Critical care nursing is that specialty within nursing that deals specifically with human responses to life-threatening problems. A critical care nurse is a licensed professional nurse who is responsible for ensuring that acutely and critically ill patients and their families receive optimal care. It focus on the utmost care of the critically ill or unstable patients. Critical care nurses can be found working in a wide variety of environments and specialties, such as general intensive care units, medical intensive care units, surgical intensive care units, trauma intensive care units, coronary care units, cardiothoracic intensive care units, and some trauma center emergency departments. Critical Care Nurses are also known as ICU nurses. They treat patients who are chronically ill or at risk for deadly illnesses. ICU nurse apply their specialized knowledge base to care for and maintain the life support of critically ill patients who are often on the verge of death.