Lit Bits: Dec 11, 2009

From the recent medical literature...

1. Hold the Epi: No Advantage Seen With IV Drugs at Out-of-Hospital Cardiac Arrest

November 25, 2009 (Oslo, Norway) — Facing off with longstanding policy and tradition, a large randomized trial found that giving IV drugs like epinephrine and atropine in the setting of out-of-hospital cardiac arrest made it more likely that patients would be admitted to the hospital but little difference in whether they survived to discharge.

That outcome was in spite of their undergoing resuscitation longer and receiving more defibrillations, and more often reattaining a spontaneous circulation, compared with another group that didn't receive IV drugs during arrest, observe the authors, led by Dr Theresa M Olasveengen (Oslo University Hospital, Norway), in this week's Journal of the American Medical Association.

The trial is only the latest of several in recent years to reappraise the efficacy of major elements of conventional cardiopulmonary resuscitation.

For now, the cornerstones of optimal cardiac resuscitation include high-quality cardiopulmonary resuscitation with minimal interruptions for anything, including any drug administration, and early defibrillation.

"These researchers present important and compelling data, which challenge the efficacy of one of the most common procedures in cardiac resuscitation: the administration of intravenous epinephrine," said Dr Bentley J Bobrow (Arizona Department of Health Services, Phoenix) in an email to heartwire. Bobrow, who wasn't involved in the study, is medical director of his state's Bureau of Emergency Medical Services & Trauma System.

"While epinephrine administration has been part of the guidelines for resuscitation for many years, there has been very little evidence supporting its benefit and some convincing evidence suggesting worse outcomes with higher doses of epinephrine," he remarked.

"The message for emergency providers is that, for now, the cornerstones of optimal cardiac resuscitation include high-quality cardiopulmonary resuscitation with minimal interruptions for anything, including any drug administration, and early defibrillation."

Olasveengen et al randomized 851 consecutive adults with nontraumatic out-of-hospital cardiac arrest to management according to advanced-cardiac-life-support guidelines with or without access to IV drug administration. In the no-IV-access group, those who achieved "return to spontaneous circulation" could receive IV drugs five minutes later, if indicated.

Those treated with access to IV drugs fared significantly better at first, but didn't outdo those managed without IV drug access for the primary end point of survival to hospital discharge.

Intravenous Drug Administration During Out-of-Hospital Cardiac Arrest: A Randomized Trial

Olasveengen TM, et al. JAMA. 2009;302(20):2222-2229.

Context: Intravenous access and drug administration are included in advanced cardiac life support (ACLS) guidelines despite a lack of evidence for improved outcomes. Epinephrine was an independent predictor of poor outcome in a large epidemiological study, possibly due to toxicity of the drug or cardiopulmonary resuscitation (CPR) interruptions secondary to establishing an intravenous line and drug administration.

Objective: To determine whether removing intravenous drug administration from an ACLS protocol would improve survival to hospital discharge after out-of-hospital cardiac arrest.

Design, Setting, and Patients: Prospective, randomized controlled trial of consecutive adult patients with out-of-hospital nontraumatic cardiac arrest treated within the emergency medical service system in Oslo, Norway, between May 1, 2003, and April 28, 2008.

Interventions: Advanced cardiac life support with intravenous drug administration or ACLS without access to intravenous drug administration.

Main Outcome Measures: The primary outcome was survival to hospital discharge. The secondary outcomes were 1-year survival, survival with favorable neurological outcome, hospital admission with return of spontaneous circulation, and quality of CPR (chest compression rate, pauses, and ventilation rate).

Results: Of 1183 patients for whom resuscitation was attempted, 851 were included; 418 patients were in the ACLS with intravenous drug administration group and 433 were in the ACLS with no access to intravenous drug administration group. The rate of survival to hospital discharge was 10.5% for the intravenous drug administration group and 9.2% for the no intravenous drug administration group (P = .61), 32% vs 21%, respectively, (P less than .001) for hospital admission with return of spontaneous circulation, 9.8% vs 8.1% (P = .45) for survival with favorable neurological outcome, and 10% vs 8% (P = .53) for survival at 1 year. The quality of CPR was comparable and within guideline recommendations for both groups. After adjustment for ventricular fibrillation, response interval, witnessed arrest, or arrest in a public location, there was no significant difference in survival to hospital discharge for the intravenous group vs the no intravenous group (adjusted odds ratio, 1.15; 95% confidence interval, 0.69-1.91).

Conclusion: Compared with patients who received ACLS without intravenous drug administration following out-of-hospital cardiac arrest, patients with intravenous access and drug administration had higher rates of short-term survival with no statistically significant improvement in survival to hospital discharge, quality of CPR, or long-term survival.

2. Occult Abdominal Trauma Common in Children With Suspected Physical Abuse

Will Boggs, MD. NEW YORK (Reuters Health) Nov 24 - Children with suspected physical abuse should be screened for abdominal trauma, according to a report from the University of Maryland School of Medicine, Baltimore.

"Children with injuries from physical abuse can have many occult injuries, including occult abdominal trauma, and physicians should consider this possibility when deciding what medical tests should be performed," lead author Dr. Wendy Gwirtzman Lane told Reuters Health.

Dr. Lane and colleagues conducted a retrospective study to examine the rate of occult abdominal trauma among 244 children with suspected physical abuse and to identify characteristics associated with screening practice.

