198 research outputs found

    Accounting for Rehabilitation Activity Uncertainty in a Pavement Life Cycle Assessment using Probability and Decision Tree Analysis

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    In any life cycle assessment (LCA) for pavements, the designer must decide on which rehabilitation activities will be used to maintain the pavement over the analysis period. While this sounds simple, the fact is that there are many different rehabilitation scenarios that could be performed when the pavement requires rehabilitation, and which one is used will impact the LCA results. This creates inherent uncertainty and variability in the LCA results solely due to the selection of the rehabilitation scenario used in the analysis. Currently, most LCA’s apply a single standard rehabilitation scenario to all pavements. The problem with this approach is that because each project is unique, the activities may or may not be representative of the actual set of activities done on that particular pavement. The only way to get meaningful indication of a project’s pavement environmental impact is to look at the impact of all (or at least most) of the potential rehabilitation activities that could be used to maintain the pavement over the analysis period. This paper shows how State Highway Agencies (SHAs) can use probability and decision tree analysis to evaluate many rehabilitation scenarios in order to determine a range of LCA results, as well as a probability adjusted, expected value LCA result. This process quantifies the underlying uncertainty that different the rehabilitation selection can have on the LCA results so that a more informed decision can be made when comparing the alternate pavement designs. A case study based on alternative designs and rehabilitation scenarios used by a SHA demonstrates the decision tree analysis process and shows how the risk profiles for the two alternatives considered are not equivalent. For this case, this results in the probability-adjusted LCA results being different than the single standard rehabilitation scenario results.CSHub@MIT research is carried out with sponsorship provided by the Portland Cement Association and the Ready Mixed Concrete Research & Education Foundation

    Critical Review and Consensus Statement for Neural Monitoring in Otolaryngologic Head, Neck, and Endocrine Surgery

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    BACKGROUND: Enhancing patient outcomes in an array of surgical procedures in the head and neck requires the maintenance of complex regional functions through the protection of cranial nerve integrity. This review and consensus statement cover the scope of cranial nerve monitoring of all cranial nerves that are of practical importance in head, neck, and endocrine surgery except for cranial nerves VII and VIII within the temporal bone. Complete and applied understanding of neurophysiologic principles facilitates the surgeon\u27s ability to monitor the at-risk nerve. METHODS: The American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) identified the need for a consensus statement on cranial nerve monitoring. An AAO-HNS task force was created through soliciting experts on the subject. Relevant domains were identified, including residency education, neurophysiology, application, and various techniques for monitoring pertinent cranial nerves. A document was generated to incorporate and consolidate these domains. The panel used a modified Delphi method for consensus generation. RESULTS: Consensus was achieved in the domains of education needs and anesthesia considerations, as well as setup, troubleshooting, and documentation. Specific cranial nerve monitoring was evaluated and reached consensus for all cranial nerves in statement 4 with the exception of the spinal accessory nerve. Although the spinal accessory nerve\u27s value can never be marginalized, the task force did not feel that the existing literature was as robust to support a recommendation of routine monitoring of this nerve. In contrast, there is robust supporting literature cited and consensus for routine monitoring in certain procedures, such as thyroid surgery, to optimize patient outcomes. CONCLUSIONS: The AAO-HNS Cranial Nerve Monitoring Task Force has provided a state-of-the-art review in neural monitoring in otolaryngologic head, neck, and endocrine surgery. The evidence-based review was complemented by consensus statements utilizing a modified Delphi method to prioritize key statements to enhance patient outcomes in an array of surgical procedures in the head and neck. A precise definition of what actually constitutes intraoperative nerve monitoring and its benefits have been provided

    Measuring the indirect effect: Voter initiatives and legislative production in the American states

