Wednesday, March 28, 2012

Lit Bits: March 28, 2012

From the recent medical literature...

1. Effect of computerized clinical decision support on the use and yield of CT pulmonary angiography in the ED.

Raja AS, et al. Radiology. 2012 Feb;262(2):468-74.

INTRO: As part of the Health Information Technology for Economic and Clinical Health Act (1), the Department of Health and Human Services meaningful use criteria for the use of electronic health records require the implementation of at least one clinical decision support (CDS) tool (2). CDS has been shown to decrease the volume of imaging orders in certain clinical contexts (3). In addition, it has been proposed that implementation of CDS can increase the appropriateness of imaging (4).

Given that the use of emergency department (ED) computed tomographic (CT) pulmonary angiography for the diagnosis of pulmonary embolism (PE) is increasing (a recent study [5] found that the number of ED CT pulmonary angiograms of the chest at one large academic institution increased fivefold from 2001 to 2007) and that evidence-based guidelines for imaging patients suspected of having PE exist (6), it may be an excellent target for evaluating the impact of CDS. If suboptimal use of CT pulmonary angiography for the evaluation of PE in the ED exists, then integrating CDS for CT pulmonary angiography into a computerized physician order entry system has the potential to increase quality and appropriateness of ED imaging while decreasing potentially unnecessary examinations.

CDS: The CDS consisted of three rules. The first rule required that ordering clinicians choose both a d-dimer level (elevated, normal, or not evaluated) and the clinical suspicion of PE (high, intermediate, or low). The second rule displayed advice in patients with an intermediate or low level of suspicion in whom a d-dimer assay was not performed (“measuring a d-dimer value in patients with a low and/or intermediate clinical suspicion of PE is an appropriate first step in the work-up of acute PE and will exclude the need for CT pulmonary angiography in some patients”). The third rule displayed a second piece of advice in patients with a normal d-dimer level and intermediate or low suspicion for PE (“based on current evidence as well as our experience at Brigham and Women’s Hospital, diagnosing an acute PE with CT pulmonary angiography in low- or intermediate-risk patients with a normal d-dimer level is extremely unlikely”) (Fig 1). At each stage, clinicians could either cancel the imaging order or ignore the advice (Fig 2).

PURPOSE: To determine the effect of evidence-based clinical decision support (CDS) on the use and yield of computed tomographic (CT) pulmonary angiography for acute pulmonary embolism (PE) in the emergency department (ED).

MATERIALS AND METHODS: Institutional review board approval was obtained for this HIPAA-compliant study, which was performed between October 1, 2003, and September 30, 2009, at a 793-bed quaternary care institution with 60,000 annual ED visits. Use (number of examinations per 1000 ED visits) and yield (percentage of examinations positive for acute PE) of CT pulmonary angiography were compared before and after CDS implementation in August 2007. The authors included all adult patients presenting to the ED and developed and validated a natural language processing tool to identify acute PE diagnoses. Linear trend analysis was used to assess for variation in CT pulmonary angiography use. Logistic regression was used to determine variation in yield after controlling for patient demographic and clinical characteristics.

RESULTS: Of 338,230 patients presenting to the ED, 6838 (2.0%) underwent CT pulmonary angiography. Quarterly CT pulmonary angiography use increased 82.1% before CDS implementation, from 14.5 to 26.4 examinations per 1000 patients (P less than .0001) between October 10, 2003, and July 31, 2007. After CDS implementation, quarterly use decreased 20.1%, from 26.4 to 21.1 examinations per 1000 patients between August 1, 2007, and September 30, 2009 (P=.0379). Overall, 686 (10.0%) of the CT pulmonary angiographic examinations performed during the 6-year period were positive for PE; subsequent to CDS implementation, yield by quarter increased 69.0%, from 5.8% to 9.8% (P=.0323).

CONCLUSION: Implementation of evidence-based CDS in the ED was associated with a significant decrease in use, and increase in yield, of CT pulmonary angiography for the evaluation of acute PE.

2. Lung-Protective Ventilation Linked to Improved Survival

Steven Fox. Medscape Medical News. March 27, 2012 — Reducing breath size and pressure settings for mechanical ventilators used in intensive care units can substantially improve long-term survival in patients with acute lung injury (ACI), according to results from the most comprehensive study to date evaluating the long-term effects of mechanical ventilation on patients with ACI.

The prospective cohort study was conducted by Dale Needham, MD, associate professor, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, and colleagues. The study was published online March 27 in the British Medical Journal.

"Average tidal volume showed a linear relation with two year survival, such that even a relatively small decrease in average tidal volume over stay in the intensive care unit was independently associated with an important decrease in risk of mortality," the authors write. "Greater use of lung protective ventilation in routine clinical practice could reduce long-term mortality in patients with acute lung injury."

Previous studies have shown that using volume-limited and pressure-limited mechanical ventilation (so-called lung-protective ventilation) in patients with acute lung injury can significantly reduce short-term mortality. One earlier randomized trial found that using such an approach resulted in an absolute 8.8% reduction in short-term mortality.

Recommended settings for lung-protective ventilation can be found on the National Heart, Lung, and Blood Institute's Acute Respiratory Distress Syndrome Network (ARDS) Web site.

In the current study, Dr. Needham and colleagues wanted to find out whether similarly favorable results could be obtained during the longer term.

They studied 2-year survival rates in 485 consecutive mechanically ventilated patients with acute lung injury who were treated in the intensive care units of 4 hospitals in Baltimore. Data on the 485 patients included 6240 ventilator settings, as measured twice each day, for a median of 8 ventilator settings per patient.

A ventilator setting was considered adherent to lung-protective ventilation if it satisfied 2 criteria:
• It had a tidal volume equal to or less than 6.5 mL/kg of predicted body weight, which is the threshold used in a seminal study of reduced tidal volumes that was conducted by ARDS to designate study sites' adherence to the goal tidal volume of 6.0 mL/kg predicted body weight.
• The setting had a plateau pressure equal to or less than 30 cm of water, which was based on documentation of respiratory therapy. When pressure-regulated modes of ventilation were used, in which plateau pressure is not measured, the researchers used peak pressure or the sum of positive end expiratory pressure and the prescribed increment in inspiratory pressure.

Dr. Needham and colleagues report that only 41% of the more than 6200 total ventilator settings adhered to recommended settings for lung-protective ventilation. About 37% of patients never received lung-protective ventilation, the researchers say.

Of the 485 patients included in the study, 311 (64%) died within 2 years, the authors say. For each 1 mL/kg predicted body weight increase in average tidal volume, there was an associated 18% increase in risk for death during the subsequent 2 years.

Further, after adjusting for the total length of time patients were on ventilation, along with other relevant factors, each additional ventilator setting that was adherent to lung-protective ventilation was associated with a 3% decrease in the risk for mortality over 2 years (hazard ratio, 0.97; 95% confidence interval [CI], 0.95 - 0.99; P = .002), the authors note.

When those figures were compared with no adherence, the authors add, estimated absolute risk reduction in mortality for a typical patient with 50% adherence to lung-protective ventilation was 4.0% (95% CI, 0.8% - 7.2%; P = .012). With full, 100% adherence, risks were reduced even further, by 7.8% (95% CI, 1.6% - 14.0%; P = .011).

