Larger Vessels (larger + vessel)

Distribution by Scientific Domains


Selected Abstracts


What You See (Sonographically) Is What You Get: Vein and Patient Characteristics Associated With Successful Ultrasound-guided Peripheral Intravenous Placement in Patients With Difficult Access

ACADEMIC EMERGENCY MEDICINE, Issue 12 2009
Nova L. Panebianco MD
Abstract Objectives:, Ultrasound (US) has been shown to facilitate peripheral intravenous (IV) placement in emergency department (ED) patients with difficult IV access (DIVA). This study sought to define patient and vein characteristics that affect successful US-guided peripheral IV placement. Methods:, This was a prospective observational study of US-guided IV placement in a convenience sample of DIVA patients in an urban, tertiary care ED. DIVA patients were defined as having any of the following: at least two failed IV attempts or a history of difficult access plus the inability to visualize or palpate any veins on physical exam. Patient characteristics (demographic information, vital signs, and medical history) were collected on enrolled patients. The relationships between patient characteristics, vein depth and diameter, US probe orientation, and successful IV placement were analyzed. Results:, A total of 169 patients were enrolled, with 236 attempts at access. Increasing vessel diameter was associated with a higher likelihood of success (odds ratio [OR] = 1.79 per 0.1-cm increase in vessel diameter, 95% confidence interval [CI] = 1.37 to 2.34). Increasing vessel depth did not affect success rates (OR = 0.96 per 0.1-cm increase of depth, 95% CI = 0.89 to 1.04) until a threshold depth of 1.6 cm, beyond which no vessels were successfully cannulated. Probe orientation and patient characteristics were unrelated to success. Conclusions:, Success was solely related to vessel characteristics detected with US and not influenced by patient characteristics or probe orientation. Successful DIVA was primarily associated with larger vessel, while vessel depth up to >1.6 cm and patient characteristics were unrelated to success. Clinically, if two vessels are identified at a depth of <1.6 cm, the larger diameter vessel, even if comparatively deeper, should yield the greatest likelihood of success. [source]


Disparity in regional and systemic circulatory capacities: do they affect the regulation of the circulation?

ACTA PHYSIOLOGICA, Issue 4 2010
J. A. L. Calbet
Abstract In this review we integrate ideas about regional and systemic circulatory capacities and the balance between skeletal muscle blood flow and cardiac output during heavy exercise in humans. In the first part of the review we discuss issues related to the pumping capacity of the heart and the vasodilator capacity of skeletal muscle. The issue is that skeletal muscle has a vast capacity to vasodilate during exercise [,300 mL (100 g),1 min,1], but the pumping capacity of the human heart is limited to 20,25 L min,1 in untrained subjects and ,35 L min,1 in elite endurance athletes. This means that when more than 7,10 kg of muscle is active during heavy exercise, perfusion of the contracting muscles must be limited or mean arterial pressure will fall. In the second part of the review we emphasize that there is an interplay between sympathetic vasoconstriction and metabolic vasodilation that limits blood flow to contracting muscles to maintain mean arterial pressure. Vasoconstriction in larger vessels continues while constriction in smaller vessels is blunted permitting total muscle blood flow to be limited but distributed more optimally. This interplay between sympathetic constriction and metabolic dilation during heavy whole-body exercise is likely responsible for the very high levels of oxygen extraction seen in contracting skeletal muscle. It also explains why infusing vasodilators in the contracting muscles does not increase oxygen uptake in the muscle. Finally, when ,80% of cardiac output is directed towards contracting skeletal muscle modest vasoconstriction in the active muscles can evoke marked changes in arterial pressure. [source]


Necrotizing vasculitis in a patient affected by autoimmune hyperthyroidism treated with propylthiouracil

DERMATOLOGIC THERAPY, Issue 2010
Angela Antonucci
ABSTRACT Necrotizing vasculitis is a complex phenomenon because of an inflammation of small and larger vessels with polymorph infiltration within the vessel walls and leukocytoclasis, occurring in several autoimmune diseases. Propylthiouracil (PTU) is a medication commonly used to treat hyperthyroidism, but it is associated with various rare side effects, such as antineutrophil cytoplasm antibody-positive vasculitis. In the last decades, multiple cases of PTU causing antineutrophilic cytoplasmic antibody have been reported, some of them fatal. The present authors report the case of a 34-year-old Caucasian female affected by autoimmune hyperthyroidism treated with PTU, presenting an antineutrophil cytoplasm antibody-positive necrotizing vasculitis, with high levels of anticardiolipin antibodies that involved the upper arms and buttocks. The clinical manifestations improved after discontinuing of PTU and immunosuppressant treatment. [source]


