ABSTRACT
The concept of risk has not clear neither in the media nor in the medical field. It appears important to us to bring details relating some definitions in the field of anaesthesia safety. This work aims to clarify the concepts of safety, of risk in a medical activity like the Anaesthesia. A search was carried Out on Medline with the following key words: Risk anaesthetic, anaesthetic Safety, anaesthetic mortality. The definitions of risk, of acceptable risk taking account of social and economic considerations are brought in this text. The ways to evaluate safety and the methods to achieve it was developed. The indicator of quality more used to evaluate safety is anaesthetic mortality. Many difficulties exist with the interpretation of data on mortality. The standards of care are normally established according to the degree of necessary safety. Concurrently to these standards exist certainly the human error which is a phenomenon towards which must direct all the efforts of improvement of safety but more especially the errors of system which are found regularly in the analysis of accidents and incident. The identification of the failures is the mandatory step to achieve safety