[Risk in anaesthesia].

Background: Modern anaesthesia is still associated with a risk of serious complications. This article focuses on frequency, causes, and prevention of the most important anaesthetic complications.

Material and Methods: The article is based on literature identified through a non-systematic search in Pub-Med, and the author's research and experience in this field.

Results: The risk of death associated with anaesthesia is closely related to patient age and physical status. In otherwise healthy patients (ASA 1), the risk of such deaths is approximately 1:250 000. Medication errors occur in approximately 1:1 000 anaesthetic procedures. The risk of awareness during general anaesthesia is approximately 1:650. Neural injury from epidural and spinal anaesthesia is rare, even more so in obstetrics. Anaphylaxis caused by muscle relaxant drugs is more common in Norway than in many other industrialized countries. Pulmonary aspiration occurs in approximately 1:7 000 anaesthetic procedures, but with low morbidity in healthy patients. The incidence of anaesthetic accidents is higher in infants than older children, and requires special competence. Serious anaesthetic complications are most often related to the cardiovascular and respiratory system. The complications are often multicausal, and human errors and organizational factors contribute in 50-70 % of the cases.

Interpretation: Optimization of the patient's preoperative health is important to improve safety. The focus of the anaesthesiology department should be education and guidelines. Systems and routines for improved safety must also take into account that human and organizational factors may cause anaesthetic accidents.