Lit Bits: Nov 26, 2011

From the recent medical literature...

1. Number of Coronary Heart Disease Risk Factors and Mortality in Patients with First MI

Risk of fatal heart attack higher without warning signs

One in seven patients who did not display risk factors suggestive of heart disease died after experiencing a heart attack compared with 1 in 28 with five risk factors, according to a study in the Journal of the American Medical Association. The survival of patients with more risk factors might be due to medications they took, researchers said. The findings were based on data from a national registry of nearly 550,000 first-time heart attack cases from 1994 to 2006

Canto JG, et al. JAMA 2011; 306(19):2120-2127.

Context: Few studies have examined the association between the number of coronary heart disease risk factors and outcomes of acute myocardial infarction in community practice.

Objective: To determine the association between the number of coronary heart disease risk factors in patients with first myocardial infarction and hospital mortality.

Design: Observational study from the National Registry of Myocardial Infarction, 1994-2006.

Patients: We examined the presence and absence of 5 major traditional coronary heart disease risk factors (hypertension, smoking, dyslipidemia, diabetes, and family history of coronary heart disease) and hospital mortality among 542 008 patients with first myocardial infarction and without prior cardiovascular disease.

Main Outcome Measure: All-cause in-hospital mortality.

Results: A majority (85.6%) of patients who presented with initial myocardial infarction had at least 1 of the 5 coronary heart disease risk factors, and 14.4% had none of the 5 risk factors. Age varied inversely with the number of coronary heart disease risk factors, from a mean age of 71.5 years with 0 risk factors to 56.7 years with 5 risk factors (P for trend less than .001). The total number of in-hospital deaths for all causes was 50 788. Unadjusted in-hospital mortality rates were 14.9%, 10.9%, 7.9%, 5.3%, 4.2%, and 3.6% for patients with 0, 1, 2, 3, 4, and 5 risk factors, respectively. After adjusting for age and other clinical factors, there was an inverse association between the number of coronary heart disease risk factors and hospital mortality adjusted odds ratio (1.54; 95% CI, 1.23-1.94) among individuals with 0 vs 5 risk factors. This association was consistent among several age strata and important patient subgroups.

Conclusion: Among patients with incident acute myocardial infarction without prior cardiovascular disease, in-hospital mortality was inversely related to the number of coronary heart disease risk factors.

2. Children with Normal CT after Blunt Head Injury Are at Low Risk for Neurological Complications

No neurosurgical interventions were required in children with blunt head injury who had GCS scores of 14 or 15 and normal head CT scans in the emergency department.

In a planned secondary analysis of a prospective observational cohort study from PECARN (the Pediatric Emergency Care Applied Research Network), investigators evaluated the frequency of neurological complications in children (age, below 18 years) with blunt head trauma (isolated or multisystem trauma), initial Glasgow Coma Scale (GCS) scores of 14 or 15, and normal emergency department head computed tomography (CT) scans. CT scans were performed at the discretion of the treating provider. Patients discharged to home were followed up at 1 week by telephone survey (capture rate, 79%); morgue and medical records were reviewed for patients with incomplete surveys.

Of 13,543 patients (mean age, 8.9 years; 20% below 2 years) who met inclusion criteria during the 2-year study period, 2485 (18%) were hospitalized. Among hospitalized patients, 137 (6%) underwent subsequent neuroimaging, and 16 (0.6%) had abnormal findings. Among discharged patients, 197 (2%) underwent subsequent neuroimaging, and 5 (0.05%) had abnormal findings. No patient in either group required neurosurgical intervention.

Comment: Children with blunt head injury who have normal GCS scores and head CT scans can be safely discharged home with postconcussive follow-up care instructions regarding signs of deterioration and outpatient follow-up before resuming physical activities, such as sports.

— Katherine Bakes, MD. Published in Journal Watch Emergency Medicine November 4, 2011

Citation: Holmes JF et al. Do children with blunt head trauma and normal cranial computed tomography scan results require hospitalization for neurologic observation? Ann Emerg Med 2011 Oct; 58:315.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/21683474

3. Cardioversion of acute AF in the short observation unit in Italy: comparison of a protocol focused on electrical cardioversion with simple antiarrhythmic treatment

Cristoni L, et al. Emerg Med J 2011;28:932-937

Background: Direct current cardioversion (DCC) has been shown to be effective for the management of atrial fibrillation (AF) in the emergency department (ED). Pharmacological cardioversion was compared with a strategy including DCC on patients with uncomplicated, recent-onset (within 48 h) AF managed in a short observation unit (SOU).

Methods: A prospective observational study was undertaken over a period of 13 months in two institutions. A DCC-centred protocol was applied to 171 AF cases in a hospital (DCC-cohort) and pharmacological cardioversion to 151 AF cases in another hospital (P-cohort). Patients remaining in AF after 24 h were admitted. The outcomes were rate of discharge in sinus rhythm, length of stay in the ED-SOU, rate of hospitalisation and complications of treatment. Data collected were analysed according to Student t test and χ2 statistics.

Results: Discharge in sinus rhythm was achieved in 159/171 cases in the DCC-cohort and 77/151 cases in the P-cohort (93% vs 51%; number needed to treat (NNT) 2.4; 95% CI 2.0 to 3.1, p less than 0.001), whereas mean length of stay was 7+7 h in the DCC-cohort and 9+6 h in the P-cohort (p=0.43). Eleven cases from the DCC-cohort and 67 from the P-cohort were admitted (admission rate 6% vs 44%; NNT 2.6; 95% CI 2.2 to 3.5, p less than 0.001). Three short-term complications occurred in the DCC-cohort and five in the P-cohort (2% vs 3%, p=0.59). Two strokes were registered in the DCC-cohort during 6-month follow-up (p undefined).

Conclusions: Electrical cardioversion of recent-onset AF in the SOU is safe, effective and reduces hospitalisations. Further studies are needed to identify the most cost-effective strategy for the management of AF patients in emergency settings.

