Is septicemia the same thing as sepsis?

Sort of. Sepsis is a term for any infection that causes a systemic inflammatory response. The most common causes of sepsis are pneumonia & urinary tract infections. When sepsis is associated with organ dysfunction, this is called severe sepsis. Septicemia is a term that some equate with sepsis; others consider septicemia equivalent to bacteremia (bacteria in the bloodstream).
Sort of. Usually the terms "bacteremia" is used to describe bacteria in the bloodstream that are not necessarily causing in inflmmatory, infecious response. Sepsis (or septicema) is the result of bacteremia when symptoms of inflammation occur.