction. Variables included in the BIOPED analysis were clinical signs or symptoms of DVT, alternate diagnosis less likely than PE, heart rate > 100 beat/min, previous DVT or PE, major surgery or immobilization within 4 weeks, active malignant neoplasm and hemoptysis.

There were 199 subjects in the BIOPED group and 200 in the V/Q scan group. During follow, 2.4% of patients not taking anticoagulant agents in the BIOPED group and 3.0% in the V/Q scan group had a venous thromboembolism event during 3-month follow-up.

The BIOPED technique eliminated the need for diagnostic imaging in 34% of patients with suspected PE, the authors report.

In the third paper, Dr. Gregoire Le Gal, from Brest University Hospital in France and his colleagues note that D-dimer testing still has a place when evaluating patients for PE who have had a previous venous thromboembolism (VTE). However, the proportion of negative results will be lower in such patients.

The researchers analyzed data from two prospective studies that included 1721 consecutive patients with suspected PE. Previous VTE was documented in 308.
The D-dimer level was less than 500 'g/L in 32.7% of those without history of VTE and in 15.9% of those with a previous VTE. Among those in whom PE was ruled out by a negative D-dimer test result and who did not receive anticoagulant agents, there were no VTEs during the next 3 months in those with or without a previous VTE.

"The combination of a low pretest probability and a negative D-dimer test result should obviate the need for further testing," Dr. Lisa K. Moores, from Walter Reed Army Medical center in Washington, DC, states in a related editorial.

However, she notes that in patients with comorbidities, elderly patients, and those with a history of VTE, "an alveolar dead-space measurement could be used in combination with pretest probability to guide the selection of patients who require further diagnostic testing."

Arch Intern Med 2006;166:147-148,169-187.

ABSTRACT for A Prediction Rule to Identify Low-Risk Patients With Pulmonary Embolism. Drahomir Aujesky, MD, and others including Michael J. Fine, MD, MSc (one of the docs behind the pneumonia clinical prediction rules we use at Kaiser). Arch Intern Med. 2006;166:169-175.

Background A simple prognostic model could help identify patients with pulmonary embolism who are at low risk of death and are candidates for outpatient treatment.

Methods We randomly allocated 15 531 retrospectively identified inpatients who had a discharge diagnosis of pulmonary embolism from 186 Pennsylvania hospitals to derivation (67%) and internal validation (33%) samples. We derived our rule to predict 30-day mortality using classification tree analysis and patient data routinely available at initial examination as potential predictor variables. We used data from a European prospective study to externally validate the rule among 221 inpatients with pulmonary embolism. We determined mortality and nonfatal adverse medical outcomes across derivation and validation samples.

Results Our final model consisted of 10 patient factors (age 70 years; history of cancer, heart failure, chronic lung disease, chronic renal disease, and cerebrovascular disease; and clinical variables of pulse rate 110 beats/min, systolic blood pressure <100 mm Hg, altered mental status, and arterial oxygen saturation <90%). Patients with none of these factors were defined as low risk. The 30-day mortality rates for low-risk patients were 0.6%, 1.5%, and 0% in the derivation, internal validation, and external validation samples, respectively. The rates of nonfatal adverse medical outcomes were less than 1% among low-risk patients across all study samples.

Conclusions This simple prediction rule accurately identifies patients with pulmonary embolism who are at low risk of short-term mortality and other adverse medical outcomes. Prospective validation of this rule is important before its implementation as a decision aid for outpatient treatment.

3. American Heart Association Does Not Recommend Isoflavone Supplements

Jan. 25, 2006 —The American Heart Association (AHA) nutrition committee found a lack of benefit from soy and therefore does not recommend isoflavone supplements in food or pills, according to a report in the January 17 Rapid Access issue of Circulation.

"Soy protein and isoflavones (phytoestrogens) have gained considerable attention for their potential role in improving risk factors for cardiovascular disease," write Frank M. Sacks, MD, and colleagues from the AHA Nutrition Committee. "This scientific advisory assesses the more recent work published on soy protein and its component isoflavones."