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    Accepted ManuscriptRecent research has identified important policy differences between voter initiative states and pure representative states despite a lack of enough observable voter initiative campaigns to explain the policy differences. This paper investigates the indirect effects of the voter initiative process on legislative production by estimating the number of bill enacted in the American states. The results indicate that legislators in voter initiative states enact more legislation as the difficulty in qualifying a voter initiative for the ballot decreases, as the legislature is less able to alter the effects of successful voter initiatives, and as the average number of voter initiatives that appear on the ballot increases. These results provide some statistical evidence of the indirect effect of the voter initiative and are consistent with the theory that policy differences in voter initiative states are the result of the indirect effect of the voter initiative process.Randolph, G.M. (2010). Measuring the indirect effect: Voter initiatives and legislative production in the American states. Public Finance Review, 38(6), 762-786

    Survival of young patients after abdominal aortic aneurysm repair

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    AbstractPurpose: This study assessed the cardiovascular disease, perioperative results, and survival after surgical abdominal aortic aneurysm repair in young patients (≤ 50 years) compared with randomly selected older patients who also underwent abdominal aortic aneurysm repair. Methods: We reviewed hospital records to identify young and randomly selected control patients (3 for each young patient, ≥ 65 years, matched for year of operation) with degenerative (atherosclerotic) abdominal aortic aneurysms undergoing repair between Jan 1, 1988, and Mar 31, 2000. Patients with congenital aneurysms, pseudoaneurysms, aortic dissections, post-coarctation dilations, aortic infection, arteritis, or aneurysms isolated to the thoracic aorta were excluded. Mortality data and cause of death were obtained from medical records and the National Death Index Results: Among 1168 patients who underwent abdominal aortic aneurysm repairs, 19 young patients (1.6%) and 57 control patients were identified. The mean age was 48.4 years in the young group and 72.2 years in the control group. There were no differences in sex or race between the two groups. When comparing existing cardiovascular disease between the groups, there were no differences in the incidence of earlier coronary revascularization (26% vs 16%) or non-cardiac vascular surgery (5% vs 9%), but aneurysms were more commonly symptomatic in young patients (53% vs 21%; P <.01). Aneurysmal disease was limited to the infrarenal aorta in similar proportions of patients (89% vs 88%). No statistically significant differences were seen in the incidence of perioperative deaths (16% young vs 9% control; P =.40) or postoperative complications (37% young vs 26% control; P =.38). The estimated survival rate of the young group was not different from that of the control group (3-year survival rate, 73% vs 69%; P =.32) or the entire cohort of patients (older than 50 years; n = 1101) who underwent repair of abdominal aortic aneurysms during the study period (3-year survival 73% vs 75%; P =.63) Conclusion: After abdominal aortic aneurysm repair, young patients had perioperative results and follow-up mortality rates similar to those of control patients. Cardiovascular disease was the predominant cause of death after abdominal aortic aneurysm repair in the young patients. When compared with an age older than 50 years at the time of abdominal aortic aneurysm repair, young age alone was not associated with increased survival. (J Vasc Surg 2002;35:94-9.

    Facial nerve electrodiagnostics for patients with facial palsy : a clinical practice guideline

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    Purpose Facial nerve electrodiagnostics is a well-established and important tool for decision making in patients with facial nerve diseases. Nevertheless, many otorhinolaryngologist-head and neck surgeons do not routinely use facial nerve electrodiagnostics. This may be due to a current lack of agreement on methodology, interpretation, validity, and clinical application. Electrophysiological analyses of the facial nerve and the mimic muscles can assist in diagnosis, assess the lesion severity, and aid in decision making. With acute facial palsy, it is a valuable tool for predicting recovery. Methods This paper presents a guideline prepared by members of the International Head and Neck Scientific Group and of the Multidisciplinary Salivary Gland Society for use in cases of peripheral facial nerve disorders based on a systematic literature search. Results Required equipment, practical implementation, and interpretation of the results of facial nerve electrodiagnostics are presented. Conclusion The aim of this guideline is to inform all involved parties (i.e. otorhinolaryngologist-head and neck surgeons and other medical specialists, therapeutic professionals and the affected persons) and to provide practical recommendations for the diagnostic use of facial nerve electrodiagnostics.Peer reviewe

    Training Courses in Laryngeal Nerve Monitoring in Thyroid and Parathyroid Surgery- The INMSG Consensus Statement

