Septic shock is the result of sepsis: a widespread infection that affects multiple areas of the body. The body is severely taxed when trying to fight this infection. In the initial phase of septic shock, patients experience a rapid increase in heart rate and breathing rate as well as a pathologically high (fever) or pathologically low (hypothermia) body temperature.
As the bacterial infection spreads, it causes the body's cells to release cytokines. These cytokines are usually quite effective at treating a localized infection. However, when released in large amounts in response to a widespread infection, they cause the blood vessels to dilate which decreases the blood pressure.
In response to this decrease in blood pressure, the heart overcompensates and begins to work at a rate that cannot be sustained for long. Once the heart muscle weakens, it cannot deliver adequate supplies of blood and oxygen to all of the body's tissues. Continued deprivation of these essential nutrients can result in multiple organ failure and even death, which results in 50 percent of patients with septic shock.
Underlying Causes
Sepsis is an abnormal infection that can be caused by any manner of bacteria or fungus. And, although rare, sepsis can also result from a viral infection although viral infections rarely end in septic shock. The most common infection sites for septic infection are the lungs, abdomen and urinary tract. If these infections involve abscesses, or the infection is released into the bloodstream (a condition called bacteremia) then the risk of sepsis is increased.
Risk Factors
About 90,000 people die of septic shock in the United States each year. And nearly all of those 90,000 acquired the septic infection and resultant septic shock while hospitalized.
The reason that most cases of septic shock occur in hospitals is that people who are most susceptible to this abnormal infection are those with compromised immune systems due to medical conditions or procedures.
The highest risk of susceptibility to septic infection and shock are young children and elderly people who are fighting significant illness or undergo medical procedures as their immune systems are not fully functional. However, adults also run a risk of developing septic shock if their immune systems are severely taxed as a result of a prolonged battle with an illness.
Otherwise healthy people who undergo medical procedures are also at risk of developing septic infection. For example, those who have implanted medical devices (such as a catheter, artificial joint of heart valve) are doubly at risk. The first risk of infection occurs during implantation when bacteria have an opportunity to enter the body. The second risk occurs after implantation: the surfaces of these devices tend to collect bacteria making septic infection more likely. And the longer the device is left inside the body (especially in the case of catheters), the greater the risk of infection.