Cf a U.S. ED study with similar results without employing an obs unit: Managing ED Patients with Recent-onset AF. J Emerg Med. 2010 Jul 15. [Epub ahead of print] http://www.ncbi.nlm.nih.gov/pubmed/20634022

4. Broken Toe? Forget the Follow-up

by Kevin Klauer, DO, Emergency Physicians Monthly, November 10, 2011

Want to save the healthcare system time and money? Forget the follow-up and make the emergency department the last stop for a range of simple injuries. First up: broken toes.

Definitive management? Aren’t we capable of finishing anything we start? In a different place, in a different time, in a world where common sense outweighs defensive medicine, we should be the last stop for certain conditions.

Toe fractures are an excellent place to start. Let’s assume that complications are expected with toe fractures. How bad could they be? Even if there is a non-union, you have nine others! Clearly, many patients cannot receive definitive management in the ED, either due to the need for specialized care (i.e., complex fracture management), assessment for response to treatment (i.e., community acquired pneumonia or cellulitis) or the need for further diagnostic evaluation (i.e., low risk chest or undifferentiated abdominal pain). In contrast to a toe, chest pain patients only have one heart, and that organ trumps a toe any day.

I have no idea how many toe fractures are seen annually in U.S. EDs. However, I would venture to guess it’s more than a baker’s dozen. Thus, the impact for providing more efficient and cost-effective care by providing definitive management for toe fractures is likely to be substantial. About a year and a half ago, I dropped a trailer hitch on my right 5th toe. I knew upon impact it was broken. I’m not a swearing man. However, I consulted the socially unacceptable thesaurus on that one. It hurt. It swelled, and it wasn’t back to normal for about 5 weeks, but I didn’t seek medical attention for it. In my “N” of one, the outcome has been good and the cost of care was $0.00. Not withstanding the lack of value of radiographic evaluation, buddy taping and buying a post-op shoe, follow-up care wouldn’t have changed the outcome.

Not only is definitive management of toe fractures a reasonable consideration, with respect to incorporating cost-saving strategies for healthcare reform, using less diagnostics makes sense also. So, what are we worried about? Sure. It’s broken. So, the reflex is to order an x-ray. However, when you already know it’s broken and you won’t do anything different with the test you’re considering ordering, just say no. In my opinion, too many radiographs are ordered due to culture and not used to improve care. Most patients want an answer, not a test. So, if you can give them a definitive answer without order a radiograph, you both might be happier.

Although there is much data on this topic, let’s just discuss one contemporary article by Van Vliet-Koppert…

The remainder of the essay is here: http://www.epmonthly.com/subspecialties/management/broken-toe-forget-the-follow-up/

5. Relationship between Pain Severity and Outcomes in Patients Presenting with Potential ACS

Edwards M, et al. Ann Emerg Med. 2011;58:501-507.

Study objective: Although lay people often assume that severe pain is more commonly associated with worse outcomes, the relationship between pain severity and outcome for patients presenting with potential acute coronary syndrome has not been well described. We hypothesize that pain severity will not be associated with acute myocardial infarction or 30-day cardiovascular complications.

Methods: We conducted a secondary analysis of a prospective cohort study of patients presenting to the emergency department (ED) with potential acute coronary syndrome. Trained research assistants collected data, including demographics, medical history, symptoms, hospital course, and 30-day outcomes (record review and telephone). Pain score on arrival (0 to 10) was abstracted from nurses' triage documentation in the electronic record. Severe pain was defined as 9 or 10. The main outcomes were the prevalence of acute myocardial infarction during index visit and composite of death, acute myocardial infarction, revascularization including percutaneous coronary intervention, or coronary bypass artery grafting at 30 days. Multivariable modeling was prespecified to adjust for age, race, sex, pain duration, thrombolysis in myocardial infarction (TIMI) score, and mode of arrival. Data are presented as relative risk (RR) with 95% confidence intervals (CI).

Results: Patients (3,306) had pain documented (mean age 51.0 years; SD 12.6 years; 57% women; 66% black). Follow-up was 93%. By 30 days, 34 patients had died, 105 patients underwent revascularization (94 percutaneous coronary intervention, 14 coronary bypass artery grafting), and 111 patients experienced acute myocardial infarction. There was not a relationship between severe pain and acute myocardial infarction (RR 1.28; 95% CI 0.93 to 1.76) or 30-day composite outcome (1.19; 95% CI 0.91 to 1.56). After adjusting for potential confounding variables, we found that the prevalence of inhospital acute myocardial infarction was related to TIMI score (adjusted relative risk [aRR] 2.00; 95% CI 1.05 to 3.80), male sex (aRR 1.48; 95% CI 1.00 to 2.18), and arrival by emergency medical services (EMS) (aRR 1.73; 95% CI 1.13 to 2.63) but not age (aRR 1.42; 95% CI 0.68 to 2.95), white race (aRR 1.25; 95% CI 0.85 to 1.86), pain duration greater than 1 hour (aRR 1.36; 95% CI 0.89 to 2.07), or severe pain (aRR 1.43; 95% CI 0.91 to 2.22). Thirty-day composite outcome was related to male sex (aRR 1.53; 95% CI 1.16 to 2.01), white race (aRR 1.43; 95% CI 1.09 to 1.87), and higher TIMI score (aRR 2.24; 95% CI 1.39 to 3.60) but was not related to age (aRR 1.26; 95% CI 0.75 to 2.11), pain duration greater than 1 hour (aRR 0.8; 95% CI 0.60 to 1.06), EMS arrival (aRR 1.23; 95% CI 0.96 to 1.60), or severe pain (aRR 1.39; 95% CI 0.95 to 1.97).

Conclusion: For patients who present to the ED with potential acute coronary syndrome, severe pain is not related to likelihood of acute myocardial infarction at presentation or death, acute myocardial infarction or revascularization within 30 days.

6. Lytics for Acute CVA

A. Stroke Mimics and Intravenous Thrombolysis

Artto V, et al. Ann Emerg Med. 2011; in press.

Study objective: The necessity for rapid administration of intravenous thrombolysis in patients with acute ischemic stroke may lead to treatment of patients with conditions mimicking stroke. We analyze stroke patients treated with intravenous thrombolysis in our center to characterize cases classified as stroke mimics.

