212 research outputs found
Influence of mechanical strains on electromagnetic signals of a microstrip antenna. FEM/BIM model
A hybrid numerical technique is proposed for a characterization of the radar cross
section of a microstrip patch antenna residing in a dielectric filled cavity which is loaded by a
sinusoidal mechanical pressure. A new 3D hexahedral finite element is developed in order to
take into account the deformed shape of the antenna within the electromagnetic computations.
The numerical tool combines the finite element and boundary integral methods to formulate a
system for the solution of the fields at the aperture and those inside the cavity. In this work,
numerical examples are presented for demonstrating the ability and the validity of the
hexahedral element
Ten Years of Experience Training Non-Physician Anesthesia Providers in Haiti.
Surgery is increasingly recognized as an effective means of treating a proportion of the global burden of disease, especially in resource-limited countries. Often non-physicians, such as nurses, provide the majority of anesthesia; however, their training and formal supervision is often of low priority or even non-existent. To increase the number of safe anesthesia providers in Haiti, Médecins Sans Frontières has trained nurse anesthetists (NAs) for over 10 years. This article describes the challenges, outcomes, and future directions of this training program. From 1998 to 2008, 24 students graduated. Nineteen (79%) continue to work as NAs in Haiti and 5 (21%) have emigrated. In 2008, NAs were critical in providing anesthesia during a post-hurricane emergency where they performed 330 procedures. Mortality was 0.3% and not associated with lack of anesthesiologist supervision. The completion rate of this training program was high and the majority of graduates continue to work as nurse anesthetists in Haiti. Successful training requires a setting with a sufficient volume and diversity of operations, appropriate anesthesia equipment, a structured and comprehensive training program, and recognition of the training program by the national ministry of health and relevant professional bodies. Preliminary outcomes support findings elsewhere that NAs can be a safe and effective alternative where anesthesiologists are scarce. Training non-physician anesthetists is a feasible and important way to scale up surgical services resource limited settings
Evidences for a Paleocene marine incursion in southern Amazonia (Madre de Dios Sub-Andean Zone, Peru)
This article presents new biostratigraphic dating, facies analysis, organic geochemical data and Nd–Sr isotopic provenance from five outcrops of southern Amazonia (MD-85, MD-177 MD-184, MD-255 and MD-256) to document for the first time the presence of a shallow marine ingression in the Paleocene of southern Amazonia basin. The co-occurrence of a selachian assemblage encompassing Potobatis sp., Ouledia sp., and Pristidae indet. with the ostracod Protobuntonia sp. and the charophytes Peckichara cf. varians meridionalis, Platychara perlata, and Feistiella cf. gildemeisteri suggests a Paleocene age for the studied deposits (most likely Thanetian but potentially Danian). Fifteen facies have been recognized and have been grouped into three facies assemblages. Facies association A corresponds to the sedimentary filling of a tide-influenced meandering channel formed in the fluvial–tidal transition zone. Facies association B is related to more distal tidal-flats, little channelized tidal inlets and saltmarsh deposits. Facies association C corresponds to a stressed shallow marine environment such as a bay or a lagoon. The d13CTOC value (- 23.4‰) of MD-184 is enriched in 13C compared to the other samples suggesting the presence of substantial amounts of marine organic matter in MD-184. The d13CTOC values of samples from other outcrops (- 27.3 to - 29.8‰) indicate a mixed organic matter origin, from terrestrial to brackish environments. The analyzed sediments have similar Nd–Sr isotopic compositions as those of the Cenozoic sediments of the Altiplano (eNd(0) values from - 6.2 to - 10.7 and 87Sr/86Sr compositions from 0.712024 to 0.719026) indicating a similar volcanic source. This multidisciplinary dataset documents the presence of a tide-dominated estuary sourced by the proto-Western Cordillera debouching into a shallow marine bay during Paleocene times. This transgression might be explained by subsidence created in response to the proto-Western Cordillera loading. Similar to Miocene marine incursions affecting the Pebas megawetland, Paleogene marine incursions in the Amazonian foreland basin associated with Andean uplift may have played a role in the Neotropical biodiversity dynamics in favoring biogeographical isolation and promoting allopatric speciation for terrestrial organisms
Antipsychotic dose escalation as a trigger for Neuroleptic Malignant Syndrome (NMS): literature review and case series report
Background: “Neuroleptic malignant syndrome” (NMS) is a potentially fatal idiosyncratic reaction to any medication which affects the central dopaminergic system. Between 0.5% and 1% of patients exposed to antipsychotics develop the condition. Mortality rates may be as high as 55% and many risk factors have been reported. Although rapid escalation of antipsychotic dose is thought to be an important risk factor, to date it has not been the focus of a published case series or scientifically defined.