In most of 22 randomized trials reviewed, isolated soy protein with isoflavones, as compared with milk or other proteins, decreased low-density lipoprotein (LDL) cholesterol concentrations by an average amount of about only 3%. This reduction was small relative to the large amount of soy protein tested in these studies, which was about 50 g, or half the usual total daily protein intake. There were no significant effects on high-density lipoprotein (HDL) cholesterol, triglycerides, lipoprotein(a), or blood pressure.

In 19 studies of soy isoflavones, there was no effect on LDL cholesterol or on other lipid risk factors. The panel also noted no demonstrated benefit on vasomotor symptoms of menopause, and mixed results in terms of slowing postmenopausal bone loss. Similarly, the efficacy and safety of soy isoflavones for prevention or treatment of cancer of the breast, endometrium, and prostate are undetermined, and evidence from clinical trials is limited but suggests a possible adverse effect.

"For this reason, use of isoflavone supplements in food or pills is not recommended," the authors write. "Thus, earlier research indicating that soy protein has clinically important favorable effects as compared with other proteins has not been confirmed. In contrast, many soy products should be beneficial to cardiovascular and overall health because of their high content of polyunsaturated fats, fiber, vitamins, and minerals and low content of saturated fat."

Circulation. Posted online January 17, 2006.

4. Myocardial Injury and Long-term Mortality Following Moderate to Severe Carbon Monoxide Poisoning.

Christopher R. Henry, BS; et al. JAMA. 2006;295:398-402.

Context Carbon monoxide (CO) poisoning is a common cause of toxicological morbidity and mortality. Myocardial injury is a frequent consequence of moderate to severe CO poisoning. While the in-hospital mortality for these patients is low, the long-term outcome of myocardial injury in this setting is unknown.

Objective To determine the association between myocardial injury and long-term mortality in patients following moderate to severe CO poisoning.

Design, Setting, and Participants Prospective cohort study of 230 consecutive adult patients treated for moderate to severe CO poisoning with hyperbaric oxygen and admitted to the Hennepin County Medical Center, a regional center for treatment of CO poisoning, between January 1, 1994, and January 1, 2002. Follow-up was through November 11, 2005.

Main Outcome Measure All-cause mortality.

Results Myocardial injury (cardiac troponin I level 0.7 ng/mL or creatine kinase-MB level 5.0 ng/mL and/or diagnostic electrocardiogram changes) occurred in 85 (37%) of 230 patients. At a median follow-up of 7.6 years (range: in-hospital only to 11.8 years), there were 54 deaths (24%). Twelve of those deaths (5%) occurred in the hospital as a result of a combination of burn injury and anoxic brain injury (n = 8) or cardiac arrest and anoxic brain injury (n = 4). Among the 85 patients who sustained myocardial injury from CO poisoning, 32 (38%) eventually died compared with 22 (15%) of 145 patients who did not sustain myocardial injury (adjusted hazard ratio, 2.1; 95% confidence interval, 1.2-3.7; P = .009).

Conclusion Myocardial injury occurs frequently in patients hospitalized for moderate to severe CO poisoning and is a significant predictor of mortality.

5. Chronic Stress at Work Raises Risk for Metabolic Syndrome

Does this apply to us??

NEW YORK (Reuters Health) Jan 19 - People with high job stress over a protracted period of time have double the risk of developing the metabolic syndrome, British investigators report. This relationship may help explain the reported link between stressors of everyday life and heart disease.

Dr. Tarani Chandola and colleagues at University College London evaluated data from the prospective Whitehall II study, which recruited 10,308 participants ages 35 to 55 from 20 civil service departments between 1985 and 1988.

Surveys regarding job demands, job control, lack of social support at work, and health behaviors were completed at baseline and in 1989, 1991-1993, and 1997-1999. There were 7034 subjects remaining at the final evaluation.

Subjects underwent clinical examinations to determine the prevalence of metabolic syndrome, defined by the presence of three or more risk factors (abdominal obesity, hypertriglyceridemia, low high density lipoprotein cholesterol, hypertension, and hyperglycemia).

As reported in BMJ Online First, published on January 19, work stress was defined as being in the lowest third of work social support, with high job demands and low job control.

Compared with subjects who never reported work stress, those who reported work stress three or more times over the 14-year study period had double the risk of metabolic syndrome.