Fifty-one of the children had at least one screening test for occult abdominal trauma, the authors report in the December Pediatrics, but only 9 of the 21 children with positive screening results had confirmatory testing with abdominal CT and/or ultrasonography.

Overall, 5 children (10% of those screened, 2% of the total sample) had injuries identified through abdominal CT and/or ultrasonography.

Four of 5 children with elevated ALT and/or AST levels had evidence of intra-abdominal injury on CT or ultrasound scans and 3 others had evidence of liver injury, yielding positive predictive values between 60% and 80%.

Children under 18 months of age were less likely to be screened than were older children, the researchers note, and children who presented in the evening were screened significantly less often than were children who presented at other times of day.

In multivariate analysis, the likelihood of occult abdominal trauma screening was higher for children presenting with probable abusive head trauma and for children evaluated in subspecialty consultation from the child protection team.

Regarding further studies, Dr. Lane said, "Our first step is to better elucidate which children should be screened. We are doing this by conducting a prospective multi-center study, in which we plan to screen all children with abusive injuries age 0-6. We anticipate that this data will allow us to make more specific screening recommendations; e.g., what age children should be screened, and with what injuries (e.g., bruises, burns, fractures, abusive head trauma). We can then look at how to improve screening rates among children who should be screened."

Pediatrics 2009;124:1595-1602.

3. Clinical Controversies: Initiation of Therapy for Asymptomatic Hypertension in the Emergency Department

Ann Emerg Med. 2009;54:791-3.

Do it: http://www.annemergmed.com/article/S0196-0644(09)00484-3/fulltext

Don’t bother: http://www.annemergmed.com/article/S0196-0644(09)01445-0/fulltext

4. Renal Stones, Pancreatitis Receive High Cumulative Radiation Doses in the ED

December 2, 2009 (Chicago, Illinois) — A study that looked at patterns of radiation exposure from computed tomography (CT) in the emergency department of a large urban level 1 trauma center found that patients who were diagnosed with renal stone disease and pancreatitis were the most likely to receive the highest exposure to radiation from CT scans.

Cumulative effective-dose data from imaging should become part of the patient's medical record, Amita Kamath, MD, from San Francisco General Hospital and the University of California at San Francisco, said here at the Radiological Society of North America 95th Scientific Assembly and Annual Meeting.

Dr. Kamath studied cumulative exposure to radiation from CT between October 2006 and March 2007 using effective-dose estimates to determine if certain patient populations were at risk for higher levels of imaging studies and radiation.

Focusing on a retrospective review of common emergency department diagnoses — altered mental status, pancreatitis, renal stone disease, and trauma, she found that renal stone disease and pancreatitis patients had the most repeat imaging and the highest radiation exposure (50 mSv or more).

Among the 10,382 patients reviewed, 91 patients were diagnosed with renal stone disease and 61 with pancreatitis.

Overall, 28% of the cohort (2890 patients) underwent at least 1 CT scan. This ranged from 20% to 22% of patients with trauma and altered mental states, to 70% of patients with pancreatitis, to 85% of patients with renal stone disease.

A mean of 2 CT scans were performed on each patient. That number ranged from 1.8 in patients with trauma and altered mental states, to 1.4 in patients with renal stone disease, to 2.7 in patients with pancreatitis.

Overall, 4% of patients received in excess of 50 mSv. The patients most likely to receive such a high dose were those with renal stone disease and pancreatitis, Dr. Kamath said.

Patients with renal stone disease were over 60 times more likely to undergo a CT scan (odds ratio [OR], 64.6; 95% confidence interval [CI], 8.5 - 493.1) than were patients with altered mental status, and those with pancreatitis were 20 times more likely to undergo a CT scan than those diagnosed with altered mental states (OR, 21.5; CI, 7.5 - 61.7). Patients with renal stone disease were nearly 8 times more likely (OR, 7.9; CI, 1.7 - 36.0) to receive more than 50 mSv over the study period, she reported.

"I think this is often because they develop complications, such as pseudocysts or necrosis, and they end up having to get repetitive imaging," she told Medscape Radiology.

Alternative imaging modalities, such as ultrasound and magnetic resonance imaging, should be considered when such patients require a follow-up study. Limiting the number of phases within the CT itself would also limit exposure, she said.

"We have known about the risks of CT radiation exposure for a while," session moderator, Larry DeWerd, PhD, from the University of Wisconsin, Madison, told Medscape Radiology. "Now we have numbers to tell us the scope of the problem."

Heightened awareness is a good thing, he added. "The more awareness there is among radiologists, the fewer repeat exams, or at least the fewer unnecessary exams, there will be. Hopefully, this could be one of the outcomes, but of course it will take time. It won't happen overnight."

Weighing in with his opinion, J. Louis Hinshaw, MD, from the University of Wisconsin Hospital and Clinics, Madison, added: "This was very interesting work and not surprising in my experience. The use of CT in the [emergency department] has been increasing dramatically, even more so over the past 5 years or so. One of the main indications that 'needs CT in the [emergency department]' is renal stones and, if positive, there is often at least 1 follow-up examination performed, sometimes leading to large cumulative radiation doses."

He endorsed the suggestion that radiation dose should become part of the medical record.

