Lit Bits: Jan 14, 2012

From the recent medical literature...

1. Serial Changes in Highly Sensitive Troponin I Assay and Early Diagnosis of Myocardial Infarction

Keller T, et al. JAMA 2011;306(24):2684-2693.

Context: Introduction of highly sensitive troponin assays into clinical practice has substantially improved the evaluation of patients with chest pain.

Objective: To evaluate the diagnostic performance of a highly sensitive troponin I (hsTnI) assay compared with a contemporary troponin I (cTnI) assay and their serial changes in the diagnosis of acute myocardial infarction (AMI).

Design, Setting, and Patients: A total of 1818 patients with suspected acute coronary syndrome were consecutively enrolled at the chest pain units of the University Heart Center Hamburg, the University Medical Center Mainz, and the Federal Armed Forces Hospital Koblenz, all in Germany, from 2007 to 2008. Twelve biomarkers including hsTnI (level of detection, 3.4 pg/mL) and cTnI (level of detection, 10 pg/mL) were measured on admission and after 3 and 6 hours.

Main Outcome Measures: Diagnostic performance for AMI of baseline and serial changes in hsTnI and cTnI results at 3 hours after admission to the emergency department.

Results: Of the 1818 patients, 413 (22.7%) were diagnosed as having AMI. For discrimination of AMI, the area under the receiver operating characteristic (ROC) curve was 0.96 (95% CI, 0.95-0.97) for hsTnI on admission and 0.92 (95% CI, 0.90-0.94) for cTnI on admission. Both were superior to the other evaluated diagnostic biomarkers. The use of hsTnI at admission (with the diagnostic cutoff value at the 99th percentile of 30 pg/mL) had a sensitivity of 82.3% and a negative predictive value (for ruling out AMI) of 94.7%. The use of cTnI (with the diagnostic cutoff value at the 99th percentile of 32 pg/mL) at admission had a sensitivity of 79.4% and a negative predictive value of 94.0%. Using levels obtained at 3 hours after admission, the sensitivity was 98.2% and the negative predictive value was 99.4% for both hsTnI and cTnI assays. Combining the 99th percentile cutoff at admission with the serial change in troponin concentration within 3 hours, the positive predictive value (for ruling in AMI) for hsTnI increased from 75.1% at admission to 95.8% after 3 hours, and for cTnI increased from 80.9% at admission to 96.1% after 3 hours.

Conclusions: Among patients with suspected acute coronary syndrome, hsTnI or cTnI determination 3 hours after admission may facilitate early rule-out of AMI. A serial change in hsTnI or cTnI levels from admission (using the 99th percentile diagnostic cutoff value) to 3 hours after admission may facilitate an early diagnosis of AMI.

2. Orthopaedic surgeons: as strong as an ox and almost twice as clever? Multicentre prospective comparative study

Subramanian P, et al. BMJ 2011;343:d7506

Introduction: A humorous anaesthetic colleague recently repeated the following popular saying while an operating table was being repaired with a mallet: “typical orthopaedic surgeon—as strong as an ox but half as bright.” Making fun of orthopaedic surgeons is a popular pastime in operating theatres throughout the country. This pursuit has recently spread to the internet; a humorous animation entitled “orthopedia vs anesthesia” had received more than half a million hits at the time of writing.1 Several comparisons of orthopaedic surgeons to primates have been published, and the medical literature contains suggestions that orthopaedic surgery requires brute force and ignorance.2 3 4

The stereotypical image of the strong but stupid orthopaedic surgeon has not been subject to scientific scrutiny. Previous studies have shown that the average hand size of orthopaedic surgeons is larger than that of general surgeons.2 3 However, a search of the worldwide scientific literature found no studies assessing the strength or intelligence of orthopaedic surgeons. In the absence of a cohort of willing oxen as a control group, and given that the phrase is popular with anaesthetists, we designed this study to compare the mean grip strength of the dominant hand and the intelligence test score of orthopaedic surgeons and anaesthetists..

Abstract: Objective: To compare the intelligence and grip strength of orthopaedic surgeons and anaesthetists.

Design: Multicentre prospective comparative study. Setting: Three UK district general hospitals in 2011.

Participants: 36 male orthopaedic surgeons and 40 male anaesthetists at consultant or specialist registrar grade.

Main outcome measures: Intelligence test score and dominant hand grip strength.

Results: Orthopaedic surgeons had a statistically significantly greater mean grip strength (47.25 (SD 6.95) kg) than anaesthetists (43.83 (7.57) kg). The mean intelligence test score of orthopaedic surgeons was also statistically significantly greater at 105.19 (10.85) compared with 98.38 (14.45) for anaesthetists.

Conclusions: Male orthopaedic surgeons have greater intelligence and grip strength than their male anaesthetic colleagues, who should find new ways to make fun of their orthopaedic friends.

Full-text (free): http://www.bmj.com/content/343/bmj.d7506

3. Diagnostic Accuracy of Pulmonary Embolism Rule-Out Criteria: A Systematic Review and Meta-analysis

Singh B, et al. Ann Emerg Med. 2012; in press

Study objective: To perform a systematic review and meta-analysis to define the diagnostic performance of pulmonary embolism rule-out criteria (PERC) in deferring the need for D-dimer testing to rule out pulmonary embolism in the emergency department (ED).

Methods: We searched EMBASE, MEDLINE, Scopus, Web of Knowledge, and all the evidence-based medicine reviews that included the Cochrane Database of Systematic Reviews through August 14, 2011, and hand searched references in potentially eligible articles and conference proceedings of major emergency medicine organizations for the previous 2 years. We selected studies that reported diagnostic performance of PERC, reported original research, and were conducted in the ED, with no language restrictions. Two investigators independently identified eligible studies and extracted data. We used contingency tables to calculate sensitivity, specificity, and likelihood ratios.

