One of the risks that can occur during general anesthesia or procedural sedation is the possibility of patient awareness. This is a condition in which the patient is awake during surgery or procedure and can recall events or surroundings. This event can occur in 1:100 open heart surgery, in painless patients in 1:1000, and in pain in 1:3000.

The effect of allogeneic blood transfusion; The effect of psychological stress; The effect of perioperative hypothermia on cancer recurrence as well as retrospective clinical evidence of the association between regional anesthesia and cancer recurrence will be discussed in the article.