Seminars in respiratory and critical care medicine
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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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Hematologic factors, in particular platelets and the coagulation system, play an important role in the pathogenesis of organ failure in the intensive care unit. Failure of these hematologic systems is common in intensive care patients and may range from isolated thrombocytopenia or prolonged global clotting tests to complex defects, such as disseminated intravascular coagulation. There are many causes for a deranged coagulation in critically ill patients, and each of these underlying disorders may require specific therapeutic management. Hence, a proper differential diagnosis and initiation of adequate (supportive) treatment strategies are crucial to reduce morbidity and mortality in critically ill patients with coagulation abnormalities.
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Semin Respir Crit Care Med · Oct 2011
ReviewImmunologic alterations and the pathogenesis of organ failure in the ICU.
Rapid and marked alterations of innate and adaptive immunity typify the host response to systemic infection and acute inflammatory states. Immune dysfunction contributes to the development of organ failure in most patients with critical illness. The molecular mechanisms by which microbial pathogens and tissue injury activate myeloid cells and prime cellular and humoral immunity are increasingly understood. ⋯ In carefully selected patients, a better therapeutic strategy might be to provide immunoadjuvants to reconstitute immune function in intensive care unit (ICU) patients. Proresolving agents are also in development to terminate acute inflammatory reactions without immune suppression. This brief review summarizes the current understanding of the fundamental immune alterations in critical illness that lead to organ failure in critical illness.
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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.