What are the chances of surviving septicemia in the intensive care unit?

Good: The overall adult survival is around 70%. Young adults do better than elderly. Keys to improving the odds include early recognition that you are "septic", early broad spectrum antibiotics based on the presumed source ( lung, soft tissue, blood vessel catheter, abdomen ), early drainage of any pus, aggressive support of the lungs, kidneys, heart to maintain good perfusion to all these.

Depends: The specifics vary based on source of sepsis and to what extent there are underlying medical problems that predisposed to sepsis. ( for example a 90 year old man with chronic kidney failure and lung cancer septic from a perforated bowel will probably do worse than a 30 year old man septic from pneumonia. That said the overall mortality rate from sepsis is in the 25% range, meaning 3/4 will survive.

Very good: Most medical centers have protocols for dealing with sepsis that have a high degree of success. What is important is whether shock occurs or not and other underlying illnesses. In the past mortality for septic shock was 35-40%, but now it can be as low as 8-10% in the best icu's.