[Measures for reducing the risks of anesthesia]. / Massnahmen zur Reduzierung des Risikos der Narkose.

To reduce the risks to human health and life has become an increasing demand by society. Physicians and engineers must develop and adopt measures to reduce such risks. The administration of anesthesia may be viewed as a closed-loop control system consisting of three major components: the anaesthesia system, the patient, and the system operator. An analysis of human element involved in the administration of anaesthesia indicates that the human brain is best qualified to make intelligent decisions; however, the reliance on human vigilance for the continuing monitoring of monotonous processes is questionable. Human error may be divided into slips, mistakes and omissions, each of them requiring different means of prevention. The events during a critical incident follow a certain sequence. Preventive measures can best be prepared by analyzing this sequence. The designer of medical equipment has four different approaches available to prevent injury to the patient: (1) to design the equipment which prevents a human error, (2) to design the equipment that injury is not possible when the human error occurs, (3) to warn of the possibility of a human error, or (4) to monitor for changes of important parameters which indicate the beginning of a critical situation. The most important safety measure is an integrated monitoring system with centralized, structured alarm announciation.

Structured alarm systems for the operating room.

The administration of anesthesia may be viewed as a closed-loop control system consisting of three major components: the anesthesia system, the patient, and the system operator. A monitoring and alarm system during anesthesia should not be limited to only one of the three major components but must include monitoring of the patient, the performance of the anesthesia system, and the action of the system operator. For an alarm system to be successful when an adverse condition occurs, an alarm must be generated and identified, the problem identified and corrected, and the patient stabilized before injury results. The authors describe the characteristics of a structured alarm system that maximizes the time available to correct a potential problem before injury begins, that clearly identifies the cause of the problem, and that prioritizes alarms according to the urgency of the required response. Alarms should be easy to temporarily silence, have built-in alarm default settings to prevent the inadvertant use of settings meant for a previous patient, and have a graphic display that enables the operator to detect problems or trends before an alarm sounds.