ALBERT

Description: [1]  The conversion of Langmuir waves into electromagnetic radiation near the local plasma frequency ( f pe ) and twice the local plasma frequency (2 f pe ) occurs in diverse heliospheric environments including along the path of type III radio bursts, at interplanetary shocks, and in planetary foreshocks. This radiation has the potential to act as probe of remote plasma conditions, provided the conversion mechanism is well understood. One candidate conversion mechanism is the antenna radiation oflocalized Langmuir waves. Antenna radiation near 2 f pe requires the presence of nonlinear currents at 2 f pe . In this work, properties of these currents are predicted from theory and compared with STEREO/WAVES observations of Langmuir wave electric fields. It is found that the observed frequency structure, polarization, and wave number ratio are consistent with nonlinear current predictions, once electric fields near 2 f pe consistent with sheath effects are taken into account.

Description: Abstract 4402 Background: Professional, evidence-based guidelines are developed to help physicians implement best practice care. Unfortunately, guidelines are not followed. Platelet transfusion guidelines have recently changed to a prophylactic transfusion threshold of 10, 000/μ L from the older threshold of 20,000/μ L. We conducted a retrospective analysis at a metropolitan teaching hospital to assess how well physicians comply with the new professional guidelines as well as the older, less stringent criteria to administer platelet transfusions. Methods: All patients admitted to the medical service who received platelet transfusions over a two month period in 2010 were reviewed. These patients represented the following services: ICU, general medicine, medical step down, interventional cardiology, CCU, and the cardiac step down unit. The indication selected in the computerized physician order entry (CPOE) system was compared to the clinical indication found in the patients’ medical record. The medical record clinical indication was then evaluated against the American Society of Hematology (ASH) 2007 “Evidence-Based Platelet Transfusion Guidelines” (Slichter SJ. Hematology 2007): bleeding and platelets ≤50, 000/μ L, pre-invasive procedure and platelets ≤50, 000/μ L, prophylactic transfusion for platelets ≤10, 000/μ L and WHO bleeding grade ≥ 2. We also assessed how the patients’ clinical indication met the older less stringent prophylactic threshold for platelet transfusion of ≤20, 000/μ L laid forth by the landmark study by Gaydos LA. et. al. (The quantitative relation between platelet count and hemorrhage in patients with acute leukemia. N Engl J Med 1962). Results: A total of 108 patients received platelet transfusions; 29 were medicine patients to tally 95 platelet transfusions. The most common patient clinical indication was “platelets ≤ 20, 000/μ L without bleeding” (27%), while the clinical indication was not specified in 16% of cases. The CPOE documented indication coincided with the patient's clinical indication from the medical record in 23% of cases. Sixty five percent of the time the patient's clinical indication failed to meet the currently accepted 2007 ASH guidelines and 36% of cases failed to meet the older less stringent guidelines. Conclusions: A majority of platelet transfusions did not meet the current professional guidelines for indication. Our pilot study suggests the need for more physician education regarding evidence-based guidelines for platelet transfusions, and in a larger context, initiatives to enhance compliance. We are currently developing an educational intervention and plan to reassess compliance with indications pre and post intervention. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 2553 Background: Inferior Vena Cava (IVC) filter placement has increased significantly over the past few decades, due to expanding indications for filter placement. Indications for filter placement vary widely depending on which professional society recommendations are followed. Our objectives were to record the number of IVC filters placed in our medium sized metropolitan teaching hospital, assess the effect of medical specialty on placement and evaluate compliance with accepted standards as set by the American College of Chest Physicians (ACCP) and the Society of Interventional Radiology (SIR). Methods: Single-center, retrospective medical record review of all patients who received an IVC filter over 26 months (01/30/2008 - 4/5/2010). Inclusion criteria included patients from both sexes, all ages, filter placement within the aforementioned dates and inpatient procedures performed by interventional radiology. A total of 443 IVC filters were placed in our institution over the time period studied. 