The authors stress that settings for ventilators should be based on patients' height, sex, and predicted weight, rather than their actual weight, because lung size remains essentially the same, regardless of how much a patient weighs, the researchers say.

Limitations include that the study is observational and lacked, at times, measurement or recording of plateau pressures.

"Given the study's findings that patients with acute lung injury often did not receive lung protective ventilation, greater efforts to implement lung protective ventilation in routine clinical practice should be undertaken to reduce patients' long term mortality," the authors conclude.

The study was supported by the National Institutes of Health, and 1 author received a clinician-scientist award from the Canadian Institutes of Health Research. The authors have disclosed no relevant financial relationships.

BMJ. Published online March 27, 2012

3. TNKase Tops Activase for Ischemic Stroke for Select Patients

By Michael Smith, MedPage Today. Published: March 21, 2012

A genetically engineered clot-buster improved clinical outcomes compared with standard thrombolytic therapy in a selected population of people with ischemic strokes, researchers reported.

In an open-label phase IIb randomized trial, tenecteplase (TNKase) also did better than alteplase (Activase) in re-establishing blood flow to the affected brain regions, according to Mark Parsons, MD, of John Hunter Hospital in Newcastle, Australia, and colleagues.

Both drugs were equally safe, Parsons and colleagues reported in the March 22 issue of the New England Journal of Medicine.

Alteplase, a recombinant tissue plasminogen activator, is the only thrombolytic drug approved for stroke, the researchers noted, but it is known for "incomplete and often delayed" reperfusion.

Tenecteplase, a genetically engineered mutant tissue plasminogen activator, is approved to treat heart attack but not stroke, but Parsons and colleagues argued it might have some pharmacokinetic advantages over the older drug that could translate into better outcomes, including better reperfusion.

To test the hypothesis, they conducted a trial in a group of stroke patients who were selected by CT imaging as being likely to benefit from early reperfusion -- those with large-vessel occlusion and a large perfusion lesion but not a large infarct core.

All told, 75 patients were randomized between 2008 and 2011 to standard treatment with alteplase or to one of two doses of tenecteplase, 0.1 or 0.25 mg/kg to a maximum dose of 10 or 25 mg, respectively.

The standard dose of alteplase is 0.9 mg/kg, with the first 10% in an initial bolus and the rest given over a one-hour period, to a maximum of 90 mg. Tenecteplase, in contrast, is given as a single bolus.

The primary outcomes were the proportion of the perfusion lesion that had blood flow re-established after 24 hours, as seen by magnetic resonance imaging, and the extent of clinical improvement at 24 hours, assessed on the National Institutes of Health Stroke Scale.

Among other things, the researchers also looked for major neurologic improvement at 24 hours, defined as a reduction from baseline of 8 or more points on the 42-point stroke scale, and excellent or good recovery at 90 days, defined as a modified Rankin score of 0, 1, or 2.

Parsons and colleagues found that the average baseline stroke scale score was 14.4 and the average time to treatment was 2.9 hours.

When researchers combined both tenecteplase groups, they found that these patients had significantly greater reperfusion (P=0.004) than those getting alteplase. The average proportion of the lesion that was reperfused with tenecteplase was 79.3%, compared with 55.4% for alteplase.

The tenecteplase patients also had significantly greater clinical improvement at 24 hours, with an average improvement on the stroke scale of 8 points compared with 3 for the alteplase patients.

At 90 days, 11 alteplase patients and 36 tenecteplase patients had an excellent or good recovery (P=0.02).

The investigators reported that the higher dose of tenecteplase was superior to the lower dose and to alteplase for all efficacy outcomes. In addition, they observed no significant between-group differences in intracranial bleeding or other serious adverse events.

The researchers cautioned that the results can't be applied directly to the usual group of stroke patients eligible for thrombolysis, since patients in this trial were selected as being most likely to benefit from thrombolytic therapy.

Nonetheless, they concluded, the results support a broader phase III trial, using the higher dose of tenecteplase.

The study was supported by the Australian National Health and Medical Research Council. Parsons reported financial links with Bayer Australia.

Parsons M, et al. N Engl J Med 2012; 366: 1099-1107. Abstract:

4. Prehospital Epinephrine for Cardiac Arrest Reduces Survival and Worsens Neurological Outcomes at 1 Month

A large observational study places added scrutiny on the use of epinephrine for out-of-hospital cardiac arrest.

A recent prospective, randomized, placebo-controlled trial of epinephrine for out-of-hospital cardiac arrest demonstrated that epinephrine increased the rate of return of spontaneous circulation but had no effect on survival to hospital discharge ( However, that study was underpowered.

Researchers in Japan conducted a prospective observational propensity analysis of data for 417,188 out-of-hospital cardiac arrests in patients aged 18 years (mean age, 72) who were treated by emergency medical services and transported to a hospital from 2005 through 2008.

The odds of return of spontaneous circulation prior to hospital arrival were significantly higher in patients who received epinephrine in the field than in those who did not (adjusted odds ratio, 2.36). However, at 1 month, patients who received epinephrine had significantly lower odds of survival (AOR, 0.46); good or moderate cerebral performance (AOR, 0.31); and no, mild, or moderate neurological disability (AOR, 0.32).

Comment: Epinephrine is thought to increase aortic and coronary artery perfusion pressure, but this might occur at the expense of other organs and systems, including the heart and cerebral microcirculation. This large study, one of few to look at long-term outcomes, demonstrates that epinephrine might provide a short-term advantage for return of spontaneous circulation but a negative effect on 1-month survival and neurological outcomes. Unfortunately, care subsequent to the prehospital phase was neither standardized nor studied. An editorialist calls for a randomized, controlled, adequately powered study to determine whether and under what circumstances epinephrine should be administered to patients with out-of-hospital cardiac arrest.
— John A. Marx, MD, FAAEM

Published in Journal Watch Emergency Medicine March 23, 2012.

Citation: Hagihara A et al. Prehospital epinephrine use and survival among patients with out-of-hospital cardiac arrest. JAMA 2012 Mar 21; 307:1161.


Associated Medscape essay:

5. Prospective study of the frequency and outcomes of patients with suspected PE administered heparin prior to confirmatory imaging.

Kline JA, et al. Thromb Res. 2012 Apr;129(4):e25-8.

OBJECTIVES: The administration of empiric systemic anticoagulation (ESA) before confirmatory radiographic testing in patients with suspected pulmonary embolism (PE) may improve outcomes, but no data have been published regarding current practice. We describe the use of ESA in a large prospective cohort of emergency department (ED) patients and report the outcomes of those treated with ESA compared with patients not receiving ESA.

METHODS: 12-center, noninterventional study of ED patients who presented with symptoms concerning for PE. Clinical data including pretest probability and decision to start ESA were recorded at point of care by attending physicians. Patients were followed for adverse in-hospital outcomes and recurrence of venous thromboembolism.

