General Anaesthesia

General anaesthesia is medically induced loss of consciousness that leaves a patient unarousable even by painful stimuli, produced with injected or inhaled drugs usually combined with painkillers and muscle relaxants. It is used to make surgery that would otherwise cause intolerable pain possible, and it is also used in intensive care and emergency settings to allow endotracheal intubation and mechanical ventilation of critically ill patients. Effective general anaesthesia is meant to produce loss of awareness, inability to feel pain, memory loss, suppressed reflexes and temporary paralysis of skeletal muscle, since uncontrolled patient movement during surgery can compromise the procedure. Because natural breathing may be inadequate under these drugs, the anaesthetist typically has to protect the patient's breathing during the procedure.