<p/>Aims: To identify cases of NMS and review risk factors for its development with a particular focus on rapid dose escalation in the 30 days prior to onset.
<p/>Methodology: A review of the literature on rapid dose escalation was undertaken and a pragmatic definition of “rapid dose escalation” was made. NMS cases were defined using DSM-IV criteria and systematically identified within a secondary care mental health service. A ratio of titration rate was calculated for each NMS patient and “rapid escalators” and “non rapid escalators” were compared.
<p/>Results: 13 cases of NMS were identified. A progressive mean dose increase 15 days prior to the confirmed episode of NMS was observed (241.7mg/day during days 1-15 to 346.9mg/day during days 16-30) and the mean ratio of dose escalation for NMS patients was 1.4. Rapid dose escalation was seen in 5/13 cases and non rapid escalators had markedly higher daily cumulative antipsychotic dose compared to rapid escalators.
<p/>Conclusions: Rapid dose escalation occurred in less than half of this case series (n=5, 38.5%), although there is currently no consensus on the precise definition of rapid dose escalation. Cumulative antipsychotic dose – alongside other known risk factors - may also be important in the development of NMS
Glucocorticoids for acute urticaria: study protocol for a double-blind non-inferiority randomised controlled trial
INTRODUCTION: This study protocol describes a trial designed to investigate whether antihistamine alone in patients with acute urticaria does not increase the 7-day Urticaria Activity Score (UAS7) in comparison with an association of antihistamine and glucocorticoids and reduces short-term relapses and chronic-induced urticaria.
METHODS AND ANALYSIS: This is a prospective, double-blind, parallel-group, multicentre non-inferiority randomised controlled trial. Two-hundred and forty patients with acute urticaria admitted to emergency department will be randomised in a 1:1 ratio to receive levocetirizine or an association of levocetirizine and prednisone. Randomisation will be stratified by centre. The primary outcome will be the UAS7 at day 7. The secondary outcomes will encompass recurrence of hives and/or itch at day 7; occurrence of spontaneous hives or itch for >6 weeks; patients with angioedema at day 7, and 2, 6, 12 and 24 weeks; new emergency visits for acute urticaria recurrences at days 7 and 14, and 3 months; Dermatology Life Quality Index at days 7 and 14, and 3 and 6 months; and Chronic Urticaria Quality of Life Questionnaire at 6 weeks.
ETHICS AND DISSEMINATION: The protocol has been approved by the and will be carried out in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. A steering committee will oversee the progress of the study. Findings will be disseminated through national and international scientific conferences and publication in peer-reviewed journals.