RESULTS: ESA was initiated 342/7932 (4.3%) of enrolled patients, including 142/618 (23%) patients with high pretest probability. Patients receiving ESA had more abnormal vital signs and were more likely to have a history of venous thromboembolism than those who did not receive ESA. Overall, 481/7,932 (6.1%) had PE diagnosed, 72/481 (15.0%) with PE had ESA, and 72/342 (21%) of ESA patients had PE. Three patients (0.9%, 95%CI: 0.2-2.5%) who received ESA suffered hemorrhagic complications compared with 38 patients (0.5%, 95%CI: 0.4-0.7%) who did not receive ESA.

CONCLUSIONS: In this multicenter sample, ED physicians administered ESA to a small, generally more acutely ill subset of patients with high pretest probability of PE, and very few had hemorrhagic complications. ESA was not associated with any clear difference in outcomes. More study is needed to clarify the risk versus benefit of ESA.

6. Asthma Improves When Triage Nurses Give Corticosteroids

Joe Barber Jr, PhD. From Medscape Medical News. March 19, 2012 — Corticosteroid initiation before physician assessment is associated with improved quality and efficiency of care in the emergency department (ED) for children with asthma, according to the findings of a time-series controlled trial.

Roger Zemek, MD, from the Children's Hospital of Eastern Ontario in Ottawa, Canada, and colleagues published their findings in the April issue of Pediatrics.

Although the benefits of early corticosteroid administration have been demonstrated, the authors note that their administration is less than optimal. "Improving efficiency in asthma management is an essential element of relieving ED overcrowding, attributable in part to suboptimal flow, because asthma is the most prevalent childhood chronic disease requiring ED visits," the authors write. "Despite evidence supporting their need, physicians underprescribe corticosteroids for children, and delays to administration remain long."

Among the 644 eligible participants (nurse-initiated phase, 336 children; physician-initiated phase, 308 children) with moderate to severe asthma, children in the nurse-initiated phase exhibited clinical improvement (defined as a reduction in the Preschool Respiratory Assessment Measure (PRAM) score ≥ 3) a median of 24 minutes (95% confidence interval [CI], 1 - 50 minutes; P = .04) earlier than those in the physician-initiated phase (158 minutes [interquartile range, 139 - 177 minutes] vs 182 minutes [interquartile range, 168 - 202 minutes]; P = .04).

The authors included children aged 2 to 17 years who had moderate to severe asthma exacerbation (defined as a PRAM score ≥ 4). The participants were divided into 2 groups: nurse-initiated and physician-initiated phases. The 2 groups were sampled consecutively for 4 months, with a 1-month training period separating the 2 phases.

The primary outcome measure was time to clinical improvement, and the secondary outcome measures were total time in the ED, time to mild status, and return ED visit within the next 7 days. Children with PRAM scores of 4 to 7 received 3 salbutamol treatments via metered-dose inhalation, whereas those with PRAM scores of 8 or higher received 3 salbutamol plus ipratropium bromide nebulizations for the first hour, followed by hourly salbutamol treatment as needed.

Nurse-initiated corticosteroid administration was also associated with decreases in the admission rate (adjusted odds ratio, 0.54; 95% CI, 0.34 - 0.86; P = .01), time to corticosteroid receipt (adjusted hazard ratio [HR], 2.40; 95% CI, 2.03 - 2.83; P less than .001), time to mild status (adjusted HR, 1.24; 95% CI, 1.03 - 1.48; P = .02), and time to discharge (adjusted HR, 1.22; 95% CI, 1.03 - 1.45; P = .02). No significant differences were found in the characteristics of the 2 groups in terms of age, sex, vital signs, or medical history, although children in the physician-initiated phase were more likely to have a documented upper respiratory tract infection preceding this hospital visit.

The exclusion criteria included the presence of chronic lung disease; chronic cardiac, metabolic, or neurological disorders; and contraindication or hypersensitivity to any of the study medications. Limitations of the study included a lack of randomization, the sampling period, and other confounders related to the seasonal variability between the phases.

The authors suggest that their findings, if implemented, could improve the treatment of asthma in the ED. "Widely adopted, this strategy could optimize the function of multidisciplinary teams and have a significant impact on the burden of asthma in EDs," the authors write.

Martin Pusic, MD, from the Columbia University Medical Center in New York City, agrees that earlier treatment would be beneficial for patients. "We know that steroids work, and that it takes 4 hours for them to [be absorbed]," Dr. Pusic told Medscape Medical News. "Earlier administration leads to earlier effectiveness."

One coauthor received honoraria and/or educational grants from AstraZeneca Canada, Merck Frosst Canada, and Nycomed Canada. The other authors and the commentator have disclosed no relevant financial relationships.

Pediatrics. 2012;129:671-680. Abstract:

7. Rocuronium and Succinylcholine Are Equally Effective at Doses of 1 mg/kg or greater

No significant differences in intubation time, conditions, or success rates were noted.

This author conducted a structured literature review of studies that compared succinylcholine and rocuronium at doses 1 mg/kg to determine whether the two agents are similarly effective in providing optimal conditions for emergency intubation. Of seven papers that were considered relevant, three were conducted in the emergency department (ED) setting, and one was a Cochrane review.

A prospective cohort analysis of 578 ED patients showed that succinylcholine provided paralysis 5 seconds earlier than rocuronium (the difference was not considered clinically relevant), and the two agents produced similar intubating conditions. A retrospective study of 327 ED patients showed no significant difference in first-attempt intubation success between the two agents (JW Emerg Med Feb 18 2011). The Cochrane review found no difference between the two agents in producing excellent or acceptable intubating conditions. The remaining four studies, which were conducted in the surgery setting, had similar findings.

Comment: Succinylcholine and rocuronium at ED-appropriate doses (above 1 mg/kg) produce virtually identical intubating conditions. At these doses, however, rocuronium paralysis lasts up to 45 minutes, versus 6 to 10 minutes for succinylcholine. Assessing a patient for a possible difficult airway and preparing a backup airway are essential in all intubations.

— Diane M. Birnbaumer, MD, FACEP. Published in Journal Watch Emergency Medicine March 16, 2012

Citation: Herbstritt A. BET 3: Is rocuronium as effective as succinylcholine at facilitating laryngoscopy during rapid sequence intubation? Emerg Med J 2012 Mar; 29:256.


8. ROMICAT II: CT-First ACS Strategy Matches Current Practice

Reed Miller. Heartwire. March 27, 2012 (Chicago, Illinois) — The coronary computed-tomography angiography (CCTA)-based strategy for screening chest-pain patients in the emergency department is safe and reduces overall patient time in the hospital but costs about the same overall as the current standard approach, the Rule Out Myocardial Infarction Using Computer Assisted Tomography II (ROMICAT II) results show.

Dr Udo Hoffman (Massachusetts General Hospital, Boston) presented results of the randomized ROMICAT II trial today at the American College of Cardiology (ACC) 2012 Scientific Sessions. The study randomized 1000 chest-pain patients with suspected acute coronary syndrome on a 1:1 ratio to either a CCTA screening approach or standard care left to the discretion of the physician.

