What are the diagnostic criteria for sepsis, severe sepsis, and septic shock?

Sepsis is defined as the clinical syndrome resulting from a disregulated inflammatory response to a non-infectious trigger.
Severe sepsis is defined as the association of sepsis with some sign of hypoperfusion or organ dysfunction.
Septic shock is defined as hypotension induced by sepsis that persists despite adequate fluid resuscitation and presents with hypoperfusion and/or organ dysfunction.
The diagnostic criteria for sepsis include at least two of the following: temperature > 38.3ºC or < 36ºC, heart rate > 90 bpm, respiratory rate > 20 rpm or pCO2 < 32 mmHg, and leukocytosis > 12,000/mm3, < 4,000/mm3, or > 10% of immature forms.