Medicina intensiva
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The use of echocardiography in intensive care units in shock patients allows us to measure various hemodynamic variables in an accurate and a non-invasive manner. By using echocardiography not only as a diagnostic technique but also as a tool for continuous hemodynamic monitorization, the intensivist can evaluate various aspects of shock states, such as cardiac output and fluid responsiveness, myocardial contractility, intracavitary pressures, heart-lung interaction and biventricular interdependence. However, to date there has been little guidance orienting echocardiographic hemodynamic parameters in the intensive care unit, and intensivists are usually not familiar with this tool. In this review, we describe some of the most important hemodynamic parameters that can be obtained at the patient bedside with transthoracic echocardiography in critically ill patients.
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Cerebral microdialysis, introduced in experimental studies 40 years ago, has been used clinically since 1992 for the neurochemical monitoring of patients in intensive care. The principles underlying this technique are closely related to brain metabolism. The study of the metabolites detected at brain interstitial tissue level, through the semipermeable membrane of the device, allows us to assess different physiological pathways in the brain, analyzing the changes that occur when they become less efficient in terms of energy, and also detecting waste products secondary to tissue damage. Despite its current limitations, this technique provides relevant information for research and the clinical management of critical neurological patients.
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Urinary tract infections (UTIs) account for 20-50% of all hospital-acquired infections occurring in the intensive care unit (ICU). In some reports UTI was found to be more frequent than hospital-acquired pneumonia and intravascular device bacteremia, with a greater incidence in developing countries. The risk factors associated with the appearance of UTI include the severity of illness at the time of admission to the ICU, female status, prolonged urinary catheterization or a longer ICU stay and poor urinary catheter management - mainly disconnection of the closed system. about the present study offers data on the epidemiology of UTI in the ICU, the identified risk factors, etiology, diagnosis, impact upon morbidity and mortality, and the measures to prevent its appearance.
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Volume expansion is used in patients with hemodynamic insufficiency in an attempt to improve cardiac output. Finding criteria to predict fluid responsiveness would be helpful to guide resuscitation and to avoid excessive volume effects. ⋯ In this review we define preload and preload-responsiveness concepts. A description is made of the characteristics of each indicator in patients subjected to mechanical ventilation or with spontaneous breathing.
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Traumatic brain injury (TBI) is a worldwide health problem that is especially prevalent in young adults. It is characterized by one or more primary injury foci, with secondary spread to initially not compromised areas via cascades of inflammatory response, excitotoxicity, energy failure conditions, and amplification of the original tissue injury by glia. In theory, such progression of injury should be amenable to management. ⋯ We highlight the role of glia in each cellular mechanism discussed. Therapeutic approaches related to the described mechanisms have been included. The discussion is completed with a working model showing the convergence of the main topics.