Results: We found 12 qualifying cohorts (studying 13,885 patients with 1,391 pulmonary embolism diagnoses), 10 prospective and 2 retrospective, from 6 countries. Pooled sensitivity, specificity, positive likelihood ratios, and negative likelihood ratios for 10 included studies were 0.97 (95% confidence interval [CI] 0.96 to 0.98), 0.23 (95% CI 0.22 to 0.24), 1.24 (95% CI 1.18 to 1.30), and 0.17 (95% CI 0.13 to 0.23), respectively. Significant heterogeneity was observed in specificity (I2=97.2%) and positive likelihood ratio (I2=84.2%).

Conclusion: The existing literature suggests consistently high sensitivity and low but acceptable specificity of the PERC to rule out pulmonary embolism in patients with low pretest probability.

_______________________

The related Reuters article can be found here: http://www.medscape.com/viewarticle/756136

For dissenting evidence, see, for example, Hugli O, et al. The pulmonary embolism rule-out criteria (PERC) rule does not safely exclude pulmonary embolism. J Thromb Haemost. 2011;9:300-4. Abstract: http://www.ncbi.nlm.nih.gov/pubmed/21091866

About this study, Singh et al explain: “Two of the included studies (Hugli et al and Righini et al) report a higher frequency of missed pulmonary embolism and have raised concern about the reliability of PERC. However, their higher failure rate likely results from the higher pulmonary embolism prevalence observed in their European settings. The threshold for pulmonary embolism diagnostic imaging in the United States is substantially lower than that in Europe, presumably because of the higher litigation risk. The PERC rule was developed for use in low probability settings.”

See too Hennessey A, et al. A Patient with a Large Pulmonary Saddle Embolus Eluding Both Clinical Gestalt and Validated Decision Rules. Ann Emerg Med 2012; in press. Abstract: http://www.annemergmed.com/article/S0196-0644(11)01801-4/abstract

See also a helpful essay reviewing PE by Rick Bukata at Emergency Physicians Monthly: http://www.epmonthly.com/columns/in-my-opinion/pe-still-a-challenging-diagnosis/

4. Modest Public Health Impact of Nontargeted Human Immunodeficiency Virus Screening in 29 EDs

Kayigan Wilson d’Almeida, MD; Arch Intern Med. 2012;172(1):12-20.

Background: To lower the number of undiagnosed infections and to improve early detection, international health agencies have promoted nontargeted human immunodeficiency virus (HIV) screening in health care settings, including emergency departments (EDs). This strategy remains controversial and has yet to be tested on a large scale. We assessed the public health impact of nontargeted HIV–rapid test (RT) screening among ED patients in the metropolitan area of Paris (11.7 million inhabitants), where half of France's new HIV cases are diagnosed annually.

Methods: During a randomly assigned 6-week period for each of the 29 participating EDs, 18- to 64-year-old patients who were able to provide consent for HIV testing were offered a fingerstick whole-blood HIV RT. Main outcome measures were the number of patients tested for HIV and their characteristics vs those of the general metropolitan Paris population and the proportion of newly diagnosed HIV-positive patients among those tested and their characteristics vs those from the national HIV case surveillance.

Results: Among 138 691 visits, there were 78 411 eligible patients, 20 962 of whom (27.0%) were offered HIV RT; 13 229 (63.1%) accepted testing and 12 754 (16.3%) were tested. The ED patients' characteristics reflected the general population distribution. Eighteen patients received new HIV diagnoses (0.14%; 95% confidence interval, 0.08%-0.22%). Like national HIV case surveillance patients, they belonged to a high-risk group (n = 17), were previously tested (n = 12), and were either symptomatic or had a CD4 lymphocyte count lower than 350/µL, suggesting late-stage infections (n = 8); 12 patients were linked to care.

Conclusions: Nontargeted HIV testing in EDs was feasible but identified only a few new HIV diagnoses, often at late stages, and, unexpectedly, most patients belonged to a high-risk group. Our findings do not support the implementation of nontargeted screening of the general population in EDs.

5. Do Emergency Physicians Admit More or Fewer Patients on Busy Days?

Albrecht R, et al. J Emerg Med. 2011;41:709-712.

Background: Although the issues concerning the impact of emergency department (ED) overcrowding have been the subject of much recent concern, there are few data regarding the effect of ED census on emergency physician behavior with respect to the decision to admit patients. Admission rates might either increase or decrease on busy days, when the system and the physician are under stress.

Study Objective: The purpose of this study was to determine if ED physicians change their admitting behavior depending on ED census.

Methods: This was a retrospective review of 3 months' data (92 consecutive days, July 9–October 9, 2006) in a community ED with an annual census of approximately 70,000 patients and an emergency medicine residency program. We defined each of the 92 days to be either “busy” (over 180 patients seen), “slow” (fewer than 147 patients seen) or “medium” (147–180 patients seen). We then compared the rates of admission to the hospital on the “busy,” “medium,” and “slow” days. We also compared each attending physician's personal rates of admission on slow days to his or her rate of admission on medium or busy days. ED staffing was constant throughout the study period. All comparisons were with chi-squared.

Results: There were 14,969 patients seen in the ED during the 92 study days. On “busy” days, 20.1% of the 3400 patients were admitted to the hospital; on “medium” days, 20.6% of the 9057 patients were admitted; on “slow” days, 19.7% of the 2512 patients were admitted. There was no significant association between the level of patient volume in the ED and rate of admission (p = 0.55). When comparing each of 14 attending physicians to him- or herself, there was no significant association found between rate of admission and ED census (all p values above 0.3). All three categories of days, “busy,” “medium,” and “slow” did not differ in terms of acuity as judged by triage level distribution.

