APRNs are essential to deliver healthcare in today?s complex environment. Certified Registered Nurse Anesthetists have met that challenge for over 150 years. Nurse Anesthetists have shifted from the intensive care unit as critical care nurses into the operating room arena. The operating room is an environment that is uniquely challenging. A critical care background is essential to meet these challenges, and all Certified Registered Nurse Anesthetists share that experience. The topic; "Certified Registered Nurse Anesthesia: Critical Care Nursing in the Operating Room", highlights critical care nursing as it is applied in the operating room setting. Critical care nurses will appreciate the knowledge base that is essential for the anesthetist. As healthcare reform demands greater efficiency, more and more procedures are performed outside the operating room. The line between the Operating Room, ICU and Interventional Radiology will become less defined. Critical care nurses are, and will be more involved in patient care while an anesthetic is administered. It is the goal of this proposed monograph to share knowledge and experience so that ICU nurses will learn more about caring for the anesthetized patient.