The average time to diagnosis was 10.4 hours in the CCTA group and 18.7 hours in the control group (p=0.001). By reducing the time to diagnosis in the patients who were not suffering ACS, the CCTA-first approach reduced chest-pain patients' average hospital stay from about 31 hours to 23 hours (p=0.0002) compared with the standard approach. About half the chest-pain patients scanned with CCTA to rule out possible noncardiac causes of their chest pain were safely discharged from the hospital within nine hours of arriving at the emergency department. Only 15% of patients receiving standard care were in and out that fast. The hospital stay for patients with ACS was about 3.5 days in both groups.

Patients in the CCTA group were much more likely to be discharged directly from the emergency department (46.7% vs 12.4%), but only slightly less likely to be admitted to the hospital (25.4% vs 31.7%). About half the patients in the control group were moved to an observation unit, compared with about a quarter of the CCTA patients.

The safety of the CCTA-based approach was comparable to that of the standard approach. There were no missed ACS cases in either group, and major adverse events within 30 days were statistically similar in both the CCTA and standard-care groups (0.4 and 1.0, p=0.37). Results of the ACRIN-PA study, presented earlier at the ACC meeting, also affirmed the safety and low-miss rate of the CCTA-first approach.

ROMICAT II also shows that the CCTA-first strategy cost about the same overall as the standard approach. The CCTA-first approach cost about 19% less per patient than the standard approach, but hospital costs were about 50% more with the CCTA approach, apparently because CCTA patients underwent more angiography (12% vs 8%, p=0.04) and a statistically insignificant greater number of coronary interventions--either percutaneous intervention or bypass surgery (6.4% vs. 4.2%, p=0.16).

If it doesn't reduce cost, how is it better?

Dr Ray Gibbons (Mayo Clinic, Rochester, MN) argues that, viewed in the context of the current healthcare-cost crisis in the US, the data do not show that the CCTA-first approach is better than the standard approach to screening potential ACS patients who come to the emergency room.

The difference in total hospital admissions--about 25% vs 32%--is probably not significant. The ROMICAT-II investigators "chose to analyze it in terms of direct discharge, but I think that's more of a matter of semantics," Gibbons told heartwire in an interview. "Will a patient really see it as different having a CCTA and being discharged vs going down the hall [to the chest-pain unit] for a few hours? Is that a big difference? I don't think so. . . . As for time in the emergency department? I'd view that as secondary.

"If the patients went home directly from the emergency department more often, which is what they should do, why aren't the costs different?" he asked. In the ROMICAT II data, the answer appears to be that the minor differences in percutaneous-intervention and bypass-surgery rates between the two groups drive more costs, he said. And, he added, the revascularization rates shown in ROMICAT-II are relatively low. Gibbons believes that if the CCTA-first strategy were tried across the country, it would be associated with much greater costs than the standard-screening approach in many areas where hospitals revascularize a much higher portion of the chest-pain patients that present to the emergency department than the centers in ROMICAT-II.

"If the outcomes are equivalent, you should try to reduce total costs, and that should be the primary goal," Gibbons said. "I know that in some areas of the country that emergency-department overcrowding is an issue, but that pales in comparison to what is happening to Medicare and the total healthcare costs in this country."

Gibbons said that Medicare data show that increased utilization of CCTA screening leads to higher revascularization rates, and "I'm very worried about the impact of CCTA on revascularization rates, because these are [often] revascularizations of low value."

Getting patients out of the emergency room faster will not save nearly as much money as keeping the very low-risk patients from ever coming to the emergency department, Gibbons said. So a next step in the effort to cut costs in ACS treatment should be to develop tools to better screen the calls of worried patients who believe they might be suffering an ACS and encourage the very low-risk patients to see their cardiologist or general practitioner rather than come to the emergency department.

9. Safety and Efficiency of a CP Diagnostic Algorithm with Selective Outpatient Stress Testing for ED Patients with Potential Ischemic CP

Scheuermeyer FX, et al. Ann Emerg Med 2012;59:256-264.e3.

Study objective: Chest pain units have been used to monitor and investigate emergency department (ED) patients with potential ischemic chest pain to reduce the possibility of missed acute coronary syndrome. We seek to optimize the use of hospital resources by implementing a chest pain diagnostic algorithm.

Methods: This was a prospective cohort study of ED patients with potential ischemic chest pain. High-risk patients were referred to cardiology, and patients without ECG or biomarker evidence of ischemia were discharged home after 2 to 6 hours of observation. Emergency physicians scheduled discharged patients for outpatient stress ECGs or radionuclide scans at the hospital within 48 hours. Patients with positive provocative test results were immediately referred back to the ED. The primary outcome was the rate of missed diagnosis of acute coronary syndrome at 30 days.

Results: We prospectively followed 1,116 consecutive patients who went through the chest pain diagnostic algorithm, of whom 197 (17.7%) were admitted at the index visit and 254 (22.8%) received outpatient testing on discharge. The 30-day acute coronary syndrome event rate was 10.8%, and the 30-day missed acute coronary syndrome rate was 0% (95% confidence interval 0% to 2.4%). Of the 120 acute coronary syndrome cases, 99 (82.5%) were diagnosed at the index ED visit, and 21 patients (17.5%) received the diagnosis during outpatient stress testing.

Conclusion: In ED patients with chest pain, a structured diagnostic approach with time-focused ED decision points, brief observation, and selective application of early outpatient provocative testing appears both safe and diagnostically efficient, even though some patients with acute coronary syndrome may be discharged for outpatient stress testing on the index ED visit.

10. Look for Warning Signs of Sudden Death in Kids

By Nancy Walsh, Staff Writer, MedPage Today. Published: March 26, 2012

Awareness of warning signs and family history are crucial for the prevention of sudden cardiac arrest in young people, according to a new policy statement from the American Academy of Pediatrics.

Pediatric sudden cardiac arrest can be lethal within minutes if unrecognized and untreated, and some 2,000 related deaths are thought to occur in the U.S. each year, according to the statement, which was published online ahead of print in the April issue of Pediatrics.

"Although [sudden cardiac arrest] may be the sentinel event, symptoms in patients with structural-functional or primary electrical disorders may, in fact, be relatively common," the statement reads.

Symptoms can include chest pain, dizziness, exercise-induced syncope, and dyspnea, which may have been disregarded by the patient and family; a detailed history also may reveal the sudden, unexplained death of a young relative.

In fact, estimates suggest these warning signs may be present in up to half of cases of sudden cardiac arrest in children.

The most common underlying causes of sudden cardiac arrest in this age group are structural or functional disorders such as hypertrophic cardiomyopathy and coronary artery anomalies, and primary cardiac electrical disorders such as familial long QT syndrome and Wolff-Parkinson-White syndrome.

The most frequent immediate event is a ventricular tachyarrhythmia, the statement authors noted.

Some types of arrhythmias, such as torsades de pointes, can be transient and may appear similar to seizures, which highlights the importance of accurate diagnosis.

The statement recommends that clinicians recognize the warning signs and symptoms of sudden cardiac arrest, including those that may incorrectly be attributed to noncardiac diseases and, thus, delay correct diagnosis.

For example, if the patient is thought to be experiencing a seizure, the likely referral may be to a neurologist, which could delay the diagnosis -- with potentially disastrous results.

Similarly, if dyspnea is the presenting symptom, the workup may focus on a respiratory etiology, so a lack of response to initial treatment should trigger a reconsideration of potential cardiac causes, they suggested.