"That is an idea that certainly has merit. There are many obstacles to overcome in order to accomplish something like that, but a national electronic medical record could make something like that possible."

Dr. Kamath, Dr. DeWerd, and Dr. Hinshaw have disclosed no relevant financial relationships.

Radiological Society of North America (RSNA) 95th Scientific Assembly and Annual Meeting: Abstract SSE22-06. Presented November 30, 2009.

5. 600 mg Clopidogrel Loading Dose Bests 300 mg in Patients with STEMI

Patients with STEMI who underwent primary PCI had better clinical outcomes — and no greater risk for bleeding — with a 600-mg loading dose compared with 300 mg.

Dangas G et al. J Am Coll Cardiol. 2009;54:1438-46.

Objectives: Our aim was to determine whether a 600-mg loading dose of clopidogrel compared with 300 mg results in improved clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

Background: A 600-mg loading dose of clopidogrel compared with 300 mg provides more rapid and potent inhibition of platelet activation.

Methods: In the HORIZONS-AMI (Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction) trial, 3,602 patients with STEMI undergoing primary PCI were randomized to bivalirudin (n = 1,800) or unfractionated heparin plus a glycoprotein IIb/IIIa inhibitor (n = 1,802). Randomization was stratified by thienopyridine loading dose, which was determined before random assignment.

Results: Patients in the 600-mg (n = 2,158) compared with the 300-mg (n = 1,153) clopidogrel loading dose group had significantly lower 30-day unadjusted rates of mortality (1.9% vs. 3.1%, p = 0.03), reinfarction (1.3% vs. 2.3%, p = 0.02), and definite or probable stent thrombosis (1.7% vs. 2.8%, p = 0.04), without higher bleeding rates. Compared with unfractionated heparin plus a glycoprotein IIb/IIIa inhibitor, bivalirudin monotherapy resulted in similar reductions in net adverse cardiac event rates within the 300-mg (15.2% vs. 12.3%) and 600-mg (10.4% vs. 7.3%) clopidogrel loading dose subgroups (pinteraction = 0.41). By multivariable analysis, a 600-mg clopidogrel loading dose was an independent predictor of lower rates of 30-day major adverse cardiac events (hazard ratio: 0.72 [95% confidence interval: 0.53 to 0.98], p = 0.04).

Conclusions: In patients with STEMI undergoing primary PCI with contemporary anticoagulation regimens, a 600-mg loading dose of clopidogrel may safely reduce 30-day ischemic adverse event rates compared with a 300-mg loading dose.

6. Images in Emergency Medicine

Young Man With Fishing Injury
http://www.annemergmed.com/article/S0196-0644(09)00405-3/fulltext

Man With Painful Swelling in Neck
http://www.annemergmed.com/article/S0196-0644(09)00611-8/fulltext

7. NFL to manage concussions with the help of neurologists

By ALAN SCHWARZ. NY Times. Published: November 22, 2009.

In a shift in the National Football League’s approach to handling concussions, the league will soon require teams to receive advice from independent neurologists while treating players with brain injuries, several people with knowledge of the plan confirmed Sunday.

For generations, decisions on when players who sustain concussions should return to play have been made by doctors and trainers employed by the team, raising questions of possible conflicts of interest when coaches and owners want players to return more quickly than proper care would suggest.

As scientific studies and anecdotal evidence have found a heightened risk for brain damage, dementia and cognitive decline in retired players, the league has faced barbed criticism from outside experts and, more recently, from Congress over its policies on handling players with concussions.

The league and Commissioner Roger Goodell have insisted that the N.F.L.’s policies are safe and that no third-party involvement is necessary, pointing to research by its committee on concussions as proof. But after an embarrassing hearing on the issue before the House Judiciary Committee last month in which the league was compared to the tobacco industry, the N.F.L. seems to have begun to embrace the value of outside opinion.

Full-text: http://www.nytimes.com/2009/11/23/sports/football/23concussion.html

8. Diagnostic Accuracy of Noncontrast Computed Tomography for Appendicitis in Adults: A Systematic Review

Hlibczuk V, et al. Ann Emerg Med 2009; in press

Study objective
We seek to determine the diagnostic test characteristics of noncontrast computed tomography (CT) for appendicitis in the adult emergency department (ED) population.

Methods
We conducted a search of MEDLINE, EMBASE, the Cochrane Library, and the bibliographies of previous systematic reviews. Included studies assessed the diagnostic accuracy of noncontrast CT for acute appendicitis in adults by using the final diagnosis at surgery or follow-up at a minimum of 2 weeks as the reference standard. Studies were included only if the CT was completed using a multislice helical scanner. Two authors independently conducted the relevance screen of titles and abstracts, selected studies for the final inclusion, extracted data, and assessed study quality. Consensus was reached by conference, and any disagreements were adjudicated by a third reviewer. Unenhanced CT test performance was assessed with summary receiver operating characteristic curve analysis, with independently pooled sensitivity and specificity values across studies.

Results
The search yielded 1,258 publications; 7 studies met the inclusion criteria and provided a sample of 1,060 patients. The included studies were of high methodological quality with respect to appropriate patient spectrum and reference standard. Our pooled estimates for sensitivity and specificity were 92.7% (95% confidence interval 89.5% to 95.0%) and 96.1% (95% confidence interval 94.2% to 97.5%), respectively; the positive likelihood ratio=24 and the negative likelihood ratio=0.08.