Methods: We identified and reviewed all cases with a diagnosis other than ischemic stroke in our large-scale single-center stroke thrombolysis registry. We compared these stroke mimics with patients with neuroimaging-negative and neuroimaging-positive ischemic stroke results.

Results: Among 985 consecutive intravenous thrombolysis–treated patients, we found 14 stroke mimics (1.4%; 95% confidence interval 0.8% to 2.4%), 694 (70.5%) patients with neuroimaging-positive ischemic stroke results, and 275 (27.9%) patients with neuroimaging-negative ischemic stroke results. Stroke mimics were younger than patients with neuroimaging-negative or -positive ischemic stroke results. Compared with patients with neuroimaging-positive ischemic stroke results, stroke mimics had less severe symptoms at baseline and better 3-month outcome. No differences appeared in medical history or clinical features between stroke mimics and patients with neuroimaging-negative ischemic stroke results. None of the stroke mimics developed symptomatic intracerebral hemorrhage compared with 63 (9.1%) among patients with neuroimaging-positive ischemic stroke results and 6 (2.2%) among patients with neuroimaging-negative ischemic stroke results.

Conclusion: Stroke mimics were infrequent among intravenous thrombolysis–treated stroke patients in this cohort, and their treatment did not lead to harmful complications.

B. Patients with Diabetes and Prior Stroke Benefit from Thrombolytic Therapy for Treatment of Acute Stroke

This finding will expand eligibility for thrombolysis in the U.S.

Concomitant diabetes mellitus and prior stroke is thought to potentially mitigate the benefits of thrombolytic therapy for acute stroke. In Europe, concomitant diabetes and prior stroke is considered a contraindication to thrombolytic therapy, whereas in the U.S., it is considered a contraindication only for patients who present in the expanded treatment window (3–4.5 hours).

Researchers used registry data to assess the effect of diabetes and prior stroke on outcomes (adjusted 90-day modified Rankin Scale score) in patients who received tissue plasminogen activator (TPA) for acute stroke (data from the Safe Implementation of Thrombolysis in Stroke–International Stroke Thrombolysis Register) and control patients who did not (data from the Virtual International Stroke Trials Archive). Analyses were controlled for the following confounding patient variables: National Institutes of Health Stroke Scale score, age, and comorbidities.

Of 29,500 patients, 19% had diabetes, 17% had prior stroke, and 6% had both. Among patients with diabetes, prior stroke, or both, those who received TPA had significantly better outcomes than those who did not receive TPA. Among patients who received TPA, those with diabetes, prior stroke, or both had similar outcomes to those with neither diabetes nor prior stroke.

Comment: This large study does not support excluding patients with diabetes mellitus, prior stroke, or both from consideration for thrombolytic therapy for treatment of acute stroke. This finding will expand eligibility for thrombolytic therapy.

— Richard D. Zane, MD, FAAEM. Published in Journal Watch Emergency Medicine November 18, 2011. Citation: Mishra NK et al. Thrombolysis outcomes in acute ischemic stroke patients with prior stroke and diabetes mellitus. Neurology 2011 Nov 22; 77:1866.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/22094479

7. Patterns and Predictors of Short-Term Death after ED Discharge

Gelareh Z. Gabayan GZ, et al. Ann Emerg Med. 2011;58:551-558.e2.

Study objective: The emergency department (ED) is an inherently high-risk setting. Early death after an ED evaluation is a rare and devastating outcome; understanding it can potentially help improve patient care and outcomes. Using administrative data from an integrated health system, we describe characteristics and predictors of patients who experienced 7-day death after ED discharge.

Methods: Administrative data from 12 hospitals were used to identify death after discharge in adults aged 18 year or older within 7 days of ED presentation from January 1, 2007, to December 31, 2008. Patients who were nonmembers of the health system, in hospice care, or treated at out-of-network EDs were excluded. Predictors of 7-day postdischarge death were identified with multivariable logistic regression.

Results; The study cohort contained a total of 475,829 members, with 728,312 discharges from Kaiser Permanente Southern California EDs in 2007 and 2008. Death within 7 days of discharge occurred in 357 cases (0.05%). Increasing age, male sex, and number of preexisting comorbidities were associated with increased risk of death. The top 3 primary discharge diagnoses predictive of 7-day death after discharge included noninfectious lung disease (odds ratio [OR] 7.1; 95% confidence interval [CI] 2.9 to 17.4), renal disease (OR 5.6; 95% CI 2.2 to 14.2), and ischemic heart disease (OR 3.8; 95% CI 1.0 to 13.6).

Conclusion; Our study suggests that 50 in 100,000 patients in the United States die within 7 days of discharge from an ED. To our knowledge, our study is the first to identify potentially “high-risk” discharge diagnoses in patients who experience a short-term death after discharge.

8. What Do We Do With a Positive Troponin Test?

Amal Mattu, MD. Medscape Emerg Med. Posted: 10/28/2011

Introduction

A physician recently emailed me with a question (paraphrasing): "Our lab recently switched over to using the new high-sensitivity troponin test and we're confused. What do we do with a positive troponin (TN) test?"

A handful of years ago, I suppose my gut response to someone asking what to do with a positive TN test would have been to tell that person to do more continuing medical education before seeing any more patients. My belief now, however, has become one of complete empathy with this physician and his colleagues. It seems that we all are having a tough time figuring this out, including our own cardiologists. The most recent high-profile article pertaining to the high-sensitivity (HS)-TN test has prompted another flurry of emails, questions, and uncertainty. Here's a quick summary and then some further thoughts about the article, TN testing, and evaluating patients with possible acute coronary syndromes.

Rapid Exclusion of Acute Myocardial Infarction in Patients With Undetectable Troponin Using a High-Sensitivity Assay

Body R, Carley S, McDowell G, et al. J Am Coll Cardiol. 2011;58:1332-1339

Study Summary

The study authors evaluated 703 patients presenting with chest pain to a large hospital's emergency department (ED) in the United Kingdom. A total of 130 (18.5%) patients were diagnosed with acute myocardial infarction (AMI) using standard, accepted criteria for diagnosis with TN testing, which incorporates a serial rise (or fall) of TN. Serial testing in this case meant that the researchers obtained a TN level (a HS-TN-T assay was used in this study) at the time of presentation and a second level at 12 hours after the onset of symptoms. Nearly half (46%) of the patients presented within 3 hours of symptom onset, so the study did incorporate many early presenters.