The authors observed a dose-response relationship. After adjusting for age, employment grade, health behaviors and excluding patients who were obese at baseline, the odds ratio for those reporting high work stress only one time was 1.11, rising to 1.47 for those reporting high job stress at two time points. The odds ratio was 2.29 for those with high job stress three or more times (p = 0.01 for trend).

Dr. Chandola's group also observed a social gradient, in which those in the lowest employment grades had more than double the risk of developing metabolic syndrome than those in the highest grades. After adjusting for work stress and health behaviors, the social gradient was no longer significant.

The mechanism underlying the relationship between work stress and metabolic syndrome remains unknown. The authors posit that the effects of stress on the autonomic nervous system, neuroendocrine activity, biological resilience, and adrenocortical function may be involved.

BMJ Online First 2006.

6. First Complex Seizure? How Many of These have Intracranial Pathology that requires Emergency Neurosurgical or Medical Intervention?

Teng D, et al.Risk of Intracranial Pathologic Conditions Requiring Emergency Intervention After a First Complex Febrile Seizure Episode Among Children. Pediatrics 2006; 117: 304-308.

OBJECTIVE. To determine the likelihood of intracranial pathologic conditions requiring emergency neurosurgical or medical intervention among children without meningitis who presented to the pediatric emergency department after a first complex febrile seizure.

METHODS. We performed a retrospective review of prospectively collected data for children in neurologically normal condition who presented to a single pediatric emergency department after a first complex febrile seizure (focal, multiple, or prolonged). The complex febrile seizure classification was determined independently by 2 epileptologists. The presence of intracranial pathologic conditions was determined through review of neuroimaging results, telephone interviews, or medical record review.

RESULTS. Data for 71 children with first complex febrile seizures were analyzed. Fifty-one (72%) had a single complex feature (20 focal, 22 multiple, and 9 prolonged), and 20 (28%) had multiple complex features. None of the 71 patients (1-sided 95% confidence interval: 4%) had intracranial pathologic conditions that required emergency neurosurgical or medical intervention.

CONCLUSIONS. For children with first complex febrile seizures, the risk of intracranial pathologic conditions that require emergency neurosurgical or medical intervention is low, which suggests that routine emergency neuroimaging for this population is unnecessary.

7. Nasal Steroids for Acute Rhinosinusitis

Because the common cold often includes both nasal and sinus symptoms, the term "rhinosinusitis" has become popular. Inflammation contributes to rhinosinusitis symptoms, and the effect of antibiotics on mild sinusitis is controversial. Therefore, researchers performed a double-blind, randomized trial in which 981 patients with acute, uncomplicated rhinosinusitis received the nasal corticosteroid mometasone furoate (Nasonex; 200 µg, either once or twice daily, for 15 days), oral amoxicillin (500 mg thrice daily for 10 days), or placebo. The study was sponsored by the maker of mometasone.

All patients had been symptomatic for 7 to 28 days with combinations of nasal congestion, nasal drainage, sinus headache, and facial pain or pressure. Patients with high fever and severe unilateral facial pain were excluded. Compared with results in the placebo group, improvement in symptoms during the 15-day treatment course was significantly greater in both mometasone groups, but not in the amoxicillin group. Improvement was greater with twice-daily than with once-daily mometasone. However, the benefit of mometasone was modest: For example, mean symptom scores (about 8.3 at baseline on a 15-point scale) declined by about 3.7 points with placebo and 4.5 points with twice-daily mometasone.

Comment: In essence, these results suggest that when common cold symptoms linger for more than a week without high fever or severe unilateral facial pain, a nasal steroid is more beneficial than amoxicillin. Wider prescribing of nasal steroids for this purpose presumably would reduce antibiotic use. However, nasal mometasone is rather expensive; it would be interesting to see whether it works better than topical and oral decongestants in these patients.

— Allan S. Brett, MD. Published in Journal Watch January 10, 2006. Source: Meltzer EO et al. Treating acute rhinosinusitis: Comparing efficacy and safety of mometasone furoate nasal spray, amoxicillin, and placebo. J Allergy Clin Immunol 2005 Dec; 116:1289-95.