The statement also addressed the issue of screening young athletes before permitting sports participation.

A variety of risk-assessment tools have been used, and although these have not been validated or assessed for sensitivity or specificity, expert opinion currently emphasizes the importance of these "ominous" findings on a preparticipation screen:
• A history of fainting or having a seizure, especially during exercise
• Past episodes of chest pain or shortness of breath with exercise
• A family member with unexpected sudden death or a condition such as hypertrophic cardiomyopathy or Brugada syndrome

The academy also considered the role of ECG screening for young athletes and referred to earlier American Heart Association guidelines that did not endorse widespread use of this test, citing the possibilities of false-positive and false-negative results, cost, and medicolegal problems.

"Wide-scale ECG screening would require a major infrastructure enhancement not currently available in the U.S.," the statement pointed out, and called for additional data and debate on the subject.

Another recommendation was regarding the "molecular autopsy," which would include a postmortem genetic analysis aimed at detecting cardiac channel abnormalities in any child with sudden cardiac death. This currently is primarily a research tool, but could provide valuable information to survivors.

As to secondary prevention of sudden death following an episode of cardiac arrest, the authors of the statement acknowledged that identification, treatment, and appropriate activity restriction can't be successful in every case.

They therefore recommended extensive placement of automated external defibrillators in schools, along with cardiopulmonary resuscitation training of staff and others.

The statement also argued in favor of the establishment of a central registry for pediatric sudden cardiac arrest.

Other groups that have endorsed the statement include the American Heart Association, the American College of Cardiology, and the Heart Rhythm Society.

American Academy of Pediatrics "Pediatric sudden cardiac arrest" Pediatrics 2012; DOI: 10.1542/peds.2012-0144.

Full-text (free) as pdf:

11. Images in Clinical Medicine

Barium Aspiration (I hope you haven’t seen this!)

Westermark Sign in Pulmonary Embolism


Eruptive Xanthoma

Spider Angioma

Sigmoid Perforation in Association with Colonoscopy

Kerion Celsi

Kayser–Fleischer Rings in Wilson's Disease

Drowsy Man with Breathlessness and Blurred Vision

Man with Confusion and Resolved Paralysis

Acute Vision Loss

12. Oral Rivaroxaban for the Treatment of Symptomatic Pulmonary Embolism

The EINSTEIN–PE Investigators. N Engl J Med. 2012; published online March 26

Introduction: Pulmonary embolism is a common disease, with an estimated annual incidence of 70 cases per 100,000 population.1,2 The condition usually leads to hospitalization and may recur; it can be fatal.3

For half a century, the standard therapy for most patients with pulmonary embolism has been the administration of heparin, overlapped and followed by a vitamin K antagonist.4,5 This regimen is effective but complex.5-9 Recently developed oral anticoagulants that are directed against factor Xa or thrombin overcome some limitations of standard therapy, including the need for injection and for regular dose adjustments on the basis of laboratory monitoring.5,10,11

Current data suggest that rivaroxaban, an oral direct inhibitor of factor Xa, is effective and safe for the prevention of venous thromboembolism after major orthopedic surgery, for the prevention of stroke in patients with atrial fibrillation, and in the treatment of acute coronary syndromes.12-14 The EINSTEIN program evaluated the concept of using rivaroxaban alone for anticoagulant therapy for acute deep-vein thrombosis and pulmonary embolism, replacing both heparin and vitamin K antagonists.15,16 This single-drug approach, starting with an increased dose for 3 weeks, appeared to be successful in treating deep-vein thrombosis. Here we report the findings for this regimen in patients with pulmonary embolism.

Background: A fixed-dose regimen of rivaroxaban, an oral factor Xa inhibitor, has been shown to be as effective as standard anticoagulant therapy for the treatment of deep-vein thrombosis, without the need for laboratory monitoring. This approach may also simplify the treatment of pulmonary embolism.

Methods: In a randomized, open-label, event-driven, noninferiority trial involving 4832 patients who had acute symptomatic pulmonary embolism with or without deep-vein thrombosis, we compared rivaroxaban (15 mg twice daily for 3 weeks, followed by 20 mg once daily) with standard therapy with enoxaparin followed by an adjusted-dose vitamin K antagonist for 3, 6, or 12 months. The primary efficacy outcome was symptomatic recurrent venous thromboembolism. The principal safety outcome was major or clinically relevant nonmajor bleeding.

Results: Rivaroxaban was noninferior to standard therapy (noninferiority margin, 2.0; P=0.003) for the primary efficacy outcome, with 50 events in the rivaroxaban group (2.1%) versus 44 events in the standard-therapy group (1.8%) (hazard ratio, 1.12; 95% confidence interval [CI], 0.75 to 1.68). The principal safety outcome occurred in 10.3% of patients in the rivaroxaban group and 11.4% of those in the standard-therapy group (hazard ratio, 0.90; 95% CI, 0.76 to 1.07; P=0.23). Major bleeding was observed in 26 patients (1.1%) in the rivaroxaban group and 52 patients (2.2%) in the standard-therapy group (hazard ratio, 0.49; 95% CI, 0.31 to 0.79; P=0.003). Rates of other adverse events were similar in the two groups.

Conclusions: A fixed-dose regimen of rivaroxaban alone was noninferior to standard therapy for the initial and long-term treatment of pulmonary embolism and had a potentially improved benefit–risk profile. (Funded by Bayer HealthCare and Janssen Pharmaceuticals; EINSTEIN-PE number, NCT00439777.)

Full-text (free at this reading):

13. Impaired Driving: What is Your Responsibility as an Emergency Physician?

Schroeder E. Ann Emerg Med. 2012;59:324-326.

You are driving home from a busy shift when you glance over at the driver next to you as she swerves out of her lane. Your heart sinks when you recognize her as the woman you just discharged. She came in toward the end of your shift with her “typical migraine” and told you that the last time she was in the emergency department (ED), she was administered a combination of medications that helped. You gave her a “migraine cocktail” of Compazine, Benadryl, and Toradol, and she was feeling better when you checked on her; thus, you told her she could go home. You assumed that she had a ride home; apparently, that was a poor assumption.

The rest of the essay (full-text free) is here:

14. Ibuprofen May KO Altitude Sickness

By Michael Smith, MedPage Today. Published: March 21, 2012

If you long for a "Rocky Mountain high" but not the headache, fatigue, dizziness, nausea, and vomiting that sometimes accompany a climb, fear not.

A randomized placebo-controlled trial found that ibuprofen reduces the incidence of mountain sickness, according to Grant Lipman, MD, of Stanford University School of Medicine in Stanford, Calif., and colleagues.

The nonsteroidal anti-inflammatory also appeared to reduce the severity of illness, Lipman and colleagues reported online in Annals of Emergency Medicine.

The issue is important for tourists, recreational mountaineers, military operations, and search and rescue missions, where participants often don't have time to prepare for the climb.

A slow ascent, allowing the body to acclimate, can reduce the chances of the condition, which Lipman said in a statement is like "a really nasty hangover." As well, prescription medications are available but they have significant risks and have to be taken well before the climb starts.

