Critical care medicine
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Critical care medicine · Apr 2003
Meta AnalysisExtended somatic support for pregnant women after brain death.
To review case reports of pregnant women who have been supported after brain death until successful delivery of their infants. From these reports and other literature about brain death, normal physiologic changes of pregnancy, and specific needs for fetal development, recommendations were made to assist in supporting pregnant women after brain death until delivery of a mature fetus who is likely to survive. ⋯ Preservation of uterine/placental blood flow is the most important priority during somatic support. Imprecise autoregulation of the uterine vasculature during maternal hypoxemia or hypotension makes this goal a significant challenge. Special considerations for nutrition; medication use; cardiovascular, respiratory, or endocrine therapy; fetal monitoring; hormone replacement; and ethical concerns are discussed.
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Critical care medicine · Apr 2003
ReviewSelective pulmonary vasodilation in acute respiratory distress syndrome.
Acute respiratory distress syndrome (ARDS) is characterized by a marked maldistribution of pulmonary perfusion in favor of nonventilated, atelectatic areas of the lungs, and it is the main cause of pulmonary right-to-left shunting and hypoxemia. Therapeutic interventions to selectively influence pulmonary perfusion in ARDS became feasible with the introduction of inhaled nitric oxide, which provided a means not only to reduce pulmonary hypertension, but also to improve matching of ventilation to perfusion and, thus, hypoxemia. Clinical studies in ARDS subsequently demonstrated that the combination of inhaled nitric oxide with other interventions, such as positive end-expiratory pressure and prone positioning, yielded beneficial and additive effects on arterial oxygenation. ⋯ Ongoing research aims to augment the effectiveness of vasodilators with specific inhibitors of phosphodiesterases or by combination with intravenous vasoconstrictors. Consequently, several alternative ways to selectively modulate pulmonary vascular tone in patients with ARDS may be available in the near future. Cost-benefit analysis of these therapeutic options will largely determine their future perspective.
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Critical care medicine · Apr 2003
Review2001 SCCM/ESICM/ACCP/ATS/SIS International Sepsis Definitions Conference.
In 1991, the American College of Chest Physicians (ACCP) and the Society of Critical Care Medicine (SCCM) convened a "Consensus Conference," the goals of which were "to provide a conceptual and a practical framework to define the systemic inflammatory response to infection, which is a progressive injurious process that falls under the generalized term 'sepsis' and includes sepsis-associated organ dysfunction as well." The general definitions introduced as a result of that conference have been widely used in practice and have served as the foundation for inclusion criteria for numerous clinical trials of therapeutic interventions. Nevertheless, there has been an impetus from experts in the field to modify these definitions to reflect our current understanding of the pathophysiology of these syndromes. ⋯ This document reflects a process whereby a group of experts and opinion leaders revisited the 1992 sepsis guidelines and found that apart from expanding the list of signs and symptoms of sepsis to reflect clinical bedside experience, no evidence exists to support a change to the definitions. This lack of evidence serves to underscore the challenge still present in diagnosing sepsis in 2003 for clinicians and researchers and also provides the basis for introducing PIRO as a hypothesis-generating model for future research.
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Critical care medicine · Apr 2003
ReviewAcute respiratory distress syndrome: lessons from computed tomography of the whole lung.
This review aims to show how computed tomography of the whole lung has modified our view of acute respiratory distress syndrome, and why it impacts on the optimization of the ventilatory strategy. ⋯ Selection of the optimal positive end-expiratory pressure level should not only consider optimizing alveolar recruitment, it should also focus on limiting lung overinflation and counterbalancing compression of the lower lobes by maneuvers such as appropriate body positioning. Prone and semirecumbent positions facilitate the reaeration of dependent and caudal lung regions by partially relieving cardiac and abdominal compression and may improve gas exchange.