Septic shock can be caused by Gram negative bacteria such as (among others) Escherichia coli, Proteus species, Klebsiella pneumoniae (which have an endotoxin on their surface that produces adverse biochemical, immunological and occasionally neurological effects which are harmful to the body), other Gram-positive cocci, such as pneumococci and streptococci, and certain fungi as well as Gram-positive bacterial toxins. Septic shock also includes some elements of cardiogenic shock. In 1992, the ACCP/SCCM Consensus Conference Committee defined septic shock: " ... sepsis-induced hypotension (systolic blood pressure < 90 mmHg or a reduction of 40 mmHg from baseline) despite adequate fluid resuscitation along with the presence of perfusion abnormalities that may include, but are not limited to: lactic acidosis, oliguria, or an acute alteration in mental status. Patients who are receiving inotropic or vasopressor agents may have a normalized blood pressure at the time that perfusion abnormalities are identified. The pathophysiology behind septic shock is as follows: 1) Systemic leukocyte adhesion to endothelial cells 2) Reduced contractility of the heart 3) Activation of the coagulation pathways, resulting in disseminated intravascular coagulation 4). Increased levels of neutrophilsThe main manifestations of septic shock are due to the massive release of histamine which causes intense dilation of the blood vessels. People with septic shock will also likely be positive for SIRS criteria. The most generally accepted treatment for these patients is early recognition of symptoms, and early administration of broad spectrum and organism specific antibiotics.
Shock is both common and has a high risk of death. In the United States about 1.2 million people present to the emergency room each year with shock and their risk of death is between 20 and 50%. Signs and symptoms
The presentation of shock is variable, with some people having only minimal symptoms such as confusion and weakness. While the general signs for all types of shock are low blood pressure, decreased urine output, and confusion, these may not always be present. While a fast heart rate is common, those on β-blockers, those who are athletic, and in 30% of cases of those with shock due to intra abdominal bleeding, heart rate may be normal or slow. Specific subtypes of shock may have additional symptoms. Dry mucous membrane, reduced skin turgor, prolonged capillary refill time, weak peripheral pulses, and cold extremities can be early signs of shock. Low volume
Hypovolemic shock is the most common type of shock and is caused by insufficient circulating volume. The most common cause of hypovolemic shock is hemorrhage (internal or external); however, vomiting and diarrhea are more common causes in children.