Tuesday, December 13, 2005

Lit Bits: December 13, 2005

From the recent medical literature...

1. Smallpox Vaccination.

In light of world-wide terrorist activities, is it advisable for emergency physicians to receive smallpox immunization? The short answer is No. This week’s JAMA catalogues some of the adverse events from the vaccine.

As you may recall, AAEM and SAEM jointly came out early with a firm recommendation that emergency physicians should not receive this vaccination in the absence of an identified case of smallpox. It appears their recommendation was prudent given the following excerpt: "A total of 38,885 smallpox vaccinations were administered, with a take rate of 92%. VAERS received 822 reports of adverse events following smallpox vaccination....

One hundred adverse events (12%) were designated as serious, resulting in 85 hospitalizations, 2 permanent disabilities, 10 life-threatening illnesses, and 3 deaths. Among the serious adverse events, 21 cases were classified as myocarditis and/or pericarditis and 10 as ischemic cardiac events that were not anticipated based on historical data. Two cases of generalized vaccinia and 1 case of postvaccinial encephalitis were detected."

URLs for the JAMA abstracts are below:

Adverse Events Associated With Smallpox Vaccination in the United States,
January-October 2003. Christine G. Casey; et al. JAMA 2005;294 2734-2743
http://jama.ama-assn.org/cgi/content/abstract/294/21/2734?etoc

Neurologic Adverse Events Associated With Smallpox Vaccination in the
United States, 2002-2004. James J. Sejvar; et al. JAMA 2005;294 2744-2750
http://jama.ama-assn.org/cgi/content/abstract/294/21/2744?etoc

2. Tell your patients: “It’s not bronchitis. It’s just a chest cold.”

Calling Acute Bronchitis a Chest Cold May Improve Patient Satisfaction with Appropriate Antibiotic Use. T. Grant Phillips, MD and John Hickner, MD, MS. J Amer Board Fam Practice 2005:18:459-463

Background: Overuse of antibiotics for acute respiratory infections is an important public health problem and occurs in part because of pressure on physicians by patients to prescribe them. We hypothesized that if acute respiratory infections are called "chest colds" or "viral infections" rather than "bronchitis," patients will be satisfied with the diagnosis and more satisfied with not receiving antibiotics.

Methods: Family medicine patients were presented with a written scenario describing a typical acute respiratory infection where they were given one of 3 different diagnostic labels: chest cold, viral upper respiratory infection, and bronchitis, followed by a treatment plan that excluded antibiotic treatment. Data was analyzed for satisfaction with the diagnosis and treatment plan based on the diagnostic label. A total of 459 questionnaires were collected.

Results: Satisfaction (70%, 63%, and 68%) and dissatisfaction (11% 13%, and 13%) with the diagnostic labels of cold, viral upper respiratory infection, and bronchitis, respectively, showed no difference (2 = 0.368, P = .832). However, more patients were dissatisfied with not receiving an antibiotic when the diagnosis label was bronchitis. A total of 26% of those that were told they had bronchitis were dissatisfied with their treatment, compared with 13% and 17% for colds and viral illness, respectively, (2 = 9.380, P = .009). Binary logistic regression showed no difference in satisfaction with diagnosis for educational attainment, age, and sex (odds ratio (OR) = 1.09, 1.00, 0.98, respectively), or for satisfaction with treatment (OR = 1.1, 1.02, 1.00, respectively).

Conclusions: Provider use of benign-sounding labels such as chest cold when a patient presents for care for an acute respiratory infection may not affect patient satisfaction but may improve satisfaction with not being prescribed an antibiotic.

3. COX 2 Inhibitors May Not be Safer for the Stomach

Non-steroidal anti-inflammatory drugs are among the most commonly prescribed drugs in England and Wales. They are widely used for musculoskeletal pain but can cause serious gastrointestinal side effects, including dyspepsia, peptic ulceration, and haemorrhage, and even result in death. Cyclo-oxygenase-2 inhibitors are a selective type of non-steroidal anti-inflammatory drug licensed in the United Kingdom for symptomatic relief in osteoarthritis and rheumatoid arthritis. They were developed to provide pain relief without the gastrointestinal side effects associated with traditional non-steroidal anti-inflammatory drugs, and their use is already recommended in UK national guidelines. The current treatment options include a traditional non-steroidal anti-inflammatory drug with an ulcer healing drug or a cyclo-oxygenase-2 inhibitor alone. However, trial data to support this, especially for elderly people, are sparse.

Considerable uncertainty surrounds the long term risks associated with cyclo-oxygenase-2 inhibitors outside the trial setting. Indeed, rofecoxib has been temporarily withdrawn owing to its adverse cardiovascular profile, and the safety profile of all cyclo-oxygenase-2 inhibitors is under review. The celecoxib long term arthritis safety study, which compared celecoxib with conventional non-steroidal anti-inflammatory drugs, has been criticised on the grounds of study design, analysis, selective presentation of results, increased rates of ulcers after six months of treatment, overall higher rates of extra gastrointestinal adverse events, and lack of data on long term safety. Although other smaller short term trials have shown fewer ulcers under endoscopy in patients taking cyclo-oxygenase-2 inhibitors, it is not known how these ulcers relate to clinical endpoints.

We undertook a population based nested case-control study, using a new general practice research database to determine the comparative risk of adverse upper gastrointestinal events in patients taking different cyclo-oxygenase-2 inhibitors and conventional non-steroidal anti-inflammatory drugs in primary care between 2000 and 2004.

Cyclo-oxygenase-2 inhibitors seem no better than conventional non-selective non-steroidal anti-inflammatory drugs in terms of the risk of an adverse upper gastrointestinal event. In a nested case-control study of more than 9000 cases of first peptic ulcer or haematemesis and almost 90 000 controls from 367 general practices throughout Great Britain, Hippisley-Cox and colleagues found that the risk of adverse events was increased with all NSAIDs included, selective and non-selective. Use of ulcer healing drugs reduced the increased risk of adverse events for all NSAIDs except diclofenac.

Hippisley-Cox J, et al. Risk of adverse gastrointestinal outcomes in patients taking cyclo-oxygenase-2 inhibitors or conventional non-steroidal anti-inflammatory drugs: population based nested case-control analysis BMJ 2005;331:1310-1316

Abstract: http://bmj.bmjjournals.com/cgi/content/abstract/331/7528/1310

4. Medical Management of Partial Small-Bowel Obstruction

Partial small-bowel obstruction caused by adhesions usually is managed initially by decompressing the gastrointestinal tract with a nasogastric (NG) tube, administering intravenous fluids, prohibiting oral intake, and waiting for spontaneous resolution. Researchers in Taiwan examined a more proactive approach in 128 patients with partial small-bowel obstructions presumed to be caused by adhesions from previous abdominal surgery.