Conclusion
We found the diagnostic accuracy of noncontrast CT for the diagnosis of acute appendicitis in the adult population to be adequate for clinical decisionmaking in the ED setting.

9. Dabigatran Non-inferior to Warfarin in the Treatment of Acute Venous Thromboembolism

Much Pricier yet without the Need for Lab Monitoring

Schulman S, et al. N Engl J Med. 2009;361:2342-2352

Background: The direct oral thrombin inhibitor dabigatran has a predictable anticoagulant effect and may be an alternative therapy to warfarin for patients who have acute venous thromboembolism.

Methods: In a randomized, double-blind, noninferiority trial involving patients with acute venous thromboembolism who were initially given parenteral anticoagulation therapy for a median of 9 days (interquartile range, 8 to 11), we compared oral dabigatran, administered at a dose of 150 mg twice daily, with warfarin that was dose-adjusted to achieve an international normalized ratio of 2.0 to 3.0. The primary outcome was the 6-month incidence of recurrent symptomatic, objectively confirmed venous thromboembolism and related deaths. Safety end points included bleeding events, acute coronary syndromes, other adverse events, and results of liver-function tests.

Results: A total of 30 of the 1274 patients randomly assigned to receive dabigatran (2.4%), as compared with 27 of the 1265 patients randomly assigned to warfarin (2.1%), had recurrent venous thromboembolism; the difference in risk was 0.4 percentage points (95% confidence interval [CI], –0.8 to 1.5; P less than 0.001 for the prespecified noninferiority margin). The hazard ratio with dabigatran was 1.10 (95% CI, 0.65 to 1.84). Major bleeding episodes occurred in 20 patients assigned to dabigatran (1.6%) and in 24 patients assigned to warfarin (1.9%) (hazard ratio with dabigatran, 0.82; 95% CI, 0.45 to 1.48), and episodes of any bleeding were observed in 205 patients assigned to dabigatran (16.1%) and 277 patients assigned to warfarin (21.9%; hazard ratio with dabigatran, 0.71; 95% CI, 0.59 to 0.85). The numbers of deaths, acute coronary syndromes, and abnormal liver-function tests were similar in the two groups. Adverse events leading to discontinuation of the study drug occurred in 9.0% of patients assigned to dabigatran and in 6.8% of patients assigned to warfarin (P=0.05).

Conclusions: For the treatment of acute venous thromboembolism, a fixed dose of dabigatran is as effective as warfarin, has a safety profile that is similar to that of warfarin, and does not require laboratory monitoring.

10. What Happens When Doctors Give Patients More Power?

Dec. 03, 2009. NEW YORK (Reuters Health) - When patients are given the responsibility for medical decisions, they may be less willing to try a potentially risky treatment, a study published Monday suggests.

The study, of 216 patients with arthritis and other similar diseases, tested patients' willingness to take a hypothetical "new" drug that carried important benefits but also a small risk of serious side effects.

It turned out that patients were less willing to try the drug when they were given complete power over the decision than when a doctor advised them to take the medication.

When given a choice rather than a doctor's order, the study found, patients appeared to give greater thought to the potential side effects of the drug.

The findings, published in the journal Arthritis Care & Research, have implications for the trend toward greater patient involvement in healthcare. Studies have shown that patients who are more active in their care tend to fare better. However, there has been less research into what happens when actual decision-making is shifted over to patients.

The current results "suggest that asking some patients to assume more responsibility for decisions involving their healthcare may have unanticipated consequences," lead researcher Dr. Liana Fraenkel, of the Yale University School of Medicine, told Reuters Health in an email.

For the study, Fraenkel and colleague Dr. Ellen Peters had patients view one of two videos. Each featured a doctor describing a hypothetical new medication for which the patients were candidates -- a pain drug or a drug designed to lower heart disease risk.

Each drug was described as "very effective" and generally safe, but with a small risk of a serious side effect: either a breakdown of tissue in the jaw, or a rare but often fatal infection that causes brain inflammation. (Both of those are side effects of drugs currently on the market.)

After seeing the video, patients rated their willingness to take the drug under two circumstances: in one, their doctor said they should take the drug and wrote a prescription; in the other, the decision was left completely to the patient.

Overall, the researchers found, patients were less open to taking the drug when the decision was theirs alone. They also expressed greater worries over side effects.

"The shift of responsibility from M.D. to patient may cause some patients to pay more attention to risks," Fraenkel explained.

She and Peters note that studies in other areas have suggested that when people have a choice about whether to take a potentially risky action, they consider those risks more carefully. For example, city dwellers who can opt to drive or take the bus are more likely to see driving as a risky endeavor than do rural residents -- who have no choice but to drive.

According to Fraenkel, the current findings suggest that to make the most informed decisions about medical treatments, patients need help in weighing the potential benefits against the risks.
"I would argue that these results highlight the need to ensure that patients have the proper support to be able to participate in decision making," she said.

SOURCE: Arthritis Care & Research, online November 30, 2009.

11. Predictors of 30-Day Serious Events in Older Patients With Syncope

Sun BC, et al. Ann Emerg Med. 2009;54:769-778.e5.

Study objective
We identify predictors of 30-day serious events after syncope in older adults.