In contrast, ibuprofen is well tolerated, widely available, and can be taken the same day as the climb, the researchers reported.

"If you are heading to the mountains," Lipman said, "take some ibuprofen the day you go."

The exact causes of mountain sickness are not known, but there is some evidence it is a result of an inflammatory process, Lipman and colleagues noted. So, it made sense to test ibuprofen in a group of 86 healthy adult volunteers who live at low altitude.

During July and August 2010, in the White Mountains of California, the volunteers were randomly assigned to take 600 milligrams of ibuprofen or an identical-appearing placebo three times a day.

The study began at an altitude of 1,240 meters (4,100 feet) at 8 a.m., after the volunteers completed questionnaires covering acute mountain sickness symptoms and demographics, had their oxygen saturation measured and received the first dose of medication.

Volunteers were then driven to a staging area at 3,545 meters (11,700 feet) and received the second medication dose at 2 p.m. Then they hiked about 4.3 kilometers (2.7 miles) to 3,810 meters (12,570 feet), where they took the third dose at 8 p.m. They spent the night and received a final dose the following morning.

The primary outcome measures were incidence and severity of mountain sickness, as calculated on the Lake Louise Questionnaire, Lipman and colleagues reported.

They found that 19 volunteers in the ibuprofen group (43%) developed acute mountain sickness compared with 29 in the placebo group (69%), for an odds ratio of 0.3 (95% CI from 0.1 to 0.8).

The number needed to treat to prevent one case of acute mountain sickness was 3.9 (95% CI 2 to 33).

Mountain sickness severity was higher in those who became ill in the placebo group than in those who became sick while taking ibuprofen -- 4.4 versus 3.2 on the questionnaire, on average -- but the difference was not statistically significant (mean difference 0.9%, 95% CI 0.3% to 3%).

The findings could prove especially useful for vacationers who are planning high-altitude trips. "You don't want to feel horrible for 15% to 20% of your vacation," Lipman said. "Ibuprofen could be a way to prevent [mountain sickness] in a significant number of the tens of millions of people who travel to high altitudes each year."

The researchers cautioned that they could not control for such things as temperature, wind speed, rate of ascent, or the underlying physiologic condition of participants.

As well, they noted, participants were self-selected and might not be similar to other hiking and climbing groups.

While other drugs are available to prevent mountain sickness, such as acetazolamide (Diamox) and dexamethasone, they have drawbacks that ibuprofen doesn't have, the researchers noted.

"The safety profile of ibuprofen makes it more attractive then dexamethasone, which has been associated with hyperglycemia, adrenal suppression, delirium, depression, insomnia, and mania," Lipman and colleagues argued. As well, acetazolamide has adverse effects -- nausea, dizziness, and fatigue -- that are usually well tolerated but "can be as debilitating as acute mountain sickness," they noted

"Availability alone makes ibuprofen an appealing drug for individuals who travel to high altitudes," they concluded.

The study was supported by the Stanford University School of Medicine and the American Alpine Club. The journal said the authors had reported no commercial, financial, and other relationships relevant to the article.

Lipman GS, et al. Ibuprofen prevents altitude illness: a randomized controlled trial for prevention of altitude illness with nonsteroidal anti-inflammatories. Ann Emerg Med 2012; DOI: 10.1016/j.annemergmed.2012.01.019.

For a little review of prophylactic agents for AMS, see

15. CT Angiography for Safe Discharge of Patients with Possible ACS

Litt HI, et al. N Engl J Med. Online March 26, 2012 (10.1056/NEJMoa1201163)

Introduction: Patients who present to the emergency department with signs and symptoms consistent with a possible acute coronary syndrome pose a diagnostic dilemma.1-6 Despite the introduction of clinical decision rules6-15 and the improved sensitivity of cardiac markers,15-17 most patients are admitted to the hospital so that an acute coronary syndrome can be ruled out, even though for most of these patients, the symptoms are ultimately found not to have a cardiac cause.

The absence of evidence of coronary disease on invasive coronary angiography is associated with a low risk of future cardiac events.18,19 Coronary computed tomographic angiography (CCTA) is a noninvasive test with a negative predictive value of nearly 100% for the detection of coronary artery disease.20

Prior studies21-30 have shown that the rate of cardiac events among patients with minimal or no coronary artery disease is very low. However, these studies were not large enough to clarify whether a CCTA-based strategy, as compared with traditional approaches, allows the safe discharge of patients after a negative test. We conducted a trial to determine the safety and efficiency of a CCTA-based strategy.

Background: Admission rates among patients presenting to emergency departments with possible acute coronary syndromes are high, although for most of these patients, the symptoms are ultimately found not to have a cardiac cause. Coronary computed tomographic angiography (CCTA) has a very high negative predictive value for the detection of coronary disease, but its usefulness in determining whether discharge of patients from the emergency department is safe is not well established.

Methods: We randomly assigned low-to-intermediate-risk patients presenting with possible acute coronary syndromes, in a 2:1 ratio, to undergo CCTA or to receive traditional care. Patients were enrolled at five centers in the United States. Patients older than 30 years of age with a Thrombolysis in Myocardial Infarction risk score of 0 to 2 and signs or symptoms warranting admission or testing were eligible. The primary outcome was safety, assessed in the subgroup of patients with a negative CCTA examination, with safety defined as the absence of myocardial infarction and cardiac death during the first 30 days after presentation.

Results: We enrolled 1370 subjects: 908 in the CCTA group and 462 in the group receiving traditional care. The baseline characteristics were similar in the two groups. Of 640 patients with a negative CCTA examination, none died or had a myocardial infarction within 30 days (0%; 95% confidence interval [CI], 0 to 0.57). As compared with patients receiving traditional care, patients in the CCTA group had a higher rate of discharge from the emergency department (49.6% vs. 22.7%; difference, 26.8 percentage points; 95% CI, 21.4 to 32.2), a shorter length of stay (median, 18.0 hours vs. 24.8 hours; P less than 0.001), and a higher rate of detection of coronary disease (9.0% vs. 3.5%; difference, 5.6 percentage points; 95% CI, 0 to 11.2). There was one serious adverse event in each group.

Conclusions: A CCTA-based strategy for low-to-intermediate-risk patients presenting with a possible acute coronary syndrome appears to allow the safe, expedited discharge from the emergency department of many patients who would otherwise be admitted. (Funded by the Commonwealth of Pennsylvania Department of Health and the American College of Radiology Imaging Network Foundation

Full-text (Currently free):

16. Variation in Use of Head CT by Emergency Physicians.

Prevedello LM, Am J Med. 2012 Feb 10. [Epub ahead of print]

OBJECTIVE: Variation in emergency department head computed tomography (CT) use in patients with atraumatic headaches between hospitals is being measured nationwide. However, the magnitude of interphysician variation within a hospital is currently unknown. We hypothesized that there was significant variation in the rates of physician head CT use, both overall and for patients diagnosed with atraumatic headaches.

METHODS: This cross-sectional study was conducted in the emergency department of a large urban academic hospital, and institutional review board approval was obtained. All emergency department visits from 2009 were analyzed, and the primary outcome measure was whether or not head CT was performed. Logistic regression was used to control for patient, physician, and visit characteristics potentially associated with head CT ordering. The degree of interphysician variability was tested, both before and after controlling for these variables.