Patients were randomized to two groups: One group received standard treatment with NG tube decompression, IV fluids, and nothing by mouth. The other group received similar standard treatment plus an oral regimen, given thrice daily, that consisted of magnesium oxide to stimulate bowel movement, simethicone to accelerate gas passage, and Lactobacillus acidophilus to promote digestion of undigested food in the bowel lumen. The proportion of patients who did not require surgery was significantly higher in the intervention group than in the control group (91% vs. 76%). In addition, the mean duration of hospital stay was significantly shorter in the intervention group (1 vs. 4 days). No obvious complications from the intervention were noted.

Comment: These results seem almost too good to be true: A safe and simple regimen appeared to dramatically hasten the resolution of partial small-bowel obstruction. Limitations of the study include confirmation of the diagnosis by plain radiography only and lack of double-blinding. Additional trials to confirm these results are warranted. At the time of publication, the full text of the original article was available free of charge.

— Allan S. Brett, MD. Published in Journal Watch November 29, 2005. Source: Chen S-C et al. Nonsurgical management of partial adhesive small-bowel obstruction with oral therapy: A randomized controlled trial. CMAJ 2005 Nov 8; 173:1165-9.

5. A Home-version of the Epley Maneuvers for Positional Vertigo

Positional maneuvers to treat benign paroxysmal positional vertigo (BPPV) can be performed in the clinician's office or at home. This randomized trial from Japan included 80 patients (age range, 24-85 years) with BPPV, diagnosed on the basis of typical symptoms and a positive Dix-Hallpike maneuver. Patients underwent an Epley procedure performed in the office, either alone or supplemented by modified Epley procedures performed three times daily at home.

At one week, repeat Dix-Hallpike maneuvers were negative in 72% of patients who were treated with a single office procedure and in 90% of patients who also performed home treatment, a significant difference. Complete resolution of symptoms was reported by 77% and 88% of patients in the two groups, respectively; this difference was not statistically significant.

Comment: These results suggest that a single office Epley procedure is effective in most patients, and that the addition of home treatment might "salvage" a small number of patients who don't respond to the office procedure.

At the time of this publication, diagrams and videos of the modified Epley procedure were available free of charge: A. Radtke et al. Neurology 2004;63:150-152. http://www.neurology.org/cgi/content/full/63/1/150
A good review article by JM Furman also provides diagrams of the Dix-Hallpike maneuver and the office Epley procedure. http://content.nejm.org/cgi/content/extract/341/21/1590

— Allan S. Brett, MD. Published in Journal Watch November 11, 2005. Source: Tanimoto H et al. Self-treatment for benign paroxysmal positional vertigo of the posterior semicircular canal. Neurology 2005 Oct 25; 65:1299-300.

6. The Difficult Stick.

Some patients just have difficult peripheral IV access. Before opening the central line kit, consider wheeling the US to the bedside and help identify those hard-to-find veins.

Ultrasonography-Guided Peripheral Intravenous Access Versus Traditional Approaches in Patients With Difficult Intravenous Access. Thomas G. Costantino, MD, et al. Ann Emerg Med 2005;46:456-461

Study objective
We assess the success rate of emergency physicians in placing peripheral intravenous catheters in difficult-access patients who were unsuccessfully cannulated by emergency nurses. A technique using real-time ultrasonographic guidance by 2 physicians was compared with traditional approaches using palpation and landmark guidance.

Methods
This was a prospective, systematically allocated study of all patients requiring intravenous access who presented to 2 university hospitals between October 2003 and March 2004. Inclusion criterion was the inability of any available nurse to obtain intravenous access after at least 3 attempts on a subgroup of patients who had a history of difficult intravenous access because of obesity, history of intravenous drug abuse, or chronic medical problems. Exclusion criterion was the need for central venous access. Patients presenting on odd days were allocated to the ultrasonographic-guided group, and those presenting on even days were allocated to the traditional-approach group. Endpoints were successful cannulation, number of sticks, time, and patient satisfaction.

Results
Sixty patients were enrolled, 39 on odd days and 21 on even days. Success rate was greater for the ultrasonographic group (97%) versus control (33%), difference in proportions of 64% (95% confidence interval [CI] 39% to 71%). The ultrasonographic group required less overall time (13 minutes versus 30 minutes, for a difference of 17 [95% CI 0.8 to 25.6]), less time to successful cannulation from first percutaneous puncture (4 minutes versus 15 minutes, for a difference of 11 [95% CI 8.2 to 19.4]), and fewer percutaneous punctures (1.7 versus 3.7, for a difference of 2.0 [95% CI 1.27 to 2.82]) and had greater patient satisfaction (8.7 versus 5.7, for a difference of 3.0 [95% CI 1.82 to 4.29]) than the traditional landmark approach.

Conclusion
Ultrasonographic-guided peripheral intravenous access is more successful than traditional "blind" techniques, requires less time, decreases the number of percutaneous punctures, and improves patient satisfaction in the subgroup of patients who have difficult intravenous access.

7. Do Low-risk "Soft Rule-outs" Need a Monitored Bed?

Is It Necessary to Admit Low-Risk Patients With Suspected Acute Coronary Syndrome to Inpatient Telemetry Beds? Esther H. Chen, MD, Angela M. Mills, MD. Ann Emerg Med 2005;46:440-444.

Inhospital cardiac monitoring had been in use for more than 30 years before the American College of Cardiology published recommendations for its use in select patients in 1991. This position statement suggested that telemetry monitoring should be mandatory for the early hospital phase of patients with initially suspected acute myocardial infarction for detecting potentially life-threatening arrhythmias. Since then, the triage and treatment of acute chest pain patients has evolved such that this liberal admission policy to monitored units has been questioned. Liberal telemetry usage stresses the limited number of monitored beds, is costly, and may result in admission delays.

In 2004, the American Heart Association published guidelines recommending 12 to 24 hours of inpatient monitoring for chest pain patients with any sign of ischemia or infarction on the initial ECG and 1 evidence-based risk factor (low systolic blood pressure, rales, or exacerbation of ischemic heart disease) until acute myocardial infarction has been excluded by negative biomarker results. Theoretically, the rationale for using continuous cardiac monitoring in patients with suspected ischemia is to detect life-threatening dysrhythmias that may require emergency intervention.

