Sepsis is a potentially life-threatening, systemic complication of an infection resulting from the spread of bacteria or their toxic products from a focus of infection. Pneumonia is the most common cause, followed by intraabdominal and urinary tract infections. No source is found in about one third of cases. The clinical presentation of sepsis is highly variable depending on the etiology.
The clinical features of septicemia intensify over time from mild to severe.
The cardinal symptoms of sepsis include:
In the elderly and immunocompromised patients, the clinical features may be quite subtle.
Early diagnosis and treatment of sepsis is the basic key in preventing the morbidity and mortality resulting from the sepsis.
Cardiac monitoring, blood pressure monitoring and pulse oxymetry are indicated in patients with septic shock. Once the patient is stabilized, the clinicians can move forward to the diagnostic workup. This involves the use of the following investigation to determine the cause and site of infection:
The following goals should be kept in mind while treating the patients with septic shock:
The mortality resulting from sepsis is usually quoted to be in the range of 20-50% . However, with the advances in the clinical trials in the past ten years, the mortality rate has been limited to 24 to 41%. The mortality greatly depends on the severity of illness.
The severity of the illness and the prognosis depend on the causative organism, site of infection, the strength of the patient’s immune system, the presence of any underlying disease and the developmet of septic shock.
There are number of causes which lead to the development of sepsis. Most of these causes are bacterial in nature but viruses and fungi can also cause sepsis.
The common gram positive organisms that cause sepsis include Staphylocossus, Streptocossus and Enterococcus; whereas Proteus, Pseudomonas and Klebsiella are the common gram negative organisms.
In previously healthy adults, the most common sources of infection are intraabdominal infections, urinary tract infections and pneumonia. In many cases of septicemia, the focus of infection may not be apparent.
Few other rare causes include parasites, fungi, viruses and mycobacteria.
In contrast, intravenous drug abuse, vascular catheterization, the presence of indwelling mechanical devices and burns are the predisposing conditions for gram positive bacteremia.
Immunosuppression and broad-spectrum antimicrobial therapy predispose the patient to fungemia.
In the United States, the per annum episodes of sepsis are 400,000 to 750,000. Sepsis is more common in the extremes of ages such as infancy or old age. Statistical data shows that the male gender more commonly develops sepsis; the sex ratio being 1.5:1.
The septic response results from the microbial signals or toxins coupled with the body response in the form of formation of cytokines, prostaglandins and the activation of complement C5a.
Bacterial signals initiate the release of inflammaory mediators from leukocytes and endothelial cells. Exotoxins (such as peptoglycan and lipoteichoic acid produced by gram positive organisms) and endotoxins (such as lipopolysacchardie produced by gram negative organisms) are the important microbial factors in this regard.
There is convincing evidence to support the belief that sepsis develops from exaggerated systemic inflammatory response which is induced by infecting organisms. Some of the inflammatory mediators include TNF (tumor necrosis factor), cytokines, leukotrienes, interleukins, eicosanoids, interferon gamma, selectins and complement C5a .
Abnormalities of coagulation and fibrinolysis
As a result of endothelial damage, clotting factors and the extrinsic clotting cascade are activated. This leads to disseminated intra-vascular coagulation (DIC) and microvascular thrombosis which ultimately results in organ dysfunction and death .
Distributive shock is characterized by the pathological vasodilatation and shunting of blood from vital to non-vital tissues and organs. Septic shock falls under this category. Disturbances in blood flow, micro-circulation and peripheral shunting of oxygen result in the deficiency of oxygen and accumulation of lactic acid.
Organ dysfunction and failure
As a result of the abnormalities in circulation, coagulation, peripheral shunting and chemical mediators, the main systems and organs of the body fail to function properly. The improper oxygenation that develops ultimately leads to organ failure and death.
Promotion of the hygienic conditions and prevention of overcrowding greatly prevents sepsis. High risk individuals must be identified beforehand to ensure early diagnosis.
Sepsis can be defined as the systemic inflammatory response to microbial invasion. It is characterized by the presence of two or more of the following four conditions .
Dysfunction of major organs occurs in severe sepsis and may lead to septic shock. Septic shock can be defined as sepsis with hypotension that is unresponsive to fluid resuscitation with signs of organ dysfunction and perfusion abnormalities such as metabolic acidosis, acute alteration in mental status, oliguria or adult respiratory distress syndrome.
Early sepsis is usually reversible whereas patients with septic shock often die even if aggressive therapy is provided. For this reason, it is necessary to detect the cause of sepsis and treat it as early as possible. Sepsis causes millions of death each year .
Sepsis is a condition in which in which microorganisms or their toxins are present in the blood. It is characterized by fever, fast breathing and heart rate and an increase in white blood cell count. Individuals at the extremes of ages (old age or infancy) or those who have poor health, or unhygienic living conditions are more prone to the development of sepsis. Sepsis can be fatal if not diagnosed and managed promptly.