The study authors found that of 130 patients diagnosed with AMI, 100% had an elevated HS-TN level at the time of presentation (95% confidence interval was 95.1%-100%). In other words, no patients who presented initially with a negative HS-TN level had a positive HS-TN on serial testing. The study authors suggested that this HS-TN level would obviate the need for serial testing and therefore allow early discharge of these patients from the ED. Sounds great! No more serial TN testing is needed, and we can now make dispositions after only 1 blood test and, at least slightly, decrease ED crowding. Right?

Viewpoint

Before we even begin to address the limitations associated with the study and its conclusions, let's first try to agree on a few things:

• Nothing in medicine is 100%: Nothing is 100% positive, 100% negative, or 100% accurate. Well, death is 100% certain, but not much else. Just like every other study in history that claimed 100% accuracy, subsequent attempts to validate this study will demonstrate numbers less than 100%.

• What we do in emergency medicine is not to rule in or rule out diseases, but we risk stratify everything. For example, if you see a patient with chest pain who has an ECG with ST-segment elevation in the anterior leads and ST-depression in the inferior leads, it risk stratifies that patient to a higher likelihood of AMI, but it doesn't definitely rule in AMI. In fact, the accuracy of such an ECG for AMI is only ~90%. Similarly, if a patient with chest pain has a normal ECG, it risk stratifies that patient to a lower likelihood of AMI but doesn't rule it out.

• This same concept of risk stratification applies to TN testing. A negative TN risk stratifies a patient to a lower likelihood of AMI but not to 0%. Also, a positive TN risk stratifies a patient to a higher likelihood of AMI, but not to 100%. This last point is critically important to remember: Positive TNs are markers of myocardial injury, but AMI is only one cause of myocardial injury. There are numerous other causes of positive TN: cardiac trauma, congestive heart failure, aortic valve disease, dysrhythmias (tachy- or brady-), rhabdomyolysis, pulmonary embolism, acute neurologic disease (including stroke and subarachnoid hemorrhage), inflammatory diseases of the heart (pericarditis, myocarditis), infiltrative diseases of the heart, sepsis, toxins, and so on.[1] In fact, many cardiologists already think that the current TN tests are too sensitive!

• The fact that there are so many causes of positive TNs is the exact reason why the international universal definition of AMI[1] incorporates serial TN testing rather than relying on an isolated positive TN. True atherosclerosis-related AMI produces a rise and fall of TNs, whereas the majority of other causes of positive TN do not produce this typical sequence of levels.

•It's important to remember that our mandate in the ED -- at least in the United States -- is not to simply evaluate patients for AMI. We also need to evaluate patients for acute coronary syndrome. Elevated levels of TN are helpful for diagnosing myocardial injury, but they are nearly worthless for diagnosing ischemia (ie, unstable angina). Therefore, what we currently have in TN is a test that, when positive, doesn't rule in acute coronary syndrome and when negative doesn't rule out acute coronary syndrome.

Putting history and ECG aside, let's focus on just the TN. How exactly are we supposed to use TN testing? First, it's important that we all change our mind-set such that we don't think of TNs as a test to rule in or rule out disease. They are only useful at risk stratifying the disease and making decisions that are based on that risk. If the TN is positive, you and your consulting cardiologists might consider cardiac catheterization or instead consider performing serial testing to distinguish between the typical rise of true AMI vs the "smoldering" elevation that is often seen in the other conditions. On the other hand, if the TN is negative, it simply risk stratifies patients to a lower likelihood of acute coronary syndrome (but not zero). Essentially, negative TNs indicate that a patient is now stable for a provocative test; they do not exclude acute coronary syndrome. The current national American College of Cardiology/American Heart Association (ACC/AHA)[2,3] and American College of Emergency Physicians (ACEP)[4] guidelines allow us to discontinue the ACS workup only after a negative provocative test; they do not allow us to discontinue the workup after negative TNs.

The remainder of the article can be found here: http://www.medscape.com/viewarticle/752166

9. Low yield of ED MRI for suspected epidural abscess

El Sayed M, et al. Amer J Emerg Med. 2011;978-982.

Purpose: The aim of this study was to estimate the yield of emergency department (ED) magnetic resonance imaging (MRI) in detecting spinal epidural abscess (SEA) and to identify clinical factors predicting positive MRI results.

Basic Procedure: We examined a cohort of patients who underwent MRI to rule out SEA, followed by a nested case-control comparison of those with positive results and a sample with negative results. A positive result was defined as osteomyelitis, discitis, or SEA. Predictor variables included temperature, presenting complaint, drug abuse status, history of SEA or back surgery, midline back tenderness, neurologic deficit, MRI level, mean white blood cell count, erythrocyte sedimentation rate, and C-reactive protein level.

Main Findings: Fourteen of the 120 available MRIs were excluded; 7 (6.6%) of the remaining 106 were positive. Temperature was 1.1°C higher in cases than controls (95% CI, 0.6-1.7).

Conclusion: Emergency department MRI for suspected SEA has a low yield. Clinical guidelines are needed to improve efficiency.

10. Rapid (60 mL/kg) versus standard (20 mL/kg) intravenous rehydration in paediatric gastroenteritis: pragmatic blinded randomised clinical trial

Freedman SB, et al. BMJ 2011;343:bmj.d6976

Introduction

Gastroenteritis remains a disease of major importance in public health. Although oral rehydration is appropriate for most children, many receive prolonged intravenous rehydration, which contributes to overcrowding in the emergency department. Given the safety of replacing fluid deficits over 24 hours in haemodynamically stable children, traditional teaching and the National Patient Safety Agency have advocated such an approach. Experts have noted, however, that there is a disparity between the slow restoration regimens recommended and the rapid rehydration regimens used by clinicians treating dehydration. The latter has the potential to reduce a child’s level of agitation and clinical signs of dehydration, in addition to enhancing alertness and appetite. These potential benefits might enable clinicians to achieve earlier rehydration with subsequent reductions in length of stay and costs. A review of rapid intravenous rehydration studies concluded that evidence of efficacy is lacking. Thus gastroenteritis treatment guidelines aimed at developed countries, where severe dehydration is uncommon, rarely provide a detailed rapid rehydration strategy.