TRIAL REGISTRATION NUMBER: NCT03545464
Prehospital score for acute disease: a community-based observational study in Japan
<p>Abstract</p> <p>Background</p> <p>Ambulance usage in Japan has increased consistently because it is free under the national health insurance system. The introduction of refusal for ambulance transfer is being debated nationally. The purpose of the present study was to investigate the relationship between prehospital data and hospitalization outcome for acute disease patients, and to develop a simple prehospital evaluation tool using prehospital data for Japan's emergency medical service system.</p> <p>Methods</p> <p>The subjects were 9,160 consecutive acute disease patients aged ≥ 15 years who were transferred to hospital by Kishiwada City Fire Department ambulance between July 2004 and March 2006. The relationship between prehospital data (age, systolic blood pressure, pulse rate, respiration rate, level of consciousness, SpO<sub>2 </sub>level and ability to walk) and outcome (hospitalization or non-hospitalization) was analyzed using logistic regression models. The prehospital score component of each item of prehospital data was determined by beta coefficients. Eligible patients were scored retrospectively and the distribution of outcome was examined. For patients transported to the two main hospitals, outcome after hospitalization was also confirmed.</p> <p>Results</p> <p>A total of 8,330 (91%) patients were retrospectively evaluated using a prehospital score with a maximum value of 14. The percentage of patients requiring hospitalization rose from 9% with score = 0 to 100% with score = 14. With a cut-off point score ≥ 2, the sensitivity, specificity, positive predictive value and negative predictive value were 97%, 16%, 39% and 89%, respectively. Among the 6,498 patients transported to the two main hospitals, there were no deaths at scores ≤ 1 and the proportion of non-hospitalization was over 90%. The proportion of deaths increased rapidly at scores ≥ 11.</p> <p>Conclusion</p> <p>The prehospital score could be a useful tool for deciding the refusal of ambulance transfer in Japan's emergency medical service system.</p
Boussignac continuous positive airway pressure for the management of acute cardiogenic pulmonary edema: prospective study with a retrospective control group
<p>Abstract</p> <p>Background</p> <p>Continuous positive airway pressure (CPAP) treatment for acute cardiogenic pulmonary edema can have important benefits in acute cardiac care. However, coronary care units are usually not equipped and their personnel not adequately trained for applying CPAP with mechanical ventilators. Therefore we investigated in the coronary care unit setting the feasibility and outcome of the simple Boussignac mask-CPAP (BCPAP) system that does not need a mechanical ventilator.</p> <p>Methods</p> <p>BCPAP was introduced in a coronary care unit where staff had no CPAP experience. All consecutive patients transported to our hospital with acute cardiogenic pulmonary edema, a respiratory rate > 25 breaths/min and a peripheral arterial oxygen saturation of < 95% while receiving oxygen, were included in a prospective BCPAP group that was compared with a historical control group that received conventional treatment with oxygen alone.</p> <p>Results</p> <p>During the 2-year prospective BCPAP study period 108 patients were admitted with acute cardiogenic pulmonary edema. Eighty-four of these patients (78%) were treated at the coronary care unit of which 66 (61%) were treated with BCPAP. During the control period 66 patients were admitted over a 1-year period of whom 31 (47%) needed respiratory support in the intensive care unit. BCPAP treatment was associated with a reduced hospital length of stay and fewer transfers to the intensive care unit for intubation and mechanical ventilation. Overall estimated savings of approximately € 3,800 per patient were achieved with the BCPAP strategy compared to conventional treatment.</p> <p>Conclusion</p> <p>At the coronary care unit, BCPAP was feasible, medically effective, and cost-effective in the treatment of acute cardiogenic pulmonary edema. Endpoints included mortality, coronary care unit and hospital length of stay, need of ventilatory support, and cost (savings).</p
Comparison of glottic views and intubation times in the supine and 25 degree back-up positions
Background: We explored whether positioning patients in a 25° back-up sniffing position improved glottic views
and ease of intubation.
Methods: In the first part of the study, patients were intubated in the standard supine sniffing position. In the
second part, the back of the operating table was raised 25° from the horizontal by flexion of the torso at the hips
while maintaining the sniffing position. The best view obtained during laryngoscopy was assessed using the
Cormack and Lehane classification and Percentage of Glottic Opening (POGO) score. The number of attempts at
both laryngoscopy and tracheal intubation, together with the use of ancillary equipment and manoeuvres were
recorded. The ease of intubation was indirectly assessed by recording the time interval between beginning of
laryngoscopy and insertion of the tracheal tube.
Results: Seven hundred eighty one unselected surgical patients scheduled for non-emergency surgery were
included. In the back-up position, ancillary laryngeal manoeuvres, which included cricoid pressure, backwards
upwards rightward pressure and external laryngeal manipulation, were required less frequently (19.6 % versus 24.
6 %, p = 0.004). The time from beginning of laryngoscopy to insertion of the tracheal tube was 14 % shorter
(median time 24 versus 28 s, p = 0.031) in the back-up position. There was no significant difference in glottic views.
Conclusions: The 25° back-up position improved the ease of intubation as judged by the need for fewer ancillary
manoeuvres and shorter time for intubation.
Trial registration: ClinicalTrials.gov Identifier: NCT02934347 registered retrospectively on 14th Oct 2016
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