8. Warfarin Reversal: Another Door-to-Drug Time Goal

Intracerebral hemorrhage (ICH) accounts for roughly 10% of strokes and 1% of all deaths in the U.S. Patients taking warfarin have a sixfold increased risk for ICH and are likely to have ongoing bleeding. Reversal of anticoagulation is first-line therapy in such cases. To assess the timing and outcomes of therapy with vitamin K and fresh frozen plasma (FFP), these authors retrospectively reviewed all cases of nontraumatic warfarin-associated ICH that presented to a single emergency department from 1998 to 2004.

After exclusions for incomplete records, initial international normalized ratio (INR) 1.4, and do-not-resuscitate orders, 69 of 160 cases were included in the analysis. At 24 hours, 57 patients (83%) had adequate reversal (defined as INR 1.4). In multivariate analyses adjusting for disease severity, researchers found that shorter times to FFP administration and to vitamin K administration each were independently associated with the likelihood of successful reversal (odds ratio, 0.8 for both agents). Neither success of anticoagulation reversal nor dose of FFP or vitamin K affected clinical outcomes at 90 days.

Comment: These authors document delays in reversal of anticoagulation and a correlation between such delays and inadequate reversal at 24 hours. Although there is no direct evidence that reversal saves lives, reversal is certainly desirable in the context of intracranial or other serious hemorrhage.

Why the delays? FFP takes time to obtain, thaw, and hang. With vitamin K, concern about anaphylactoid reactions might result in delays. Although intravenous vitamin K is associated with rare anaphylactoid reactions, such concerns do not have a place in the treatment of life-threatening warfarin-associated hemorrhages. Only 27 deaths from vitamin K anaphylactoid reaction have ever been reported in the English-language literature. (See J Thromb Thrombolysis 2001; 11:175-83). If vitamin K cannot be given intravenously, it should be given orally.

— Daniel J. Pallin, MD, MPH. Published in Journal Watch Emergency Medicine January 17, 2006. Source: Goldstein JN et al. Timing of fresh frozen plasma administration and rapid correction of coagulopathy in warfarin-related intracerebral hemorrhage. Stroke 2006 Jan; 37:151-5.

9. Exercise Is Associated with Reduced Risk for Incident Dementia among Persons 65 Years of Age and Older

This could be useful for us!

The authors followed 1740 persons who did not have cognitive impairment at baseline. During a mean follow-up of 6.2 years, 158 participants developed dementia; the incidence rate was 13.0 per 1000 person-years for those who exercised 3 or more times per week at baseline and 19.7 per 1000 person-years for those who exercised less frequently. The results were similar in the 107 participants who developed Alzheimer disease.

However, the existing evidence does not prove that regular exercise is associated with a lower dementia risk.

Larson and colleagues provide important evidence that more physical exercise is associated with lower rates of dementia, adding significantly to several other recent studies on the association between physical activity and dementia risk. We now need randomized trials to examine the effect of physical activity on cognitive function measures, and we need researchers to include clinical dementia end points in ongoing trials of lifestyle modification.

Eric B. Larson, et al. Ann Intern Med 2006; 144:73-81

10. Early Symptoms May Allow Earlier Diagnosis of Meningococcus in Children

Web MD. News Author: Laurie Barclay, MD

Jan. 13, 2006 — Early symptoms may allow earlier diagnosis of meningococcus in children, according to the results of a study reported in the January 11 Early Online Publication issue of The Lancet.

"Recognizing early symptoms of sepsis could increase the proportion of children identified by primary-care physicians and shorten the time to hospital admission," lead author Matthew Thompson, MD, from the University of Oxford in the United Kingdom, said in a news release. "The framework within which meningococcal disease is diagnosed should be changed to emphasize identification of these early symptoms by parents and clinicians."

The investigators analyzed questionnaires completed by parents and primary-care records for the course of illness before hospitalization in 448 children, aged 16 years or younger, with meningococcal disease. Of the 448 cases, 103 (23%) were fatal, and microbiological techniques confirmed the diagnosis in 373 cases. The remaining cases were diagnosed on the basis of purpuric rash and either meningitis or evidence of septicemic shock.