Profit and Price Effects of Multi-species Individual Transferable Quotas

JOURNAL OF AGRICULTURAL ECONOMICS, Issue 1 2005
Diane P. Dupont
Regulators in many countries have adopted individual transferable quotas as a means of dealing with the open access problem inherent in fisheries. Using individual vessel data prior to and after the introduction of ITQs in Canada's multi-species Scotia-Fundy mobile gear fishery, the paper uses an index number profit decomposition to compare vessel performance over time and across individual vessels. The approach allows us to undertake both an ex post evaluation of short-term impacts of ITQs and an ex ante evaluation of longer term impacts. With respect to short-term impacts, the results suggest that larger vessels have benefited the most from the introduction of ITQs, but that all vessels have enjoyed increases in the prices received for those fish species that are included in the quota program. With respect to longer-term impacts, the transferability provisions of the ITQ program have encouraged exit and more efficient operations to prevail. [source]


Liver resection using heat coagulative necrosis: indications and limits of a new method

ANZ JOURNAL OF SURGERY, Issue 9 2009
Gregor A. Stavrou
Abstract Background:, A new approach towards achieving bloodless liver resection is the use of heat coagulative necrosis. The latest stage of this technique is a four-probe device (Habib Sealer), which we used for a variety of resections to find the best indications for the method. Methods:, Between 2005 and 2006 we performed 28 liver resections in 20 consecutive patients. The most common indication was metastatic colorectal cancer (75%). We treated a heterogeneous patient collective in terms of tumour localization and extent of resection. Resection was performed after creating a necrotic zone. The device achieved an area of coagulation of 1-cm width in which even larger vessels and bile ducts were safely sealed. Results:, Operative spectrum covered atypical resections (8), one- or bisegmentectomies at different locations (15), hemihepatectomies (4) and one extended right hepatectomy. With one exception intra-operative blood loss was lower than 100 mL. Four patients (20%) developed operation-related complications comprising abscess formation at the resection site. Follow-up shows tumour-free survival for 13 of 18 patients 12 months after resection. Conclusion:, Liver resection using the sealer device seems safe. In proximity of hilar structures or large vessels the method is not favourable for the fear of thermal damage. Extended resections are possible but not parenchyma saving. Good indications are atypical (deep) resections , especially in Segment IVb. [source]


Falkland Islands cruise ship tourism: an overview of the 1999,2000 season and the way forward

AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 1 2002
Rebecca J. Ingham
Abstract 1.Falkland Islands' tourism is evolving at an increasing pace. A record number of passengers, 23 497, visited the Islands during the 1999,2000 season. This rise was due to an increase in both the frequency of vessel visits and the average passenger capacity of vessels, with the number of luxury cruise ships of >1000 passengers steadily increasing. The Falklands' industry is made up of three types of vessel: the expedition cruise vessels (ca. 100,200 passengers); larger cruise vessels (ca. 400 passengers), and the luxury cruise vessels (ca. 1000 passengers). 2.The cruise ship industry has seen a diversification within the market, with cruises now available to a wider audience thus increasing the need for new experiences and landing sites. A similar diversification is being seen within the Islands themselves as the capacity to take larger vessels at remote sites is being developed. Whilst the expedition cruise vessels visiting the Islands are operating to high environmental standards as members of the International Association of Antarctic Tour Operators (IAATO), vessels with 400+ passengers may not become members of IAATO, due to Article III of the organization's Bylaws which limits the number of passengers. These larger capacity vessels are therefore not subject to the same self-regulating guidelines. The implications of increasing passenger numbers in the islands are discussed with regard to pressures on both the wildlife and vegetation. 3.This study outlines the need for an island-wide approach and a legislative framework to ensure high standards of operation are adhered to within the Islands from all visiting vessels and that accurate information is provided to all visitors along with a suitable code of conduct. The collection, collation and analysis of visitor data to identify trends and implement appropriate management strategies, and further research into the potential impacts of tourism on wildlife in the Falklands are also recommended. Copyright © 2002 John Wiley & Sons, Ltd. [source]