372 research outputs found
Oxygenation Impairment during Anesthesia: Influence of Age and Body Weight.
No full textWHAT WE ALREADY KNOW ABOUT THIS TOPIC
During anesthesia oxygenation is impaired, especially in the elderly or obese, but the mechanisms are uncertain.
WHAT THIS ARTICLE TELLS US THAT IS NEW
Pooled data were examined from 80 patients studied with multiple inert gas elimination technique and computed tomography. Oxygenation was impaired by anesthesia, more so with greater age or body mass index. The key contributors were low ventilation/perfusion ratio (likely airway closure) in the elderly and shunt (atelectasis) in the obese.
BACKGROUND
Anesthesia is increasingly common in elderly and overweight patients and prompted the current study to explore mechanisms of age- and weight-dependent worsening of arterial oxygen tension (PaO2).
METHODS
This is a primary analysis of pooled data in patients with (1) American Society of Anesthesiologists (ASA) classification of 1; (2) normal forced vital capacity; (3) preoxygenation with an inspired oxygen fraction (FIO2) more than 0.8 and ventilated with FIO2 0.3 to 0.4; (4) measurements done during anesthesia before surgery. Eighty patients (21 women and 59 men, aged 19 to 69 yr, body mass index up to 30 kg/m) were studied with multiple inert gas elimination technique to assess shunt and perfusion of poorly ventilated regions (low ventilation/perfusion ratio [VA/Q]) and computed tomography to assess atelectasis.
RESULTS
PaO2/FIO2 was lower during anesthesia than awake (368; 291 to 470 [median; quartiles] vs. 441; 397 to 462 mm Hg; P = 0.003) and fell with increasing age and body mass index. Log shunt was best related to a quadratic function of age with largest shunt at 45 yr (r =0.17, P = 0.001). Log shunt was linearly related to body mass index (r = 0.15, P < 0.001). A multiple regression analysis including age, age, and body mass index strengthened the association further (r = 0.27). Shunt was highly associated to atelectasis (r = 0.58, P < 0.001). Log low VA/Q showed a linear relation to age (r = 0.14, P = 0.001).
CONCLUSIONS
PaO2/FIO2 ratio was impaired during anesthesia, and the impairment increased with age and body mass index. Shunt was related to atelectasis and was a more important cause of oxygenation impairment in middle-aged patients, whereas low VA/Q, likely caused by airway closure, was more important in elderly patients. Shunt but not low VA/Q increased with increasing body mass index. Thus, increasing age and body mass index impaired gas exchange by different mechanisms during anesthesia
Georges Louis Schmid : Banquets de philosophes chez Diderot, d'Holbach, Helvétius et Mably, Présentation
No full textG.-L. Schmid : Philosophical banquets with Diderot, d'Holbach, Helvétius and Mably. Text presented by Hans Ulrich Seifert.
George Louis Schmid (1720-1805) was a Swiss man of letters and author of two Physiocrat-inspired works which were quite successful in their day. He left a diary of his stay in Paris in 1767-9. Although the original has vanished, extracts from it (with descriptions of ten visits to Diderot, d'Holbach, Helvétius and Mably between 25th August 1767 and 28th March 1768) have survived in a German translation. II appears in the Miscellen fur die neueste Weltkunde, a periodical published in the Aargau by Heinrich Zschokke. This article provides an annotated re-translation of the text into French and a short survey of Schmid's life and works.Seifert Hans-Ulrich. Georges Louis Schmid : Banquets de philosophes chez Diderot, d'Holbach, Helvétius et Mably, Présentation. In: Dix-huitième Siècle, n°19, 1987. La franc-maçonnerie. pp. 223-244
Can outcome prediction data change patient outcomes and organizational outcomes?