Conclusion: The likelihood of a patient's admission vs. discharge is not affected by ED patient volume. Furthermore, we found no evidence that an individual physician's admitting behavior was associated with ED patient volume.

6. Is Nasogastric Lavage Beneficial for Acute Gastrointestinal Bleeding?

The procedure increased the likelihood of early endoscopy but not better patient outcomes, such as lower mortality. The question merits prospective analysis.

Nasogastric lavage (NGL) was once a standard initial procedure for all patients with acute gastrointestinal (GI) bleeding, but its use is now under debate. Although some data suggest that patients with a bloody NGL are more likely to have severe bleeding (Gastrointest Endosc 2004; 59:172), the test's presumed benefits — confirming an upper GI source of bleeding, clearing the stomach for better endoscopic visualization, and reducing the risk for aspiration — have not been tested.

To evaluate the effects of NGL during triage on clinical outcomes, investigators conducted a retrospective database study of 632 patients from a Veterans Administration hospital. To control for confounding factors that might influence the decision to perform lavage, researchers identified 24 variables a priori that were associated with receiving NGL and used them to develop a propensity score — or likelihood of undergoing NGL — among patients with acute GI bleeding. They then matched 193 patients who received lavage and 193 who did not by propensity score and compared clinical outcomes.

Patients who underwent NGL were more likely to have an endoscopy (odds ratio, 1.71) and to receive it sooner (hazard ratio, 1.49) than other patients. Lavage did not affect mortality, length of hospital stay, or the need for transfusions or surgery. Bloody aspirates were associated with high-risk lesions at endoscopy (OR, 2.69).

The authors conclude that NGL is associated with receiving early endoscopy and might be useful in triage but does not affect clinical outcomes.

Comment: This paper will be of interest to many physicians caring for patients with upper GI bleeding and likely will be interpreted differently, depending on when they are seeing the patient and what they are trying to accomplish. One thing remains clear though — routine use of NGL in these patients is not justified. We already know that NGL cannot be used to exclude ongoing upper GI bleeding as one sixth of patients with active bleeding will have a negative NGL. Now, this study demonstrates that NGL results in no difference in a number of important clinical outcomes. However, certain targeted uses of NGL — such as to enhance visualization before endoscopy, thereby assisting in lesion identification — were not part of this study. These possible roles for NGL as an adjunctive tool to enhance endoscopy or to improve specific patient outcomes will require appropriately designed prospective studies. Until then, routine use of NGL in patients with upper GI bleeding is not indicated, but there are likely selected patients who might benefit from this intervention.

— David J. Bjorkman, MD, MSPH (HSA), SM (Epid.). Published in Journal Watch Gastroenterology December 2, 2011. Citation(s): Huang ES et al. Impact of nasogastric lavage on outcomes in acute GI bleeding. Gastrointest Endosc 2011 Nov; 74:971.
Medline abstract (Free): http://www.ncbi.nlm.nih.gov/pubmed/21737077

Pallin DJ and Saltzman JR. Is nasogastric lavage in patients with acute upper GI bleeding indicated or antiquated? Gastrointest Endosc 2011 Nov; 74:981.
Medline abstract (Free): http://www.ncbi.nlm.nih.gov/pubmed/22032314

7. Emergency Medicine Top Stories of 2011 from Journal Watch

A perspective on the most important research in the field from the past year

We are pleased to provide you with our Top 10 list for 2011. In other years, we have provided two lists: one reflecting our editors' selections and one based on total number of page views. We have come to know that the latter list, while interesting, does not reflect the needs or interests of emergency medicine clinicians but rather reflects the final common pathway of a very large, heterogeneous pool of Web searches. So, we no longer will provide that list. Instead, we have selected the most important studies covered by Journal Watch Emergency Medicine in 2011. Each of these summaries is worth a read, and, in many cases, linking to the original source — the published study — is valuable.

We hope that you continue to enjoy our annual lists and our ongoing efforts to keep you informed about medical information that will affect how you think and how you practice.

Full-text (free): http://emergency-medicine.jwatch.org/cgi/content/full/2011/1230/1

8. "Wait and see" approach to the ED cardioversion of acute AF

Doyle B, et al. Emerg Med Int. 2011. Epub 2011 Nov 17.

Objective. Acute atrial fibrillation often spontaneously resolves. This study aimed to investigate the outcomes and satisfaction of an evidence-based ED protocol employing a "wait and see" approach.

Methods. A prospective observational cohort study of adult patients presenting to the Emergency Department with stable acute atrial fibrillation was performed. Patients were excluded if they were considered to be unstable, need hospitalization, or poor candidates for ED procedural sedation. Routine care was provided on the index visit, and suitable candidates were discharged and asked to return to the ED the following day for possible electrical cardioversion. Outcome measures included spontaneous reversion to sinus rhythm, success of cardioversion, length of stay, adverse event and return visits for AF within 30 days, and patient satisfaction.

Results. Thirty five patient encounters were analysed over a 21-month period. Twenty two of the 35 patients (63%) had spontaneous resolution of atrial fibrillation upon presentation for potential cardioversion. All of the remaining patients underwent successful cardioversion to normal sinus rhythm without significant adverse events recorded. No patients required hospitalization. Three patients (9%) returned to the ED within 30 days for recurrence of atrial fibrillation. All patients were reported to be "very satisfied" with this approach.

Conclusion. A "wait and see" approach to the ED electrical cardioversion of atrial fibrillation showed that almost two-thirds of patients had spontaneous resolution without requiring cardioversion or observation in the ED or hospital. All patients were successfully reverted to normal sinus rhythm and had a high degree of satisfaction.