Accordingly, there might be a select group of patients at such low risk for dysrhythmias or other cardiac complications that telemetry monitoring would not be clinically useful. Therefore, we searched the literature to determine whether telemetry monitoring was useful in the inpatient management of patients with potential acute coronary syndrome and whether there was a subset of patients who might be safely admitted to unmonitored beds.

The Bottom Line
A review of the available literature evaluating the clinical utility of inpatient telemetry showed that continuous cardiac monitoring played a small role in identifying patients at risk for adverse events or clinical deterioration. Chest pain patients with an initial normal or nonspecific ECG result and normal cardiac marker results and without recurrent chest pain are at low risk for adverse cardiac events, including life-threatening dysrhythmias, and therefore may not benefit from continuous cardiac monitoring. Although this is not a "zero-risk" strategy, because a few patients may develop a major adverse event, it would still be within the standard of care to admit these low-risk chest pain patients to an unmonitored unit.

8. A Fib in the ED. Just how do we manage these patients?

Analysis of Current Management of Atrial Fibrillation in the Acute Setting: GEFAUR-1 Study
Carmen del Arco, MD, et al (from Spain). Ann Emerg Med 2005;46:424-430.

Background
Atrial fibrillation constitutes a growing health care problem because of its increasing prevalence, substantial complications, and associated costs. Although general agreement exists in literature about the role of stroke prophylaxis in these patients, the optimal strategy for the management of the arrhythmia remains uncertain: cardioversion and treatment with antiarrhythmic drugs to maintain sinus rhythm (rhythm control) or just control of the ventricular rate, allowing atrial fibrillation to persist.

A number of clinical trials have been conducted to determine the optimal medical management of atrial fibrillation, but these were not acute studies; they studied patients with minimally symptomatic long-term atrial fibrillation. Additionally, some reluctance exists to follow their conclusions in routine practice that patients' clinical characteristics and conditions of work greatly vary from those of randomized clinical trials.

Importance
Emergency departments (EDs) account for a large and increasing number of visits (>102 million in United States in 1999), mainly of aged persons and patients with cardiovascular diseases, important at-risk populations for atrial fibrillation. Additionally, atrial fibrillation is the most frequently managed arrhythmia in the ED, with a prevalence of 1.1% to 3.6% of the general medical ED visits. ED practice differs greatly from the "ideal" conditions of clinical trials and constitutes an accurate reflection of routine practice in patients' clinical profile and management. Thus, the study of the patterns of management of atrial fibrillation in this setting could help to identify areas for quality assessment and management improvement in the ED routine practice.

Goals of This Investigation
The objectives of this current analysis of the Spanish Atrial Fibrillation in Emergency Medicine (GEFAUR-1: Grupo para el Estudio de la FibrilaciĆ³n Auricular en URgencias) study were to determine the current management (rhythm or rate control) of atrial fibrillation, its effectiveness, and the factors related to the election of each strategy, identifying areas for management improvement, in a representative sample of the acute-setting daily practice.

ABSTRACT
Study objective
Limited information relative to the management of atrial fibrillation in the emergency department (ED) daily practice is available. This study evaluates current management of atrial fibrillation in this setting to identify areas for practice improvement.

Methods
This was a prospective multicenter observational study carried out in 12 EDs. Adults in whom atrial fibrillation was demonstrated in an ECG obtained in the ED were included. Clinical variables and atrial fibrillation management in the ED were prospectively collected by the treating physicians using a standardized questionnaire. Patients with rapid ventricular response (>100 beats/min) were considered eligible for rate control, and patients with recent-onset episodes (<48 hours) were eligible for rhythm control.

Results
Of 1,178 patients, 41% presented with a rapid ventricular response and 21% had recent-onset episodes. Rhythm control was attempted in 42% of eligible patients, with antiarrhythmic drugs in 88% of cases (I-C drugs in 44% of patients; amiodarone in 43% of patients). Overall effectiveness of pharmacologic cardioversion was 63% (amiodarone 54.5%, flecainide 93%), whereas electrocardioversion was effective in 87.5% of cases. Rate control was performed in 68.3% of eligible patients (overall effectiveness 47.8%); digoxin was used in 67% of cases (effectiveness 45%). Both strategies were selected in 4.5% of cases, whereas no treatment for atrial fibrillation was performed in 60% of patients.

Conclusion
In our ED population, rate-control effectiveness is poor and rhythm control is not attempted in most recent-onset episodes. Methods to improve rate-control effectiveness, the selection of patients for rhythm control, and the use of electrocardioversion appear warranted.

9. Blood Cultures for Community-acquired Pneumonia??

JCAHO requires we obtain blood cultures before abx on admitted pts. Is this requirement evidence-based? Does it improve management?

Do Emergency Department Blood Cultures Change Practice in Patients With Pneumonia? Kennedy M, et al.Ann Emerg Med 2005;46:393-400

Study objective
Although it is considered standard of care to obtain blood cultures on patients hospitalized for pneumonia, several studies have questioned the utility and cost-effectiveness of this practice. The objective of this study is to determine the impact of emergency department (ED) blood cultures on antimicrobial therapy for patients with pneumonia.

Methods
We performed a prospective, observational, cohort study of consecutive adult (age =18 years) patients treated at an urban university ED between February 1, 2000 and February 1, 2001. Inclusion criteria were radiographic evidence of pneumonia, clinical evidence of pneumonia, and blood culture obtained. Blood cultures were classified as positive, negative, or contaminant based on previously established criteria. Additionally, data were collected on antimicrobial sensitivities, empiric antibiotic therapy, antibiotic changes, and reasons for changes.

Results
There were 3,926 ED visits with blood cultures obtained for any reason, of which 3,762 (96%) were available for review. Of these, 414 of 3,762 (11%) patients met pneumonia study inclusion criteria, and blood cultures identified 29 of 414 (7.0%) patients with true bacteremia. In the 414 patients, blood culture results altered therapy for 15 patients (3.6%) with suspected pneumonia, of which 11 (2.7%) patients had their coverage narrowed; only 4 (1.0%) patients had their coverage broadened because of resistance to empiric therapy. For the 11 patients with bacteremia whose therapy was not altered, culture results actually supported narrowing therapy in 8 (1.9%) cases, but this was not done.