The timeframe for clinical diagnosis was narrow because most children had only nonspecific symptoms in the first 4 to 6 hours but were moribund by 24 hours. Only 165 children (51%) were hospitalized after the first consultation, and median time to hospitalization was 19 hours. Early symptoms of sepsis, including leg pains, cold hands and feet, and abnormal skin color, occurred in 72% of children at a median time of 8 hours. Classic features of hemorrhagic rash, meningism, and impaired consciousness developed late, with a median onset of 13 to 22 hours.

"We have identified three important clinical features — leg pain, cold hands and feet, and abnormal skin color — that are signs of early meningococcal disease in children and adolescents," the authors write. "Classic clinical features of meningococcal disease appear late in the illness."

Study limitations include retrospective data collection and associated recall bias and lack of data for children with other illnesses to compare symptom frequency.

"Encouraging recognition of sepsis symptoms (and perhaps measurement of vital signs) in primary care could reduce the proportion of cases missed at first consultation from a half to a quarter," the authors conclude. "However, achieving earlier diagnosis for the final 25% needs increased awareness of the early symptoms of sepsis and a change in help-seeking behavior by parents as well as clinicians."

The Meningitis Research Foundation and the Medical Research Council supported this study. The authors have disclosed no relevant financial relationships.

In an accompanying comment, Cristiana M. Nascimento-Carvalho, MD, and Otávio A. Moreno-Carvalho, MD, from the University of Bahia in Salvador, Brazil, note that early diagnosis can be challenging because the initial, nonspecific symptoms are similar to those of many common, self-limiting viral illnesses. The editorialists recommend a study to determine positive and negative predictive values of leg pain, cold extremities, and abnormal skin color for the diagnosis of meningococcal disease.

"Until this information is available, doctors should be encouraged to schedule clinical review within 4 - 6 hours if early meningococcal disease cannot be ruled out at the first contact," Drs. Nascimento-Carvalho and Moreno-Carvalho write. "To wait for the late signs of meningitis, such as neck stiffness, photophobia, and bulging fontanelle, is a glaring mistake if meningococcal disease is to be promptly diagnosed, because those signs usually arise as late as 12 - 15 h after onset of illness.... The recognition of early signs of meningococcal disease could reduce subsequent mortality."

ABSTRACT from the Lancet, Posted online January 11, 2006.

Background
Meningococcal disease is a rapidly progressive childhood infection of global importance. To our knowledge, no systematic quantitative research exists into the occurrence of symptoms before admission to hospital.

Methods
Data were obtained from questionnaires answered by parents and from primary-care records for the course of illness before admission to hospital in 448 children (103 fatal, 345 non-fatal), aged 16 years or younger, with meningococcal disease. In 373 cases, diagnosis was confirmed with microbiological techniques. The rest of the children were included because they had a purpuric rash, and either meningitis or evidence of septicaemic shock. Results were standardised to UK case-fatality rates.

Findings
The time-window for clinical diagnosis was narrow. Most children had only non-specific symptoms in the first 4–6 h, but were close to death by 24 h. Only 165 (51%) children were sent to hospital after the first consultation. The classic features of haemorrhagic rash, meningism, and impaired consciousness developed late (median onset 13–22 h). By contrast, 72% of children had early symptoms of sepsis (leg pains, cold hands and feet, abnormal skin colour) that first developed at a median time of 8 h, much earlier than the median time to hospital admission of 19 h.

Interpretation
Classic clinical features of meningococcal disease appear late in the illness. Recognising early symptoms of sepsis could increase the proportion of children identified by primary-care clinicians and shorten the time to hospital admission. The framework within which meningococcal disease is diagnosed should be changed to emphasise identification of these early symptoms by parents and clinicians.

11. Chest radiographs negative for one in five acute heart failure patients

January 13, 2006. By Anne Harding. NEW YORK (Reuters Health) - Nearly one in five patients admitted to an emergency department with decompensated heart failure will have negative chest radiography results, a new analysis of registry data suggests.

The findings are consistent with past research suggesting that the test will find no signs of congestion in a substantial proportion of acute heart failure patients, Dr. Sean P. Collins of the University of Cincinnati, Ohio, told Reuters Health.

"The chest X-ray is still really an invaluable tool in the emergency physician's workup of heart failure," he said. But physicians who suspect heart failure in a patient should not conclude it isn't there if a chest radiograph is negative, he added.

