[Preoperative stress. Research approach and methods of treatment].

The scientific approach to preoperative stress includes the identification of stressors and the measurement of stress responses. The stress responses include physiological (sympathetic nervous system, hypothalamic--hypophyseal and adrenocortical system), psychological (anxiety, depression etc.) and behavioural ones. The choice of variables to be measured should allow answers for our questions, i.e., they must be adequate and economic, without or only minimal disturbance of the preoperative situation. The value of physiological and biochemical parameters is often overestimated. Their assessment is indicated in special scientific settings. For simple questions such as premedication studies, the measurement of blood pressure and heart rate is sufficient. Anxiety should be self-estimated by the patient, using visual analogue scales, questionnaires or adjective check lists. Depression and other emotional stress responses can be assessed if necessary. For physicians and nurses, an observation of the patient's behavioural stress responses is a useful criterion for assessing patient stress. One important stress-reducing approach is prevention: identification and avoidance of stressors. This includes organisation and a high degree of self-control by the medical personnel. Premedication with benzodiazepines is the most successful pharmacological approach.