Conclusion
Blood cultures rarely altered therapy for patients presenting to the ED with pneumonia. More discriminatory blood culture use may potentially reduce resource utilization.

Free Full-text: http://download.journals.elsevierhealth.com/pdfs/journals/0196-0644/PIIS019606440500716X.pdf

10. Chronic A Fib. A Life Sentence?

Left Atrial Radiofrequency Ablation During Mitral Valve Surgery for Continuous Atrial Fibrillation: A Randomized Controlled Trial

George Doukas, FRCSI; et al. JAMA. 2005;294:2323-2329.

Context Although left atrial radiofrequency ablation (RFA) is increasingly used for the treatment of chronic atrial fibrillation during mitral valve surgery, its efficacy to restore sinus rhythm and any resulting benefits have not been examined in the context of an adequately powered randomized trial.

Objective To determine whether intraoperative RFA of the left atrium increases the long-term restoration of sinus rhythm and improves exercise capacity.

Design, Setting, and Patients Randomized, double-blind trial performed in a single UK tertiary referral center with enrollment between December 2001 and November 2003. A total of 101 patients referred for mitral valve surgery with at least 6 months’ history of uninterrupted atrial fibrillation were assessed for eligibility; 97 were enrolled. Patients were followed up for 12 months.

Intervention Patients were randomly assigned to undergo mitral valve surgery and RFA of the left atrium (n = 49) or mitral valve surgery alone (controls; n = 48).

Main Outcome Measures The primary outcome measure was presence of sinus rhythm at 12 months; secondary measures were patient functional status and exercise capacity (assessed by shuttle-walk test), left atrial contractility, and left atrial and left ventricular dimension and function and plasma levels of B-type natriuretic peptide.

Results At 12 months, sinus rhythm was present in 20 (44.4%) of 45 RFA patients and in 2 (4.5%) of 44 controls (rate ratio, 9.8; 95% CI, 2.4-86.3; P<.001). Restoration of sinus rhythm in the RFA group was accompanied by a greater improvement in mean (SD) shuttle-walk distance compared with controls (+94 [102] m vs +48 [82] m; P = .003) and a greater reduction in the plasma level of B-type natriuretic peptide (–104 [87] fmol/mL vs –51 [82] fmol/mL; P = .03). Patients randomized to receive RFA had similar rates of postoperative complications and deaths as control patients.

Conclusions Radiofrequency ablation of the left atrium during mitral valve surgery for continuous atrial fibrillation significantly increases the rate of sinus rhythm restoration 1 year postoperatively, improving patient exercise capacity. On the basis of its efficacy and safety, routine use of RFA of the left atrium during mitral valve surgery may be justified.

11. Hypertension Increases risk of Cognitive Decline in Elderly

December 6, 2005

LONDON (Agence de Presse Medicale for Reuters Health) - Uncontrolled hypertension appears to increase the risk of cognitive decline in the elderly, especially verbal fluency, according to a study published in Neuropsychology.

Christopher Brady and colleagues at Harvard Medical School and the Boston University School of Public Health examined the influence of age and hypertensive status on several cognitive tests via multiple regression in 357 men without dementia, with stable hypertensive status over 3 years and no comorbidities.

The men, who lived in the community and averaged 67 years old, were a subset of the 2,280 men in the Veteran Affairs Normative Aging Study, a longitudinal study that started in 1963 and added neuropsychological tests in 1993.

The findings showed that age was negatively associated with performance on all but the Digit Span Backward test. Older men in the sample with uncontrolled hypertension did significantly worse on specific tests of verbal fluency (generating words in a given category) and immediate recall of a word list (short-term memory).

In particular, with increasing age, uncontrolled hypertensives exhibited significantly larger decrements on category fluency (2.4 times greater) and immediate recall (1.3 times greater), compared with normotensives.

By the age of 80, men with uncontrolled hypertension could generate seven fewer words in a given category and recall about one and a half fewer words on average, than the other 80-year-old men in the study, the researchers said.

"The findings suggest that uncontrolled hypertension produces specific cognitive deficits beyond those attributable to age alone," they added.

The results are also consistent with other studies that suggest anti-hypertensive drugs do not hurt cognition -- men with controlled hypertension using antihypertensive drugs did as well as men without hypertension.

The researchers speculate that hypertension somehow exacerbates the normal effects of age on the frontal lobes, making it even harder to quickly retrieve information such as words.

The authors raise the possibility that the proportion of cognitive problems among older people with uncontrolled hypertension in the general population may actually be larger than seen in the study, because this sample used healthy men with no other health problems.

"Because a large proportion (37%) of older adults have uncontrolled hypertension and, furthermore, because hypertension prevalence increases, whereas hypertension control decreases, with increasing age, a substantial proportion of older adults may exhibit exacerbated age-related cognitive deficits that may be under-recognised in both research and clinical settings," they conclude.

Neuropsychology 2005;19:770-777.

12. C. difficile Causing Severe Diarrhea in Low-risk Patients

December 2, 2005

NEW YORK (Reuters Health) - Clinicians should be alert to cases of severe Clostridium difficile-associated disease (CDAD) in the absence of traditional risk factors, such as recent hospitalization or antimicrobial use, according to an article in the Morbidity and Mortality Weekly Report for December 2.

Following several reported cases of serious CDAD in otherwise healthy patients, the Pennsylvania and Philadelphia Departments of Health and the Centers for Disease Control and Prevention requested reports of peripartum and community-acquired CDAD.

Ten peripartum cases of CDAD were reported from Pennsylvania, New Hampshire, New Jersey and Ohio, and 23 community-acquired CDAD cases were reported from the Philadelphia area, with onset dates ranging from February 2003 to June 2005.

According to lead author Dr. E. Chernak with the Philadelphia Department of Public Health and colleagues, eight patients reported no exposure to antimicrobial agents within 3 months before CDAD onset. Seven cases occurred in patients who had close contact with a person with diarrheal illness.
Eight patients had bloody diarrhea, and 15 required hospitalization or an emergency department visit. Relapse occurred in 13 cases.

"Certain features of CDAD that have been uncommon in the past, such as close-contact transmission, high recurrence rate, young patient age, bloody diarrhea, and lack of antimicrobial exposure, might be changing," the authors maintain.

They recommend that patients with diarrhea lasting longer than 3 days or with bloody diarrhea or high fever should seek medical attention.