Full-text (free): http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3226298/

9. Video + Direct Laryngoscopy

by Richard Levitan, MD. Emergency Physicians Monthly, December 22, 2011

While some still debate the relative merits of direct vs. video laryngoscopy, the newest set of laryngoscopes make it easy, offering the best of both worlds.

At the recent Society for Airway Management conference there was a debate on Direct Laryngoscopy (DL) vs. Video Laryngoscopy (VL). While I love imaging and the mechanical and teaching advantages of look-around-the-curve video laryngoscopes, there is beauty in the simplicity, speed, and emergency applicability of direct laryngoscopy. DL is faster and does better with fluids, bleeding, and vomitus while tube delivery is much more straightforward with hyperangulated video devices. When VL is used in large series it does not perform better overall than DL, although there are cases when DL is very hard and VL easy. Alternatively, I have had some hard or impossible VL cases where DL was a slam dunk.

It occurred to me after the conference that the debate was in some ways pointless, given the new array of DL/VL devices which make both options available to you. With hyperangulated devices like the Glidescope, McGrath Series 5, or Storz Dorges Blade video laryngoscope, the angulation of the blade prevents any direct view. If the video fails, from fluids or any other reason, there is no direct view. This is not the case with DL/VL combination devices. Intubation can be done via direct line of sight, just as a standard instrument would be used, or under video, or as a combination. In the setting of emergency airways, especially trauma airways, I think this has great value.

Currently available DL/VL devices include the Storz C-Mac, the new McGath Mac (now to be distributed by Covidien), and the Glidescope Direct Trainer…

The remainder of the text (free) here: http://www.epmonthly.com/subspecialties/technology/video--direct-laryngoscopy-/

10. Effective Antibiotic Treatment Prescribed by Emergency Physicians in Patients Admitted to the ICU with Severe Sepsis or Septic Shock: Where is the Gap?

Capp R, et al. J Emerg Med. 2011;573-580.

Background: Antibiotic selection made within the first hour of recognition of severe sepsis and septic shock has been shown to decrease mortality.

Objective: The purpose of this study was to determine what antibiotics are being prescribed and to identify factors influencing ineffective antibiotic coverage in patients with severe sepsis or septic shock. In addition, we explore an alternative method for antibiotic selection that could improve organism coverage.

Methods: This was a retrospective review of emergency department (ED) patients admitted to an intensive care unit (ICU) over a 12-month period with a culture-positive diagnosis of either severe sepsis or septic shock. Appropriate antibiotic therapy was defined as effective coverage of the offending organism based on final culture results.

Results: Of the 1400 patients admitted to the ICU, 137 patients were culture positive and met the criteria for severe sepsis or septic shock. Effective antibiotic coverage was prescribed by emergency physicians in 82% (95% confidence interval [CI] .74–.88) of cases. Of the 25 patients who received ineffective antibiotics, the majority had infections caused by resistant Gram-negative organisms. Health care-associated pneumonia guidelines were applied to all patients, regardless of the source of infection, and were 100% sensitive (95% CI .93–1) for selecting patients who had infections caused by highly resistant organisms.

Conclusion: Emergency physicians achieved 82% effective antibiotic coverage in patients with severe sepsis or septic shock. The gap seems to be in coverage of highly resistant Gram-negative organisms. An alternative approach to antibiotic prescription, utilizing a set of guidelines for community- and health care-associated infections, was found to be 100% sensitive in selecting patients who had infections caused by the more resistant organisms.

11. Ciclesonide Trumps Antibiotics for Pediatric Otitis Media

Fran Lowry, Medscsape. November 22, 2011 (Boston, Massachusetts) — The nasal corticosteroid spray ciclesonide is more effective than a broad-spectrum oral antibiotic for the treatment of children with otitis media with effusion, according to a small study presented in an oral session here at the American College of Allergy, Asthma & Immunology 2011 Annual Scientific Meeting.

A resolution of otitis media with effusion occurred after 8 days of treatment with the aqueous nasal spray, but it took 14 days for a resolution in children treated with amoxicillin and clavulanate, Safa Nsouli, MD, director of the Danville Asthma and Allergy Clinic in California, reported.

In an open-label study, Dr. Nsouli and colleagues randomized 40 atopic children, 6 to 11 years of age, with otitis media with effusion to 1 of 2 groups: 2 sprays of ciclesonide 50 µg per nostril daily (n = 20); or amoxicillin and clavulanate potassium 90 mg/kg per day in 2 divided doses every 12 hours (n = 20). Both treatments were given for a 2-week period.

The effectiveness of the 2 treatments was assessed objectively using pneumatic otoscopy, impedance tympanometry, and audiometry.

"There is a nasal obstruction that occurs with otitis media. If we eliminate the nasal obstruction with ciclesonide, we decrease the aspiration reflex of the nasopharyngeal secretions into the middle ear that occur via the eustacian tube," Dr. Nsouli told Medscape Medical News.

"We also reduce the allergic inflammatory obstruction of the eustacian tube. Ciclesonide decreases those mechanisms, which helps clear the otitis media much faster than a plain antibiotic treatment that works only on the bacteria," he said. "It's like having a clogged sink. You can try to clean the sink but it is impossible unless the sink is unplugged and drained."

In addition to resolving otitis media symptoms more rapidly, ciclesonide is a safer option, Dr. Nsouli said.

"I am sure many doctors and parents have noticed that their pediatric patients with otitis media can be on several antibiotic courses, sometimes for 6 to 8 months, with no results. They have even inserted an ear tube for drainage of the secretions. Our study shows that we can eliminate the long-term course of antibiotics," Dr. Nsouli said.

Heartening Results

Medscape Medical News invited Chitra Dinakar, MD, professor of pediatrics at the University of Missouri at Kansas City, for her views on this study.