Dr. Collins and his colleagues reviewed data from the Acute Decompensated Heart Failure National Registry (ADHERE). Among the 85,376 patients for whom chest radiographs and an admitting diagnosis were available, 15,937, or 18.7%, had no signs of congestion on chest radiography. There was no difference in the percentage of negative chest radiography based on race or sex.
Patients with negative chest X-rays were more likely to have been admitted to the hospital with a diagnosis other than heart failure than those with positive chest radiography (23.3% vs. 13.0%, respectively).

"Clinicians should consider the prevalence of chest radiography that lacks signs of congestion when evaluating patients for possible acute decompensated heart failure," Dr. Collins and his team conclude in the January issue of the Annals of Emergency Medicine.

In an editorial accompanying the study, Dr. Richelle J. Cooper of the UCLA Emergency Medicine Center points out the limitations of the ADHERE data, including the inability to confirm a patient's discharge diagnosis and the biased nature of the sample.

"Until there is better research to suggest differently, I will continue to order a simple chest radiograph and not feel angst that I am missing clinically important cases of heart failure because the radiograph is 'negative,'" she concludes.

Ann Emerg Med 2006;47:13-21.

12. Clinical Cases Make Blog a Popular Resource

WebMD. Posted 01/04/2006. Nicholas Genes, MD, PhD

When people first learn about medical blogs, they assume that these sites are simply online diaries written by healthcare professionals. And it's true that many are. But medical blogs come in all shapes and sizes, a testament to the diversity and inventiveness of their writers. Many blogs feature educational content, and some are exclusively educational, such as the Clinical Cases and Images Blog, managed by Dr. Ves Dimov.

Dr. Dimov started this blog as an outgrowth of a learning tool, also called "Clinical Cases and Images," which he developed with residents at Case Western Reserve University in Cleveland, Ohio. Now a hospitalist at the Cleveland Clinic, Dr. Dimov has continued adding to the site, making it a tremendous resource for physicians and students around the world. Featuring step-by-step guides to line placement, x-ray interpretation, and more, the site fills a gap in medical textbooks and everyday practice. His work has received praise from numerous sources, including the British Medical Journal.

Check it out: http://clinicalcases.blogspot.com/

13. The Minimally Symptomatic Hernia: "If It's Not Broken, Don't Fix It"

Watchful Waiting vs Repair of Inguinal Hernia in Minimally Symptomatic Men
A Randomized Clinical Trial. Fitzgibbons RJ, et al. JAMA. 2006;295:285-292. And editorial: 328-329.

January 18, 2006. By Anthony J. Brown, MD. NEW YORK (Reuters Health) - Men who experience few or no symptoms from an inguinal hernia do not require immediate surgery, instead they can be safely followed and treated if symptoms worsen, new research shows. If adopted by the greater surgical community, this approach could markedly reduce the number of hernia repairs performed.

Out of fear that incarceration and other problems may occur, "surgeons are generally taught that all hernias should be repaired at diagnosis," lead author Dr. Robert J. Fitzgibbons, from Creighton University in Omaha, Nebraska told Reuters Health. "Our study questioned this conventional wisdom and found that a watchful waiting approach can be safely applied to men with minimal symptoms. I suspect that 50% of patients with hernias could keep them for the rest of their lives and never have a problem."

One of the key findings "was that there didn't appear to be any penalty for waiting to perform surgery," Dr. Fitzgibbons said. "The concern had been that waiting could lead to worse hernias that are more difficult to repair and associated with greater complications. But in our study, the complication rate for patients having initial surgery and those having delayed surgery was exactly the same."

The study, which is reported in The Journal of the American Medical Association for January 18, involved 720 men with minimally symptomatic inguinal hernias who were randomized to receive immediate surgery or watchful waiting. With the latter approach, subjects were seen at 6 months and then annually to determine if hernia symptoms worsened, an indication for surgery.

At 2-year follow-up, the rate of pain limiting activities in each group was not significantly different, hovering around 3.5%. Likewise, both groups experienced a similar improvement in the physical component score of the Short Form-36 survey.

