Anaesthesiology is the branch of medicine concerned with pain treatment during the perioperative period (i.e. before, during, and after a surgical surgery). It includes anesthesia, critical emergency medicine, intensive care medicine, and pain medicine. An anesthesiologist or anesthetist is a physician who specializes in anesthesiology. Worldwide the number of heart, nerve and other chronic conditions is increasing at an alarming rate, which triggers the use of anesthetic devices.