Anaesthesiology is a branch of medicine concerned with the safe use of sedatives or anaesthesia to create a whole or partial lack of responsiveness or unconsciousness in the patient during surgery. When a patient is unconscious, the surgery can be completed without incident, and the patient is kept stress- and pain-free the entire time. Doctors who specialise in safely delivering anaesthesia for surgical procedures are known as anaesthesiologists. The quality of the anaesthesia administered during surgery and the anesthesiologist's experience are key factors in the procedure's success.