Septic Shock
Septic shock refers to patients with evidence of systemic inflammation, infection, and hypotension that is refractory to fluid esuscitation. Sepsis, severe sepsis, and septic shock are terms that have been used to define a continuum of systemic response to infection. In 1992 a consensus was reached to apply specific definitions for these terms as they relate to people with critical illness. Since systemic inflammation associated with an infectious process is also a common cause of critical illness in veterinary medicine, these definitions have been extrapolated for use in dogs and cats.
SIRS is a systemic response to a severe insult and consists of changes in two of more of the following criteria:
Sepsis describes a condition in which systemic inflammation (SIRS) occurs along with evidence of infection. In addition to the changes listed above, these patients must have either a positive microbiological culture, histological evidence of infection, or intracellular bacteria visualized on cytology. Other abnormalities that are frequently found in dogs or cats with sepsis include hypoglycemia, hyperbilirubinemia, hypoalbuminemia, and thrombocytopenia. Coagulation times including the PT and the aPTT may be prolonged in those animals developing DIC. During the initial stages of sepsis, compensatory mechanisms ensure adequate oxygen delivery to tissues despite changes in vascular resistance. Septic shock develops when compensatory mechanisms are overwhelmed. Tissues are no longer adequately perfused, and oxygen delivery cannot be maintained despite aggressive fluid resuscitation. In veterinary medicine, little is known about the true incidence of septic shock. Cats with systemic inflammation in general are much more susceptible to profound hypotensionthat is difficult to correct. Successful treatment of septic shock is basedon restoration of oxygen delivery through the useof fluid therapy, antibiotics, identification of anunderlying cause, and vasopressors. |
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