"Studies have shown that only about 1 in 3 children with middle-ear effusion who undergo myringotomy and placement of ventilation tubes have a bacterial pathogen identified; in general, qualitative studies suggest low bacterial densities in such effusions," Dr. Dinakar noted. "Additionally, inflammatory exudates or infiltration of neutrophils in the fluid is typically not found.

Despite this, pediatricians encounter patients with "fluid in the ear" who are given multiple course of antibiotics, raising concerns about "the development of multidrug-resistant pathogens and the effects of antibiotics on a young child's natural flora and immune system," she said.

"It is heartening to note that this small open-label study showed more rapid resolution of symptoms with a nasal steroid, compared to a course of an appropriate antibiotic, at least in the short-term assessment period of 2 weeks," Dr. Dinakar said.

Dr. Nsouli has disclosed no relevant financial relationships. Dr. Dinakar reports financial relationships with AstraZeneca and GlaxoSmithKline.

American College of Allergy, Asthma & Immunology (ACAAI) 2011 Annual Scientific Meeting: Abstract 62. Presented November 6, 2011.

12. Images in Medicine

Lung Herniation after Cough-Induced Rupture of Intercostal Muscle
http://www.nejm.org/doi/full/10.1056/NEJMicm1106070

Pneumopericardium Associated with a Peptic Ulcer
http://www.nejm.org/doi/full/10.1056/NEJMicm1107529

Image Challenge: What’s This?
http://www.nejm.org/image-challenge?ci=12222011

A Head Shot
http://www.nejm.org/doi/full/10.1056/NEJMicm1009118

13. Low-dose diltiazem in atrial fibrillation with rapid ventricular response.

Lee J, et al. Am J Emerg Med. 2011 Oct;29(8):849-54.

OBJECTIVES: Diltiazem is one of the most commonly used medications to control the rapid ventricular response in atrial fibrillation (AF). The recommended starting dose is an intravenous bolus of 0.25 mg/kg over 2 minutes. To avoid hypotension, we have empirically used a lower dose of diltiazem. We compared the efficacy and safety of different doses of diltiazem in rapid AF.

METHODS: A retrospective chart review was undertaken in patients who presented to the emergency department with rapid AF. Patients were divided into 3 groups according to diltiazem dosage: low dose (≤ 0.2 mg/kg), standard dose (greater than 0.2 and ≤ 0.3 mg/kg), and high dose (more than 0.3 mg/kg). We compared the rates of therapeutic response (adequate rate control) and complications (such as hypotension). Multivariate regression analysis was used to determine the effect of diltiazem dose on the occurrence of complications.

RESULTS: A total of 180 patients were included in the analysis. There were no significant differences in the rates of therapeutic response for the low-, standard-, and high-dose groups (70.5%, 77.1%, and 77.8%; P = .605). The rates of hypotension in the low-, standard-, and high-dose groups were 18%, 34.9%, and 41.7%, respectively. After adjusting confounding variables, the rate of hypotension was significantly lower in the low-dose group in comparison with the standard-dose group (adjusted odds ratio, 0.39; 95% confidence interval, 0.16-0.94).

CONCLUSIONS: Low-dose diltiazem might be as effective as the standard dose in controlling rapid AF and reduce the risk of hypotension.

14. When balance is bias (in scientific journalism)

Trevor Jackson, magazine editor. BMJ 2011;343:d8006

Sometimes the science is strong enough for the media to come down on one side of a debate

In his 2010 BBC television series Wonders of the Solar System, the physicist Brian Cox made a remark that offended some horoscope lovers. “Despite the fact that astrology is a load of rubbish, Jupiter can in fact have a profound influence on our planet. And it’s through a force . . . gravity.” The BBC received a number of complaints, including one from a viewer who said that Cox made his comment without an “alternative opinion being allowed.” The complainant griped that the programme made no attempt to “consider such questions from the perspective of an astrologer, who draws upon a very different body of observation and knowledge built over thousands of years.” Cox later gave the BBC a statement (which it declined to issue) saying, “I apologise to the astrology community for not making myself clear. I should have said that this new age drivel is undermining the very fabric of our civilisation.”

This tale, which beautifully points up the ridiculousness of always demanding balance in science communication, is told by Steve Jones, emeritus professor of human genetics at University College London, in a report published this year. The BBC Trust commissioned Jones to review the impartiality and accuracy of the BBC’s coverage of science; and although Jones found much to praise, he expresses concern about the BBC’s guidelines on “due impartiality.” These, Jones found, had a distorting effect, creating a sense of equivalence where there was none, and privileging maverick and dissident views so that they appeared as valid as established scientific fact. (This is not to say that established facts cannot be disproved. But the onus is on the claimants to prove or disprove their case within the rigorous paradigms of modern scientific research—witness the current debates on the invariability of the speed of light.)

Jones found that BBC journalists, in their quest for objectivity and impartiality—entirely understandable aims in coverage of politics and arts—risked giving the impression in their science reporting that there were two equal sides to a story when clearly there were not. As Jones says, “There is widespread concern that [the BBC’s] reporting of science sometimes gives an unbalanced view of particular issues because of its insistence on bringing in dissident voices into what are in effect settled debates.”

The dangers of this approach are clear in journalistic coverage of subjects such as the MMR (measles, mumps, rubella) vaccine—as the BMJ has previously shown—and climate change. A 2003 study into coverage of MMR showed that the media’s insistence on giving equal weight to both the views of the anti-vaccine camp and to the overwhelming body of scientific evidence exonerating the vaccine from its alleged adverse effects made people think that scientists themselves were divided over the safety of the vaccine, when they were not. The quest for balance created what Jones and others have called “false balance,” and in the case of the MMR vaccine helped fuel a public health disaster.

