Multiple System Organ Failure in the Adult Respiratory Distress Syndrome

Abstract

Recently completed studies suggest that patients with the adult respiratory distress syndrome (ARDS) manifest early evidence of multiple-site endothelial injury. Extrapulmonary disease is usually the cause of death in these patients. Furthermore, prognosis in individual cases of ARDS is strongly influenced by specific organ failures (e.g., hepatic and renal failure). The mechanisms by which ARDS and extrapulmonary organ system failure interact, however, are poorly delineated. We address three aspects of the multisystemic nature of ARDS. First, we analyze evidence that suggests ARDS is a multisystem disorder fron the outset, involving panendothelial injury mediated by cellular interactions and humoral substances that act similarly at many vascular target sites. Second, we discuss the role of three extrapulmonary organs in the modulation of ARDS: the liver, the gastrointestinal mucosa, and the kidneys. Third, we address the unifying hypothesis that uncontrolled ongoing inflammation, which is often but not always caused by infection, is the essential link between ARDS and its progression to multiple system organ failure.Mortality rates for the adult respiratory distress syndrome (ARDS) have remained high for over twenty years despite many improvements in respiratory support [1][2][3][4][5]. It is now recognized that the cause of death in ARDS is most often related to sequential failure of multiple organ systems [1,3,6-10]. It is clear that prognosis in individual cases of ARDS is strongly influenced both by previous underlying organ dysfunction and by the specific organ failures that ensue during the clinical course of ARDS [11][12][13][14][15][16][17][18][19][20][21] ; however, the mechanisms by which ARDS and extrapulmonary organ system failure interact are multifaceted and poorly understood.We address three aspects of the multisystemic nature of ARDS. First, we discuss the hypothesis that ARDS is inherently a multisystem disorder from the outset that involves panendothelial injury.Second, we discuss the role of specific organ systems on the modulation of ARDS, focusing on the modulating effect of the liver, the gastrointestinal tract, and the kidneys. Third, we address the unifying hypothesis that ongoing inflammation, usually caused by uncontrolled infection, is the essential link between ARDS and multiple organ dysfunction.ARDS as the Pulmonary Manifestation of Panendothelial Disease . ARDS, as initially described by Petty and Ashbaugh [22] and by Ashbaugh and co-workers [23], appeared to be a process during which pulmonary capillary endothelial permeability abnormalities arose in the setting of nonpulmonary disease. It is now more common to think of ARDS as a disease that concurrently affects all capillary beds throughout the body. The lung is the most visible target because increased microvascular permeability results in alveolar flooding, which is a potentially fatal event. If a patient lives, however, and the inciting process is left unchecked, obvious dysfunction will ultimately develop in other organs in...

Multiorgan Failure: The Latest Concepts

“…First, they hypothesize that ARDS is a &dquo;panendothelial injury mediated by cellular interactions and humoral substances that act similarly at many vascular target sites.&dquo; Second, they focus on &dquo;the role of three extrapulmonary organs in the modulation of ARDS: the liver, the gastrointestinal mucosa, and the kidneys.&dquo; Finally, they emphasize that uncontrolled infection is the &dquo;essential link between ARDS and its progression to multiple system organ failure.&dquo; Major concepts examined include the concept of ARDS as the pulmonary manifestation of panendothelial disease; the mechanism of a panendothelial injury, including the role of granulocytes and the role of mononuclear phagocytes and the peptide cytokine products they secrete ; and the roles of platelets, endothelial cells, eicosanoids, and ischemia-reperfusion injury [ 1 ]. First, they hypothesize that ARDS is a &dquo;panendothelial injury mediated by cellular interactions and humoral substances that act similarly at many vascular target sites.&dquo; Second, they focus on &dquo;the role of three extrapulmonary organs in the modulation of ARDS: the liver, the gastrointestinal mucosa, and the kidneys.&dquo; Finally, they emphasize that uncontrolled infection is the &dquo;essential link between ARDS and its progression to multiple system organ failure.&dquo; Major concepts examined include the concept of ARDS as the pulmonary manifestation of panendothelial disease; the mechanism of a panendothelial injury, including the role of granulocytes and the role of mononuclear phagocytes and the peptide cytokine products they secrete ; and the roles of platelets, endothelial cells, eicosanoids, and ischemia-reperfusion injury [ 1 ].…”