Because of its potential benefits, and despite a paucity of evidence, rapid intravenous rehydration has gradually become incorporated into clinical practice9 and is recommended in a leading textbook of emergency medicine. This procedure, however, is not without risks. A recent study of fluid bolus resuscitation in febrile African children had to be stopped early because of increased mortality in the bolus group. Moreover, advocates for rapid intravenous rehydration4 suggest that serum should be routinely tested to enable the detection of severe hyponatraemia or hypernatraemia, which necessitates specific therapeutic approaches to reduce the risk of central pontine myelinolysis and cerebral oedema, respectively. As only 30% of academic paediatric emergency medicine physicians routinely check electrolytes in the United States, the widespread use of rapid intravenous rehydration might place children at unnecessary risk. Given the established safety of standard rehydration in haemodynamically stable children, the lack of evidence of benefit, and the potential complications that might arise with the widespread use of rapid intravenous rehydration, a rigorous evaluation of this more aggressive approach is needed.

We carried out a pragmatic randomised, blinded, comparative effectiveness trial among haemodynamically stable children in whom oral rehydration had failed and who were deemed to require intravenous rehydration. Our primary objective was to determine whether treatment with rapid intravenous rehydration resulted in a clinically important increase in the number of children achieving rehydration compared with standard treatment.

Abstract

Objective: To determine if rapid rather than standard intravenous rehydration results in improved hydration and clinical outcomes when administered to children with gastroenteritis.

Design: Single centre, two arm, parallel randomised pragmatic controlled trial. Blocked randomisation stratified by site. Participants, caregivers, outcome assessors, investigators, and statisticians were blinded to the treatment assignment.

Setting: Paediatric emergency department in a tertiary care centre in Toronto, Canada.

Participants: 226 children aged 3 months to 11 years; complete follow-up was obtained on 223 (99%). Eligible children were aged over 90 days, had a diagnosis of dehydration secondary to gastroenteritis, had not responded to oral rehydration, and had been prescribed intravenous rehydration. Children were excluded if they weighed less than 5 kg or more than 33 kg, required fluid restriction, had a suspected surgical condition, or had an insurmountable language barrier. Children were also excluded if they had a history of a chronic systemic disease, abdominal surgery, bilious or bloody vomit, hypotension, or hypoglycaemia or hyperglycaemia.

Interventions: Rapid (60 mL/kg) or standard (20 mL/kg) rehydration with 0.9% saline over an hour; subsequent fluids administered according to protocol.

Main outcome measures: Primary outcome: clinical rehydration, assessed with a validated scale, two hours after the start of treatment. Secondary outcomes: prolonged treatment, mean clinical dehydration scores over the four hour study period, time to discharge, repeat visits to emergency department, adequate oral intake, and physician’s comfort with discharge. Data from all randomised patients were included in an intention to treat analysis.

Results: 114 patients were randomised to rapid rehydration and 112 to standard. One child was withdrawn because of severe hyponatraemia at baseline. There was no evidence of a difference between the rapid and standard rehydration groups in the proportions of participants who were rehydrated at two hours (41/114 (36%) v 33/112 (30%); difference 6.5% (95% confidence interval −5.7% to 18.7%; P=0.32). The results did not change after adjustment for weight, baseline dehydration score, and baseline pH (odds ratio 1.8, 0.90 to 3.5; P=0.10). The rates of prolonged treatment were similar (52% rapid v 43% standard; difference 8.9%, 21% to −5%; P=0.19). Although dehydration scores were similar throughout the study period (P=0.96), the median time to discharge was longer in the rapid group (6.3 v 5.0 hours; P=0.03).

Conclusions: There are no relevant clinical benefits from the administration of rapid rather than standard intravenous rehydration to haemodynamically stable children deemed to require intravenous rehydration.

Full-text: http://www.bmj.com/content/343/bmj.d6976

11. Febrile Infants Aged 30 to 90 Days with Positive Urinalyses Require LP

Despite the authors' conclusion that lumbar puncture is not needed, this study failed to show lower risk for meningitis in febrile infants with urinary tract infections.

Paquette K et al. Pediatr Emerg Care. 2011 Nov;27(11):1057-61.

Is a lumbar puncture necessary when evaluating febrile infants (30 to 90 days of age) with an abnormal urinalysis?

OBJECTIVES: Guidelines for the management of febrile infants aged 30 to 90 days presenting to the emergency department (ED) suggest that a lumbar puncture (LP) should be performed routinely if a positive urinalysis is found during initial investigations. The aim of our study was to assess the necessity of routine LPs in infants aged 30 to 90 days presenting to the ED for a fever without source but are found to have a positive urine analysis.

METHODS: We retrospectively reviewed the records of all infants aged 30 to 90 days, presenting to the Montreal Children's Hospital ED from October 2001 to August 2005 who underwent an LP for bacterial culture, in addition to urinalysis and blood and urine cultures. Descriptive statistics and their corresponding confidence intervals were used.

RESULTS: Overall, 392 infants were identified using the microbiology laboratory database. Fifty-seven patients had an abnormal urinalysis. Of these, 1 infant (71 days old) had an Escherichia coli urinary tract infection, bacteremia, and meningitis. This patient, however, was not well on history, and the peripheral white blood cell count was low at 2.9 × 10/L. Thus, the negative predictive value of an abnormal urinalysis for meningitis was 98.2%.

CONCLUSIONS: Routine LPs are not required in infants (30-90 days) presenting to the ED with a fever and a positive urinalysis if they are considered at low risk for serious bacterial infection based on clinical and laboratory criteria. However, we recommend that judicious clinical judgment be used; in doubt, an LP should be performed before empiric antibiotic therapy is begun..