Methods
We reviewed the medical records of older adults (age ≥60 years) who presented with syncope or near syncope to one of 3 emergency departments (EDs) between 2002 and 2005. Our primary outcome was occurrence of a predefined serious event within 30 days after ED evaluation. We used multivariable logistic regression to identify predictors of 30-day serious events.

Results
Of 3,727 potentially eligible patients, 2,871 (77%) met all eligibility criteria. We excluded an additional 287 patients who received a diagnosis of a serious clinical condition while in the ED. In the final study cohort (n=2,584), we identified 173 (7%) patients who experienced a 30-day serious event. High-risk predictors included age greater than 90 years, male sex, history of an arrhythmia, triage systolic blood pressure greater than 160 mm Hg, abnormal ECG result, and abnormal troponin I level. A low-risk predictor was a complaint of near syncope rather than syncope. A risk score, generated by summing high-risk predictors and subtracting the low-risk predictor, can stratify patients into low- (event rate 2.5%; 95% confidence interval [CI] 1.4% to 3.6%), intermediate- (event rate 6.3%; 95% CI 5.1% to 7.5%), and high-risk (event rate 20%; 95% CI 15% to 25%) groups.

Conclusion
We identified predictors of 30-day serious events after syncope in adults aged 60 years and greater. A simple score was able to stratify these patients into distinct risk groups and, if externally validated, might have the potential to aid ED decisionmaking.

12. Rapid Influenza Test Helps Identify Low-Risk Febrile Infants

A positive rapid influenza test result predicted low risk for serious bacterial infection in febrile infants younger than 3 months.

Strategies for evaluating febrile infants younger than 3 months commonly use laboratory markers to identify patients at low risk for serious bacterial illness (SBI). In a prospective multicenter study, investigators in Spain evaluated whether rapid influenza tests can help identify low-risk patients. During the 2003–2008 influenza seasons, the investigators enrolled 381 infants younger than 3 months (22% aged 28 days) with fever 38°C from an unknown source who were evaluated with blood culture and rapid influenza tests. Patients who had been treated previously with antibiotics were excluded.

Overall, 3 of 113 patients (2.6%) with positive rapid influenza test results had SBI, compared with 47 of 268 patients (17.5%) with negative results. All SBIs in the positive group were from a urinary source. Blood cultures were positive in 0% of patients with positive rapid influenza test results, compared with 8 patients (3%) with negative rapid influenza test results (Streptococcus agalactiae in 4 patients, Neisseria meningitidis in 2, Streptococcus pneumoniae in 1, and Staphylococcus aureus in 1).

Comment: Historically, febrile infants younger than 1 month have been the most difficult to risk stratify. Unfortunately, these authors did not analyze the results by age, making the generalizability of these findings to that higher-risk, youngest age group unclear. However, when these results are coupled with those from previous studies that have demonstrated a low risk for bacteremia in infants with an identifiable viral source of fever, incorporating rapid influenza tests into risk stratification algorithms seems reasonable. Although rapid influenza tests have variable sensitivity, for well-appearing infants between ages 1 and 3 months with positive rapid influenza test results, urine analysis and culture are sufficient to exclude bacteremia. Caution: These investigators looked at seasonal influenza and not 2009 pandemic H1N1 influenza, which has been associated with higher rates of concomitant bacterial pneumonia.

— Katherine Bakes, MD. Published in Journal Watch Emergency Medicine November 13, 2009. Citation: Mintegi S et al. Rapid influenza test in young febrile infants for the identification of low-risk patients. Pediatr Infect Dis J 2009 Nov; 28:1026.

13. Anxieties Over Acetaminophen: FDA Panel Recommends Reducing Doses, Discarding Combination Drugs In Light of Liver Failures

Ann Emerg Med. 2009;54:A13-A16.

Full-text: http://www.annemergmed.com/article/S0196-0644(09)01642-4/fulltext

14. To Sellick or Not to Sellick?

A study of magnetic resonance images demonstrates occlusion of the hypopharynx by Sellick maneuver but does not prove that the maneuver has clinical value.

Routine use of Sellick maneuver (posterior displacement of the cricoid cartilage to occlude the alimentary tract) during rapid sequence intubation is no longer recommended because of inadequate proof of benefit and evidence that it might make intubation or ventilation more difficult (JW Emerg Med Jun 1 2000 and JW Emerg Med Jun 29 2007). To determine whether and how the maneuver occludes the alimentary tract, researchers obtained magnetic resonance images of 24 nonsedated volunteers with and without Sellick maneuver in three head and neck positions (sniffing, head extended, neutral).

Axial images showed a reduction in diameter of the postcricoid hypopharynx from an average of 7.3 mm without the maneuver to 4.7 mm with the maneuver in each position. The compressed diameter was less than the estimated wall thickness (6.1 mm) of the hypopharynx at this level, indicating complete occlusion.

Comment: An earlier study showed that the esophagus often slips left or right when Sellick maneuver is applied, thus avoiding compression by the cricoid cartilage. This study shows that the hypopharynx behind the cricoid cartilage was effectively occluded in these nonsedated patients, regardless of whether lateral displacement occurred at other levels of the esophagus. This finding's clinical meaning is not clear, nor does it help us decide whether to use Sellick maneuver. Editorialists express divergent opinions regarding the merit of the maneuver. Sellick maneuver should be considered optional until we have outcome data that support its use. However, Sellick maneuver is probably worthwhile during bag-mask ventilation, because previous research has shown that it minimizes flow of gases to the stomach.

