| Multisystem Organ Failure |
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Information AboutMultisystem Organ Failure |
| CATEGORIES ABOUT MULTIPLE ORGAN DYSFUNCTION SYNDROME | |
| intensive care medicine | |
| organ failure | |
| causes of death | |
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The use of "multiple organ failure" should be avoided since that term was based upon physiologic parameters to determine whether or not a particular organ was failing. Intensive Care Medicine by Irwin and Rippe ORIGIN Originally patients were classified as having sepsis or the sepsis syndrome. This resulted in two concepts: the systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). DEFINITION Multiple organ dysfunction syndrome is the presence of altered organ function in acutely ill patients such that Homeostasis cannot be maintained without intervention. It usually involves two or more organ systems. AETIOLOGY The condition usually results from infection, injury (accident, surgery), hypoperfusion and hypermetabolism. The primary cause triggers an uncontrolled Inflammatory Response . In operative and non-operative patients Sepsis is the most common cause. Sepsis may result in Septic Shock . In the absence of infection a sepsis-like disorder is termed Systemic Inflammatory Response Syndrome (SIRS). Both SIRS and sepsis could ultimately progress to multiple organ dysfunction syndrome. However, in one-third of the patients no primary focus can be found. PATHOPHYSIOLOGY A definite explanation has not been found. Local and systemic responses are initiated by tissue damage. Respiratory failure is common in the first 72 hours after the original insult. Followng this one might see hepatic failure (5-7 days), gastrointestinal bleeding (10-15 days), and renal failure (11-17 days) Gut hypothesis The most popular theory to explain MODS in critically ill patients is the gut hypothesis. Due to splanchnic hypoperfusion and the subsequent mucosal ischaemia there are structural changes and alterations in cellular function. This results in increased gut permeability, changed immune function of the gut and increased translocation of Bacteria . Hepatic dysfunction leads to toxins escaping into the systemic circulation and activating an immune response. This results in tissue injury and organ dysfunction. Endotoxin macrophage theory -α (TNF-α), Interleukin -1, interleukin-6, Thromboxane A2, Prostacyclin , platelet activating factor, and Nitric Oxide . Tissue hypoxia-microvascular hypothesis As a result of macro- and microvascular changes insufficient supply of oxygen occurs. Hypoxemia causes organ dysfuntion and cell death. Integrated hypothesis Since in most cases no primary cause is found, the condition could be part of a compromised homeostasis involving the previous mechanisms. DIAGNOSIS The European Society of Intensive Care organized a consensus meeting in 1994 to create the "Sepsis-Related Organ Failure Assesment (SOFA)" score to describe and quantitate the degree of organ dysfunction in six organ systems. Using similar physiologic variables the Multiple Organ Dysfunction Score was developed. Four clinical phases have been suggested:
MANAGEMENT At present there is no agent that can reverse the established organ failure. Therapy therefore is limited to supportive care, i.e. safeguarding hemodynamics, and respiration. Maintaining adequate tissue oxygenation is a principal target. Starting enteral nutrition within 36 hours of admission to an Intensive Care Unit has reduced infectious complications. PROGNOSIS Mortality varies from 30% to 100%. The chance of survival is dimished as the number of organs involved increases. Since the 1980s the mortality rate has not changed. SEE ALSO
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