Bacteremia is the presence of bacteria in the bloodstream. It can occur spontaneously, from indwelling GU or IV catheters, or after dental, GI, GU, wound care, or other procedures. If the immune system and the bodys natural defense barriers cannot keep the bacteria contained, they can enter the bloodstream and infect the rest of the body quickly. Bacteremia may cause metastatic infections, including endocarditis, especially in those with valvular heart abnormalities. Transient bacteremia is often asymptomatic but may cause fever. Bacteremia is a serious, life-threatening condition. Development of other symptoms usually suggests more serious infection, such as pneumonia, septic arthritis, osteomyelitis, cellulitis, meningitis, and sepsis, possibly resulting in death. Patients with certain underlying heart conditions should receive prophylactic antibiotics before procedures that can cause significant bacteremia.
Bacteremia usually occurs in children less than 3 years old or in children with focal infections or in children who have sepsis (ie, clinical evidence other than fever of a systemic response to infection). Children with sepsis generally appear ill, have an increased heart rate or respiratory rate and may have a change in temperature (typically fever, although hypothermia is often seen in very young infants and newborns). Severe sepsis results in hypotension, hypoperfusion, or organ dysfunction. Septic shock occurs in children who do not respond to adequate volume resuscitation or require vasopressors or inotropes.
Bacteremia frequently elicits a vigorous immune system response. The constellation of findings related to this response (such as fever, chills, or hypotension) is referred to as sepsis. In the setting of more severe disturbances of temperature, respiration, heart rate or white blood cell count, the response is characterized as septic shock, and may result in multiple organ dysfunction syndrome. Bacteremia is the principal means by which local infections are spread to distant organs (referred to as hematogenous spread). Bacteremia is typically transient rather than continuous, due to a vigorous immune system response when bacteria are detected in the blood.