— Ron M. Walls, MD, FRCPC, FAAEM. Published in Journal Watch Emergency Medicine December 11, 2009. Citation: Rice MJ et al. Cricoid pressure results in compression of the postcricoid hypopharynx: The esophageal position is irrelevant. Anesth Analg 2009 Nov; 109:1546.

15. Acute Metformin Overdose: Examining Serum pH, Lactate Level, and Metformin Concentrations in Survivors Versus Nonsurvivors: A Systematic Review of the Literature

Dell'Aglio DM, et al. Ann Emerg Med. 2009;54:818-823.

Study objective
Metformin is known to cause potentially fatal metabolic acidosis with an increased lactate level in both overdose and therapeutic use. No association between mortality and serum pH, lactate level, or metformin concentrations, though intuitive, has yet been described. This systematic literature review is designed to evaluate the association between mortality and serum pH, lactate level, and metformin concentrations in acute metformin overdose.

Methods
We reviewed the literature by using the MEDLINE, EMBASE, CINAHL, and TOXNET databases for cases of metformin overdose with documented mortality data and values of serum pH, lactate level, and metformin concentrations. When available, patient age, patient sex, and whether patients received intravenous sodium bicarbonate therapy or hemodialysis were also analyzed. Cases meeting inclusion criteria were analyzed to determine whether a difference in distribution of nadir serum pH, peak serum lactate level, or peak serum metformin concentrations existed between overdose survivors and nonsurvivors.

Results
We identified 10 articles that had 1 or more cases meeting our inclusion criteria. In total, there were 22 cases of metformin overdose (5/22 died) that met inclusion criteria. No intentional overdose patients died whose serum pH nadir was greater than 6.9, maximum lactate concentration less than 25 mol/L, or maximum metformin concentration less than 50 μg/mL (therapeutic range 1 to 2 μg/mL). Intentional overdose patients with a nadir serum pH less than 6.9 had 83% mortality (5/6), those with lactate concentration greater than 25 mmol/L had 83% mortality (5/6), and those with metformin concentration greater than 50 μg/mL had 38% mortality (5/12). Nadir serum pH and peak serum lactate and metformin concentration distributions in survivors and nonsurvivors revealed that survivors had a median nadir pH of 7.30, interquartile range (IQR) 7.22, 7.36; nonsurvivors, a median nadir pH of 6.71, IQR 6.71, 6.73; survivors, a median peak lactate level of 10.8 mmol/L, IQR 4.2, 12.9; nonsurvivors, a median peak lactate level of 35.0 mmol/L, IQR 33.3, 39.0; survivors, a median peak metformin level of 42 μg/mL, IQR 6.6, 67.6; and nonsurvivors, a median peak metformin level of 110 μg/mL, IQR 110, 110.

Conclusion
No cases of acute metformin overdose meeting the study's inclusion criteria were found in which patients with a nadir serum pH greater than 6.9, peak serum lactate concentrations less than 25 mmol/L, or peak serum metformin concentrations less than 50 μg/mL died. Patients with acute metformin overdose who died had much lower serum pH nadirs and much higher peak serum lactate and metformin concentrations than those who survived.

16. Downwardly Mobile: The Accidental Cost of Being Uninsured

Uninsured adults are almost twice as likely as insured adults to die after blunt or penetrating trauma.

Rosen H et al. Arch Surg. 2009;144:1006-11.

Hypothesis: Given the pervasive evidence of disparities in screening, hospital admission, treatment, and outcomes due to insurance status, a disparity in outcomes in trauma patients (in-hospital death) among the uninsured may exist, despite preventive regulations (such as the Emergency Medical Treatment and Active Labor Act).

Design: Data were collected from the National Trauma Data Bank from January 1, 2002, through December 31, 2006 (version 7.0). We used multiple logistic regression to compare mortality rates by insurance status.

Setting: The National Trauma Data Bank contains information from 2.7 million patients admitted for traumatic injury to more than 900 US trauma centers, including demographic data, medical history, injury severity, outcomes, and charges.

Patients: Data from patients (age, 18 years; n = 687 091) with similar age, race, injury severity, sex, and injury mechanism were evaluated for differences in mortality by payer status.

Main Outcome Measure: In-hospital death after blunt or penetrating traumatic injury.

Results: Crude analysis revealed a higher mortality for uninsured patients (odds ratio [OR], 1.39; 95% confidence interval [CI], 1.36-1.42; P less than .001). Controlling for sex, race, age, Injury Severity Score, Revised Trauma Score, and injury mechanism (adjusted for clustering on hospital), uninsured patients had the highest mortality (OR, 1.80; 95% CI, 1.61-2.02; P less than .001). Subgroup analysis of young patients unlikely to have comorbidities revealed higher mortality for uninsured patients (OR, 1.89; 95% CI, 1.66-2.15; P less than .001), as did subgroup analyses of patients with head injuries (OR, 1.65; 95% CI, 1.42-1.90; P less than .001) and patients with 1 or more comorbidities (OR, 1.52; 95% CI, 1.30-1.78; P less than .001).

Conclusions: Uninsured Americans have a higher adjusted mortality rate after trauma. Treatment delay, different care (via receipt of fewer diagnostic tests), and decreased health literacy are possible mechanisms.