The investigative journalist Nick Davies, in his 2008 book Flat Earth News—an examination of falsehood, distortion, and propaganda in the world’s media—says that the insistence on balance is one of the factors that stops journalists getting at the truth. “Neutrality requires the packaging of conflicting claims, which is precisely the opposite of truth telling. If two men go to mow a meadow and one comes back and says ‘The job’s done’ and the other comes back and says ‘We never cut a single blade of grass,’ neutrality requires the journalist to report a controversy surrounding the state of the meadow, to throw together both men’s claims and shove it out to the world with an implicit sign over the top declaring, ‘We don’t know what’s happening—you decide’.” Another seasoned UK journalist, Malcolm Dean, takes a similar line on balance in his 2011 book Democracy Under Attack, as does the Science Media Centre, in its evidence to the ongoing Leveson inquiry into media ethics. If journalists will not decide where the truth lies, this puts the onus on readers and viewers; and given that scientists are not always expert communicators, there is a real risk that the anti-science view will hold sway.

Davies’s and Dean’s position reflects that of the US academics Maxwell T Boykoff and Jules M Boykoff, who have researched the reporting of climate change. In two seminal papers, the Boykoffs identified the journalistic norm of balance—the refusal to privilege the high level consensus that anthropogenic climate change is a reality over the views of right wing mavericks and oil industry funded commentators—as one of the factors that has sown doubt and confusion among the public.

In his recent book Who Speaks for the Climate?, Maxwell Boykoff shows that the journalistic norm of balance in news reporting “has served to amplify outlier views on anthropogenic climate change, and concurrently engendered an appearance of increased uncertainty regarding anthropogenic climate science. This, in turn, has entered into an already highly contested arena where it has permeated climate policy discourse and decision-making.”

Part of the problem is that it takes time for a scientific consensus to emerge, and the media are impatient. Few scientists would nowadays argue that smoking does not cause lung cancer, that the world was created in six days, or that the earth is flat, but that wasn’t always the case. Davies shows how the oil industry began mobilising its public relations campaign against the notion of anthropogenic climate change in 1989, years before any scientific consensus could emerge on global warming.

So what is to be done? In the current climate, as media outlets have to produce ever more copy with fewer resources, the outlook is bleak. The BBC hopes that a new stipulation in its editorial guidelines—“due weight,” the recognition that, for example, minority views should not necessarily be given equal weight to the prevailing consensus12—and an online training module on the specific demands of science reporting will help. Steve Jones says he is yet to see any evidence of the difference this can make, but it is a start. Also, researchers themselves should hone their communication skills.

Meanwhile, some science journalism will continue to be weighed in the balance and found wanting.

References: http://www.bmj.com/content/343/bmj.d8006

15. Surge Reported in Energy Drink ED Visits

Laird Harrison. Medscape. November 28, 2011 — The number of emergency department visits associated with nonalcohol energy drinks is surging, according to a report from the US Substance Abuse and Mental Health Services Administration (SAMHSA).

In 2005, the agency recorded 1,128 such visits and in 2009 it recorded 13,114 such visits, with the highest number occurring in 2008 (16,055). Data are not yet available for 2010.

"Energy drinks used in excess or in combination with alcohol or drugs can pose a serious health risk," said SAMHSA administrator Pamela S. Hyde in a press release.

The agency defines energy drinks as flavored beverages containing high amounts of stimulants such as caffeine. The drinks are marketed to youth and are consumed by up to 50% of children, adolescents, and young adults.

The report, entitled Emergency Department Visits Involving Energy Drinks, is based on data from SAMHSA's 2005 to 2009 Drug Abuse Warning Network (DAWN) reports. DAWN is a public health surveillance system that monitors drug-related hospital emergency department visits reported in the United States.

The report found that in 44% of emergency department visits involving energy drinks, the drinks were taken together with other substances, such as alcohol, pharmaceuticals, and illicit drugs. This combination of energy drinks and other substances of abuse was greatest in young adults 18 to 25 years of age (52%).

The vast majority (77%) of these visits were made by people 18 to 39 years of age, and 64% were made by males, according to the report.

Energy-drink-related emergency department visits involving males were twice as likely as those involving females to include the use of alcohol (20% vs 10%) or illicit drugs (12% vs 5%).

Female visits were more likely than male visits to involve the combined use of energy drinks and pharmaceuticals (35% vs 23%).

Studies indicate that excessive caffeine intake from energy drinks can cause adverse reactions, such as arrhythmias, hypertension, and dehydration. Combining energy drinks with substances of abuse raises the risk for serious, even life-threatening, injury and for the likelihood of engaging in risky behaviors, such as driving under the influence.

The National Institute on Alcohol Abuse and Alcoholism has developed a pocket guide for healthcare professionals and others to help with screening and brief intervention for youth who might have alcohol problems, including cases involving energy drinks.

"The beverage industry, consumer groups, community coalitions, the healthcare community, teachers, parents, and others must get the word out that quick-fix energy drinks are not a solution and carry great risks, especially in combination with other substances of abuse," said Ms. Hyde.

The report (full-text, free): http://www.samhsa.gov/data/2k11/WEB_DAWN_089/WEB_DAWN_089_HTML.pdf

Pocket Guide: http://pubs.niaaa.nih.gov/publications/Practitioner/YouthGuide/YouthGuidePocket.pdf

16. Acetaminophen May Be Bad for Asthmatic Kids

McBride JT. Pediatrics. 2011;128;1181.