"The findings underscore the fact that antimicrobial exposure is not benign," the authors add, "and that judicious antimicrobial use in all health-care settings should continue to be emphasized."

Mor Mortal Wkly Rep CDC Surveill Summ 2005;54:1201-1205.

Wednesday, November 02, 2005

Lit Bits: November 2, 2005

From the recent medical literature...

1. The Case of the Febrile Injection Drug User.

IV drug users who report having a fever with no localizing findings pose a particular diagnostic problem. Infective endocarditis will be diagnosed in what percent of IV drug users hospitalized with fever?

The Answer is:

Infective endocarditis will be diagnosed in up to 20% of injection-drug users hospitalized with fever (NEJM, November 3, 2005, pg. 1949).

2. Elderly with acute coronary syndrome less likely to get recommended care

October 26, 2005

NEW YORK (Reuters Health) - Elderly patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) are less likely to receive recommended care, a new observational multicenter study shows.

However, Dr. Karen P. Alexander of the Duke Clinical Research Institute in Durham, North Carolina and colleagues report, patients over 75 who did receive treatment that followed American College of Cardiology/American Heart Association (ACC/AHA) guidelines had the same reduced risk of death as their younger counterparts.

A number of past studies have found frequent underuse of cardiac drugs in elderly NSTE ACS patients, Dr. Alexander and her team report in the October 18th issue of the Journal of the American College of Cardiology.

To determine if the new ACC/AHA guidelines may have changed this pattern, the researchers compared care in 56,963 patients with NSTE ACS treated at 443 US hospitals. The patients were stratified into four groups: younger than 65, 65 to 74, 75 to 84, and 85 or older. Thirty-five percent of the patients were 75 or older, while 11% were 85 or older.

The new guidelines, Dr. Alexander and her team note, do not offer different recommendations based on age, "apart from encouraging attention to comorbidities, preferences, and appropriate dosing of medications in elderly patients."

Even after controlling for contraindications and comorbidities, the researchers found, the use of several therapies remained less frequent in older patients. Elderly patients were less likely to receive antiplatelet and antithrombin therapy in the first 24 hours of care, less likely to receive invasive care, and less likely to be discharged on lipid-lowering agents and clopidogrel.

Specifically, while 92% of patients older than 85 had positive cardiac markers, only 29.9% were given clopidogrel and 12.8% received platelet glycoprotein IIb/IIIa inhibitors. After age 65, less than 50% received invasive care, and that number fell to 11.2% after age 85.

"A formal test for interaction between treatment and age was significant because of the larger difference in mortality between younger and older patients given fewer therapies compared with those given all therapies," the researchers write. "This indicates a similar or greater impact of treatment on outcomes in elderly patients."

Dr. Alexander and her team conclude by noting that clinicians may be "understandably cautious" about using newer treatments and more invasive care in their older patients at high risk.

In an editorial accompanying the study, Drs. H. Vernon Anderson of the University of Texas Health Science Center in Houston and Richard G. Bach of Washington University Medical Center in St. Louis argue that physicians should begin to look at elderly ACS patients in terms of opportunities rather than risks.

"The opportunity score would give an estimate of the benefit to be gained by a treatment or group of treatments," they explain. "Patients with higher baseline risks from the underlying disease, such as the elderly, would have higher opportunity scores for benefit, even allowing for some of the greater risks from the treatment."

J Am Coll Cardiol 2005;46:1479-1489

3. New coma measurement system validated

October 26, 2005. NEW YORK (Reuters Health) - A group of neurologists from the Mayo Clinic College of Medicine in Rochester, Minnesota has developed and validated a new coma scale, which they say is a reliable and easy-to-use tool that has the potential to replace the Glasgow Coma Scale (GCS).

The so-called FOUR (Full Outline of UnResponsive) Score consists of four components -- eye, motor, brainstem, and respiration -- to determine coma depth. A score of four represents normal functioning in each category, while a score of zero indicates nonfunctioning.

Dr. Eelco F. M. Wijdicks, a Mayo Clinic neurologist and inventor of the FOUR score, said the widely adopted GCS has "many drawbacks" and misses key elements of a neurological exam of comatose patients. The inability of the GCS to test brainstem reflexes is an "important shortcoming," he added.

Dr. Wijdicks and colleagues prospectively studied the FOUR score in 120 ICU patients with diverse acute neurological conditions (not just trauma) and compared it with the GCS.

They report in the October issue of the Annals of Neurology that the agreement among raters -- neuroscience nurses, neurology residents, and neurointensivists -- was "good to excellent." The interrater reliability of the FOUR score and the GCS was of equal magnitude, according to the researchers.

In the experience of Dr. Wijdicks and colleagues, "the FOUR score provides greater neurological detail than the GCS, recognizes a locked-in syndrome, and is superior to the GCS due to the availability of brainstem reflexes, breathing patterns, and the ability to recognize different stages of herniation."

The team also reports that in this study the likelihood of dying in the hospital was higher for the lowest total FOUR score when compared with the lowest total GCS score.

"With the FOUR Score, in contrast to the GCS, we can in a far more detailed way provide the family information on the patient's status and what the outcome will be," Dr. Wijdicks said.

Ann Neurol 2005;58:585-593.

4. Salt-water Cellulitis.

A patient presents to the ED with a cellulitis resulting from exposure of a laceration to salt water. What organism is of concern? What is the treatment?

Vibrio vulnificus should be considered. Standard antimicrobial therapy is with doxycycline (NEJM, Vol. 350, pg. 908).

5. When should we thrombolyse patients with pulmonary embolism?

A systematic review of the literature . T Harris and S Meek. Emergency Medicine Journal 2005;22: 766-771

ABSTRACT
The early mortality in pulmonary embolism (PE) is largely predicted by the associated cardiovascular response, with progressive right ventricular failure, hypotension, shock, and circulatory arrest being associated with increasing mortality. Thrombolysis may improve the prognosis of PE associated with these varying degrees of circulatory collapse, but has no place in the treatment of small emboli with no cardiovascular compromise, as it carries a significant risk of haemorrhage. This review sets out to guide the emergency physician in deciding which patients with PE may benefit from thrombolysis.

6. Cricoid pressure in emergency rapid sequence induction

John Butler, Consultant and Ayan Sen, Clinical Fellow. Emergency Medicine Journal 2005;22:815-816

ABSTRACT
A short cut review was carried out to establish cricoid pressure reduced aspiration during rapid sequence induction (RSI) of anaesthesia. A total of 241 papers were identified using the reported search, of which three represented 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 these best papers are tabulated. There is little evidence to support the widely held belief that the application of cricoid pressure reduces the incidence of aspiration during a rapid sequence intubation.