17. CDC: 10,000 H1N1 Flu Deaths in US by mid-Nov

from WebMD. Daniel J. DeNoon. December 10, 2009 — H1N1 influenza killed 10,000 Americans, sent 213,000 to the hospital, and sickened 50 million — a sixth of the population — by mid-November, the US Centers for Disease Control and Prevention (CDC) estimates.

The CDC's new estimates reflect a flood of new cases from mid-October to mid-November, as the current wave of the US flu pandemic was climbing to its peak. The numbers represent the middle of a range of estimates made using statistical calculations to correct for underreporting of cases, hospitalizations, and deaths.

"Sadly, there were nearly 10,000 deaths: 1,100 in children and 7,500 among young adults," CDC director Thomas R. Frieden, MD, MPH, said at a news conference. "That is much higher than we would see in a usual flu season. This is a flu that is much harder on young people and that has largely spared the elderly."

The new estimates suggest that about 15% of the population — 1 in 6 Americans — has had the H1N1 flu.

"That leaves most Americans not infected or vaccinated and still susceptible to H1N1 flu," Frieden said. "Even if there were a lot of infections without symptoms and adding in those who have been vaccinated, that still leaves a lot of people unprotected. Only time will tell what the future will hold — but the more people who get vaccinated, the lower the probability of a third wave of the pandemic."

Full-text (free) at CDC: http://www.cdc.gov/h1n1flu/estimates_2009_h1n1.htm

18. Exploring Emergency Physician–Hospitalist Handoff Interactions: Development of the Handoff Communication Assessment

Apker J, et al. Ann Emerg Med. 2009; in press.

Study objective
We develop and evaluate the Handoff Communication Assessment, using actual handoffs of patient transfers from emergency department to inpatient care.

Methods
This was an observational qualitative study. We derived a Handoff Communication Assessment tool, using categories from discourse coding described in physician-patient communication, previous handoff research in medicine, health communication, and health systems engineering and pilot data from 3 physician-hospitalist handoffs. The resulting tool consists of 2 typologies, content and language form. We applied the tool to a convenience sample of 15 emergency physician-to-hospitalist handoffs occurring at a community teaching hospital. Using discourse analysis, we assigned utterances into categories and determined the frequency of utterances in each category and by physician role.

Results
The tool contains 11 content categories reflecting topics of patient presentation, assessment, and professional environment and 11 language form categories representing information-seeking, information-giving, and information-verifying behaviors. The Handoff Communication Assessment showed good interrater reliability for content (kappa=0.71) and language form (κ=0.84). We analyzed 742 utterances, which provided the following preliminary findings: emergency physicians talked more during handoffs (67.7% of all utterances) compared with hospitalists (32.3% of all utterances). Content focused on patient presentation (43.6%), professional environment (36%), and assessment (20.3%). Form was mostly information-giving (90.7%) with periodic information-seeking utterances (8.8%) and rarely information-verifying utterances (0.4%). Questions accounted for less than 10% of all utterances.

Conclusion
We were able to develop and use the Handoff Communication Assessment to analyze content and structure of handoff communication between emergency physicians and hospitalists at a single center. In this preliminary application of the tool, we found that emergency physician–to-hospitalist handoffs primarily consist of information giving and are not geared toward question-and-answer events. This critical exchange may benefit from ongoing analysis and reformulation.

19. Price of Nonadherance to Antihypertensives

Mazzaglia G, et al. Circulation. 2009;120:1598-1605.

Introduction: High blood pressure (BP) is one of the most preventable causes of cardiovascular disease morbidity and mortality. The use of antihypertensive drug therapy (AHT) has been shown to reduce the risk of stroke and coronary heart disease by an estimated 34% and 21%, respectively, in long-term randomized controlled trials (RCTs). Generally, AHT should be maintained indefinitely. However, findings in clinical practice have raised concerns about the high extent of undertreatment and nonadherence to AHT, which hampers the effectiveness of these medications. In RCTs, antihypertensive drug discontinuation rates range from 5% to 10% per year, and rates up to 50% to 60% after 6 months have been reported in actual practice.

Adherence to AHT has been associated with improved BP, decreased hospitalizations rates, and lower medical care costs. A recent cohort study has also confirmed that the long-term survival advantages associated with improved adherence to AHT after acute myocardial infarction (AMI) appear to be class specific and correlated positively in a dose-response–type fashion. This evidence suggests that the benefits associated with adherence to evidence-based therapies are mediated by drug effects rather than the adoption of healthier lifestyles that often accompanies adherent behaviors (ie, healthy adherer effect).

To the best of our knowledge, less attention has been paid to understanding how nonadherence to AHT might affect the occurrence of cardiovascular events (CVEs) among patients who had not experienced any major cardiovascular outcome. The aim of the present study was to describe adherence to AHT and its association with concurrent drug use, comorbidities, and cardiovascular risk factors. Furthermore, we assessed the impact of adherence on the incidence of CVE among newly diagnosed hypertensive patients.