12. Standard Therapy Is Sufficient for Most Patients with Saddle PE

In this small retrospective study, most patients responded to unfractionated heparin.

Saddle pulmonary embolism: Is it as bad as it looks? A community hospital experience.

Sardi A et al. Crit Care Med. 2011 Nov;39(11):2413-8.

BACKGROUND: Saddle pulmonary embolism represents a large clot and a risk for sudden hemodynamic collapse. However, the clinical presentation and outcomes vary widely. On the basis of the findings of right heart dysfunction on echocardiograms, computed tomography angiography, or cardiac enzyme elevation, some argue for the use of thrombolytics or catheter thrombectomy even for hemodynamically stable patients.

OBJECTIVE: To investigate the outcomes and management of patients with saddle pulmonary embolism, including radiographic appearance (estimate of clot burden) and echocardiographic features.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: This study is a retrospective evaluation of all patients with computed tomography angiography positive for pulmonary embolism from June 1, 2004, to February 28, 2009. Two radiologists selected those with saddle pulmonary embolism and evaluated the clot burden score. The clinical information, echocardiography, treatments, and outcomes of these patients were extracted via chart review. Saddle pulmonary embolism was found in 37 of 680 patients (5.4%, 95% confidence interval 4% to 7%) with documented pulmonary embolism on computed tomography angiography. For patients with saddle pulmonary embolism, the median age was 60 yrs and 41% were males. Major comorbidities were neurologic (24%), recent surgery (24%), and malignancy (22%). Transient hypotension occurred in 14% and persistent shock in 8%. One patient required mechanical ventilation. Echocardiography was performed in 27 patients (73%). Right ventricle enlargement and dysfunction were found in 78% and elevated pulmonary artery systolic pressure in 67%. Computed tomography angiography demonstrated a high median pulmonary artery clot burden score of 31 points. The median right ventricle to left ventricle diameter ratio was 1.39. Inferior vena cava filters were placed in 46%. Unfractionated heparin was administered in 33 (87%) and thrombolytics in four (11%). The median hospital length of stay was 9 days. Two of 37 saddle pulmonary embolism patients (5.4%) died in the hospital (95% confidence interval 0.7% to 18%).

CONCLUSIONS: Most patients with saddle pulmonary embolism found on computed tomography angiography responded to the standard management for pulmonary embolism with unfractionated heparin. Although ominous in appearance, most patients with saddle pulmonary embolism are hemodynamically stable and do not require thrombolytic therapy or other interventions.

13. Oxygen therapy for AMI: a systematic review and meta-analysis

Burls A, et al. Emerg Med J2011;28:917-923

Oxygen (O2) is widely recommended in international guidelines for treatment of acute myocardial infarction (AMI), but there is uncertainty about its safety and benefits. A systematic review and meta-analysis were performed to determine whether inhaled O2 in AMI improves pain or the risk of death.

Cochrane CENTRAL Register of Controlled Trials, MEDLINE, MEDLINE In-Process, EMBASE, CINAHL, LILACS and PASCAL were searched from start date to February 2010. Other sources included British Library ZETOC, Web of Science, ISI Proceedings, relevant conferences, expert contacts. Randomised controlled trials of inhaled O2 versus air in patients with suspected or proven AMI of less than 24 h onset were included. Two authors independently reviewed studies to confirm inclusion criteria met, and undertook data abstraction. Quality of studies and risk of bias was assessed according to Cochrane Collaboration guidance. Main outcomes were death, pain, and complications. Measure of effect used was the RR.

Three trials (n=387 patients) were included. Pooled RR of death on O2 compared to air was 2.88 (95%CI 0.88 to 9.39) on ITT analysis and 3.03 (95%CI 0.93 to 9.83) in confirmed AMI. While suggestive of harm, this could be a chance occurrence. Pain was measured by analgesic use. Pooled RR for the use of analgesics was 0.97 (95%CI 0.78 to 1.20).

Evidence for O2 in AMI is sparse, of poor quality and pre-dates advances in reperfusion and trial methods. Evidence is suggestive of harm but lacks power and excess deaths in the O2 group could be due to chance. More research is required.

Systematic review registration number Original protocol registered with the Cochrane Collaboration. RevMan ID 848507032313175590, doi:10.1002/14651858.CD007160.

14. Images in (Emergency) Medicine

Lingual Zoster
http://www.nejm.org/doi/full/10.1056/NEJMicm1107466

Man with Rash and Nausea
http://www.annemergmed.com/article/S0196-0644(11)00352-0/fulltext

Man with Shoulder Pain after a Fall
http://www.annemergmed.com/article/S0196-0644(11)00360-X/fulltext

Unilateral Facial Swelling With Fever
http://www.annemergmed.com/article/S0196-0644(11)00716-5/fulltext

15. Chest compressions linked to physical fitness

Russo SG, et al. BMC Emerg Med 2011;11:20

Assessment of BMI and physical fitness, particularly focusing on the upper body, can predict quality of external chest compressions, with rescuers with higher BMI and greater physical fitness performing better quality external chest compressions and experiencing less fatigue.

Full-text (free): http://www.biomedcentral.com/1471-227X/11/20/abstract

16. Do Alert, Neurologically Intact Trauma Patients with Persistent Midline Tenderness and Negative CT Results Require C-Spine MRI? Maybe

Ackland HM, et al. Ann Emerg Med. 2011;58:521-530.

Study objective: We aim to determine the prevalence and factors associated with cervical discoligamentous injuries detected on magnetic resonance imaging (MRI) in acute, alert, neurologically intact trauma patients with computed tomography (CT) imaging negative for acute injury and persistent midline cervical spine tenderness. We present the cross-sectional analysis of baseline information collected as a component of a prospective observational study.

Methods: Alert, neurologically intact trauma patients presenting to a Level I trauma center with CT negative for acute injury, who underwent MRI for investigation of persistent midline cervical tenderness, were prospectively recruited. Deidentified images were assessed, and injuries were identified and graded. Outcome measures included the presence and extent of MRI-detected injury of the cervical ligaments, intervertebral discs, spinal cord and associated soft tissues.