7. U.S. panel urges pertussis vaccine for adults

October 28, 2005. By Paul Simao

ATLANTA (Reuters) - U.S. adults should be vaccinated against pertussis to stop its spread among infants, who are especially vulnerable to the infection, a federal advisory panel recommended on Wednesday.

The Centers for Disease Control and Prevention's advisory committee on immunization unanimously approved the recommendation amid signs that pertussis is becoming more common, especially among teenagers.

Nearly 19,000 cases were reported across the United States in 2004, a sharp increase from previous years.

"This vote will help curtail that trend and help us stop the spread of pertussis," said Dr. Bill Schaffner, an infectious diseases expert and a member of the CDC advisory committee, which met in Atlanta.

Health experts advise that infants receive the DTP vaccine at 2-month intervals after birth, followed by a fourth dose about 1 year later and a booster between the ages of 4 and 6 years.

Immunity, however, only lasts between 5 and 10 years.

Prompted by rising numbers of cases among middle school and high school students, the CDC advisory committee recently recommended that adolescents between the ages of 11 and 18 receive the Tdap vaccine, which protects against tetanus, diphtheria and pertussis, in place of the previously recommended diphtheria tetanus booster.

It extended that recommendation on Wednesday to include adults to protect vulnerable newborns from exposure to an infected parent or other adult.

The recommendation, if followed, could also help reduce the number of adults with chronic cough caused by pertussis, Schaffner said. The Tdap vaccine, however, is not licensed for use in seniors.

8. Intensive statin therapy should begin soon after ACS, study shows

October 28, 2005. NEW YORK (Reuters Health) - Prompt, intensive statin therapy in patients with acute coronary syndromes (ACS) leads to a greater reduction in clinical events at 30 days than does standard statin therapy, researchers report in the October 18th issue of the Journal of the American College of Cardiology.

The rapidity of the response, investigator Dr. Christopher P. Cannon told Reuters Health, "surprised all of us, but the implication is that patients hospitalized for ACS need to leave the hospital on high-dose statin -- since there is such early benefit."

As he commented, "It is a big change."

Dr. Cannon, with the TIMI Study Group at Harvard Medical School, Boston, and colleagues examined data from the Pravastatin or Atorvastatin Evaluation and Infection Therapy -- Thrombolysis in Myocardial Infarction 22 trial, known as PROVE IT - TIMI 22. In that study, more than 4,100 patients with ACS were randomized to standard therapy with pravastatin 40 mg or intensive therapy with atorvastatin 80 mg.

The original study results showed that intensive therapy improved outcomes at 2 years. In the current analysis, the researchers "sought to evaluate the timing of this benefit by examining the very early clinical benefit as well as the late effects of intensive statin therapy."

At 30 days, the composite endpoint of death, MI or rehospitalization for recurrent ACS was reached by 3% of the intensive therapy patients and by 4.2% of those on standard therapy, for a hazard ratio of 0.72 (p = 0.046).

Among stable patients, the corresponding endpoint rates were 9.6% and 13.1% (HR = 0.72; p = 0.003).

In light of these findings, continued Dr. Cannon, "we start immediately with the highest dose of a strong statin, and then monitor for safety, but also then afford the patient the very rapid clinical benefit in avoiding a second heart attack."

He added, "We used to take a slower approach, check the fasting blood tests, and slowly up-titrate the statin dose. Now we do the reverse."

In summary, he and his colleagues conclude in their paper, "Treatment of patients with ACS should begin in-hospital with high-dose intensive statin therapy to achieve these early clinical benefits and should be continued long-term."

J Am Coll Cardiol 2005;46:1405-1410.

9. Esophageal Intubations.

Amer J Emerg Med 2005;23: 754-758 Aaron E. Bair, MDa, Erik G. Laurin, MDa, Brandi J. Schmitt, MSb

Abstract
Introduction
Early detection of an inadvertent esophageal intubation can be particularly challenging in cases when the current standard of care, carbon dioxide detection, is unreliable. We sought to determine the sensitivity and specificity of an inexpensive and portable device, the gum elastic bougie (Eschmann Tracheal Tube Introducer, SIMS Portex, Inc, Keene, NH), as an endotracheal tube placement confirmation device.

Methods
We conducted a prospective blinded trial in 20 human cadavers. Each cadaver was randomized to a mixed series of 5 esophageal and 5 tracheal intubations. Each intubation was assessed with the bougie twice, once by a novice to the technique, and once by an assessor who was constant through the trial. Assessors used the bougie to feel for clicks of the tracheal rings and to appreciate hang up of the bougie as it was advanced into the smaller airways. Absence of these findings was presumed to indicate an esophageal intubation. Actual placement was confirmed by bronchoscopy. Each assessor made an independent determination of tube location. Descriptive statistics were used to summarize the data.

Results
Overall, 93% (95% confidence interval [CI], 86%-97%) of tracheal placements were correctly identified. The constant assessor was able to correctly identify 98% (95% CI, 90%-100%). Tracheal rings were detected in 92% of tracheal placements. Ring clicks were 95% specific for tracheal intubation. Hang up was reported in 100% of tracheal placements with a specificity of 84%. Overall, 95% (95% CI, 88%-98%) of esophageal intubations were detected. The constant assessor detected 100% of esophageal intubations.

Conclusion
In the cadaver model used in this study, the gum elastic bougie (Eschmann Tracheal Tube Introducer) shows promise as an endotracheal tube confirmation device.

10. The San Francisco Syncope Rule vs physician judgment and decision making

Quinn, Stiell, et al.Amer J Emerg Med 2005; 23:782-786

Syncope is a transient loss of consciousness with a return to preexisting neurologic function. A common problem, 1 of 4 people will faint during their lifetime, and 1% to 2% of all emergency department (ED) visits and hospital admissions are related to a transient loss of consciousness [1-4].

Patients with syncope create a difficult dilemma for physicians. Most causes are benign, but occasionally, it is a symptom associated with significant morbidity and mortality. Some patients will require emergent hospitalization for workup and treatment of life-threatening or potentially life-threatening causes, others should get outpatient evaluation, whereas some patients need no further evaluation.

