Seminars in respiratory and critical care medicine
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Semin Respir Crit Care Med · Oct 2011
Organ dysfunction: general approach, epidemiology, and organ failure scores.
Multiorgan dysfunction syndrome represents a continuum of cumulative organ dysfunction from very mildly altered function to total and, rarely, irreversible organ failure and is the major cause of death in the intensive care unit (ICU). The terms multiple organ failure syndrome (MOFS), multiple organ system failure (MOSF), and multiple organ failure (MOF) have since been used to describe this syndrome. Infections were initially thought to be the main cause of multiorgan dysfunction; however, other insults, such as severe trauma, burn injuries, and noninfectious inflammatory diseases may precipitate a similar condition. ⋯ Scoring systems for organ dysfunction/failure were designed primarily as descriptive tools, aimed at establishing standardized definitions to stratify and compare patients in the ICU in terms of morbidity rather than mortality. Sequential evaluation of organ dysfunction during the ICU stay may track disease progression and may be useful prognostically. We discuss the various scoring systems developed over the past 2 decades and present a rational approach to their role in assessing and following critically ill patients.
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Lung failure is the most common organ failure seen in the intensive care unit. The pathogenesis of acute respiratory failure (ARF) can be classified as (1) neuromuscular in origin, (2) secondary to acute and chronic obstructive airway diseases, (3) alveolar processes such as cardiogenic and noncardiogenic pulmonary edema and pneumonia, and (4) vascular diseases such as acute or chronic pulmonary embolism. This article reviews the more common causes of ARF from each group, including the pathological mechanisms and the principles of critical care management, focusing on the supportive, specific, and adjunctive therapies for each condition.
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The physiological and biochemical abnormalities that constitute multiple organ failure represent cellular perturbations that, importantly, need to be reconciled with a lack of significant cell death together with availability but impaired utilization of oxygen. In conjunction with the relatively rapid ability of the organ to recover in surviving patients, a paradigm of metabolic shutdown triggered by a decrease in mitochondrial energy production appears increasingly valid. This review discusses data demonstrating temporal changes in oxygen utilization through the septic process, evidence for mitochondrial derangements, and recovery of mitochondrial function preceding clinical recovery.
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Semin Respir Crit Care Med · Aug 2011
ReviewMolecular assays for the detection and characterization of respiratory viruses.
Patient care providers face an enormous challenge in diagnosing vial respiratory diseases because of similar clinical manifestations, as well as insensitivity and/or slow conventional laboratory detection methods. Nucleic acid-targeted molecular assays are playing critical roles in rapid detection, screening, and identification of respiratory viral pathogens due to their high sensitivity and specificity, short test turnaround time, as well as automatic and high-throughput processing. ⋯ Incorporated with cutting edge techniques, these methods can be used to detect one or more pathogens in a single reaction tube qualitatively and quantitatively. Although the molecular assays have been increasingly used in the clinical setting, laboratorians and clinicians should well know the limitations of these molecular assays to wisely choose the right tests and correctly interpret test results.