Methods and Results— Using data obtained from 400 Italian primary care physicians providing information to the Health Search/Thales Database, we selected 18 806 newly diagnosed hypertensive patients 35 years of age during the years 2000 to 2001. Subjects included were newly treated for hypertension and initially free of cardiovascular diseases. Patient adherence was subdivided a priori into 3 categories—high (proportion of days covered, 80%), intermediate (proportion of days covered, 40% to 79%), and low (proportion of days covered, 40%)—and compared with the long-term occurrence of acute cardiovascular events through the use of multivariable models adjusted for demographic factors, comorbidities, and concomitant drug use. At baseline (ie, 6 months after index diagnosis), 8.1%, 40.5%, and 51.4% of patients were classified as having high, intermediate, and low adherence levels, respectively. Multiple drug treatment (odds ratio, 1.62; 95% CI, 1.43 to 1.83), dyslipidemia (odds ratio, 1.52; 95% CI, 1.24 to 1.87), diabetes mellitus (odds ratio, 1.40; 95% CI, 1.15 to 1.71), obesity (odds ratio, 1.50; 95% CI, 1.26 to 1.78), and antihypertensive combination therapy (odds ratio, 1.29; 95% CI, 1.15 to 1.45) were significantly (P less than 0.001) associated with high adherence to antihypertensive treatment. Compared with their low-adherence counterparts, only high adherers reported a significantly decreased risk of acute cardiovascular events (hazard ratio, 0.62; 95% CI, 0.40 to 0.96; P=0.032).

Conclusions— The long-term reduction of acute cardiovascular events associated with high adherence to antihypertensive treatment underscores its importance in assessments of the beneficial effects of evidence-based therapies in the population. An effort focused on early antihypertensive treatment initiation and adherence is likely to provide major benefits.

Full-text (free): http://circ.ahajournals.org/cgi/content/full/120/16/1598

20. Serious Bacterial Infection in Recently Immunized Young Febrile Infants

Wolff M, et al. Acad Emerg Med. 2009;16:1284-1298.

Objective: The objective of this study was to investigate the prevalence of serious bacterial infection (SBI) in febrile infants without a source aged 6–12 weeks who have received immunizations in the preceding 72 hours.

Methods: The authors conducted a medical record review of infants aged 6–12 weeks with a fever of 38.0°C or higher presenting to the pediatric emergency department (ED) over 88 months. Infants were classified either as having received immunizations within the 72 hours preceding the ED visit (recent immunization [RI]) or as not having received immunizations during this time period (no recent immunization [NRI]). Primary outcome of an SBI was based on culture results; only patients with a minimum of blood and urine cultures were studied.

Results: A total of 1,978 febrile infants were studied, of whom 213 (10.8%) had received RIs. The overall prevalence of definite SBI was 6.6% (95% confidence interval [CI] = 5.5 to 7.7). The prevalence of definite SBI in NRI infants was 7.0% (95% CI = 5.9 to 8.3) compared to 2.8% (95% CI = 0.6 to 5.1) in the RI infants. The prevalence of definite SBI in febrile infants vaccinated in the preceding 24 hours decreased to 0.6% (95% CI = 0 to 1.9). The prevalence of definite SBI in febrile infants vaccinated greater than 24 hours prior to presentation was 8.9% (95 CI = 1.5 to 16.4). The relative risk of SBI with RI was 0.41 (95% CI = 0.19 to 0.90). All SBIs in the RI infants were urinary tract infections (UTI).

Conclusions: Among febrile infants, the prevalence of SBI is less in the initial 24 hours following immunizations. However, there is still a substantial risk of UTI. Therefore, urine testing should be considered in febrile infants who present within 24 hours of immunization. Infants who present greater than 24 hours after immunizations with fever should be managed similarly to infants without RIs.

21. Soft Tissue Infections and ED Disposition: Fever Predicts Need for Inpatient Admission

Sabbaj A, et al. Ann Emerg Med. 2009;16:1290-1297.

Objectives: Little empiric evidence exists to guide emergency department (ED) disposition of patients presenting with soft tissue infections. This study's objective was to generate a clinical decision rule to predict the need for greater than 24-hour hospital admission for patients presenting to the ED with soft tissue infection.

Methods: This was a retrospective cohort study of consecutive patients presenting to a tertiary care hospital ED with diagnosis of nonfacial soft tissue infection. Standardized chart review was used to collect 29 clinical variables. The primary outcome was >24-hour hospital admission (either general admission or ED observation unit), regardless of initial disposition. Patients initially discharged home and later admitted for more than 24 hours were included in the outcome. Data were analyzed using classification and regression tree (CART) analysis and multivariable logistic regression.

Results: A total of 846 patients presented to the ED with nonfacial soft tissue infection. After merging duplicate records, 674 patients remained, of which 81 (12%) required longer than 24-hour admission. Using CART, the strongest predictors of >24-hour admission were patient temperature at ED presentation and mechanism of infection. In the multivariable logistic regression model, initial patient temperature (odds ratio [OR] for each degree over 37°C = 2.91, 95% confidence interval [CI] = 1.65 to 5.12) and history of fever (OR = 3.02, 95% CI = 1.41 to 6.43) remained the strongest predictors of hospital admission. Despite these findings, there was no combination of factors that reliably identified more than 90% of target patients.

Conclusions: Although we were unable to generate a high-sensitivity decision rule to identify ED patients with soft tissue infection requiring >24-hour admission, the presence of a fever (either by initial ED vital signs or by history) was the strongest predictor of need for >24-hour hospital stay. These findings may help guide disposition of patients presenting to the ED with nonfacial soft tissue infections.