A growing number of studies have documented such a strong association between acetaminophen exposure and asthma that it is possible that much of the dramatic increase in childhood asthma over the past 30 years has been related to the use of acetaminophen. Although this possibility has been widely acknowledged, commentators have been reluctant, without a randomized clinical trial, to conclude that acetaminophen causes asthma and, with rare exception, have not recommended changes in practice. As a pediatric pulmonologist, I am entrusted with the care of many asthmatic children and, at some level, with the respiratory health of all children in my area. Given this role, I must decide when and how to act on the possibility that acetaminophen is detrimental to asthmatic children. Considering currently available data, I now recommend that any child with asthma or a family history of asthma avoid using acetaminophen.

The epidemiologic association between acetaminophen use and asthma prevalence and severity in children and adults is well established. A variety of observations suggest that acetaminophen use has contributed to the recent increase in asthma prevalence in children: (1) the strength of the association; (2) the consistency of the association across age, geography, and culture; (3) the dose-response relationship; (4) the timing of increased acetaminophen use and the asthma epidemic; (5) the relationship between per-capita sales of acetaminophen and asthma prevalence across countries; (6) the results of a double-blind trial of ibuprofen and acetaminophen for treatment of fever in asthmatic children; and (7) the biologically plausible mechanism of glutathione depletion in airway mucosa. Until future studies document the safety of this drug, children with asthma or at risk for asthma should avoid the use of acetaminophen.

Full-text in Pediatrics (free): http://pediatrics.aappublications.org/content/128/6/1181.full

New York Times Essay: http://www.nytimes.com/2011/12/20/health/evidence-mounts-linking-acetaminophen-and-asthma.html

17. Consensus Criteria Predict Futile Prehospital Trauma Resuscitation

None of 294 patients had meaningful survival, and EMS resuscitation triggered hospital costs approaching $4 million.

In 2003, the National Association of Emergency Medical Services (EMS) Physicians and the American College of Surgeons Committee on Trauma published guidelines on when to withhold or terminate prehospital resuscitation in traumatic cardiopulmonary arrest (TCPA). Using data from a level I trauma registry from 2003 through 2010, researchers studied prehospital TCPA patients aged 18 years for whom these guidelines were violated. Criteria to withhold or terminate care were (1) blunt trauma with apnea, pulselessness, and no organized electrocardiogram activity; (2) penetrating trauma with the preceding clinical presentation and no other signs of life; (3) 15 minutes of cardiopulmonary resuscitation without return of spontaneous circulation; or (4) EMS-witnessed TCPA followed by 15 minutes of unsuccessful resuscitation en route to the emergency department (ED).

Among 294 patients, mechanism of injury was blunt in 90 (31%) and penetrating in 204 (69%). Overall, 274 patients (93%) died in the ED, and 12 (4%) died during surgery. Of the 8 patients who reached the intensive care unit, 7 died in the ICU, and 1 (0.3%) survived but had a Glasgow Coma Scale score of 6 and was discharged to a long-term care facility.

Comment: The charges for hospital care for these 294 patients totaled nearly US$4 million, and the one surviving patient had a horrible outcome. These data strongly support the existing guidelines and the need to ensure that EMS personnel understand and adhere to them.

— John A. Marx, MD, FAAEM. Published in Journal Watch Emergency Medicine December 9, 2011. Citation: Mollberg NM et al. The consequences of noncompliance with guidelines for withholding or terminating resuscitation in traumatic cardiac arrest patients. J Trauma 2011 Oct; 71:997.

18. The Wait that Matters

Maa J. N Engl J Med. 2011 Jun 16;364(24):2279-81.

She was 69 years old and, with the exception of mild heart disease, was in excellent health. One day, around mid-morning, she noticed that her heartbeat was irregular and she felt slightly short of breath. Using her home blood-pressure cuff, she found that her pulse was 130. Since her blood pressure was stable, she decided to forgo a call to 911 and instead asked her husband to drive her to the local hospital — one of the most highly regarded academic medical centers on the West Coast.

After waiting about an hour to be seen, she was diagnosed with rapid atrial fibrillation around 8 o'clock on a Thursday evening. Given her age, the emergency department (ED) staff and the consulting cardiologist decided to admit her to the hospital. The medical team started giving her intravenous heparin for anticoagulation and planned to perform electrical cardioversion the following day if a transesophageal echocardiogram (TEE) confirmed the absence of an atrial thrombus.

Because no inpatient bed was available, the patient was kept in the ED overnight. The narrowness of the stretcher and the noise and bright lights of the ED hallway made it hard for her to get much sleep. The following day, shortly before noon, she was wheeled upstairs to a bed.

Early in the afternoon, the cardiologist stopped by to let her know that because her admission had been delayed, it would not be possible to complete her procedures before the end of the workday. Therefore, she would remain in the hospital receiving intravenous heparin and oral warfarin throughout the weekend and would undergo TEE and cardioversion the following Monday.

The next day, without warning, the patient sustained a massive embolic stroke…

The remainder of the essay (free): http://www.nejm.org/doi/full/10.1056/NEJMp1101882

19. How fast does the Grim Reaper walk? Receiver operating characteristics curve analysis in healthy men aged 70 and over

Stanaway FF, et al. BMJ 2011;343:d7679

Introduction

The Grim Reaper, the personification of death, is a well known mythological and literary figure. Reported characteristics include a black cloak with cowl, a scythe, and cachexia. High quality scientific research linking the Grim Reaper to mortality has been scarce, despite extensive anecdotes.

Walking speed is a commonly used objective measure of physical capability in older people, predicting survival in several cohort studies. A recent meta-analysis found that being in the lowest fourth of walking speed compared with the highest was associated with a threefold increased risk of mortality. Moreover, the association between slow walking speed and mortality seems consistent across several ethnic groups and shows a dose-response relation.8 Although the association between walking speed and mortality has been well documented, the plausible biological relation between the two remains unclear.