Results: There were 178 patients recruited during a 2-year period to January 2009. Of these, 78 patients (44%) had acute cervical injury detected on MRI. There were 48 single-column injuries, 15 two-column injuries, and 5 three-column injuries. Of the remaining 10 patients, 6 had isolated posterior muscle edema, 2 had alar ligamentous edema, 1 had epidural hematoma, and 1 had atlanto-occipital edema. The injuries to 38 patients (21%) were managed clinically; 33 patients were treated in cervical collars for 2 to 12 weeks, and 5 patients (2.8%) underwent operative management, 1 of whom had delayed instability. Ordinal logistic regression revealed that factors associated with a higher number of spinal columns injured included advanced CT-detected cervical spondylosis (odds ratio [OR] 11.6; 95% confidence interval [CI] 3.9 to 34.3), minor isolated thoracolumbar fractures (OR 5.4; 95% CI 1.5 to 19.7), and multidirectional cervical spine forces (OR 2.5; 95% CI 1.2 to 5.2).

Conclusion: In patients with cervical midline tenderness and negative acute CT findings, we found that a subset of patients had MRI-detected cervical discoligamentous injuries and that advanced cervical spine degeneration evident on CT, minor thoracolumbar fracture, and multidirectional cervical spine forces were associated with increased injury extent. However, a larger study is required to validate which variables may reliably predict clinically important injury in such patients, thereby indicating the need for further radiographic assessment.

17. Using appendicitis scores in the pediatric ED

Mandeville K, et al. Amer J Emerg Med 2011:29:972-977.

Study Objective: The aims of the study were to prospectively evaluate the Alvarado and Samuel (pediatric appendicitis score [PAS]) appendicitis scoring systems in children and determine performance based on sex.

Methods: Children with abdominal pain concerning for appendicitis were recruited. Nine parameters evaluated by the scores were documented before imaging/surgery consultation. Test characteristics were calculated on all patients and by sex.

Results: Two hundred eighty-seven patients enrolled; median age was 9.8 years; and 155 (54%) were diagnosed with pathologic examination-confirmed appendicitis. Patients with appendicitis had mean PAS of 7.6, and those without had mean of 5.6 (P less than .001). Patients with appendicitis had a mean Alvarado of 7.2, and those without had a mean of 5.2 (P < .001). In appendicitis patients, PAS cutoff of 6 or greater would give 137 correct diagnoses; sensitivity, 88%; specificity, 50%; and positive predictive value (PPV), 67%. An Alvarado cutoff of 7 or greater would give 118 correct diagnoses; sensitivity, 76%; specificity, 72%; and PPV, 76%. Both performed better in males than females.

Conclusion: Regardless of sex, neither PAS nor Alvarado has adequate predictive values for sole use to diagnose appendicitis.

18. Yoga Works for Chronic Low Back Pain: A Randomized Trial

Tilbrook HE, et al. Ann Intern Med. 2011; 155;569-578.

Background: Previous studies indicate that yoga may be an effective treatment for chronic or recurrent low back pain.

Objective: To compare the effectiveness of yoga and usual care for chronic or recurrent low back pain.

Design: Parallel-group, randomized, controlled trial using computer-generated randomization conducted from April 2007 to March 2010. Outcomes were assessed by postal questionnaire. (International Standard Randomised Controlled Trial Number Register: ISRCTN 81079604)

Setting: 13 non–National Health Service premises in the United Kingdom.

Patients: 313 adults with chronic or recurrent low back pain.

Intervention: Yoga (n = 156) or usual care (n = 157). All participants received a back pain education booklet. The intervention group was offered a 12-class, gradually progressing yoga program delivered by 12 teachers over 3 months.

Measurements: Scores on the Roland–Morris Disability Questionnaire (RMDQ) at 3 (primary outcome), 6, and 12 (secondary outcomes) months; pain, pain self-efficacy, and general health measures at 3, 6, and 12 months (secondary outcomes).

Results: 93 (60%) patients offered yoga attended at least 3 of the first 6 sessions and at least 3 other sessions. The yoga group had better back function at 3, 6, and 12 months than the usual care group. The adjusted mean RMDQ score was 2.17 points (95% CI, 1.03 to 3.31 points) lower in the yoga group at 3 months, 1.48 points (CI, 0.33 to 2.62 points) lower at 6 months, and 1.57 points (CI, 0.42 to 2.71 points) lower at 12 months. The yoga and usual care groups had similar back pain and general health scores at 3, 6, and 12 months, and the yoga group had higher pain self-efficacy scores at 3 and 6 months but not at 12 months. Two of the 157 usual care participants and 12 of the 156 yoga participants reported adverse events, mostly increased pain.

Limitation: There were missing data for the primary outcome (yoga group, n = 21; usual care group, n = 18) and differential missing data (more in the yoga group) for secondary outcomes.

Conclusion: Offering a 12-week yoga program to adults with chronic or recurrent low back pain led to greater improvements in back function than did usual care.

Full-text (free): http://www.annals.org/content/155/9/569.full.pdf+html

19. CNS Events in Children with Sickle Cell Disease Presenting Acutely with HA

Hines PC, et al. J Pediatr. 2011;159:472-478

Background. The incidence of headache as a chief complaint in children with sickle cell disease (SCD) is relatively common and not too different from the incidence in healthy children. However, the higher baseline risk for intracranial pathology in patients with SCD makes evaluation of headache in this population more concerning for clinicians. The goal of this study was to use existing data to determine whether an approach could be devised that would help guide clinicians on how aggressive to be in evaluating patients with SCD and headache.

Methods. The participants were children and young adults, ages 5-21 years, with homozygous SCD who were treated in the pediatric emergency department of a single children's hospital from 2001 to 2005. All patients had a chief complaint of headache. By reviewing various inpatient, emergency department, and outpatient records, the investigators obtained clinical data about the presentation of headache including vital signs, physical exam findings, and neurologic exam findings. They also collected data on medical history such as whether a child participated in transfusion protocols, participated in hydroxyurea protocols, and had a history of seizures or central nervous system (CNS) pathology such as stroke and obtained results of any previous CNS imaging.

