Seminars in respiratory and critical care medicine
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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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Acute renal failure (now acute kidney injury) is a common complication of critical illness affecting between 30 and 60% of critically ill patients. The development of a consensus definition (RIFLE--risk, injury, failure, loss, end-stage system) has allowed standardization of reporting and epidemiological work. Multicenter multinational epidemiological studies indicate that sepsis is now the most common cause of acute renal failure in the intensive care unit (ICU) followed by cardiac surgery-associated acute kidney injury. ⋯ Data from large observational studies and randomized, controlled trials consistently indicate that a positive fluid balance in patients with acute renal failure represents a major independent risk factor for mortality and provides no protection of renal function. The pendulum is clearly swinging away from a fluid-liberal approach to a fluid-conservative approach in these patients. Finally, there is a growing appreciation that acute renal failure may identify patients who are at increased risk of subsequent chronic renal dysfunction and mortality, opening the way to post-ICU interventional trials.
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Central nervous system (CNS) failure represents a spectrum of disease ranging from mild neurological impairment that may have motor, sensory, visual, speech, cognitive manifestations, or a combination thereof, to comatose states and brain death. This article summarizes the common causes of CNS failure and analyzes the role of clinical, radiological, laboratory, and other ancillary testing in establishing the underlying diagnosis and assessing severity of CNS failure in each condition; we also comment on various treatment options for each of the causes of CNS failure.
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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.