It has been suggested that the use of hospitalization for patients with syncope is inefficient and highly variable [5-10]. Many things can cause syncope and the potential diseases that cause it span multiple specialties, making it difficult to develop an optimal disposition for these patients. Accordingly, a survey of physicians revealed that the disposition of patients with syncope was the second most common decision problem for North American physicians [11]. A highly sensitive and specific decision rule that would aid and improve physician decision making could have the potential to significantly reduce health care costs and improve efficiency and patient care.

The San Francisco Syncope Study is a prospective multiphase study. Phase 1 involved derivation of a decision rule using 684 patients to help predict patients at risk for acute outcomes. Variables were assessed for their interobserver agreement and univariate association with acute outcomes. The final San Francisco Syncope Rule (SFSR), derived from recursive partitioning of the most important variables, was found to be highly sensitive and specific (Fig. 1) [12]. To justify the time and effort involved in validating and disseminating a decision rule, it is important to know if the rule can improve upon the diagnostic accuracy and reliability of unstructured physician judgment and eventual decision making. We sought to determine whether the SFSR would have performed better than physician decision making during phase 1 of the study.

Abstract
Objective
To compare a clinical decision rule (San Francisco Syncope Rule [SFSR]) and physician decision making when predicting serious outcomes in patients with syncope.

Methods
In a prospective cohort study, physicians evaluated patients presenting with syncope and predicted the chance (0%-100%) of the patient developing a predefined serious outcome. They were then observed to determine their decision to admit the patient. All patients were followed up to determine whether they had a serious outcome within 7 days of their emergency department visit. Analyses included sensitivity and specificity to predict serious outcomes for low-risk patients and comparison of areas under the receiver operating characteristic curve for the decision rule, physician judgment, and admission decisions.

Results
During the study period, there were 684 visits for syncope with 79 visits resulting in serious outcomes. The area under the receiver operating characteristic curve was 0.92 (95% confidence interval [CI], 0.88-0.95) for the SFSR compared with physician judgment 0.89 (95% CI, 0.85-0.93) and physician decision making 0.83 (95% CI, 0.81-0.87). Physicians admitted 28% of patients in a low-risk group, with a median length of stay of 1 day (interquartile range, 1-2.5 days). The SFSR had the potential to absolutely decrease admissions by 10% in this low-risk group and still predict all serious outcomes.

Conclusions
Physician judgment is good when predicting which patients with syncope will develop serious outcomes, but contrary to their judgment, physicians still admit a large number of low-risk patients. The SFSR performs better than current physician performance and has great potential to aid physician decision making.

11. Use of spiral CT contrast angiography and US to exclude the diagnosis of PE in the ED

Anderson, Stiell, Wells, et al. J Emerg Med 2005;29:399-404.

The diagnosis of pulmonary embolism remains problematic. The clinical signs and symptoms of this diagnosis are mimicked by other disorders and the diagnostic test, ventilation-perfusion lung scanning, is both insensitive and non-specific (1,2). In recent years much attention has been directed towards the use of spiral computed tomography (CT) contrast angiography for the investigation of patients with suspected pulmonary embolism. However, the accuracy of spiral CT contrast angiography is uncertain and its sensitivity may be as low as 70%.

Despite its relatively poor sensitivity, spiral CT contrast angiography is used in many centers as the sole imaging test to exclude the diagnosis of pulmonary embolism. The purpose of this study was to determine the safety of a management strategy to exclude the diagnosis of pulmonary embolism in high-risk patients presenting to the Emergency Department on the basis of a negative spiral CT contrast angiography scan and negative lower extremity venous ultrasound imaging.

Abstract
Spiral computed tomography (CT) contrast angiography is a promising imaging modality for the diagnosis of pulmonary embolism but the negative predictive value of this test remains controversial. We performed a multi-center prospective cohort study to determine the safety of relying on a negative spiral CT contrast angiography scan to exclude pulmonary embolism. Patients presenting to the Emergency Departments of three tertiary care institutions with clinically suspected pulmonary embolism were potentially eligible for the study. Patients underwent a clinical evaluation to categorize pretest probability into low, moderate, and high categories, and had D-dimer testing performed. Patients at low pretest probability with normal D-dimer were considered to have pulmonary embolism excluded.

The remaining patients underwent spiral CT contrast angiography scan of the pulmonary arterial circulation and bilateral venous ultrasound of the proximal leg veins. Patients who were confirmed to have pulmonary embolism or deep vein thrombosis were treated with anticoagulant therapy. Patients in whom the diagnosis of pulmonary embolism was excluded did not receive anticoagulant therapy and were followed for a 3-month period for the development of venous thromboembolic complications.

Eight hundred fifty-eight (858) patients were enrolled in this study. Three-hundred sixty-nine (369) patients had low pretest probability and negative D-dimer results and no further diagnostic tests were performed. None of these patients subsequently developed venous thromboembolic complications (0%, 95% confidence interval [CI] 0% to 1.0%). The remaining 489 were referred for spiral CT contrast angiography scan and ultrasound.

Sixty-seven patients were confirmed to have pulmonary embolism and an additional 15 patients with negative CT scans had proximal deep vein thrombosis (DVT) on ultrasound for a total prevalence of venous thromboembolism of 82/489 (16.8%). Two of 409 patients who had pulmonary embolism excluded in the initial evaluation phase developed proximal venous thromboembolism (0.5%; 95% CI 0% to 1.8%) in the 3-month follow-up period. These findings suggest that the combination of a negative spiral CT contrast angiography scan and normal venous ultrasound imaging safely excludes the diagnosis of pulmonary embolism in the Emergency Department setting.

12. Clinical decision rules and cervical spine injury in an elderly patient: A word of caution

Thomas B. Barry, MD, Robert M. McNamara, MD. J Emerg Med 2005;29:433-436

Abstract
We report a case of a clinically significant cervical spine fracture in an elderly patient without midline cervical tenderness. Application of the NEXUS rule by the treating physicians ruled out the need for radiography. However, knowledge of the Canadian C-spine rule and clinical judgment prompted obtaining a three-view trauma series of the cervical spine and, when the patient's pain increased, a computed tomography scan of the cervical spine. A type III fracture of the dens was found. In review of the case it was recognized that application of the NEXUS rule for this patient was problematic regarding the assessment of mental status. Specifically, the treating physicians did not strictly adhere to the detailed explanations attached to the NEXUS criteria regarding mental status. Clinicians may wish to preferentially apply the Canadian rule for patients over the age of 64 years.