48.1% (213) of these filters were placed by interventional radiology. Of these, 187 were reviewed with 26 excluded do to incomplete patient records available at the time of review (July 2010). Medical records were reviewed for patient demographics, clinical course, and compliance with accepted guidelines set by the ACCP and SIR. Results: The average age was 75.3 years and 43.9% of the patients were males. 76.2% of patients were on the medical service (internal medicine and its subspecialties) whereas 22.8% were on non medical services. 87.2 % of filters were recommended by medicine and its subspecialties and 12.8% by non medical specialties. 43.3% of filters placed met guidelines established by the ACCP (Table 1). 79.1% of filters placed met SIR guidelines (Table 2). No documentation was available to assess compliance for 20.9% of filters. 46% of filters placed by internal medicine and its subspecialties met ACCP criteria whereas only 25% of filters recommended by non medicine specialties were compliant with criteria (p value=0.039, 95% CI). Physicians within internal medicine and its subspecialties were compliant with SIR guidelines for 84% of the filters placed, whereas only 46% of non medicine physicians met these indications (p=0.001, 95% CI). 35.8% of filters placed met SIR criteria but did not meet ACCP guidelines. Conclusions: Indications for IVC filter placement varied significantly in this study, less than half of filters placed met ACCP guidelines, yet over three-fourths met criteria set by the SIR, especially when comparing medicine and non medicine specialties. In analyzing the filters which meet indications set by SIR but not ACCP it becomes apparent that most of these are placed for patients classified as “fall risks”, failures of anticoagulation, limited cardiopulmonary reserve and medication noncompliance. Further research needs to be guided towards evaluating if these indications truly merit the placement of an IVC filter. This study strongly suggests a need for harmonization of current guidelines espoused by professional societies. A limitation of our study was that 230 filters placed by vascular surgery and interventional cardiology were not reviewed. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 4331 Intro: Evidence-based guidelines are developed and promoted to help physicians implement best practice care. The American Society of Hematology (ASH) platelet transfusion guidelines changed in 2007 to a prophylactic transfusion threshold of 10, 000/μL from the previous 20,000/μL. We conducted a retrospective analysis at a metropolitan teaching hospital to assess how well physicians are complying with the new professional guidelines as well as the older, less stringent criteria to administer platelet transfusions. We then assessed the effect of an educational intervention on transfusion practices. Methods: All patients receiving platelet transfusions over a five-month period from Jan-Feb, and April-June 2010, admitted to the medical, critical care and cardiac services were reviewed. The medical record clinical indication was then evaluated against the ASH 2007 “Evidence-Based Platelet Transfusion Guidelines” (Slichter SJ. Hematology 2007): bleeding and platelets ≤50, 000/μL, pre-invasive procedure and platelets ≤50, 000/μL, prophylactic transfusion for platelets ≤10, 000/μL and WHO bleeding grade ≥ 2. We also assessed how the patients’ clinical indication met the previous prophylactic threshold for platelet transfusion of ≤20, 000/μL laid forth by the landmark study by Gaydos LA. et. al. (The quantitative relation between platelet count and hemorrhage in patients with acute leukemia. N Engl J Med 1962). Following initial data collection, we implemented an educational intervention by giving a lecture, reviewing all indications for platelet transfusions, and distributing a pocket card to the house-staff on the medical wards in August, 2010. We subsequently gathered post-intervention data following the methods described above for four consecutive months from Sept-December, 2011. Results: Eighty-six patients on the selected units received a total of 241 platelet transfusions. Fifty nine percent of the time the patient's clinical indication failed to meet the currently accepted 2007 ASH guidelines and 37% of cases failed to meet even the older guideline. Eighty-one patients received a total of 237 platelet transfusions post-intervention. Forty-seven percent of the time the patient's clinical indication failed to meet the currently accepted 2007 ASH guidelines and 19% of cases failed to meet the older guideline. Conclusions: Based on the significant difference observed between the pre- and post-educational intervention groups, our initial study shows that updating physicians on current evidence-based guidelines for platelet transfusions is a simple and effective means to improve transfusion practices. Periodic educational interventions may prove to even further enhance physician compliance with up-to-date guidelines and we plan to implement additional educational interventions throughout the upcoming academic year. Disclosures: No relevant conflicts of interest to declare.