RESULTS: Of 55,286 emergency department patient encounters, 4919 (8.9%) involved head CT examinations. Unadjusted head CT ordering rates per physician ranged from 4.4% to 16.9% overall and from 15.2% to 61.7% in patients diagnosed with atraumatic headaches, with both rates varying significantly between physicians. Two-fold variation in head CT ordering overall (6.5%-13.5%) and approximately 3-fold variation in head CT ordering for atraumatic headaches (21.2%-60.1%) persisted even after controlling for pertinent variables.

CONCLUSION: Emergency physicians vary significantly in their use of head CT both overall and in patients with atraumatic headaches. Further studies are needed to identify strategies to reduce interphysician variation in head CT use.

17. Clinical presentation of acute PE: survey of 800 cases.

Miniati M, et al. PLoS One. 2012;7(2):e30891.

BACKGROUND: Pulmonary embolism (PE) is a common and potentially fatal disease that is still underdiagnosed. The objective of our study was to reappraise the clinical presentation of PE with emphasis on the identification of the symptoms and signs that prompt the patients to seek medical attention.

METHODOLOGY/PRINCIPAL FINDINGS: We studied 800 patients with PE from two different clinical settings: 440 were recruited in Pisa (Italy) as part of the Prospective Investigative Study of Acute Pulmonary Embolism Diagnosis (PISAPED); 360 were diagnosed with and treated for PE in seven hospitals of central Tuscany, and evaluated at the Atherothrombotic Disorders Unit, Firenze (Italy), shortly after hospital discharge. We interviewed the patients directly using a standardized, self-administered questionnaire originally utilized in the PISAPED. The two samples differed significantly as regards age, proportion of outpatients, prevalence of unprovoked PE, and of active cancer. Sudden onset dyspnea was the most frequent symptom in both samples (81 and 78%), followed by chest pain (56 and 39%), fainting or syncope (26 and 22%), and hemoptysis (7 and 5%). At least one of the above symptoms was reported by 756 (94%) of 800 patients. Isolated symptoms and signs of deep vein thrombosis occurred in 3% of the cases. Only 7 (1%) of 800 patients had no symptoms before PE was diagnosed.

CONCLUSIONS/SIGNIFICANCE: Most patients with PE feature at least one of four symptoms which, in decreasing order of frequency, are sudden onset dyspnea, chest pain, fainting (or syncope), and hemoptysis. The occurrence of such symptoms, if not explained otherwise, should alert the clinicians to consider PE in differential diagnosis, and order the appropriate objective test.

Full-text (free):

18. Health Insurance Status Change and ED Use Among US Adults

Ginde AA, et al. Arch Intern Med. Published online March 26, 2012. doi:10.1001/archinternmed.2012.34

Background Recent events have increased the instability of health insurance coverage. We compared emergency department (ED) use by newly insured vs continuously insured adults and by newly uninsured vs continuously uninsured adults.

Methods We analyzed 159 934 adult respondents to the 2004 through 2009 National Health Interview Survey. Health insurance status was categorized as newly insured (currently insured but lacked health insurance at some point during the prior 12 months) vs continuously insured and as newly uninsured (currently uninsured but had health insurance at some point during the prior 12 months) vs continuously uninsured. We analyzed the number of ED visits during the prior 12 months using multivariable Poisson regression.

Results Overall, 20.7% of insured adults and 20.0% of uninsured adults had at least 1 ED visit. However, 29.5% of newly insured adults compared with 20.2% of continuously insured adults had at least 1 ED visit. Similarly, 25.7% of newly uninsured adults compared with 18.6% of continuously uninsured adults had at least 1 ED visit. After adjusting for demographics, socioeconomic status, and health status, recent health insurance status change was independently associated with greater ED use for newly insured adults (incidence rate ratio [IRR], 1.32; 95% CI, 1.22-1.42 vs continuously insured adults) and for newly uninsured adults (IRR, 1.39; 95% CI, 1.26-1.54 vs continuously uninsured adults). Among newly insured adults, this association was strongest for Medicaid beneficiaries (IRR, 1.45) but was attenuated for those with private insurance (IRR, 1.24) (P less than .001 for interaction).

Conclusions Recent changes in health insurance status for newly insured adults and for newly uninsured adults were associated with greater ED use. As policy and economic forces create disruptions in health insurance status, new surges in ED use should be anticipated.

19. Hold Off on Antibiotics for Sinus Infection, New Guidelines Urge

By Michael Smith, MedPage Today. Published: March 21, 2012

Action Points

A. New guidelines for acute sinusitis address issues that include the inability of existing clinical criteria to accurately differentiate bacterial from viral acute rhinosinusitis and excessive and inappropriate antimicrobial therapy.

B. Point out that the guidelines recommend empiric antimicrobial therapy with amoxicillin-clavulanate rather than amoxicillin alone when the clinical diagnosis of acute bacterial rhinosinusitis is established.


Between 90% and 98% of sinus infections won't respond to antibiotics, so doctors should hesitate before reaching for the prescription pad, according to new guidelines for the treatment of rhinosinusitis from the Infectious Diseases Society of America.

"There is no simple test that will easily and quickly determine whether a sinus infection is viral or bacterial, so many physicians prescribe antibiotics 'just in case,'" commented Anthony Chow, MD, of the University of British Columbia in Vancouver, who chaired the panel that developed the guidelines.

But, he added in a statement, "if the infection turns out to be viral -- as most are -- the antibiotics won't help and in fact can cause harm by increasing antibiotic resistance, exposing patients to drug side effects unnecessarily and adding cost."

The guidelines, published online in Clinical Infectious Diseases, offer primary care physicians 18 recommendations to help ensure appropriate treatment, ranging from how to tell bacterial from viral infections to when to call in a specialist.

Although most cases are viral, the guidelines suggest suspecting a bacterial cause when:
Symptoms or signs are persistent, lasting at least 10 days without any evidence of clinical improvement.

The disease onset is characterized by severe symptoms or signs of high fever (of at least 39° C or 102° F) and purulent nasal discharge or facial pain lasting for at least three or four days.
The disease gets worse with a new onset of fever, headache, or increase in nasal discharge following a typical viral upper respiratory infection that lasted five or six days and had appeared to be improving.

Where a bacterial cause is likely, the guidelines suggest prompt treatment with an antibiotic.

Many previous guidelines had suggested empiric therapy with the beta-lactam antibiotic amoxicillin, but an increasing proportion of respiratory pathogens now produce beta-lactamase, which breaks down the drug.

So, the new guidelines say, initial therapy should add clavulanate, a beta-lactamase inhibitor, to the amoxicillin.

The recommendation applies to both adults and children.

Because of increasing rates of drug resistance, the guidelines also recommend not using other common antibiotics, including azithromycin (Zithromax), clarithromycin (Biaxin), and trimethoprim-sulfamethoxazole (Septra).

The new guidelines also say that a shorter treatment time for adults -- five to seven days, rather than 10 to 14 -- is long enough to treat a bacterial infection without encouraging resistance.

Children should still be treated for 10 days to two weeks, the guidelines say.