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    Intraoperative neural monitoring (IONM) is now an integral aspect of thyroid surgery in many centers. Interest in IONM and the number of institutions that perform monitored thyroidectomies have increased throughout the world in recent years. For surgeons considering the introduction of IONM in their practice, specific training in IONM devices and procedures can substantially shorten the learning curve. The International Neural Monitoring Study Group (INMSG) has been at the forefront of IONM technology and procedural adoption since the introduction of neural monitoring in thyroid and parathyroid surgery. The purpose of this document is to define the INMSG consensus on essential elements of IONM training courses. Specifically, this document describes the minimum training required for teaching practical application of IONM and consensus views on key issues that must be addressed for the safe and reliable introduction of IONM in surgical practice. The intent of this publication is to provide societies, course directors, teaching institutions, and national organizations with a practical reference for developing IONM training programs. With these guidelines, IONM will be implemented optimally, to the ultimate benefit of the thyroid and parathyroid surgical patients

    Consensus Statement on the Terminology and Classification of Central Neck Dissection for Thyroid Cancer

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    Background: The primary goals of this interdisciplinary consensus statement are to review the relevant anatomy of the central neck compartment, to identify the nodal subgroups within the central compartment commonly involved in thyroid cancer, and to define a consistent terminology relevant to the central compartment neck dissection. Summary: The most commonly involved central lymph nodes in thyroid carcinoma are the prelaryngeal (Delphian), pretracheal, and the right and left paratracheal nodal basins. A central neck dissection includes comprehensive, compartment-oriented removal of the prelaryngeal and pretracheal nodes and at least one paratracheal lymph node basin. A designation should be made as to whether a unilateral or bilateral dissection is performed and on which side (left or right) in unilateral cases. Lymph node plucking or berry picking implies removal only of the clinically involved nodes rather than a complete nodal group within the compartment and is not recommended. A therapeutic central compartment neck dissection implies that nodal metastasis is apparent clinically (preoperatively or intraoperatively) or by imaging (clinically N1a). A prophylactic/elective central compartment dissection implies nodal metastasis is not detected clinically or by imaging (clinically N0). Conclusion: Central neck dissection at a minimum should consist of removal of the prelaryngeal, pretracheal, and paratracheal lymph nodes. The description of a central neck dissection should include both the indication (therapeutic vs. prophylactic/elective) and the extent of the dissection (unilateral or bilateral).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78103/1/thy.2009.0159.pd

    Effectiveness of core needle biopsy in the diagnosis of thyroid lymphoma and anaplastic thyroid carcinoma: A systematic review and meta-analysis

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    Both anaplastic thyroid carcinoma (ATC) and thyroid lymphoma (TL) clinically present as rapidly enlarging neck masses. Unfortunately, in this situation, like in any other thyroid swelling, a routine fine-needle aspiration (FNA) cytology is the first and only diagnostic test performed at the initial contact in the average thyroid practice. FNA, however, has a low sensitivity in diagnosing ATC and TL, and by the time the often "inconclusive" result is known, precious time has evolved, before going for core-needle biopsy (CNB) or incisional biopsy (IB) as the natural next diagnostic steps

    Perioperative pain management and opioid-reduction in head and neck endocrine surgery: An American Head and Neck Society Endocrine Surgery Section consensus statement

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    BACKGROUND: This American Head and Neck Society (AHNS) consensus statement focuses on evidence-based comprehensive pain management practices for thyroid and parathyroid surgery. Overutilization of opioids for postoperative pain management is a major contributing factor to the opioid addiction epidemic however evidence-based guidelines for pain management after routine head and neck endocrine procedures are lacking. METHODS: An expert panel was convened from the membership of the AHNS, its Endocrine Surgical Section, and ThyCa. An extensive literature review was performed, and recommendations addressing several pain management subtopics were constructed based on best available evidence. A modified Delphi survey was then utilized to evaluate group consensus of these statements. CONCLUSIONS: This expert consensus provides evidence-based recommendations for effective postoperative pain management following head and neck endocrine procedures with a focus on limiting unnecessary use of opioid analgesics
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