37 research outputs found

    Scenarios in the development of Mediterranean cyclones

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    The Mediterranean is one of the most cyclogenetic regions in the world. The cyclones are concentrated along its northern coasts and their tracks are oriented more or less west-east, with several secondary tracks connecting them to Europe and to North Africa. The aim of this study is to examine scenarios in the development of Mediterranean cyclones, based on five selected winter seasons (October–March). We detected the cyclones subjectively using 6-hourly Sea-Level Pressure maps, based on the NCAR/NCEP reanalysis archive. <br><br> HMSO (1962) has shown that most Mediterranean cyclones (58%) enter the Mediterranean from the Atlantic Ocean (through Biscay and Gibraltar), and from the south-west, the Sahara Desert, while the rest are formed in the Mediterranean Basin itself. Our study revealed that only 13% of the cyclones entered the Mediterranean, while 87% were generated in the Mediterranean Basin. The entering cyclones originate in three different regions: the Sahara Desert (6%), the Atlantic Ocean (4%), and Western Europe (3%). <br><br> The cyclones formed within the Mediterranean Basin were found to generate under the influence of external cyclonic systems, i.e. as "daughter cyclones" to "parent cyclones" or troughs. These parent systems are located in three regions: Europe (61%), North Africa and the Red Sea (34.5%) and the Mediterranean Basin itself (4.5%). The study presents scenarios in the development of Mediterranean cyclones during the winter season, emphasizing the cyclogenesis under the influence of various external forcing. <br><br> The large difference with respect to the findings of HMSO (1962) is partly explained by the dominance of spring cyclones generating in the Sahara Desert, especially in April and May that were not included in our study period

    Pain management at the end of life: A comparative study of cancer, dementia, and chronic obstructive pulmonary disease patients

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    Background: Limited data exist concerning the unique pain characteristics of patients with non-cancer terminal diseases referred for inpatient hospice care. Aims: To define the unique pain characteristics of patients admitted to an acute inpatient hospice setting with end-stage dementia or chronic obstructive lung disease (or chronic obstructive pulmonary disease) and to compare them to patients with end-stage cancer. Design: Retrospective patient chart review. Demographic, physiological, pain parameters, and medication utilization data were extracted. Associations between pain characteristics, medication utilization, and admission diagnoses were assessed. Analyses included descriptive statistics. Setting/participants: In total, 146 patients admitted to an acute inpatient hospice between 1 April 2011 and 31 March 2012 with an underlying primary diagnosis of chronic obstructive pulmonary disease (n = 51), dementia (n = 48), or cancer (n = 47). Results: Pain was highly prevalent in all diagnostic groups, with cancer patients experiencing more severe pain on admission. Cancer patients received a significantly higher cumulative opioid dose compared with dementia and chronic obstructive pulmonary disease patients. Pain control within 24 h of pain onset was achieved in less than half of all patient groups with chronic obstructive pulmonary disease patients the least likely to achieve pain control. Conclusions: Despite the fact that pain is the most common complaint at the end of life, pain management may be suboptimal for some primary diagnoses. Admission diagnosis is the strongest predictor of pain control. Patient with cancer achieve the best pain control, and chronic obstructive pulmonary disease patients are the least likely to have their pain adequately treated

    Pulse oximetry: fundamentals and technology update

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    Meir Nitzan,1 Ayal Romem,2 Robert Koppel31Department of Physics/Electro-Optics, Jerusalem College of Technology, Jerusalem, Israel; 2Pulmonary Institute, Shaare Zedek Medical Center, Jerusalem, Israel; 3Neonatal/Perinatal Medicine, Cohen Children's Medical Center of New York/North Shore-LIJ Health System, New Hyde Park, NY, United StatesAbstract: Oxygen saturation in the arterial blood (SaO2) provides information on the adequacy of respiratory function. SaO2 can be assessed noninvasively by pulse oximetry, which is based on photoplethysmographic pulses in two wavelengths, generally in the red and infrared regions. The calibration of the measured photoplethysmographic signals is performed empirically for each type of commercial pulse-oximeter sensor, utilizing in vitro measurement of SaO2 in extracted arterial blood by means of co-oximetry. Due to the discrepancy between the measurement of SaO2 by pulse oximetry and the invasive technique, the former is denoted as SpO2. Manufacturers of pulse oximeters generally claim an accuracy of 2%, evaluated by the standard deviation (SD) of the differences between SpO2 and SaO2, measured simultaneously in healthy subjects. However, an SD of 2% reflects an expected error of 4% (two SDs) or more in 5% of the examinations, which is in accordance with an error of 3%–4%, reported in clinical studies. This level of accuracy is sufficient for the detection of a significant decline in respiratory function in patients, and pulse oximetry has been accepted as a reliable technique for that purpose. The accuracy of SpO2 measurement is insufficient in several situations, such as critically ill patients receiving supplemental oxygen, and can be hazardous if it leads to elevated values of oxygen partial pressure in blood. In particular, preterm newborns are vulnerable to retinopathy of prematurity induced by high oxygen concentration in the blood. The low accuracy of SpO2 measurement in critically ill patients and newborns can be attributed to the empirical calibration process, which is performed on healthy volunteers. Other limitations of pulse oximetry include the presence of dyshemoglobins, which has been addressed by multiwavelength pulse oximetry, as well as low perfusion and motion artifacts that are partially rectified by sophisticated algorithms and also by reflection pulse oximetry.Keywords: oxygen saturation, pulse oximetry, photoplethysmography, arterial blood, venous bloo
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