Findings. The investigators identified 73 patients who presented with 102 episodes of headache during the study period, with 83% of those visits being conducted in the emergency department and the remainder in an acute access hematology clinic. Headache was the exclusive complaint in 60 of the 102 visits, whereas headache was an accompanying complaint in the other 42 visits. Across all visits, 6.9% of the headache episodes were associated with new or changes in known intracranial pathology. However, only 42% of the headache visits in children with SCD prompted imaging. Therefore, the frequency of new pathology in patients with SCD with headache who received imaging was 16.3%. Children with an acute CNS event were much more likely to have a history of a stroke, a transient ischemic attack, or a seizure (40%-60%) than children who did not have CNS events (4.6%-8.5%). With respect to neurologic complaints at presentation, 40%-50% of the children with an acute CNS event had vision changes, weakness, any focal weakness, or numbness compared with only 0%-8.2% of children with no CNS events. At least 1 focal neurologic complaint was found upon presentation in 85% of the children with an acute CNS event compared with 9.5% of the children with no CNS pathology. Similarly, 85% of the children with an acute CNS event had at least 1 neurologic exam abnormality compared with only 5.3% of the children without CNS events.

The investigators concluded that a history of stroke, transient ischemic attack, or the presence of neurologic symptoms or focal neurologic findings suggest a higher risk for CNS pathology in patients with SCD and acute headache. They emphasized that 6.9% of the visits for acute headache in children with SCD were associated with evidence of acute CNS pathology compared with frequencies of 0.5% in healthy children noted in other studies.

Comment: William T. Basco, Jr., MD. Medscape Emerg Med. Posted: 11/04/2011 Full-text: http://www.medscape.com/viewarticle/752295

20. Treating primary headaches in the ED: can droperidol regain its role?

Faine B, et al. Amer J Emerg Med. 2011; in press

Objective: The aim of this study was to describe the use and efficacy of low-dose (≤2 mg) droperidol for the treatment of primary headaches (ie, migraine, cluster, tension-type headache and trigeminal autonomic cephalalgias, and other primary headaches) in the emergency department (ED).

Methods: A report was generated from a pharmacy database to identify all adult patients who received low-dose droperidol in the ED over a 7-month period; a subsequent retrospective chart review was conducted. Low-dose droperidol was defined as a cumulative dose of ≤2 mg. Patients who received droperidol for any other reason than the treatment of a headache were excluded. Data were analyzed descriptively.

Results: Seventy-three cases in which droperidol was administered for the treatment of a headache were identified over the 7-month period. Most doses (92%) administered were 1.25 mg or less. Fifty-three patients (73%) had complete resolution or significant improvement of headache symptoms as subjectively or objectively (eg, numerical pain scale) documented by the treating physician. Eight patients (11%) had minimal improvement in their headaches symptoms; 12 patients (16%) received no relief after the administration of droperidol. The average time to discharge from the ED was 94.8 ± 67.2 minutes. No cardiac arrhythmias were noted. Other adverse events included 2 cases of extrapyramidal side effects; one patient reported restlessness/anxiousness and the other patient had dystonia.

Conclusion: The administration of low-dose (≤2 mg) droperidol may be safe and effective for the treatment of primary headaches in the ED.

21. Intraosseous Bests IV Access During Out-of-Hospital Cardiac Arrest: A Randomized Controlled Trial

Reades R, et al. Ann Emerg Med. 2011;58:509-516.

Study objective; Intraosseous needle insertion during out-of-hospital cardiac arrest is rapidly replacing peripheral intravenous routes in the out-of-hospital setting. However, there are few data directly comparing the effectiveness of intraosseous needle insertions with peripheral intravenous insertions during out-of-hospital cardiac arrest. The objective of this study is to determine whether there is a difference in the frequency of first-attempt success between humeral intraosseous, tibial intraosseous, and peripheral intravenous insertions during out-of-hospital cardiac arrest.

Methods: This was a randomized trial of adult patients experiencing a nontraumatic out-of-hospital cardiac arrest in which resuscitation efforts were initiated. Patients were randomized to one of 3 routes of vascular access: tibial intraosseous, humeral intraosseous, or peripheral intravenous. Paramedics received intensive training and exposure to all 3 methods before study initiation. The primary outcome was first-attempt success, defined as secure needle position in the marrow cavity or a peripheral vein, with normal fluid flow. Needle dislodgement during resuscitation was coded as a failure to maintain vascular access.

Results: There were 182 patients enrolled, with 64 (35%) assigned to tibial intraosseous, 51 (28%) humeral intraosseous, and 67 (37%) peripheral intravenous access. Demographic characteristics were similar among patients in the 3 study arms. There were 130 (71%) patients who experienced initial vascular access success, with 17 (9%) needles becoming dislodged, for an overall frequency of first-attempt success of 113 (62%). Individuals randomized to tibial intraosseous access were more likely to experience a successful first attempt at vascular access (91%; 95% confidence interval [CI] 83% to 98%) compared with either humeral intraosseous access (51%; 95% CI 37% to 65%) or peripheral intravenous access (43%; 95% CI 31% to 55%) groups. Time to initial success was significantly shorter for individuals assigned to the tibial intraosseous access group (4.6 minutes; interquartile range 3.6 to 6.2 minutes) compared with those assigned to the humeral intraosseous access group (7.0 minutes; interquartile range 3.9 to 10.0 minutes), and neither time was significantly different from that of the peripheral intravenous access group (5.8 minutes; interquartile range 4.1 to 8.0 minutes).

Conclusion: Tibial intraosseous access was found to have the highest first-attempt success for vascular access and the most rapid time to vascular access during out-of-hospital cardiac arrest compared with peripheral intravenous and humeral intraosseous access.

22. The Captain Morgan Technique for the Reduction of the Dislocated Hip

We highlighted this article in an earlier Lit Bits. It’s now in print and available for free. See below.

Article full-text: http://www.annemergmed.com/article/S0196-0644(11)01307-2/fulltext

Video: http://www.annemergmed.com/article/S0196-0644(11)01307-2/attachment?filename=mmc1.mpg