What is the difference between systemic inflammation and systemic inflammatory response syndrome?

Objective criteria: Systemic inflammation could mean just about anything and is vague terminology. Systemic inflammatory response syndrome is a syndrome and has a specific set of objective criteria such as requirements for fever, pulse, etc.

Definition: "systemic inflammation" is a generic term of inflammation in the body. The systemic inflammatory response syndrome, or sirs, is a particular reaction of the body after an infection (which is called sepsis) or trauma or other injury. The specific components of sirs are available to review online (simply "google" sirs). So, it's sort of similar but not exactly. Hope this helps!