Which Patients with Atrial Fibrillation Do Not Need Anticoagulation Therapy with Warfarin?

Anticoagulation therapy with warfarin is not indicated for use in patients with non- valvular atrial fibrillation who are at low risk for embolic cerebral vascular events. The classification of "low risk for embolic stroke" is defined as a 1 percent annual risk for stroke or lone atrial fibrillation (i.e., age younger than 65 years without history of hypertension, transient ischemic attack, stroke, coronary heart disease, recent congestive heart failure, or diabetes). Anticoagulation therapy with warfarin is beneficial in patients with atrial fibrillation who are at moderate or high risk for stroke. Patients with absolute contraindications to anticoagulation therapy (e.g., thrombocytopenia, recent trauma or surgery, hemorrhagic stroke, alcoholism) should not take warfarin. [Strength of recommendation: A, based on meta-analyses of large randomized controlled trials (RCTs).

Particle Acceleration at Ultra-Relativistic Shocks and the Spectra of Relativistic Fireballs

We examine Fermi-type acceleration at relativistic shocks, and distinguish between the initial boost of the first shock crossing cycle, where the energy gain per particle can be very large, and the Fermi process proper with repeated shock crossings, in which the typical energy gain is of order unity. We calculate by means of numerical simulations the spectrum and angular distribution of particles accelerated by this Fermi process, in particular in the case where particle dynamics can be approximated as small-angle scattering. We show that synchrotron emission from electrons or positrons accelerated by this process can account remarkably well for the observed power-law spectra of GRB afterglows and Crab-like supernova remnants. In the context of a decelerating relativistic fireball, we calculate the maximum particle energy attainable by acceleration at the external blast wave, and discuss the minimum energy for this acceleration process and its consequences for the observed spectrum.Comment: To appear in Proceedings of the 5th Huntsville Gamma-Ray Burst Symposium. LaTeX, 6 pages, 2 figures, uses aipproc.sty and epsfi

An eigenfunction method for particle acceleration at ultra-relativistic shocks

We adapt and modify the eigenfunction method of computing the power-law spectrum of particles accelerated at a relativistic shock front via the first-order Fermi process (Kirk, J.G., Schneider, P., Astrophysical Journal 315, 425 (1987)) to apply to shocks of arbitrarily high Lorentz factor. The power-law index of accelerated particles undergoing isotropic small-angle scattering at an ultrarelativistic, unmagnetized shock is found to be s=4.23 +/- 0.2 (where s=d\ln f/ d\ln p, with f the Lorentz-invariant phase-space density and p the momentum), in agreement with the results of Monte-Carlo simulations. We present results for shocks in plasmas with different equations of state and for Lorentz factors ranging from 5 to infinity.Comment: 4 pages, 2 figures, contribution to the Proceedings of the 5th Huntsville GRB Symposiu

Relapse Prevention with Deaf Persons

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Which treatments are effective for cervical radiculopathy?

Initial treatment options comprise rest, cervical immobilization, anti-inflammatory drugs (nonsteroidal and steroidal), pain relievers (including muscle relaxants and antiepileptics), and physical therapy (strength of recommendation [SOR]: B, cohort studies). As many as 60% of patients who fail initial treatments report long-term pain relief with epidural corticosteroid injections (SOR : C, case series)

Combined Oral Contraceptives for Mothers Who Are Breastfeeding

There is currently no evidence of harm; however, few patients have been studied and existing studies have many limitations. Therefore, it is not possible to definitively answer this question at this time. The existing low-quality evidence suggests that combined oral contraceptives may reduce the volume of breast milk but not affect the growth of infants. [Strength of Recommendation: B, based on inconsistent or limited-quality patient-oriented evidence

What clinical clues differentiate migraine from sinus headaches?

Evidence-based answer: Patients with sinus headaches have thick nasal discharge, fever, chills, sweats, or abnormally malodorous breath (SOR: B, cross-sectional study). The 5 symptoms that are most predictive of migraine are: pulsatile quality, duration of 4 to 72 hours, unilateral location, nausea or vomiting, and disabling intensity (SOR: B, retrospective cohort). As the number of these symptoms increases, so too, does the likelihood that the patient has a migraine (SOR: B, systematic review of retrospective cohort studies). Most patients diagnosed with sinus headache actually have a migraine headache (SOR: B, 2 cross-sectional studies)

How should we manage a patient with a positive PPD and prior BCG vaccination?

Prior bacille Calmette-Guérin (BCG) vaccination increases the likelihood of a positive tuberculosis (TB) 5TU purified protein derivative (PPD) skin test. The PPD response following BCG vaccine varies with age at vaccination, number of years since the BCG vaccination, number of times vaccinated, and number of PPDs performed. An induration of greater than 14 mm is unlikely to be due to prior BCG vaccination (strength of recommendation [SOR]: A, based on meta-analysis of validation cohort studies)

Hands off Tobacco: A School-Based Tobacco Control Programming for Deaf and Hard of Hearing Youth

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Do annual pelvic exams benefit asymptomatic women who receive regular Pap smears?

Q: Do annual pelvic exams benefit asymptomatic women who receive regular Pap smears? Evidence-based answer: No evidence exists to support a clinical benefit from annual pelvic examinations for asymptomatic women who receive Pap smears every 3 to 5 years. However, the American College of Obstetricians and Gynecologists (ACOG) committee on gynecologic practice recommends annual pelvic exams (strength of recommendation [SOR]: C, expert opinion). Urine testing alone reliably diagnoses gonorrhea and chlamydia (SOR: A, systematic review of cohort studies). Pelvic examinations unreliably detect adnexal masses (SOR: B, single cohort study); pelvic exams accompanied by ultrasound fail to affect outcomes in ovarian cancer screening (SOR: B, cohort studies). Pelvic exams aren't necessary before prescribing oral contraceptive pills (OCPs) (SOR: C, expert opinion). Vulvar carcinoma has a low prevalence and is usually symptomatic ((SOR: B, ecologic study and a case series)