الفهرس 
Pathophysiology of SepsisOnly 14 pages are availabe for public view
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Abstract
Sepsis is a common and serious disease with substantial morbidity and mortality despite recent advances in supportive care and disease-specific treatments. It is defined as an infection with concurrent systemic manifestations that are the result of the host response. This response, known as systemic inflammatory response syndrome (SIRS).
Gram negative bacilli (mainly Escherichia coli, Klebsiella species, and Pseudomonas aeruginosa) and Gram positive cocci (mainly staphylococci and streptococci) are the commonest microbes isolated from patients with severe sepsis and septic shock. Fungi, mostly Candida, account for only about 5% of all cases of severe sepsis.
Bacterial cell walls, endotoxins, and exotoxins are powerful activators of innate and acquired immune responses, molecules expressed by pathogens interact with Toll-like receptors on immune cells, activating the immune response, cytokines are important in the pathogenesis of sepsis.
Persons at risk for sepsis include those who have experienced trauma and those with chronic disease, low immune function, recent surgery and those with large wounds.
Symptoms of sepsis include fever, rapid heart rate and rapid breathing. In more severe cases, blood pressure drops and shock may occur.
Rapid treatment is urgent in sepsis. The longer treatment is delayed, the less likely sepsis can be treated effectively. Treating the infection with appropriate antibiotics is essential for success.
The use of PCT and other markers as an antimicrobial stewardship tool is extremely attractive in the current climate of increasingly antibiotic resistant microbes.
Intravenous antibiotic therapy should be initiated immediately after obtaining appropriate cultures, since early initiation of antibiotic therapy is associated with lower mortality. The choice of antibiotics can be complex and should consider the patient’s history (eg, recent antibiotics received) comorbidities, clinical context (eg, community or hospital acquired), Gram stain data, and local resistance patterns. Poor outcomes are associated with inadequate or inappropriate antimicrobial therapy (ie, treatment with antibiotics to which the pathogen was later shown to be resistant in vitro). They are also associated with delays in initiating antimicrobial therapy, even short delays (eg, an hour)
The choice of antibiotics should be guided by the susceptibility of likely pathogens in the community and the hospital, as well as any specific knowledge about the patient, including drug intolerance, underlying disease. Although restricting the use of antibiotics, and particularly broad-spectrum antibiotics, is important for limiting superinfection and for decreasing the development of antibiotic resistant pathogens, patients with severe sepsis or septic shock warrant broad-spectrum therapy until the causative organism and its antibiotic susceptibilities are defined.
Prompt identification and treatment of the site of infection are essential. Sputum and urine should be collected for gram stain and culture. Intra-abdominal fluid collections should be percutaneously sampled. Blood should be taken from two distinct venipuncture sites and from indwelling vascular access devices and cultured aerobically and anaerobically
Although intensive care units (ICUs) account for fewer than ten percent of total beds in most hospitals, more than 20 percent of all nosocomial infections are acquired in ICUs. ICU-acquired infections account for substantial morbidity, mortality, and expense. Infections and sepsis are the leading cause of death in non-cardiac ICUs and account for 40 percent of all ICU expenditures.
Antibiotic resistance is a form of drug resistance whereby some (or, less commonly, all) sub-populations of a microorganism, usually a bacterial species, are able to survive after exposure to one or more antibiotics; pathogens resistant to multiple antibiotics are considered multidrug resistant (MDR) or, more colloquially, superbugs. Microbes, rather than people, develop resistance to antibiotics. Antibiotic resistance is a serious and growing phenomenon in contemporary medicine and has emerged as one of the pre-eminent public health concerns of the 21st century, particularly as it pertains to pathogenic organisms (the term is especially relevant to organisms which cause disease in humans)
Strategies to prevent the emergence and spread of multidrug-resistant bacteria in ICUs can be separated into two major categories: strategies that attempt to improve the efficacy and utilization of antimicrobial therapy and infection control measures.