No full textPURPOSE OF REVIEW: Intensive care medicine consumes a high share of healthcare costs, and there is growing pressure to use the scarce resources efficiently. Accordingly, organizational issues and quality management have become an important focus of interest in recent years. Here, we will review current concepts of how outcome data can be used to identify areas requiring action. RECENT FINDINGS: Using recently established models of outcome assessment, wide variability between individual ICUs is found, both with respect to outcome and resource use. Such variability implies that there are large differences in patient care processes not only within the ICU but also in pre-ICU and post-ICU care. Indeed, measures to improve the patient process in the ICU (including care of the critically ill, patient safety, and management of the ICU) have been presented in a number of recently published papers. SUMMARY: Outcome assessment models provide an important framework for benchmarking. They may help the individual ICU to spot appropriate fields of action, plan and initiate quality improvement projects, and monitor the consequences of such activity
Volcanism : with 401 figures, 396 in color
No full textVolcanic eruptions are the most dramatic expression of dynamic processes in the interior of planet Earth. The author, an internationally renowned specialist in the field of volcanology, explains in a concise and easy to understand manner the basics and recent advances in the field of volcanology. Based on plate tectonics and illustrated with nearly 400 color figures, the book offers insights into the generation of magmas and the tectonic setting, composition and origin of volcanoes. An overview of volcanic structures is followed by process-oriented chapters which discuss the role of explosive mechanisms and transport of volcanic material in eruption columns and pyroclastic density currents. The final chapters deal with eruption forecast, their influence on climate and benefits of volcanism. Students and scientists from a broad range of fields will find this book an attractive and up-to date source of information on the current understanding of volcanoes, volcanic eruptions and their impacts on, and benefits to, society
Respiratory function during anesthesia: effects on gas exchange
No full textAnaesthesia causes a respiratory impairment, whether the patient is breathing spontaneously or is ventilated mechanically. This impairment impedes the matching of alveolar ventilation and perfusion and thus the oxygenation of arterial blood. A triggering factor is loss of muscle tone that causes a fall in the resting lung volume, functional residual capacity. This fall promotes airway closure and gas adsorption, leading eventually to alveolar collapse, that is, atelectasis. The higher the oxygen concentration, the faster will the gas be adsorbed and the aleveoli collapse. Preoxygenation is a major cause of atelectasis and continuing use of high oxygen concentration maintains or increases the lung collapse, that typically is 10% or more of the lung tissue. It can exceed 25% to 40%. Perfusion of the atelectasis causes shunt and cyclic airway closure causes regions with low ventilation/perfusion ratios, that add to impaired oxygenation. Ventilation with positive end-expiratory pressure reduces the atelectasis but oxygenation need not improve, because of shift of blood flow down the lung to any remaining atelectatic tissue. Inflation of the lung to an airway pressure of 40 cmH2O recruits almost all collapsed lung and the lung remains open if ventilation is with moderate oxygen concentration (< 40%) but recollapses within a few minutes if ventilation is with 100% oxygen. Severe obesity increases the lung collapse and obstructive lung disease and one-lung anesthesia increase the mismatch of ventilation and perfusion. CO2 pneumoperitoneum increases atelectasis formation but not shunt, likely explained by enhanced hypoxic pulmonary vasoconstriction by CO2. Atelectasis may persist in the postoperative period and contribute to pneumonia
Models for intensive care training. A European perspective.
No full textThe diversity of European culture is reflected in its healthcare training programs. In intensive care medicine (ICM), the differences in national training programs were so marked that it was unlikely that they could produce specialists of equivalent skills. The Competency-Based Training in Intensive Care Medicine in Europe (CoBaTrICE) program was established in 2003 as a Europe-based worldwide collaboration of national training organizations to create core competencies for ICM using consensus methodologies to establish common ground. The group's professional and research ethos created a social identity that facilitated change. The program was easily adaptable to different training structures and incorporated the voice of patients and relatives. The CoBaTrICE program has now been adopted by 15 European countries, with another 12 countries planning to adopt the training program, and is currently available in nine languages, including English. ICM is now recognized as a primary specialty in Spain, Switzerland, and the UK. There are still wide variations in structures and processes of training in ICM across Europe, although there has been agreement on a set of common program standards. The combination of a common "product specification" for an intensivist, combined with persisting variation in the educational context in which competencies are delivered, provides a rich source of research inquiry. Pedagogic research in ICM could usefully focus on the interplay between educational interventions, healthcare systems and delivery, and patient outcomes, such as including whether competency-based program are associated with lower error rates, whether communication skills training is associated with greater patient and family satisfaction, how multisource feedback might best be used to improve reflective learning and teamworking, or whether increasing the proportion of specialists trained in acute care in the hospital at weekends results in better patient outcomes
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