Risk assessment in the formulation of anaesthesia safety standards.

Risk assessment involves identifying hazards and then estimating their chance of occurrence and their severity. Risk management involves the cost-effective reduction of risk to levels perceived to be acceptable to society; risk levels set by experts may not be accepted, as perceived risk is strongly influenced by the nature of the adverse outcome and the context in which it was incurred. An understanding of the psychology of risk perception may lessen the negative impact of disasters and may better prepare the victims and their relatives. In formulating the international anaesthesia safety standards an attempt was made to base decisions on sound risk assessment and management principles. A review of the literature revealed that the hazards which posed most risks to patients were hypoxic gas mixtures, gas flow, circuit, endotracheal tube, airway and ventilation problems. These constituted one to two thirds of all incidents during anaesthesia, and account for most causes of brain damage that are dealt with by medical insurance companies. The size of the settlements provides evidence that these are viewed as very serious problems. Minimum standards were formulated with this information in mind; in recommending a sequence for equipment purchases great emphasis was placed on preventing the patient from breathing hypoxic gas mixtures, and on continuous monitoring of the adequacy of the airway, ventilation, the circulation and tissue oxygenation.