We assessed whether the relation between slow walking speed and mortality results from the increased likelihood of being caught by Death. By assessing this relation using receiver operating characteristics curve analysis, we hypothesised we would be able to determine the walking speed of the Grim Reaper—information of importance to public health…

Abstract

Objective: To determine the speed at which the Grim Reaper (or Death) walks.

Design: Population based prospective study.

Setting: Older community dwelling men living in Sydney, Australia.

Participants: 1705 men aged 70 or more participating in CHAMP (Concord Health and Ageing in Men Project).

Main outcome measures: Walking speed (m/s) and mortality. Receiver operating characteristics curve analysis was used to calculate the area under the curve for walking speed and determine the walking speed of the Grim Reaper. The optimal walking speed was estimated using the Youden index (sensitivity+specificity−1), a common summary measure of the receiver operating characteristics curve, and represents the maximum potential effectiveness of a marker.

Results: The mean walking speed was 0.88 (range 0.15-1.60) m/s. The highest Youden index (0.293) was observed at a walking speed of 0.82 m/s (2 miles (about 3 km) per hour), corresponding to a sensitivity of 63% and a specificity of 70% for mortality. Survival analysis showed that older men who walked faster than 0.82 m/s were 1.23 times less likely to die (95% confidence interval 1.10 to 1.37) than those who walked slower (P=0.0003). A sensitivity of 1.0 was obtained when a walking speed of 1.36 m/s (3 miles (about 5 km) per hour) or greater was used, indicating that no men with walking speeds of 1.36 m/s or greater had contact with Death.

Conclusion: The Grim Reaper’s preferred walking speed is 0.82 m/s (2 miles (about 3 km) per hour) under working conditions. As none of the men in the study with walking speeds of 1.36 m/s (3 miles (about 5 km) per hour) or greater had contact with Death, this seems to be the Grim Reaper’s most likely maximum speed; for those wishing to avoid their allotted fate, this would be the advised walking speed.

20. Corticosteroids Impart No Benefit after Single-Dose Etomidate for Intubation

Moderate-dose hydrocortisone infusion did not affect outcomes in intubated patients without septic shock who had etomidate-related adrenal insufficiency.

Some physicians have expressed concern about adrenal suppression associated with etomidate use, but is this suppression clinically relevant? Researchers in France prospectively studied 97 patients with acute medical or traumatic conditions without septic shock who underwent intubation with etomidate plus succinylcholine in the prehospital or emergency department settings. Patients were randomized to receive continuous infusions of hydrocortisone (200 mg/day) or saline for 42 hours, starting 6 hours after intubation. Postintubation sedation was maintained with a variety of sedative and analgesic agents (not etomidate). Patients received vasopressor support and insulin as required to maintain target mean arterial blood pressure of 65 to 90 mm Hg and serum glucose levels of below 10 mmol/L.

Six hours after etomidate administration, 91% of patients randomized to the hydrocortisone group and 84% randomized to the control group met criteria for adrenal insufficiency based on corticotrophin stimulation tests and serum hormonal assays. No significant differences were noted between groups in rate of decline of Sequential Organ Failure Assessment scores, duration of mechanical ventilation, length of stay in the intensive care unit, or 28-day mortality.

Comment: Hydrocortisone treatment is not without risk and does not seem to benefit the group of patients studied. Etomidate, with its stable cardiovascular profile, remains an induction agent of choice for emergency intubation, particularly in multitrauma patients with brain injury whose outcomes might be worsened by inadequate systemic blood pressure for cerebral perfusion.

— Kristi L. Koenig, MD, FACEP. Published in Journal Watch Emergency Medicine January 13, 2012. Citation: Payen JF et al. Corticosteroid after etomidate in critically ill patients: A randomized controlled trial. Crit Care Med 2012 Jan; 40:29.

Medline abstract (Free): http://www.ncbi.nlm.nih.gov/pubmed/21926601

Marik PE. Etomidate in critically ill patients: Is it safe? Crit Care Med 2012 Jan; 40:301.
Medline abstract (Free): http://www.ncbi.nlm.nih.gov/pubmed/22179348

21. How to keep those New Year’s resolutions

Psychologists have identified successful ways of meeting self-determined goals, but they may not work if you’re a perfectionist.

Harv Health Lett. 2006 Jan;31(3):1-2.

Full-text (free): http://harvardhealth.staywell.com/viewNewsletter.aspx?NLID=47&INC=yes

“Exploring Change” as a New Year’s Resolution

In preparation to making changes, I will be exploring how changes are made. (A clever deferral strategy, wouldn’t you say?)

An introduction to the psychology of decision making can be found here: “The Mechanics of Choice” by Eric Wargo. The Observer, Vol.25, No.1 January, 2012

After years of tinkering, psychological scientists are figuring out how the gears turn when we make decisions. Full-text (free): http://tinyurl.com/dx62hfj

Some Fascinating Reading for Winter 2012 on Change: Cognitive, social, and historical

Daniel Kahneman (Nobel Laureate), Thinking: Fast and Slow (New York: Farrar, Straus and Giroux, 2011). http://www.amazon.com/dp/0374275637/ Ranked by the New York Times among their top 5 best non-fiction books of 2011 http://www.nytimes.com/2011/12/11/books/10-best-books-of-2011.html

Chip Heath and Dan Heath, Switch: How to Change Things when Change is Hard (New York: Broadway Books, 2010). http://www.amazon.com/dp/0385528752/

Timothy D. Wilson, Redirect: The Surprising New Science of Psychological Change (New York: Little, Brown and Company, 2011). http://www.amazon.com/dp/0316051888/

Steven Pinker, The Better Angels of our Nature: Why Violence Has Declined (New York: Penguin Group, 2011). http://www.amazon.com/dp/0670022950/