Twenty-three percent of patients assigned to watchful waiting crossed over to the surgery group, typically due to an increase in hernia-related pain. As noted, these patients were not at heightened risk for surgical complications compared with men who had their hernias repaired immediately.

One patient in the watchful waiting group developed acute hernia incarceration without strangulation within 2 years of enrollment in the study. In addition, another patient in the group had acute incarceration with bowel obstruction at 4 years. Thus, the hernia accident rate was 0.0018 events per patient-year.

Dr. Fitzgibbons believes the new findings will lead many surgeons to "discuss nonoperative options with their hernia patients." He said that for medicolegal reasons, surgeons may have been reluctant to adopt a watchful waiting approach in the past. "But now there is good scientific evidence that it's a reasonable strategy and that takes the medicolegal burden away."

"If the results of this study are reproduced in other populations and for other types of hernia, then the era of preventive hernia repair should go the way of prophylactic tonsillectomy, cholecystectomy, and appendectomy," Dr. David R. Flum, from the University of Washington in Seattle, comments in a related editorial.

14. Aspirin Prevents Cardiovascular Disease in Healthy Adults

By Karla Gale. NEW YORK (Reuters Health) Jan 17 - Low-dose aspirin is effective in preventing cardiovascular events, even among men and women without preexisting cardiovascular disease (CVD), results of a meta-analysis show. However, aspirin also increases the risk of major bleeding, so clinicians must weigh the drug's relative risks and benefits before prescribing it as primary prophylaxis.

"Everyone accepts that aspirin works as secondary prevention," senior author Dr. David L. Brown told Reuters Health. "For primary prevention, especially for women, there is a paucity of data. But despite that lack of data, the American Heart Association and other organizations have been recommending the use of aspirin for primary prevention in women at high risk."

Dr. Brown, a physician at the State University of New York in Stony Brook, and his associates therefore conducted a meta-analysis of prospective, randomized controlled trials of aspirin therapy in patients without cardiovascular disease published between 1966 and 2005. According to their report in the Journal of the American Medical Association for January 18th, they identified six trials that enrolled 51,342 women and 44,114 men. Weighted mean duration of follow-up was 6.4 years, and aspirin doses ranged from 100 mg every other day to 500 mg daily.

Among women, aspirin prophylaxis reduced the odds of a cardiovascular event by 12% (p = 0.03). It did not significantly alter the risk of MI or hemorrhagic stroke, but it did reduce the risk of ischemic stroke by 24% (p = 0.008). Among men, aspirin reduced the risk of major cardiovascular events by 14% (p = 0.01), and of MI by 32% (p = 0.001). While it had no effect on the risk of ischemic stroke among men, it did increase their risk of hemorrhagic stroke by 69% (p = 0.03).

Both genders taking aspirin had a 70% increased risk of major bleeding. The drug appeared to have no effect on cardiovascular or all-cause mortality among men or women.

Dr. Brown's group points out that the study populations were at very low risk. They estimated that the number needed to treat to prevent one cardiovascular event over a mean of 6.4 years was 333 women and 270 men. "While the overall numbers are less in a lower risk population that has not yet had an event, the benefit in terms of reduction of risk is of a similar order of magnitude as it is in the secondary prevention studies," Dr. Brown said. "In my own practice, I recommend one baby aspirin per day for patients who have no obvious increased risk of bleeding and who have one or more risk factors for CVD."

He noted that "instruments used to calculate risk, primarily the Framingham risk calculator, calculate risk of MI, which is great for men because aspirin reduces the risk of MI in men. However, it does not make a lot of sense to use a calculator of risk for MI in women when aspirin does not appear to prevent MI in women, but prevents stroke."

"So a future area of research is to come up with a risk calculator for stroke in women to make the discussion with them about taking aspirin or not more quantitative."

JAMA 2006;295:306-313.

What is your risk for cardiovascular events? Use the calculator: http://hin.nhlbi.nih.gov/atpiii/calculator.asp?usertype=prof

According to the American Heart Association, “Consider 75–160 mg aspirin per day for people at higher risk, especially those with a 10-year CHD risk of 10 percent or greater.” http://www.americanheart.org/presenter.jhtml?identifier=4704

15. Which Kids with Blunt Head Trauma Need Imaging?

Oman JA, et al (including Jerry Hoffman) for the NEXUS II Investigators. Performance of a Decision Rule to Predict Need for Computed Tomography Among Children With Blunt Head Trauma. Pediatrics 2006; 117: e238-e246.