The treating physicians for this patient concluded that the NEXUS criteria indicated no need for CSR in this patient. In this case, the physicians did not go beyond the Glasgow Coma Scale, orientation, and general impression to determine 'normal alertness' in the application of NEXUS. Of note, the specific explanation attached to NEXUS for this item is as follows: "An altered level of alertness can include any of the following: 1) Glasgow Coma Scale of 14 or less; b) disorientation to person, place, time, or events; c) inability to remember three objects at 5 minutes; d) delayed or inappropriate response to external stimuli; or e) other."

The treating physicians for this patient did not address three-item recall at 5 min or complete a detailed assessment of the mental status. In an elderly patient, the NEXUS broad category of 'other' could presumably mean a complete mental status examination given the difficulty in recognizing cognitive defects without such testing. This report suggests that elderly patients should routinely undergo more formal mental status testing in the application of the NEXUS criteria. On the other hand, the Canadian rule with its age criteria eliminates the need for such an approach for patients over the age of 64 years, as they will all require CSR. Given the imprecise definition of altered alertness under NEXUS, the Canadian rule may be preferable for the elderly.

For the original canadian study, seeStiell IG, Wells GA, Vandemheen K, et al.. The Canadian C-spine Radiography Rule for alert and stable trauma patients. JAMA. 2001;286:1841-1848.

13. Oral anticoagulation can safely be self managed

Fitzmaurice et al BMJ 2005;331:1057

Appropriately trained, patients taking oral anticoagulants long term can safely and effectively use a point of care device to manage their own anticoagulation. In a multicentre open randomised trial of more than 600 patients taking warfarin, Fitzmaurice and colleagues found that the percentage of time spent within the therapeutic range and the incidence of adverse events were similar in patients who self managed and those who received routine care provided by anticoagulation clinics. The intervention also improved management of patients with initially poor control.

Abstract: http://bmj.bmjjournals.com/cgi/content/abstract/331/7524/1057

14. Vaccinating children against pneumococcal disease protects older adults too

In 2000, the United States authorities licensed a 7 valent pneumococcal vaccine (PCV 7) for children younger than 5 years. The incidence of invasive pneumoccocal disease in this age group fell quickly, but the benefits also extended to older US citizens. Active surveillance across eight distinct geographical areas shows that the incidence of invasive diseases, such as pneumonia, meningitis, and bacteraemia of unknown origin, has continued to fall among elderly US citizens, and has now reached the government target of 42 cases per 100 000 for the over 65s.

Researchers estimate that in 2002 and 2003, there were 12 500 fewer cases of invasive disease and 1100 fewer deaths among elderly US citizens compared with the two years before the vaccine was introduced. Adults aged between 75 and 84 years benefited most. In this age group the incidence of invasive pneumoccocal disease in 2002-3 was 35% lower than the corresponding incidence in 1998-9.

The authors think it likely that the new children's vaccine is responsible for these trends. An analysis that stratified invasive disease by serotype showed that most of the overall decline among elderly people was accounted for by the serotypes in the childhood vaccine. Disease caused by other serotypes remained stable.

JAMA 2005;294: 2043-51.

15. Drug-Resistant Avian Flu Virus Reported

The H5N1 avian flu virus has now spread from Asia to Europe. The virus is already a great threat to the world’s poultry industry, but the greater threat is that it will mutate, enabling easy infection and spread among humans. The only defenses against a new pandemic are immunization and antiviral treatment.

In vitro testing has shown that most H5N1 isolates are sensitive to the antiviral drug oseltamivir (Tamiflu). This has led many countries to stockpile the drug (for example, the U.K. has allocated funds to obtain enough to treat over 20% of its population). Flu viruses mutate readily, however, leading to concern that drug resistance could rapidly develop in an epidemic.

An international team reports that a 14-year-old Vietnamese girl infected with the H5N1 virus, and treated for 3 days with oseltamivir, developed resistance to the drug. Fortunately, the girl recovered. When ferrets were infected with the resistant virus, oseltamivir was ineffective. The oseltamivir-resistant strains of the virus were, however, easily killed by zanamivir (Relenza), in vitro and in the ferrets.

Comment: This report is discouraging, though not surprising. It calls into question the public-health value of investing in huge stockpiles of oseltamivir. Although the authors argue that their data suggest it might be useful to stockpile zanamivir, the data provide no reason to believe that resistance to that drug would not develop just as rapidly.

— Anthony L. Komaroff, MD; Published in Journal Watch November 4, 2005
Source: Le QM et al. Isolation of drug-resistant H5N1 virus. Nature 2005 Oct 20; 437:1108.

16. Reliability of Urine Collection in Young Children

The gold standard for diagnosis of urinary tract infection (UTI) is urine culture. Because bag-collected urine culture specimens are unreliable in young children, catheter specimens are most often used (or at least recommended) for children who are not toilet trained. However, catheter specimens can be difficult to obtain, can traumatize the child and family, and can introduce infection. These researchers sought to determine whether urinalysis of bag specimens can be used to screen for UTIs.

Paired bag and catheter specimens were collected from 303 non–toilet-trained children (age, <3 years) who presented to an emergency department with signs or symptoms suggestive of UTI (e.g., fever of unknown source, dysuria, foul-smelling urine). A positive urinalysis was defined as more than five white blood cells per high-power field on microscopic examination, or greater than trace leukocyte esterase or positive nitrite on dipstick testing. Culture of urine obtained by catheterization served as the gold standard. According to dipstick testing, urinalysis of the bag specimen was significantly more sensitive than urinalysis of the catheter specimen (0.85 vs. 0.71).

Comment: The authors conclude that selective catheterization (i.e., only if urinalysis of a bag specimen is positive) is appropriate in non–toilet-trained children with low likelihood of having a UTI (e.g., febrile children without UTI symptoms, recurrent UTIs, reflux, or impaired renal function). This strategy is consistent with American Academy of Pediatrics guidelines, which recommend that, when urinalysis is negative, clinicians may follow the clinical course without initiating antimicrobial therapy. An editorialist argues that the key is deciding which children do, in fact, have low likelihood of UTI.

— Robert A. Dershewitz, MD, MSc. Published in Journal Watch November 4, 2005

Source: McGillivray D et al. A head-to-head comparison: "Clean-void" bag versus catheter urinalysis in the diagnosis of urinary tract infection in young children. J Pediatr 2005 Oct; 147:451-6; Wald ER. To bag or not to bag. J Pediatr 2005 Oct; 147:418-20.