Regardless of the cause of the infection, the guidelines discourage decongestants and antihistamines, which don't help and in some cases can make symptoms worse.

On the other hand, nasal steroids can help ease symptoms in people who have sinus infections and a history of allergies.

Saline nasal irrigation might help relieve some symptoms, the guidelines say, although it might not be as helpful in children because of the discomfort of the therapy.

The work was supported by the Infectious Diseases Society of America.

Chow reported financial links with Inimex, Migenix, Bayer, Merck, Wyeth, MEDACorp Clinical Advisors, Pfizer, Merck-Frosst Canada, and Core Health.

Chow AW, et al. IDSA clinical practice guideline for acute bacterial rhinosinusitis in children and adults. Clin Infect Dis 2012; DOI: 10.1093/cid/cir1043

Full-text (free):

20. When to Transfuse? A Review

Here’s a rule of thumb with which we’d all agree: “While definitive data are lacking at this time, the likelihood of a transfusion being of benefit is high when the patient's hemoglobin is less than 6 g/dL (60 g/L) and is low when it is greater than 10 g/dL (100 g/L).” Up-To-Date. “Indications for red cell transfusion in the adult” Feb 2012

In our Sept 13, 2010 issue of Lit Bits we brought you highlights from this helpful review: Walsh TS, et al. Managing anaemia in non-bleeding critically ill adults: state of the evidence. BMJ 2010; 341:c4408. Scroll down to #16.

For the most recent guidelines, see Napolitano LM, et al. Clinical practice guideline: red blood cell transfusion in adult trauma and critical care. Crit Care Med. 2009;37(12):3124.

Below I append a few paragraphs from a nice (free online) review: Collins TA. Packed red blood cell transfusions in critically ill patients. Crit Care Nurse. 2011;31(1):25-33; quiz 34.

Transfusion Trigger

The hemoglobin value that should trigger a transfusion of RBCs is currently under debate. The Surviving Sepsis Campaign Guidelines recommend giving patients a transfusion when the hemoglobin level is less than 7 g/dL with a goal of maintaining a hemoglobin level of 7 to 9 g/dL; however, this does not include patients with active hemorrhage, myocardial ischemia, or lactic acidosis.23 On the other hand, the American Society of Anesthesiologists Task Force does not recommend giving a patient a transfusion on the basis of the patient’s hemoglobin value, but rather recommends that the decision be based on the clinical situation.31,32 Because of the continuing debate over transfusion, health care providers should continue to monitor each patient’s clinical picture. The health care team should watch for blood loss, monitor for signs of inadequate perfusion and ischemia in the form of vital signs and urine output, and track the patients’ hemoglobin values.31

Number of Units Transfused

The number of units of RBCs appears to correlate with increased mortality, so the number of units transfused should be as few as possible.2,26,27,29,30 When a provider decides to give a patient a transusion of RBCs, 2 units are often transfused. It is, however, not always necessary to transfuse 2 units of blood. The expected response in hemoglobin level should be an increase of 1 g/dL per unit of blood transfused. If a stable patient with no known history of heart disease or active hemorrhage has a hemoglobin level of 7 g/dL and is given a transfusion of 1 unit of blood, the hemoglobin level should increase to 8 g/dL. One unit of blood should be transfused, and then the hemoglobin level should be measured. If an appropriate response in the level is noted, it may not be necessary to transfuse more blood products. However, if an appropriate response is not noted, then more blood should be transfused. This advice may not apply in emergency situations, in patients with active hemorrhage, or in patients showing signs of ischemia. Transfusing only 1 unit of blood decreases the risk of mortality and also decreases the risk of transfusion-transmitted infections.

Age of Stored Blood and Leukoreduction

Taylor et al25 reported that 65.3% of patients received blood products close to or over their expiration date, which highlights the importance of noting the expiration date before administration. As previously discussed, health care providers should know whether their institution uses leukoreduced or nonleukoreduced blood products. Leukoreduced blood is given universally in some countries and institutions; however, leukoreduction is associated with a significant cost. The cost for each unit of blood that undergoes leukoreduction ranges approximately from $30 to $100.33,34

References and full-text here:

21. Calorie Intake Rises as Sleep Time Drops

Does this mean night shifts contribute to obesity? Now we have an excuse!

By Crystal Phend, Senior Staff Writer, MedPage Today. March 15, 2012

Not getting enough sleep may lead to weight gain, according to a laboratory sleep restriction study finding a big boost in calorie intake.

Healthy individuals ate almost 550 extra calories when they missed out on an average 1 hour 20 minutes of sleep, Andrew D. Calvin, MD, MPH, of the Mayo Clinic in Rochester, Minn., and colleagues found.

But activity didn't increase to compensate during the extra time awake, the group reported at the American Heart Association's Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism (EPI/NPAM) meeting in San Diego.

Those unburned calories likely "would accumulate and eventually translate into extra fat," Calvin explained in an interview with MedPage Today. "Lack of sleep probably does contribute to weight gain and obesity."

There's no magic number for sleep duration that would keep one thin, though, he cautioned.

Sleep needs vary by individual, so people should aim for what feels like enough, Calvin suggested.

"At this point our best recommendation for individuals is if they are looking to maintain a healthy weight or to lose weight, they should make sure they get enough sleep," he said.

Clinicians too need to consider sleep -- not just related to weight, but for any number of health problems, Calvin suggested.

"It is always worthwhile to ask about sleep," he told MedPage Today. "It's a simple first step."

His group's study included 17 healthy adults ages 18 to 40 who spent eight days and nights in a lab where they were free to eat whatever food they wanted, but were randomized to have their normal sleep time cut by a third, or to sleep normally.

For the sleep-deprived individuals, continuous brain wave monitoring showed that they spent only 5.2 hours asleep compared with 6.5 hours at baseline, a modest difference similar to what often happens in everyday life, the researchers noted.

The extra time awake didn't raise active energy expenditure as measured by inclinometers and accelerometers; neither group saw a significant change.

However, sleep restriction raised average calorie intake by 549 kcal per day compared with baseline; the controls actually cut their calorie intake by 143 kcal per day in the lab (P less than 0.01 for difference).

It's possible that people got hungry to counteract tiredness or that they simply had more opportunities to eat given the longer time spent awake, Calvin noted. But adjusting for the extra time awake with an analysis of calories-per-hours-of-wakefulness still showed a surplus in the sleep restriction group.

That suggests "there are real biologic changes that are happening because of a lack of sleep that make people eat more," Calvin pointed out.

But exactly what those impacts are remains unclear.

The researchers suspected they would see a change in hormones that regulate appetite and did find trends for increased leptin with sleep deprivation (+8.4% versus -9.8% among controls, P=0.12) and decreased ghrelin (-4.9% versus +4.6%, P=0.38). However, those shifts were the opposite of what was expected and "more consistent with a consequence of a positive energy balance than a cause," the researchers explained.

From the American Heart Association:

Calvin AD, et al “Insufficient sleep increases caloric intake but not energy expenditure" EPI/NPAM 2012; Abstract MP030.

22. HLA Class II Locus and Susceptibility to Podoconiosis

Whoops, sorry. Not really ED-related…