RESUMEN
Traumatic brain injury (TBI) and hemorrhagic shock due to uncontrolled bleeding are the major causes of death after severe trauma. Mortality rates are threefold higher in patients suffering from multiple injuries and additionally TBI. Factors known to impair outcome after TBI, namely hypotension, hypoxia, hypercapnia, acidosis, coagulopathy and hypothermia are aggravated by the extent and severity of extracerebral injuries. The mainstays of TBI intensive care may be, at least temporarily, contradictory to the trauma care concept for multiple trauma patients. In particular, achieving normotension in uncontrolled bleeding situations, maintenance of normocapnia in traumatic lung injury and thromboembolic prophylaxis are prone to discussion. Due to an ongoing uncertainty about the definition of normotensive blood pressure values, a cerebral perfusion pressure-guided cardiovascular management is of key importance. In contrast, there is no doubt that early goal directed coagulation management improves outcome in patients with TBI and multiple trauma. The timing of subsequent surgical interventions must be based on the development of TBI pathology; therefore, intensive care of multiple trauma patients with TBI requires an ongoing and close cooperation between intensivists and trauma surgeons in order to individualize patient care.
Asunto(s)
Lesiones Traumáticas del Encéfalo/terapia , Cuidados Críticos/métodos , Traumatismo Múltiple/terapia , Anticoagulantes/administración & dosificación , Anticoagulantes/efectos adversos , Presión Sanguínea/fisiología , Volumen Sanguíneo/efectos de los fármacos , Volumen Sanguíneo/fisiología , Encéfalo/irrigación sanguínea , Lesiones Traumáticas del Encéfalo/mortalidad , Lesiones Traumáticas del Encéfalo/fisiopatología , Dióxido de Carbono/sangre , Circulación Cerebrovascular/efectos de los fármacos , Circulación Cerebrovascular/fisiología , Comorbilidad , Oxigenación por Membrana Extracorpórea , Escala de Coma de Glasgow , Humanos , Lesión Pulmonar/mortalidad , Lesión Pulmonar/fisiopatología , Lesión Pulmonar/terapia , Monitoreo Fisiológico/métodos , Traumatismo Múltiple/mortalidad , Traumatismo Múltiple/fisiopatología , Respiración Artificial , Choque Hemorrágico/mortalidad , Choque Hemorrágico/fisiopatología , Choque Hemorrágico/terapia , Tromboembolia/prevención & control , Vasoconstrictores/efectos adversos , Vasoconstrictores/uso terapéuticoRESUMEN
Because of the high vulnerability of the brain as a primary target, neuroanaesthesia requires a close look at basic physiological principles and factors of influence during surgery and subsequent intensive care. Anticipatory management is crucial for anaesthesia within the scope of neurosurgical interventions: essential components of anaesthesia management must already be prepared before the surgical procedure. Intracranial compliance and pressure determine the patient's fate; accordingly they have to be assessed correctly and measured continuously. Advanced methods of monitoring allow sophisticated and individually focused treatment thus contributing to patient safety. Only few pharmacologic approaches have been proven with solid evidence, yet some new studies have revealed interesting brain protective effects of pharmacological and/or adjuvant therapeutic measures. For the treatment of intracranial hypertension, osmotherapy is still of the highest value. Decompressive craniotomy seems to have become a promising alternative, although this must be judged to date as a last resort therapy. Perioperative care of patients with complex intracranial pathologies thus needs a close interaction and cooperation between the operation theatre and intensive care units in the sense of continuous track anaesthesia.
Asunto(s)
Anestesia , Procedimientos Neuroquirúrgicos , Atención Perioperativa/normas , Anestésicos por Inhalación , Anestésicos Intravenosos , Circulación Cerebrovascular , Humanos , Hipnóticos y Sedantes , Hipertensión Intracraneal/terapia , Presión Intracraneal/fisiología , Complicaciones Intraoperatorias/prevención & control , Complicaciones Posoperatorias/prevención & control , PremedicaciónRESUMEN
A local electrode atom probe has been employed to trace the onset of Cu clustering followed by their coarsening and subsequent growth upon rapid (10s) annealing of an amorphous Fe73.5Si15.5Cu1Nb3B7 alloy. It has been found that the clustering of Cu atoms introduces heterogeneities in the amorphous matrix, leading to the formation of Fe rich regions which crystallizes pseudo-homogeneously into Fe-Si nanocrystals upon annealing. In this paper, we present the data treatment method that allows for the visualization of these different phases and to understand their morphology while still quantifying them in terms of their size, number density and volume fraction. The crystallite size of Fe-Si nanocrystals as estimated from the atom probe data are found to be in good agreement with other complementary techniques like XRD and TEM, emphasizing the importance of this approach towards accurate structural analysis. In addition, a composition driven data segmentation approach has been attempted to determine and distinguish nanocrystalline regions from the remaining amorphous matrix. Such an analysis introduces the possibility of retrieving crystallographic information from extremely fine (2-4 nm sized) nanocrystalline regions of very low volume fraction (< 5 Vol%) thereby providing crucial in-sights into the chemical heterogeneity induced crystallization process of amorphous materials.
RESUMEN
A gastrinoma was found in 12 of 23 patients with Zollinger-Ellison syndrome. Those with gastrinoma were not different from those without as regarded fasting gastrin level, increased gastrin secretion after secretin and calcium, acid secretion, or survival time. Five of the 23 patients have died, four immediately postoperatively, the fifth of the metastasizing tumour. Treatment with the H2-receptor antagonist cimetidine avoided emergency operation and thus decreased operative mortality, giving time for localization by ultrasound, computed tomography and selective arteriography. The rate of false-negative results was high. Transhepatic selective catheterization of the pancreatic veins with gastrin determination gives localization of the tumour and identification of the secreted hormone. In three patients tumour resection was possible under cover of H2-receptor antagonist administration which normalized gastrin and acid secretion. There is a change in the treatment of the Zollinger-Ellison syndrome, away from total gastrectomy to conservative treatment with H2-receptor antagonists and an attempt of curative treatment by removal of the tumour.