OBJECTIVE. To assess the ability of the NEXUS II head trauma decision instrument to identify patients with clinically important intracranial injury (ICI) from among children with blunt head trauma.

METHODS. An analysis was conducted of the pediatric cohort involved in the derivation set of National Emergency X-Radiography Utilization Study II (NEXUS II), a prospective, observational, multicenter study of all patients who had blunt head trauma and underwent cranial computed tomography (CT) imaging at 1 of 21 emergency departments. We determined the test performance characteristics of the 8-variable NEXUS II decision instrument, derived from the entire NEXUS II cohort, in the pediatric cohort (0–18 years of age), as well as in the very young children (<3 years). Clinically important ICI was defined as ICI that required neurosurgical intervention (craniotomy, intracranial pressure monitoring, or mechanical ventilation) or was likely to be associated with significant long-term neurologic impairment.

RESULTS. NEXUS II enrolled 1666 children, 138 (8.3%) of whom had clinically important ICI. The decision instrument correctly identified 136 of the 138 cases and classified 230 as low risk. A total of 309 children were younger than 3 years, among whom 25 had ICI. The decision instrument identified all 25 cases of clinically important ICI in this subgroup.

CONCLUSIONS. The decision instrument derived in the large NEXUS II cohort performed with similarly high sensitivity among the subgroup of children who were included in this study. Clinically important ICI were rare in children who did not exhibit at least 1 of the NEXUS II risk criteria.

16. Another approach to working up the possible PE

Effectiveness of Managing Suspected Pulmonary Embolism Using an Algorithm Combining Clinical Probability, D-Dimer Testing, and Computed Tomography
Writing Group for the Christopher Study Investigators.* JAMA. 2006;295:172-179.

Context Previous studies have evaluated the safety of relatively complex combinations of clinical decision rules and diagnostic tests in patients with suspected pulmonary embolism.

Objective To assess the clinical effectiveness of a simplified algorithm using a dichotomized clinical decision rule, D-dimer testing, and computed tomography (CT) in patients with suspected pulmonary embolism.

Design, Setting, and Patients Prospective cohort study of consecutive patients with clinically suspected acute pulmonary embolism, conducted in 12 centers in the Netherlands from November 2002 through December 2004. The study population of 3306 patients included 82% outpatients and 57% women.

Interventions Patients were categorized as "pulmonary embolism unlikely" or "pulmonary embolism likely" using a dichotomized version of the Wells clinical decision rule. Patients classified as unlikely had D-dimer testing, and pulmonary embolism was considered excluded if the D-dimer test result was normal. All other patients underwent CT, and pulmonary embolism was considered present or excluded based on the results. Anticoagulants were withheld from patients classified as excluded, and all patients were followed up for 3 months.

Main Outcome Measure Symptomatic or fatal venous thromboembolism (VTE) during 3-month follow-up.

Results Pulmonary embolism was classified as unlikely in 2206 patients (66.7%). The combination of pulmonary embolism unlikely and a normal D-dimer test result occurred in 1057 patients (32.0%), of whom 1028 were not treated with anticoagulants; subsequent nonfatal VTE occurred in 5 patients (0.5% [95% confidence interval {CI}, 0.2%-1.1%]). Computed tomography showed pulmonary embolism in 674 patients (20.4%). Computed tomography excluded pulmonary embolism in 1505 patients, of whom 1436 patients were not treated with anticoagulants; in these patients the 3-month incidence of VTE was 1.3% (95% CI, 0.7%-2.0%). Pulmonary embolism was considered a possible cause of death in 7 patients after a negative CT scan (0.5% [95% CI, 0.2%-1.0%]). The algorithm was completed and allowed a management decision in 97.9% of patients.

Conclusions A diagnostic management strategy using a simple clinical decision rule, D-dimer testing, and CT is effective in the evaluation and management of patients with clinically suspected pulmonary embolism. Its use is associated with low risk for subsequent fatal and nonfatal VTE.